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ETI for Electronics & Computing Enthusiasts

EXCEL -10NIX

BEFORE YOU BUY ANYWHERE ELSE TALK TO US.WE ARE NOW IN OUR 5th YEAR!

Fluctuating prices, call for best price. You can't beat thebest! we will not be undersold.1-800-268-3798 Modem 921-4013 (300 or 1200 Baud)(4161 921-8941 ee our GIANT Catalogue In this Issue. Telex 065-24218

SpecREal

Any Software AvailableSable red Softwa

November Software Specials Witness $42.95 Locksmith $125.00 NEW Book SpecialsSea Dragon $41.00 DOS Tool Kit $89.00

Castle Wolf enstein $34.95 Evolution $39.00 Apple Software 1983 $22.00Wizardry $47.95 Apple Panic $36.00 Crosswire $36.50 The Blue Book $26.95Knight of Diamonds $26.97 Frogger $41.00 Screen Writer II $159.95 CP/M Assembly LanguageUltima II $64.95 Flight Simulator $48.00 Lisa $119.95 Programming $15.00Pinball Construction $42.95 Pinball $39.00 Zaxon $49.95 The Power of Multiplan $17.95Suspended $46.95 Fork I $39.00 Computer Baseball $39.00 A User Guide to the Unix System $20.00Chess, Odesta $74.95 Deadline $48.00 David's Midnight Magic $39.00 Motorola CMOS Data $12.95Cosmic Balance $39.95 Ulysses $47.00 Typing Tutor II $24.95 Motorola Linear Data $12.95Miner 2049'er S38.95 Temple of Apshai $46.50 Flip 'n File 50 $39.00 TTL Data Book $14.00

_domicronicsencGemini 10X81/2", Dot Matrix,80 Column, 120c.p.s. Regularprice $615.

PAPER $10.45For your printer

Control Data, 91/2" x 11" plain, 500sheets Other sizes available.

RF MODS $18.00Applesoft Tutorial $14.44DOS Manuals $25.00

SLIMLINE IBM compatibleDISK DRIVES SA455

5349.00

PRINTER SPECIALSGemini 15 $59915", Dot Matrix, 132 column, 100 c.p.s.

EPSON MX8OFT 579581/2", Dot Matrix with GRAFTRAX +

EPSON MX100 $99515", Dot MAtrix with GRAFTRAX +EPSON RX8O (NEW) 5495Replaces MX80

EMP 310 MODEM300 baud, attractively packaged, readyto use. Normal price $199Special price: $99 With Phone: $124

Smart Modem300 baud, IBM compatible $294micromodem Apple compatible $274$394.00

Cat Novation $159

CONTROLLER 584.00

EPSON FX80 (NEW) $79881/2", Dot Matrix, 80 column, 160 c.p.s.

TTX PRINTER $789Daisy Wheel

P DA -232 RS232 $119.00

Apple compatible. Wizard BPO-16.16K parallel buffer printer card

$184.00Wizard - IPI parallel intelligentprinter interface $85.00

5" Green Screen MonitorsKit $59

$9.95Open frame.Requires 12V.Ideal for 6502computers.

Requires SyncSeparator Board

Don't hesitate to contact us on our price hotline 921-8941 forthe most competitive prices in Canada!

16K RAM Card

$55.00Expand you 48K APPLE to 64K. TheMULTIFLEX 16K RAM Card allows otherlanguages to be loaded into your Applefrom disk or tape. Allows APPLE CP/Musers to run CP/M 56.

Multiflex EPROMProgrammer $69FEATURES:EPROM programmer for APPLE com-puters.*Programmes 2716, 2732, 2732A, 2764.*ZIF socket for the EPROM.`Complete with software.`Built-in programming supply.

We have a large selection of books andmagazines

PROTO BOARDS 514.00

80 -Column CardFEATURES:*Gives 80 columns and upper/lower caseon your APPLE II/11+ +/lle computer.*Works with PASCAL and CP/M.`Auto -switch between 40 columns and 80columns.*Full inverse video.

AppleTM compatible attractivelypackaged disk drives ready to plug in

$279Controller $89

Exceltronix Computer Division Computers at unbeatableprices! (416) 921-8941, 319 College St., Toronto, Ontario

M5T 152No returns or exchanges after 7 days. 15.,c, restocking charge. This month onlywe will ship free of charge to Ontario residents only.

Circle No. 7 on Reader Service Card.

SURPLUSTRONICSwe will not be undersold

AsReviewed

In ET1MaY1983

64K RAM (8.4164 chips) 80 x 24 video included on board Floppy Disk Controller included FIVE additional slots Z80 blank PCB included Powerful power supply (5V 5A, + 12V 2

up to 3A peak, -5V 0.5A, -12V 0.5A) Hydro -approved whereas many othersare not! Superb quality plastic case Excellent keyboard including numeric

keypad EPROMS (blank) included

NOW

OUR FAMOUS6502 BOARDNOW NEW & IMPROVED VIDEO SECTION

This 6502 board is a vast improvement on others available: High QUALITY pc board Excellent service Now at a reduced price $599 kit

Available in Kit. Availablepreassembled (with all sockets, conn, discrete, flow soldered & cleaned.IC's to be inserted by user not tested)

only $29. on top of kit cost.Complete assembled & tested

(blank EPROMS $689

you receive a FREE Z80 PC BOARD ANDFREE 128K RAM DISK PC BOARD when you orderthe complete package (either Kit or A&T) (BLANK

6502/8088Board

CALL FOR PRICING

NEW 8088 BOARDCOLOUR GRAPHICS256K RAM or 1MEG. using new 256KRAM Chips. Floppy controller I/O And much more Sold with all parts including blank

EPROMS

TO BE RELEASED OCT. 30To be released Oct. 30 Compatible with ??? Yes you guessedit. At a price so low you won't believe it.Please call for ordering & pricing. De-mand is overwhelming. Orders will befilled (On a first come first served basis).

CALL FOR PRICES

5" Green ScreenMonitors. $59

Open frame.Requires 12V.Ideal for 6502computers. NN

.11

Requires SyncSeparator Board Kit $9.95

Peripherals for your APPLE TM

16K RAM Card - complete A&T $55.00

Eprom Programmer- A&T with $69.00software to program 2716, 2732, 2732Aand 2764.

Z80 Card - (no software) A&T $57.00

80x24 Video Board $75.00(runs CP/M & Pascal)

Wizard Printer Interface card with Epsonpersonality Eprom (works great withGEMINI 10X)Complete $79.00

Our own Printer interface card A&Twith blank personality Eprom $49.00

128K RAM Disk A&T (no software)$199.00

APPLETM Compatible Disk Drives attrac-tively packaged, ready to plug in

$269.00

Disk Drive Controller A&T $79.00

Our Disk Drive Controller, A&T, with twoblank 2716's $49.00

GEMINI 10X Printers $359.00

Wild Card provides back-up copies ofprotected software with just the push ofa button $139.00

Our Crazy Card provides back-up copiesof protected software with just the pushof a button only $59.00

PDA 232 $118.00

Huge variety of surplus stock at low, low prices. Newshipments arriving. No reasonable offers refused.This sale expires Sept. 30, 1983.

Circle No. 22 on Reader Service Card

Surplustronics, 310 College Street, Toronto, Ontario, M5T 1S3 (416) 925-8603.

Mail Orders add $3.00 minimum for shipping &handling. Ontario residents add 7% P.S.T. Visa,Mastercard and American Express cards accepted: send card number, expiry data, name ofbank and signature. Send certified cheque ormoney order, do not send cash.

This month only, we will ship free of chargeto Ontario Residents only.

1-800-268-3798 (416) 925-6558

EXCELTRONIX(416) 921-89411-80

Bulletin Bd. (416) 921-4013 Telex 065-24218Monitors tovi

Zenith ZVM-123 Green$134

Zenith ZVM-122 Amber$195

Amdek Colour -1 $395Amdek Amber - 300A $239

68-3798Multlflex

IntelligentTerminal

(As Reviewed in Oct. '82 ETI)An excellent low costterminal kit from

Assembled & Tested withcase and PIS

$350

$195

MUielfieX lay $995Super System-S100 Based-Z-80A Processor-runs CP/M-EPROM ProgrammerBASIC Package includes-CPU card w. 64K-Video BoardDisk ControllerSA455 Drive-CP/M Operating System

OPTIONS

Power Supply: 5V 4A,12V 2A, -5V 0.5 A, -12V0.5A $99Keyboard(no case) $99

Memory Chips4164 - 150 ns (1x64K single (+5V)

8.441.741.992.498.94

supply)4116-200ns (1x16k)4116.150 ns (1x16k)2114L-200 ns (1 kx4 static)6116-150 ns (2kx8 static RAM)(Pin compatible with 2716 uses negligibleamount of power)2016-150 ns (2kx8 static) 8.742102L-200 ns (1kx1 static) 1.945101-CMOS RAM 3.842708-(1kx8) EPROM 6.742716-(2kx8 EPROM single + 5V) 4.942732-(4kx8 EPROM single + 5V) 7.942532-(4kx8 EPROM single 5V) 8.742764-(8kx8) EPROM single 5V) 11.94

ft

WE HAVE ASPECTACULAR

STOCK OF74LS PARTS

ATREASONABLE

PRICES.OEM

ENQUIRIESINVITED

Diskettes51/4" Diskettes Boxes of 10Maxell MD -1Maxell MD -2VerbatimCDCDysan3M -Ectype (with library$4.95)2 Ectype Diskettes inbinder sheet

36.0064.0034.0026.9538.4438.44

case worth27.44

a plastic5.89

SPECIAL Free calculator when youpurchase 5 boxes of 3M diskettes.

Featuring theMultlflex Apple -Compatible OrlyStarting Sept. 1,1983. 1 yr. warran-ty attractivelypackaged fullycompatible 1000'ssold!!

only$269

PRICE POLICYRemember that at Exceltronix allprices are negotiable for quantitypurchases. If you cannot afford largequantities on your own how aboutstarting a Co-op.

JoysticksSelf -Centering $39.95With two adjustable controlsSuper offer

Kraft Joystick $74.00TG JoysticksDeLuxe Model

TG Paddles $64.95De Luxe Model

Deluxe Table Top Model$59.00

Also available at $299with 90 day warranty!

a. Teac Slim Driveb. Micro-Sci DriveSA400L Mechanismc. Quentin DriveSiemens Mechanismd. ATI FDD-810 Slim Type

Controller $89Coming SoonCommodore & IBMperipherals!

MAIL ORDERSSend a certified cheque or money order (do not send cash). Minimumorder is $10 plus $3 minimum for shipping. Ontario residents mustadd 7°. provincial sales tax. Visa. Mastercard and American Ex-press accepted: send card No . signature. expiry date and name ofbank.

This month only. we will ship free of charge to OntarioResidents only.

master charge

-11

Head Office: 319 COLLEGE STREET, TORONTO, ONTARIO. CANADA. M5T 1S2 (416) 921.8941Circle No. 7 on Reader Service Card.

The Magazine for Electronics & Computing Enthusiasts

Electronics----790;11y

November 1983Vol. 7 No. 11ISSN 0703-8984

Member

Audit IIof Circulations

Features6 Book Review

ASTI Microwave Filter Manual.

18 RoboticsSend R2D2 out to throttle the neighbour's bark-ing dog? Not just yet, as Bill Markwick reports.

24 Introduction to Fibre OpticsWouldn't you know it. They come up with agadget to make really neat table lamps and peo-ple want to make phone lines out of them.

28 Computer SurveyWouldn't you know . . . sorry. We present 50popular computers and their basic specifica-tions, from the $70 ZX81 on up.

38 Product ReviewFluke 70 -series multimeters.

4 OMilitary LasersWouldn't you know it. They come up with agadget that can fix detached retinas and Reaganwants to blast commies with it.

42

52

Computer ReviewThe Dragon 32 doesn't breathe fire, but it has amean byte.

Designer's NotebookSwitched Capacitor Filters, Part 2.57 Designing Microsystems, Part 3More on the basic CPU.

62 WheatstoneBest known around folkclubs for his concertina,and best known to dentists for his bridge, we of-fer a thumbnail bio of this pioneer.

7A Computing Today"1111 Introducing FORTH

ProjectsPlaymate Part 1A titillating title conceals the fact that this is abattery powered instrument amplifier with a bigbag of built-in effects.ZX81 User -Defined GraphicsStill playing with blocks? Solder some wires, adda few gates, and you're the Renoir of the videotube. If you're clever.

Our CoverA look at facts and myths aboutrobotics appears on page 18; photocourtesy of Ford Motor Co. ofCanada. The Dragon 32 computer isreviewed on page 42; photo by JohnRudzinski.

Schematic Diagram of a High PowerLaser

Compressor/LimiterYou know in the$50,000 album re-cording when thelead singer sud-denly leans intothe mike andsneezes? Well, thisproject preventsher from over-loading the tape.

ADVERTISERS' INDEX

Active Components Sales Corp 54Advance Micro -Electronics 63Allan Crawford & Associates 76, 77Alla Vista Computers 43A.P. Products 80Arkon Electronics ISAudiovision 71BCS Electronics 21, 75Brunelle Instruments Inc $4C&H Electronics Plus 36, 37Daetron 34Decoder Products International 75DPE Electronics Canada Ltd 51Electronic Control Systems 55Electronic Packaging Systems 34Exceltronix 2, 4Fastron 75Fujicomp Inc. 27Gladstone Electronics 79H. Rogers Electronic Instruments 31Innovative Electronics & Devices 34I & S Software Library 54JLS Computers 36JMT Inc. 55Kaientai Electronics Merchants 72Kitstronic International Ltd. 39McGraw Hill 33Metermaster 65Micro Computech Electronics Ltd 58, 59Orion Electronic Supplies 8 9Parts Galore 45, 73Satellite Systems Ltd. 36Scarborough Computers 31Smith Corona 29Surplus Electro Quebec 7Surplustronics 3Unitron Computer Corporation 61World of Commodore 17

NEWSSTAND DISTRIBUTION:Master Media, Oakville, Ontario

SUBSCRIPTIONS$18.95 (one year), $33.95 (two years). For US add$3/yr., other countries add $5/yr. Please specify ifsubscription is new or a renewal.

BIN DERSBinders made especially for ETI are available for$9.25 including postage and handling. Ontarioresidents please add provincial sales tax,BACK ISSUES AND PHOTOCOPIESPrevious issues of ETI Canada are available directfrom our offices for $4.00 each; please specify bymonth, not by feature you require. See order card forIssues available.

We can supply photocopies of any articlepublished in ETI Canada; the charge is $2.00 per arti-cle, regardless of length. Please specify both issueand article.

COMPONENT NOTATION AND UNITSWe normally specify components using an interna-tional standard. Many readers will be unfamiliarwith this but It's simple, less likely to lead to errorand will be widely used everywhere sooner or later.ETI has opted for sooner!Firstly decimal points are dropped and substitutedwith the multiplier: thus 4.7uF is written 4u7.Capacitors also use the multiplier nano (onenanofarad is 1000pF). Thus 0.1uF Is 100nF, 5600pFIs 5n6. Other examples are 5.6pF = 5p6 and 0.5pF= Op5.Resistors are treated similarly: 1.8Mohms is 1M8,56kohms Is the same, 4.7kohms is 4k7, 100ohms is100R and 5.60hms Is 5R6.

PCB SuppliersETI magazine does NOT supply PCBs or kits but wedo issue manufacturing permits for companies tomanufacture boards and kits to our designs, Con-tact the following companies when ordering boards.

Please note we do not keep track of what isavailable from who so please don't contact us for in-formation on PCBs and kits. Similarly do not askPCB suppliers for help with projects.

K.S.K. Associates, P.O. Box 266, Milton, Ont. L9T4N9.B-C-D Electronics, P.O. Box 6326, Stn. F,Hamilton, Ont., L9C 6L9.Wentworth Electronics, R.R.No.1, Waterdown,Ont.,LOR 2H0.Danocinths Inc., P.O. Box 261, Westland MI 48185,USA.Arkon Electronics Ltd., 409 Queen Street W., Toron-to, Ont., M5V 2A5.Beyer & Martin Electronic Ltd., 2 Jodi Ave., Unit C,Downsview, Ontario M3N 1H1.Spectrum Electronics, 14 Knightswood Crescent,Brantford, Ontario N3R 7E6.

POSTAL INFORMATIONSecond Class Mail Registration No.3955. Mailingaddress for subscription orders, undeliverablecopies and change of address notice is:Electronics Today International, Suite 601,25 Overlea Blvd., Toronto, Ontario, M4H 1131.

Columns, News andInformationFor Your Information.. 6 Order Form 55Next Month 35 Subscriptions 56

Fun of Electronics 46Classifieds 4750 Top Projects 78ETI Specials 69Tech Tips 76

for your infor olio

ETI Magazine is Published by:

Moorshead PublicationsEditorial and Advertising OfficesSuite 601, 25 Overlea Boulevard,Toronto, Ontario, M4H 1B1Telephone (416) 423-3262

Publisher: HaIvor W. MoorsheadEditor: Bill MarkwickEditorial Assistant: R. Allan RyanProduction Manager:Ann RodriguesProduction: Susan Cross

Robin Mills -O'NeillDoug Goddard

Subscription Diane NeillDepartment: Lisa Salvatori

Accounts Department: Pirjo DunphyAdvertising Omar VogtRepresentatives: Rick MayAdvertising TrafficCo-ordinator: Claire ZyvitskiAdvertising Services: Carolyn Wyatt

Sharon CerneccaGeneral Manager: Senga HarrisonExecutiveVice -President: V. Kenneth Marskell

COPYRIGHTAll material is subject to worldwidecopyright protection. All PCB patternsare copyright and no company can sellboards to our design without our permis-sion.

LIABILITYWhile every effort has been made to en-sure that all constructional projects refer-red to In this magazine will operate as In-dicated efficiently and properly and thatall necessary components are available,no responsibility whatsoever is acceptedin respect of the failure for any reason atall of the project to operate efficiently orat all whether due to any fault in thedesign or otherwise and no responsibilityis accepted for the failure to obtain com-ponent parts In respect of any such pro-ject. Further no responsibility is acceptedin respect of any injury or damage causedby any fault in design of any such projectas aforesaid.

Editorial QueriesWritten queries can only be answeredwhen accompanied by a self-addressed,stamped envelope. These must relate torecent articles and not involve the staff inany research. Mark such letters ETI-Query. We cannot answer telephonequeries.

6-NOVEMBER-1983-ETI

Voice/Data ModemAdminet Inc., a new Canadiancommunications firm, has an-nounced a low price, local areamodem that can transmit bothvoice and data simultaneously over

standard unconditioned telephonewiring. The Adminet modem hasbeen designed as a stand-alonedevice to achieve the added featureof inexpensive digital communica-tions on any existing analog PBXlocal telephone system. Capable ofoperating at full or half duplex atspeeds up to 9600 baud, the new

device achieves high performancedata transmission without interfer-

normal tele-phone and voice functions, all ofwhich continue to be simultan-eously available on the same singlecircuit. Each PBX line to be pro-vided with a data option retrofitrequires a pair of modems. For in-formation, contact Adminet Inc.,27 Goulburn Ave., Ottawa, On-tario KIN 8C7 (613) 563-9709.

Northern Telecom Limited's U.S.subsidiary, Northern TelecomInc., today announced a com-prehensive operating agreementwith Hewlett-Packard Corpora-tion. Under terms of the agreementthe two companies will work to im-prove the functional capabilitiesand reduce the cost of interconnec-ting the Northern Telecom SL -1digital business communicationssystem or private branch exchange(PBX), and the HP 3000 BusinessComputer System. Three inter-faces are covered in the agreement.They permit the SL -1 to switchdata between the HP 3000 com-puter and HP terminals over ex-isting telephone wiring.

If you're into energy, its conserva-tion, or the use thereof, you'll beinterested in the 6th AnnualEnergy Lifestyle Show to be heldOct. 21, 22, 23 at the Toronto In-ternational Centre, Airport Rd.,Mississauga. They claim to have100,000 square feet of "energy -efficient displays and exhibitors".Along with energy -efficient ex-hibitors, you can see the world'ssmallest twin -engine plane, homeelectronics and security, andhome -renewal demonstrations.

Sound SwitchThe Sound Activated Switch, asolid state electronic unit that ac-tivates lighting by the sound ofhuman activity, is available fromNational Technical Systems(NTS). The plug-in unit, which isUL listed, is rated to handle up to300 watts of incandescent light. Itprovides a greater measure ofsecurity than timers because itturns lights on at the sound of adoorbell or an attempted break-in,giving a much more realistic im-pression that someone is home.The unit is available by mail-orderfrom companies such as Heath orEdmund Scientific. A retail net-work is under way.

'-"F

osaesivinto

Robotics EncodersA comprehensive line of modularand housed shaft angle encodersgeared for use in robotics isavailable from Encoder Division,Litton Systems Inc. The encodersare ideal for precise sensing controlin the pincer, wrist, and othermoving joints in robotic applica-tions. Several configurations canbe specified. The low-cost modularoptical encoders consist of aphotohead assembly, hub -discassembly, and cover for easy in-stallation. Housed incremental en-coders are also available. They areideal for control systems that re-quire small size and high resolu-tion. Size ranges for both themodular and housed encoders arefrom 1.5" to 2.2" in diameter. Foradditional information about Lit-ton's line of encoders for roboticsapplications, contact Litton'sCanadian Distributors: EP Elec-tronics International Inc., 187Denison Street, Markham, On-tario, L3R 185 (416)475-8316).

For your iriformation512K -Bit Memory Chip

mtr*maamci witwitant

1011.1.11.41.An experimental computer mem-ory chip that can store more than ahalf -million bits of information,nearly twice the capacity of anychip yet reported, was described ata technical conference by engineersfrom IBM's semiconductor facilityin Essex Junction, Vermont. Thenew component is a 512K -bitdynamic random access memory

(RAM) chip. Since, in computerterminology, "K" stands for 1024,the chip actually holds 524,288 bitsof information. It is the first com-plete chip ever to use an electronictechnique called "plate pushing"to read data out of its storage cells.Plate pushing - previously usedonly in greatly simplified test cir-cuits - produces an electricalsignal nearly twice as large as thatproduced by conventional datareading methods. With thisstronger signal, it is possible to in-crease the chip's density and relia-bility while maintaining high per-formance. The new chip measures7.96 mm by 8.6 mm (about3/8 -inch square). Data can beretrieved from its storage cells in120 nanoseconds (billionths of asecond). The smallest photolitho-graphic images in the chip's circuitpattern are just 1.5 micrometerswide, about 1/50th the diameter ofa human hair.

DNR Problems

After last month's project for theDynamic Noise Reduction projectwent to press, we discovered thatNational Semiconductor is restric-ting sale of the IC to high -volumemanufacturers. We regret any in-convenience caused to our readers.

PCB Repair ToolCompanies involved in repairingprinted circuit boards requiringcomponent replacement canminimize discards with Nu -Concept's HART, for "Hot -AirReplacement Terminal". The unitis said to solder and desolder onsuch difficult boards as multi -layer

The Color Disk Drive from RadioShack, a division of Tandy Cor-poration, turns the ExtendedBASIC Color Computer into adisk system at a new low price. TheColor Disk #0 Kit (26-3022) for theoriginal Color Computer is nowoffered for $599. It was $799. TheColor Disk #1, 2 or 3 (26-3032),which requires the Disk #0, is nowoffered for $399. It was $599.These disk drives are available atRadio Shack computer centres andparticipating Radio Shack storesand dealers nationwide. A ColorDisk Drive gives 156K of userstorage for program and data files.It can also be used with color disksoftware.

or aluminum. Just the ticket forremoving and replacing chip car-riers or gate arrays. PC fans canobtain more information fromTom Dvorak, Rte. 309 and Ad-vance Line, Colmar, PA 18915,(215) 822-8400.

Triple -Trace ScopeB&K-Precision has just introducedtheir new 60 MHz triple traceoscilloscope, model 1560. The1560 oscilloscope is a dual timebase, delayed sweep unit ideal fortroubleshooting, maintenance ofvideo systems and computer ter-minals, as well as for broadcast

studio applications. Features forthe 1560 include: 1 mV/div. sen-sitivity; rectangular CRT with in-ternal graticule and scale illumina-tion; X10 sweep magnification;X -Y operation and Z axis input.B&K-Precision products are repre-sented in Canada by Atlas Elec-tronics Limited, 50 WingoldAvenue, Toronto, Ontario, withbranch offices in Montreal, Ot-tawa, Winnipeg, and Vancouver.

ATTENTIONDISTRIBUTORS!

1983 introductory OfferRotary Switches available in

1P12P - 2P6P3P4P - 4P3P

1111111=M1101/1

ANY

99c QUANTITY

EACHIMMEDIATE DELIVERY BY RETURN MAIL

FREE SAMPLE!WITH STAPLED BUSINESS

CARD TO YOUR LETTERHEAD

Contacts: Silver plated brass ensures alife>10,000 cycles. Indexing: 30°

Material: Glass filled nylon.Stops: Adjustable 2-12 fully rotating

Quebec Residents add 9% Sales TaxPostage & Handling add $2.00 per order

SURPLUS ELECTRO QUEBEC2264 Montee Gagnon, Blainville,

Quebec, Canada J7E 4HS


ORION ELECTRONICS COMPUTER ROOM ORION ELECTRONICS COMPUTER ROOM

Z Sinclair Timex 1000 Computer EtcZcc

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Assembled $511.00The ZX81's advancedcapability.The ZX81 uses the same fastmicroprocessor (Z80A), but in-corporates a new, more power-ful 8K BASIC ROM - the"trained intelligence" of thecomputer. This chip works indecimals, handles logs andtrig, allows you to plot graphs,and builds up animateddisplays. And the ZX81 incor-porates other operationrefinements - the facility toload and save named programson cassette, or to select a pro-gram off a cassette throughthe keyboard.

New, improved specification.Unique 'one -touch' key wordentry: eliminates a great dealof tiresome typing. Key words(PRINT, LIST, RUN, etc.) havetheir own single -key entry.'Unique syntax -check andreport codes identify program-ming errors immediately. Fullrange of mathematical andscientific functions accurate

to eight decimal places.Graph -drawing and animated -display facilities. 'Multi-dimensional string andnumeric arrays. Up to 26FOR/NEXT loops. 'Randomizefunction. Programmable inmachine code. 'CassetteLOAD and SAVE with namedprograms. '1K -byte RAM ex-pandable to 16K. 'Full editingfacilities. 'Able to drive thenew Sinclair ZX Printer (to beavailable shortly).

If you own a ZX80...The new 8K BASIC ROM as us-ed in the ZX81 is available as adrop -in replacement chip.(Complete with new keyboardtemplate and operatingmanual). With the exception ofanimated graphics, all the ad-vanced features of the ZX81are now available on your ZX80- including the ability to drivethe Sinclair ZX Printer.

Sinclair's new 8K Extended Basic offers features foundonly on computers costing three or four times as much.*Continuous display, Including moving graphics. Multi-dimensional string and numerical arrays. 'Math andscientific functions accurate to 8 decimals. Unique onetouch entry of "key words" (i.e. basic and system com-mands). 'Automatic syntax error detection. Randomizefunction. Built-in Interface for ZX Printer. Connects tostandard TV and cassette recorder. 164 page manualincluded. 'Power supply (9V at 650 ma) optional for$14.95. 1K of memory is included.Etc...

$119.00Designed exclusively for use with the ZX81 (and ZX80with 8K basic ROM), the printer offers full

COhanumerics and highly sophisticated graphics.PY command prints out exactly what is on screen. At

last you can have a hard copy of your program listingand results. Printing speed is 50 characters per second,with 32 characters per line and 9 lines per vertical inch.Connects to rear of ZX81 - using a stackable connectorso you can use a RAM pack as well. A 65 ft paper roll, in-structions included. Requires 9 volts, 1.2 amp powersupply (option extra).

Printer PaperSingle Roll C751 per roll 6 95Package of 3 16.95Power Supply (500 mA) $9.95Power Supply (650 mA) $14.95Power Supply (1 Amp) $19.95

Add Vision To Your Computer!Announcing the

MicronEyeBullet

Solid state digital imagingsystem.

128 x 256 element resolution. Electronic shutter may be manu-

ally or software controlled.

Capable of transmitting up to4 feet, 15 frames per second.

Low power consumption(250mw), 5V at 50ma.

Available for the followingcomputers: Apple II', Commo-dore 64', IBM-PC', TRS-80 CC'

Source code provided. Sample programs included -

explore MicronEye's capabilities!

Includes all hardware, softwareand optics for "plug -and -go"operation!

ICRONTECHNOLOGY INCORPORATE

Applications Graphics input Games Digitizing Automated process control Pattern recognition Robotics Security More ...use your imagination!

BooksCOMPLETE ZX81 BASIC COURSE - inc 2tapes 3995NOT ONLY 30 PROGRAMS: 1K 15.95MACHINE LANGUAGE MADE SIMPLE 19.95UNDERSTANDING ZX81 ROM 19.95TIS 1000: PROGRAMS, GAMES andGRAPHICS 16.95LEARNING TIS BASIC 23.95THE BASIC HANDBOOK 29.9549 EXPLODING GAMES 16.95COMPUTER FOR KITS SINCLAIR EDITION 8.95MASTERING MACHINE CODE ON YOUR 2)(81 20.95TiS 1000 USERS GUIDE (Volt) 16.95EXPLORERS GUIDE TO THE Z/(131 16.95EX81 POCKET BOOK 18.95GETAWAY GUIDE 16.95GETTING AOUAINTED WITH YOUR ZX81 16.95HardwareZ.X131 Asa.

L( Print64K RAM (Memotech)Orlon 64K32K RAM (Mernotech)16K RAM (Sinclair)Power Supply (650 M.A.)Power Supply (1 AMP)Keyboard (uncased) . 47 Keys, Assembledno soldering redMetal Case I or aboveMemopak Centronics Type Parallel PrinterInterlaceMemopak ZX81 KeyboardMemo Ca lc

5800119.00199.00149.00119.0059.001.1.9519.95

109.9529.95

119.0013900

7995

Interface for any serial printer 8 4 cassetterecorders; Includes plugs, cords and a detIladmanual.

U)c.)

zOQUww

Oc7.0

CP-100-A SeikoshaGraphic Printer

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Playmate Guitar Effects/AmpThe sounds of the superstarin your own room - or in themiddle of a field! ThePLAYMATE will help youon your way. Design anddevelopment.by Phil Walker

THE PLAYMATE is a small practiceamplifier giving a few watts output whilealso providing some of the basic effectsused by many musicians. It is ideallysuited to those who do not carry all thevarious effects units around in their guitarcases, but would like to be able to practiseat odd moments or in out-of-the-wayplaces.

In addition to the amplifier and stan-dard tone controls, etc, various distortionand wah-wah effects are possible. As a by-product of the circuitry a sustain effect isalso possible.

The sound output is provided by asmall internal loudspeaker and the wholemodule is powered from a small poweradapter or batteries. An external footpedal could be used with the wah effect ifrequired. This consists of a variableresistor and a couple of other resistors toprovide the necessary control current. Theinternal control is still active at this timeand can be used to set an operating range.The CircuitThe circuit is generally straightforward. Itconsists of an input buffer with a gain ofabout 50, followed by a signal compres-sion stage which reduces the dynamicrange greatly in order to feed the effectscircuitry at a constant level. The effectsconsist of a distortion -inducing stage forfuzz and a variable band-pass filter for thewah wah. After the effects stages, thedynamic range of the signal is restored tonormal before being fed to the mixer, tonecontrols and power output stages.

The input buffer consists of a single3140 CMOS op -amp whose gain is set at48 by R2, R3. The following dynamicrange compressor consists of one part of aLM13600 dual transconductanceamplifier. The gain of this device is afunction of the amplifier bias current, theinput diode current and the load resistor.The output buffer of the device is usedhere as a peak detecting rectifier whichcharges a capacitor (C3) to the peak valueof the output signal less two base -emitterdrops (about 1V4). If this voltage is

FU

PLAYMATE

T

greater than about OV7, the resulting cur-rent flowing through the input linearisingdiodes causes the effective stage gain todecrease and keep the output level cons-tant.

Distorting The FactsDistortion effects in this project are oftwo types. The first is mainly even -harmonic, generated by half -wave -rectifying the input, inverting it and thenmixing it with the original signal, allowinga range of no distortion to complete fre-quency doubling. In addition to this,overload type distortion is provided by ahigh gain clipping amplifier using non-linear feedback (IC3a,3b).

Wah wah sound effects are producedby a current -controlled state variablefilter. The control current determines thecentre frequency of the pass band, while atwo -gang variable resistor sets the band-width and compensates for inevitable gainchanges.

Tone controls are of a standard typeand use frequency -selective feedback net-works around an op -amp. The followingpower amplifier has been designed to havea low quiescent current. This is importantif batteries are to be used, as manyamplifiers of the IC variety take 30 mA ormore, or are designed for single rail work-ing.

The LM13600This device is used for two functions inthis project. One of these is the com-pressor/expander while the other is thewah wah. In both of these, use is made ofthe fact that the gain of the device isdependent on the amplifier bias currentand the linearising diode current (provid-ed that the input current is less than halfthe diode current). In fact, the outputresistor also determines the gain but is notso easily varied.

If the diode current is zero, then themanufacturers' data sheet shows that thetransfer function of the device is:-

= x q x =

labC

2KT

x V,,

26 x 10

If the diode current is not zero and thesignal current is less than 10,2 then thetransfer function is:-

Io 2 x x

Ip

whereI, = signal current

= amp. bias currentIp = lin. diode current

= output current

If we use resistors for input and output, itcan be seen that the voltage gain of a stageusing this device can be controlled easilyby use of the bias and linearising diodecurrents.

Figure 3 shows the basic circuit for avoltage amplifier and from it we can showthat the output voltage Vo is dependent onthe bias and diode currents.

V. = V, x 2 x x RL

R1, x IDIi. = V,./

R Therefore

and the gain V.= 2 x

Iab, RL

\Tin ID R1

10-NOVEMBER-1983-ETI

INPUTBUFFER

COMPRESSOR FUZZ WAH EXPANDER

MIXER

VOLUME

.6 ---TONE POWER AMP

-cc

Fig. 1 Block diagram of the Playmate.

Fig. 2 Internal circuitry of the LM13600 - an operational transconductance amplifier!

Fig. 3 Basic voltage amplifier circuit.

Compressing With TheLM13600Figure 5 shows the circuit used in this pro-ject to compress the dynamic range of thesignal input. For very small signals ID isvirtually zero and the amplifier operateswith a very high gain. As the signal in-creases, the output peak voltage will reach

a level sufficient to charge the capacitor Cto about one diode drop. If the inputsignal tries to increase further, theresulting current into the input diodes willcause their impedance to fall, thus in-creasing the attenuation of the input andmaintaining a constant output level.At any time the current flowing into thediodes is:-

ID = 2 x (V0 - 3 x 0.7)

R2

The 3 x 0.7 represents the voltage dropsassociated with the base -emitter junctionsof the output buffer transistors and thevoltage drop of the linearising diodes.This voltage does vary with temperatureand current, and since another controlcurrent is required for the expander func-tion, this is derived by using a resistor andcommon base transistor. The configura-tion gives a current output which tracksthe compressor control current very close-

ly, since it has the same number of junc-tions in series.

The LM13600 As An ExpanderIf the current produced by the above cir-cuit is fed into the bias current input of avirtually identical stage while the diodecurrent is held a constant, then the voltagegain equation above shows that the gainof the circuit will be increased as the cur-rent increases. Moreover the product ofthe two gains will be constant giving an in-variant overall signal transfer function.

Continued on page 66

ETI-NOVEMBER-1983-11

ZX81 User -Defined Graphics DTo make your ZX81 a whole lotbetter, we present a project thatgives 16K RAM pack ownersthe facility for user -definedgraphics.

THE RESTRICTIONS imposed by theSinclair defined character set can con-siderably reduce the impact of many pro-grams and the attractions of having user -definable graphics are apparent. Whileseveral manufacturers supply modules toexpand the character set, the cost must bea rather daunting prospect to the im-pecunious '81 owner.

It is possible, however, to obtainuser -definable graphics on the 16K ZX81for a total expenditure of less than a fewdollars and some clever work with asoldering iron! It must be said, however,that this is not a project for the fain-thearted, involving as it does a certainamount of modification and solderingwithin the computer; it also renders thecomputer unusable without the RAMpack.

Principle of OperationIn normal operation the pattern of eachcharacter is defined by eight successivebytes in the ROM. Each byte representsthe display for one of the eight lines of thecharacter, and each binary bit one dot ofthat line: Fig. 1 clarifies the way that thisworks. As there are 64 characters, a totalof 512 (64 x 8) bytes are required, andthese are located at the top of the ROMfrom addresses 7680 to 8191 (1E00 to1FFF in hexadecimal). An examination ofthese addresses reveals that the charactergenerator is being addressed exclusivelywhen lines A9 to Al2 are high.

The additional circuit operates bydetecting when these four lines aresimultaneously high with the ROM chipselect line, and instead of allowing theROM to be switched on, the internal 1KRAM is activated (this is not normally us-ed when the 16K RAM pack is attached).This can then be filled with characters ofthe programmer's choice. The circuitdiagram is given in Fig. 2.ConstructionThe circuit is constructed on a PCB asshown in Fig. 3. Use fairly thin (insulated)wire, preferably wily colour coding, forthe leads between the PCB and computer.The length of the leads will need to be ad-justed carefully during connection to the

MEMORY MAPADDRESS: -

7680

CHARACTER FORMATLETTER T'

7696 771

BINARY No. DECIMALEQUIVALENT

0 0 0 0 0 0 0 0 0

0 1 1 1 1 1 0 0 124

0 1 0 0 0 0 1 0 66

0 1 0 0 0 0 1 0 66

0 0 0 124

0 1 0 0 0 1 0 0 68

0 1 0 0 0 0 1 0 66

0 0 0 0 0 0 0 0 0

8120

SPACE te Ell en El IIPO R S T U

8 BYTES/CHARACTER

0 124 66 66 124 681 66 0

Fig I Memory map of the character generator and the method of character generation, illustratedby the letter 'R'.

computer PCB in order to keep themodification as neat as possible.

Installation AndComputer ModificationsTo open the computer, remove all leadsand accessories and then peel off the rub-ber pads on the underside of the com-puter, taking care to ensure that theadhesive film is removed with the pads.Now remove the five Phillips screws visi-ble on the underside of the computer;note that these are of different lengths andmust not be mixed on re -assembly. Thebase of the computer can now be liftedaway to reveal the computer printed cir-cuit board held in place by a further twoPhillips screws, which must also beremoved. The board is still attached to thecase through the ribbon connector andshould be carefully folded over thekeyboard when you want to turn it over,since the ribbon connector is not easy todisconnect or reconnect.

The positioning of the switch doesneed to be thought out fairly carefully inorder to ensure that it does not foulanything. Providing the switch is not toobig, it should fit through the top of thecase. Just in front of the RAM pack,towards the centre of the computer offersthe most room, but do make sure beforedrilling the hole that it will all go backtogether (including the RAM pack con-

nection) without fouling. If you find theprospect of drilling holes in your belovedcomputer a little daunting, the leads canbe brought out through one of the existingholes to a floating switch.

The addressing of the RAM andROM chips is performed in a slightly dif-ferent way by the computer and it istherefore necessary to disconnect the 10address lines to the RAM chip(s), recon-necting nine of them to the (A0' to A8')ROM chip address lines and the tenth toeither a ground or a logic high. This can-not be done easily from the underside ofthe board, as the address tracks servicingthe 1K RAM also service the 16K RAMpack. The most straightforward (ifsomewhat inelegant) solution is to removethe RAMs from their sockets, to bend therelevant legs through 90° and then toreplace the RAMs in their sockets, butwith 10 of the pins sticking out at rightangles. It is now necessary to solder theaddress leads to these legs and into thecomputer PCB - Figs. 4a, b, c and d givedetails.

Spot Your RAMBefore doing this, it will be necessary todecide whether your particular ZX81 is ofthe 2114 RAM or 4118 RAM type. Theformer consists of two separate chips asshown in Fig. 4a; the latter has only oneand the position of this is shown as a dot-ted outline. Identify each of the address


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pin numbers from Fig. 4d and run a leadfrom this to the relevant computer PCBhole as shown in Fig. 4c. In the case of the2114 type it is also necessary to run leadsbetween the two ICs. If you find difficultyin soldering directly to the IC pins, it mayhelp to have a very thin strip ofVeroboard pushed over the pins andsolder to this. The leads to the switch cannow be soldered into place.

Figure 5 shows the nine connectionsto be made to the other side of the com-puter board; the letters for each connec-tion correspond with those of Fig. 3.Resistor `1228' is removed from the com-puter PCB and the ROM chip select inputand output connections are made throughthe resulting holes as shown. Figure 5 alsoidentifies the RAMCS' track, which mustbe (carefully!) cut through. The PCB fitsunder the keyboard by the side of theheatsink.

Testing and ReassemblyIt is worth quickly testing the computer atthis stage. First, however, check, checkand check again that all the joints andconnections are correct and that there areno solder bridges between tracks.

Place the RAM pack in position andconnect the TV lead and power supplylead. With the switch in 'normal' modethe computer should operate quite nor-mally. In 'user' mode a regular patternshould cover the screen (each space nowcalling up the same random character).The program given below can be enteredin 'normal' mode and run in 'user' modeto ensure that the modification is func-tioning correctly:

10 SLOW20 FOR N = 1 TO 6430 PRINT CHR$ N;40 NEXT N50 FOR N = 7680 TO 819160 POKE N, 25570 NEXT N

When run in 'user' mode the screenshould suddenly black out, apart from thetop two lines, which should then pro-gressively fill one character position at atime from left to right, each individualcharacter filling from top to bottom.

Reassembly of the computer is simplya reversal of the disassembly procedure.Ensure that no leads are trapped betweenthe pillars and the board and that the cor-rect screws are used; short ones at thefront, long at the back.

Operation of User GraphicsIt is unlikely that you will want to redefineall 64 of the available characters and themost likely requirement will be to havefour or five special characters among theexisting ones. As it is not possible todisplay both the Sinclair graphics and theuser graphics at the same time, the

45V

USER

NORMAL 0

A9A10AllAl2

ROMCS(FROM ULA)

NOTE:IC1 IS 742091 or 74LS20IC2 IS 7400N or 741500

RAMC,(TO INTERNALRAM ONLY)

ROMCS' (TO ROM)

Fig. 2 Circuit diagram of the user -graphic modification.

ow it r sThe inputs of the quad NAND gate 1Claare connected to the four address lines A9to Al2. The output of this gate is inverted(using the NAND gate 1C2b with its two in-puts connected together) and used as one ofthe four inputs for 1C2a. The third, nput isprovided by the switch, which in 'user'mode supplied a high and in 'normal' modea low. The fourth input is held permanentlyhigh.

Thus, when the switch is in 'user' modeand the ROM and the character generatorare being addressed, all the inputs to 1C1bwill be high and the output will be low: in

any other circumstances the output will behigh. This, therefore, satisfies the conditionrequired by the RAMCS' line to the internal'user' RAM.

The output of IC2d provides the newROM chip select line (ROMCS') by perfor-ming a logical NAND between the newRAMCS' output and the inverse of theROMCS input from the ULA. Thus, whenthe user RAM is being selected, the outputwill always be high, and when the RAM isnot being selected the output will copy theROMCS input.

'SY (X)SNITCH

MINIA10 In

INPUT 121=ITCHAllAl2 RA

RAMS' OUTPUT IV)OV

ROMCS OUTPUT ir

Fig. 3 Component overlay for the offboardcomponents. The letters correspond to Fig. 5.

simplest solution is to copy the Sinclairgraphic set into the user RAM, and thento select some little -used primarycharacters and redefine them.

The exact way that this is done canvary, but my usual approach is to copy theSinclair graphics into the user RAM atswitch on. Listing 1 gives a short program(using machine code) to achieve this.When entering the REM statement (line 1)it must be entered exactly as listed. Theoutlines of the graphic characters havebeen added to clarify wkich symbols touse, and don't miss the three spaces in line1 which require keying in. The keyword inline 1 is entered by first typing THEN(shifted 3), followed by GOSUB anddeleting THEN using the Edit functions,but leaving the GOSUB intact. As a quickcheck that the line has been entered cor-rectly, PEEK 16526 should return 118.The program borrows some of the unused

Parts ListResistors (all 1/4W, 507o)R1 1k0

Semiconductors1C1 74LS201C2 74LS00

MiscellaneousSW1 SPST miniature toggle or

slide switchPCB

computer RAM to temporarily store the512 bytes read from the ROM and shouldnot, therefore, be used as part of a largerprogram, otherwise this may be overwrit-ten and corrupted. If this is a problem, theprogram can be written entirely in BASICand listing 2 gives such a program.

Having thus copied the Sinclairgraphics into the user RAM, each pro-gram can then amend the characters as re-quired and preferably restore the originalones at termination.

Listing 3 gives a program enabling upto 10 new characters to be defined withthe aid of a visual display and the infor-mation stored in the REM statement ofline 1. Only the primary characters (withtheir inverse) can be redefined and theseare the first 64 characters of the list onpage 181 of the Sinclair manual. When allthe characters have been defined and"FINISHED?" is answered with "Y",


ZX81 User -Defined Graphics

the program deletes itself, excepting theREM statement. This can then be used asthe first line of the main program and acall for USR 16514 will exchange theSinclair characters with the new charactersrequired; a further call of USR 16514 willexchange them back.

When entering the REM statement oflisting 3, it is important to use noughtsand to have exactly the right number(166). This can be checked by PEEKING16680, which should return 118.

This program (ie listing 3) requiresthe machine code values given alongside itto be POKED into the REM statement.Listing 4 gives a suitable program for do-ing this and this should be entered and runimmediately after entering the REM state-ment. All of this program (except theREM statement) may then be deleted andthe rest of listing 3 entered.

If more than 10 characters need to bedefined, it will be necessary to add 10 fur-ther zeroes to the REM statement for eachextra character required; the final address(currently 16671) in line 320 will have tobe increased by 10 for each extracharacter, as will the value held by the twobytes in addresses 16561 and 16562 (cur-rently 16681). This latter value is held inthe usual Z80 manner, ie. low byte firstand high byte second. Having added onthe required number of tens to 16681,divide by 256 to give the high byte (beingthe whole number part of the result) andmultiply the remainder by 256 to give thelow byte. For example, 16691/256 =65.19922. Now 0.19922 x 256 = 51, so wehave to POKE 16561, 51 and POKE16562, 65.

Because the graphics are completelyunaffected by RUN, NEW, LOAD, andso on, it is also possible to enhance manyof your existing games and programs byredefining specific characters used in thegame before loading the program. Thuschess games using I, K, Q etc can haveproper chess symbols, missiles canmagically turn from As into Cruise look-alikes, and so on.

1 REM .5 2) 2 coSUB WAN2 POKE 16522,50-.-, LET U=U5R 165144 PRINT -SWITCH TO

,4E PRESS --CONY---5 STOP6 POKE 16522,307 POKE 16519,50S LET u=uSR 16514 POKE 16519,30

Listing 1 BASIC program to copy Sinclaircharacter set into user RAM, using a machinecode routine.

10 PAST20 DIM c(512)30 FOR Am7550 TO 319140 LET OtR-76791APEEKSO NEXT A60 PRINT "SWITCH TO --Liam-- APRESS "-CONT..--70 STOP50 FOR Am7680 TO 319190 POKE A,C(A-76791100 NEXT A

Listing 2 BASIC program to copy Sinclaircharacter set into user RAM.

UHFMODULATOR

b.

c.

AsA10All412

R

U

RAMCS' V

00O

00

OO

0000

0°

0O 0

OV

d.9

8

7

6

4

2

3

Fig. 4 General view of the component side ofthe computer PCB, with 2114 RAM type (4118type shown dotted). Only six of the 10 new con-nections are shown (a). The RAM address pinsare bent outwards (b). Connections into theZX81 PCB from the RAM chip(s) are shown in(c), while (d) gives the address pinouts for theRAM.

REMOVERESISTOR

1R28)

V

*5V RoMCS' ROMCSITO ROM) (FROM ULA)

Fig 5 Connections to the underside of the ZX81 PCB. RAMCS' connections are shown for both the2114 type (dotted) and the 4118 type (solid) RAM ICs.


Further Hardware

ModificationsWhile this project was conceived as a verylow-cost entry into user -definablegraphics, several modifications could bemade to bring a greater degree ofsophistication to their operation. Themanual switching could be replaced bysoftware switching, for example: if youhave an input/output port, this can bedone by using one of the output port linesas the switch input for 1C1b.

Only half of the 1K memory is usedand the A10 address line from the RAMchip could be switched between high andlow instead of being fixed to a high, thusallowing two pages of user graphics to beavailable. Again, this could be a softwareswitch controlled by an input/outputport.

1 REM' 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

5 LET AD.1655010 DIM A(8,8)20 FOR Y.1 TO30 PRINT XXXXXXXX-,Y40 NEXT Y50 PRINT -A5CDEFG61-50 PRINT AT 1750,"INPUT PIXEL

COORD ES. RI . HIT NEULINE TO PINI5H-70 INPUT .3$50 IP RS.-- THEN GOTO 16090 IF CODE A$(1)<CODE R$(2) TM

EN GOTO 70100 LET Y=CODE R$(2)-28110 LET X=CODE A$(1)-37120 IF X)8 OR X41 OR '1)0 OR Yi1THEN GOTO 70130 LET R(X,Y)=R6S (R(X,Y)-1)140 PRINT AT Y-1,X-1,CHR$ (61+A(X,Y)+67)150 COTO 70160 CLS103 PRINT RT 15,0,-UHICH CHRRAC

TER IS TO CHANGE, -1,0 INPUT .$180 LET CA.7880+8*CODE AS190 LET H5=INT (CR/256)200 LET L8=CR-256+H6210 POKE AD,LE7220 POKE AD+1,HE7230 LET AD=RD+2240 FOR Y=1 TO 8250 LET D=0260 FOR X=1 TO 5270 LET D=D+R(X,Y)+2++i8-X7250 NEXT X=90 POKE AD ,0300 LET AD=RD+I110 NEXT V320 IF AD<16671 THEN COTO 350330 PRINT RT 15,0; -YOU HAVE DEFINED THE MAXIMUM OF 10 CHARACTERS. IF YOU UISH TO DEFINE MORE CHARRCTERS PLEASE SEE TEXT OF RRTICLE, OTHERUISE TYPE PRINT U5R 16360-340 STOP50 PRINT RT

PE Y6.0 INPUT R$

370 IF R$11)= -Y- THEN PRINT USA16560300 CL5390 GOTO 10

15,0:-4.***AMMERNMIAOR N

Listing 3 Program for defining new charactersand storing the information in the REM state-ment for later use (left): the values above are tobe POKEd into the REM statement of line 1 us-ing listing 4.

ADDRESS1651416519

6217

10166

3364

196 64213_

16524 223 1 13 016529 42 136 64 209165341553916544

217329O36

1923735

101761

2098

2250

165491654916554

2372370

1751759

225225al

1200

101024

16559 215 33 41 55 19516564 3 4

500 PRINT -UHRT 15 THE START RCDRESS? (NORMALLY 16514)"510 INPUT R515 CLS520 PRINT AT 0,0; -INPUT NEXT NOTO BE POKED. TYPE 999 TO TERMZ

NRTE-530 INPUT D540 IF 0=999 THEN STOP550 IF <0 OR >255 THEN GOTO 5

30560 POKE R,D570 SCROLL560 PRINT AT 16,0,R,D590 LET R=R+1600 GOTO 520

EEO

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Book ReviewASTI

IF YOU WERE ambitious enough tobuild your own satellite earth station(ETI, July/Aug., '83), or if you've just in-stalled a commercial unit, or if you sellcommercial units, you've probably comeacross the problem that plagues everyoneat some point: electrical interference withthe video and/or audio. This interferenceis not surprising; the electromagneticspectrum is full of all sorts of nasties justwaiting to ride into your system on top ofthe tiny signal available from satellites.

The next problem you have is one ofinformation; where do you find reliablehelp for such a new technology?

HelpTo your aid comes the Microwave FilterCompany of Syracuse, N.Y. They'veprepared a thick 3 -ring binder describingthe various causes and cures. Their in-terest in the matter is twofold: they wouldnaturally like you to look into their com-prehensive line of filters, and they alsowant to see filters used correctly. To thisend, they've prepared this well -written,well -produced reference work.

System PlanningInterference can be minimized to beginwith by carefully surveying the site; for in-stance, the dish can be located in the elec-trical "shadow" of metal structures toblock interference and not the signal.Chapters One and Two give an insight in-to the basic workings of satellitemicrowave transmission and reception,with regard for proper siting of theantenna.

Station BasicsHow can the miniscule signal from asatellite possibly be amplified enough todrive a receiver, and how do you findanything out by measurements? ChapterThree covers the simple calculations thatcan be used to determine power gain andnoise figure. Formulae are included forthe Low Noise Amplifier's performance,and for determining the variouscharacteristics of the parabolic antenna.

SourcesWhere does interference come from?After seeing the impressive listings in

Getting the best from yoursatellite receiver system.

By Bill Markwick

ASTIThe Avoidance/Suppression ApproachTo Eliminating Terrestrial InterferenceAt TVRO Earth Stations

f.

NiPe-ASTI: Avoidance/Suppression of

Terrestrial InterferenceThe book is presently selling for $125 U.S., a considerable amount even if you

compare it to other large technical tomes, but on the other hand, there doesn't seem tobe any other book with so much TVRO information all in one place.

ASTI, and Microwave's TVRO products, can be obtained from Microwave FilterCompany, Inc., 6743 Kinne St., East Syracuse, New York 13057 (315) 437-3953.

Chapter Four, you'll wonder how yoursignal ever gets through at all. Potentialoffenders are given along with their fre-

quencies, and the electromagnetic bandsare busy indeed. The need for more spec-trum space means that commercial


transmitters are now edging upward intothe gigaHertz region, just where TVsatellite broadcasts are found. There mayalso be some pickup of harmonics fromradar and other systems.

Doing SomethingChapter Five has full -colour photos of theeffects of various spurious signals oncolour -TV reception; each photo gives thedB level of the offending interference.Chapter Six then goes into considerabledetail on selecting the antenna; they're notall the same, and the efficiency of thedish/LNA determines the upper limit ofthe quality of signal. The electronics get agoing-over; even the connecting cablescan make a big difference.

Perhaps you feel that the sitingmeasurement should be professionallydone; expensive specialised equipmentmay be necessary, and considerable adviceis given on what to check for in a survey.

You'll notice that we haven't evenreached the section on filters yet; thisshould give some idea of the depth of theinformation given. The philosophy is thatthe installation should be optimised forreception, and filters added last, sincefilters inevitably remove some portion ofthe bandwidth. I mention this lest I'vegiven the impression that the book servesas a catalog for the company's products;this isn't true in the least.

FilteringFilters can be inserted at quite a fewpoints in the chain; it all depends on thetype and frequency of the interference.There are bandpass filters and trapsdesigned for the feedhorn, just ahead ofthe LNA; they can also be placed after theamplification and ahead of thedownconverter. There are 60 and 80 MHztraps to clean up the 70 MHz output ofthe downconverter; instructions are givenon how to build your own tunable units.Colour photos show the remarkable im-provement upon insertion.

Special InstallationsIf you install a system to feed more thanone receiver, such as hotel or con-dominium TV, you'll appreciate the over-view in the last chapters. Multiple -sethookups are naturally prone to spurioussignal pickup due to the extra wiring in-volved, and there is a wealth of installa-tion tips and explanations of filter actions.There's even a BASIC program forcalculating the severity of interferencebased on sit measurements.

And FinallyThe production of the binder is beautiful-ly done, with heavyweight reinforcedpages and dividers between chapters. Theschematics and charts are first-rate, andideas are presented clearly in a structured

flow. It isn't a book for beginning elec-tronics enthusiasts, however, and assumesthat the reader has reasonable competencein working with RF.

CID

1-711I '11

SEE US ATworld ofcommodoreINTERNATIONAL CENTRE, TORONTODEC. 8-11, 1983

To commemorate their 25th anniversary, Commodorepresents The World of Commodore, the first all -Commodore computer show ever held in Canada. TheWorld of Commodore offers users an opportunity toexamine a tremendous variety of software, peripheralsand accessories for Commodore computers, and topreview Commodore's newest product offerings.

Over 70 exhibitors from Canada, the U.S., Britain, andEurope will be displaying hundreds of different brandsof business software, educational software, home soft-ware, personal use software and peripherals approvedby Commodore for use on their computers. Many ofthese products will be shown for the first time inCanada at The World of Commodore and products willbe available for sale at very attractive prices.

A special feature of The World of Commodore will bean exhibit documenting Commodore's 25 -year history,and previewing some of the company's plans for thefuture. As an added bonus, your World of Commodorepass is also good for The Home Entertainment Fair,being held at the same time in an adjoining facility.

If you use a Commodore computer, or simply want tofind out what the computer revolution is all about, youwon't want to miss The World of Commodore, thelargest exhibition ever held in Canada of Commodorecomputers and products designed for use withCommodore computers.

The World of Commodore and Home Entertainment Fairare being held December 8 to 11 at the InternationalCentre, 6900 Airport Rd., Mississauga. Parking is free,and VIA Rail runs right to the Centre.

For further information, contact Hunter Nichols Inc.,721 Progress Ave., Scarborough, Ont. M1H 2W7.Phone: (416) 439-4140.



RoboticsTHE SALESMAN AT the computershow had a large crowd around his boothto see and hear the voice recognition unit.He grandly waved his microphone like atalk -show host, and spoke into it: "Whatis eight minus two?" "Eight minus two,"said the computer in an astoundinglylifelike voice, "is sixteen."

"Heh, heh," said the salesman as thecrowd roared, "looks like a little softwareproblem here."

That little incident seems to nicelysum up robots and the implied artificialintelligence that goes with them; they canbe absolutely amazing in a variety oftasks, but it doesn't take much to tripthem up into a display of equally amazingstupidity. We're still a long way from theHollywood view of robotics.

HollywoodRobots in their cinematic incarnation aresuch natural scenestealers that science -fiction movies are full of them. Fordramatic reasons, they tend to behumanoid in actions and appearance, andif possible, loveable. The Star Warsrobots come to mind; even R2D2, whowasn't people -shaped, was as cute as allget out. In the interest of screen appeal,script writers have ignored practicallimitations to making a machine performhuman functions; audiences have seen somany motorized tin people that the imageis firmly fixed; however, it's a long wayfrom the reality of "intelligent"machines. And that brings up a goodquestion: if mechanical humanoids areimpractical at present, then just what is arobot?

The Blurred DefinitionWhat would the difference be between,say, a microcomputer and a robot? Well,you might say that the robot hasmechanical motion, that it's self-contained and can move around the roomand pick things up. But what if the microhas voice recognition and can answer aperson? If we say that a robot is a machinethat can perform tasks normally done byhumans, what of the material -cuttingrobots that just look like a bandsaw?There's a bomb -disposal robot made inOntario that looks like a go-cart with aTV camera on it; is there a category forthat one?

It's probably safe to go by intuitionat this point; you can call just about anymachine a robot and get away with it.We're really more concerned with the

From squawking toys thatstumble around the carpet to

huge automotive weldingmachines, robots are almost

as commonplace as thecomputer.

by Bill Markwick

A General Electric robot welding arm. The arm isequipped with laser light and "eyes" which can

watch the weld and correct the motion of the arm.The image "seen" is displayed on a TV monitor

for use by curious humans.


strengths and weaknesses of machine in-telligence; you can make a blanket state-ment and say that if a machine can betaught to do a reasonably complex taskand perform it without human guidance,it's a robot. Of course, a programmablewashing machine might then be called arobot. That's the trouble with pigeonholedefinitions.

The Housebroken RobotThis year saw the unveiling of severalmakes of home robots from companiessuch as Heath, RB Robots, and An-drobot. To keep the cost to a reasonablesum, most home robots have that oildrumR2D2 look, running on little wheels andslowly waving little arms under control ofa microprocessor.

It's interesting that the manufac-turers have invested millions in developingand building these little units without anyreal idea what they're good for. At theHeath press conference for the Canadianrelease of the Hero 1, reporters watched ittrundle around the carpet and listened toit blare out with its gargley that -does -not -compute voice, and then asked,reasonably, "But what's it for?" Thecompany officials replied that they sort ofdidn't know, that home computers wereleft up to the hobbyist's ingenuity at first,that uses would be found. It's program-mable. You can make it do just aboutanything.

At the end of the conference peoplefiled past a reporter who was doggedlytrying to make it pick up a plastictumbler; it kept knocking it over.

RB Robots, makers of the RB5X, area little more aggressive in their marketing.Press releases published in magazines andnewspapers have led the public to believethat RB5X can fetch a beer, vacuum thecarpet, and put out fires. Indeed it can;the questionable point is just how well itcan do any of these things. To get you abeer, it requires a special refrigerator toallow for the limitations of its guidanceand arm systems; none of the home robotshave sensors sophisticated enough to opena regular refrigerator, much less find aspecific item inside. Their "vision",which is usually infrared or ultrasonicranging, is limited to there -or -not -theregeneral detection. The vacuuming is ac-complished with a battery -powered add-on; the vision and/or a programmedcourse lets it steer around a room withoutbumping into much. However, since6 -amp domestic vacuums often leavesomething to be desired, it's doubtful ifthe tiny toy can pick up much dirt. It alsowon't reach under chairs.

As far as fire extinguishing goes, theheat sensors in the robot are connected toan external system, such as watersprinklers or CO2 nozzles. Perhaps it'sbetter than trusting to a simple smokedetector, or no detector at all.

The main point is that they're toys;fascinating ones, but toys nonetheless.Their efficient microprocessors may meanthat they can easily be programmed to do1000 separate steps with only 4K of on-board memory, making them idealteaching aids for learning industrialrobotics, but their general uses arelimited. A spokesman for Androbot wasquoted as saying that robots can get thepaper, pick up after you, and put looseshoes in the closet. They simply won't.They aren't smart enough. The homerobots can certainly be programmed(labouriously) to pick up a certain shoeand put it in a certain closet, but let loosein a room without painstaking guidance,they're just as likely to pick up the cat andstuff it under the sink.

Smartening Them UpSince we're largely unaware of the im-mense complexity of our own brain'sfunctioning, we tend to think thatrecognizing and picking up a specific ob-ject is an extremely simple thing to do. In-fants can do it, so it should be a piece ofcake for a microprocessor, especially sincemicros and their memories are nowbecoming smaller, cheaper and moresophisticated.

In fact, recognizing an object andpicking it up is a phenomenally com-plicated procedure. It involves re-quirements of vision, touch and memoryfar exceeding any but the most expensiveindustrial machines, and even then thefunction is still a bit primitive.

It's possible for a home robot to con-nect to a home computer via cable orradio, and it might be tempting to imaginetheir capabilities expanded by addingseveral megabytes of memory and multi-ple microprocessors. However, you wouldalso have to add an upgraded visionsystem with higher resolution and betterranging, fairly comprehensive touch sen-sors, and more complicated motorizing ofthe arm or arms. Controlling all thesewould require a tremendous amount ofmemory, and the high cost of themechanical parts would mean that youwould be approaching the level of expen-sive industrial robots.

They Sell AnywayIn case you think the above is a bit harshon the little domestics and their salesmen,there's no getting away from the fact thatthey probably have the appeal of theultimate gadget. Those who are lovers ofgadgets, and this seems to be the majorityof us, will be overjoyed to know that youcan hook up some of the robots tomicrocomputers such as the Apple; thisexpands their capabilities to include suchthings as voice recognition and moreelaborate movement control.

ETI-NOvEMBER-1983-19

Robotics

Of course they can't do anythinguseful, and they work in a cumbersomestupid sort of way. But they're fun, man!

If we leave the fans of the littledomestics programming them to greetcallers at the door with peculiar messages,we arrive at robots which were designedfrom the start to be as useful as possible.

IndustrialsWorker robots just had to happen. Oncemotor control signals could be stored oneway or the other, experimenters naturallytried to make creations that would dotasks of some sort; in fact, the word"robot" comes from a Slavic root mean-ing "forced labour". The gadget fans justwanted to see the things go; the en-trepreneurs' eyes glimmered with the con-cept of an employee that wouldn't needcoffee breaks or parking lots.

Early robots were a long way fromthe present models; the first applicationsof servo -control would probably havebeen punched tapes running factorymachines which did complex butrepetitive tasks. They wouldn't have look-ed like our concept of robots at all; justmotors and solenoids mounted on a latheor drill press. However, it wasn't long un-til microprocessors met with improvedservo -motor manufacturing, and roboticsemerged from dedicated one -job applica-tions to more versatile units which couldbe "taught" to do a variety of tasks.

According to the Matsushita robotcompany, there are definite categories ofindustrial robots. These are:1. Manual Manipulator. These are thenoted "Waldoes" of science -fiction fame.They consist of a set of arms whichduplicate the movements of a human con-troller; they're really a power assist for theperson, and are used to isolate theoperator from a hazardous procedure.2. Variable sequence. This is amanipulator operating from preset in-structions that can be easily changed.3. Playback Robot. These learn anoperation by memorising the sequencesperformed by a human demonstrator. Forinstance, the person could move a paint -spray arm along a certain path on a carbody; the robot would then reproduce thison the assembly line.4. Intelligent Robots. Despite the con-tentious word "intelligence", these robotshave enough processing power and exter-nal sensors to make decisions based on thefacts they are capable of recognizing.

Unmanned Factories?There's no doubt that robots areeverywhere in industry; the first caseshave been reported in both the US andJapan where maintenance workers havebeen killed while servicing large assemblyline robots. This naturally brings to mind

the movie scenario of robots runningberserk and smashing their way down thestreet. In fact, the accidents were causedby the absence of proper safety interlockswhich would have disabled the machinesduring servicing; it could have happenedwith any large industrial machine.

In any case, robots are a familiar partof any large factory, and wfll becomemore so as the technology improves. Theusual description of a robot employeereads: works 24 hours a dray without cof-fee breaks; repeats its tasks tirelessly;works in hazardous areas; works forabout one-third the cost of a person;doesn't ask for any sort of fringe benefits,and never goes on strike. All this is true.However, Mr. H.A. Poling, executiveVice -President of the Ford Motor Com-pany, said in a speech to a robotics con-ference in 1982: "But there are otherthings that robots won't do. They neverlaugh at a joke, or say good morning.They never give a pat on the back, orremember a birthday. They don't buycars, and they don't vote in favour of newlabour agreements."

This is an interesting point on the"humanity" of robots; they just don'thave any. On the positive side, they takeover boring or distasteful or dangerousjobs. This raises the question of what todo with the employee who's been displac-ed. The robotics industry hurries to pointout that robots create more jobs than theyeliminate: the increased production resultsin more sales; more servicing, and moresupport staff. Mr. Poling points out thatFord has never laid off anyone as a resultof robots, saying "if a job has disap-peared, we have retrained or upgraded."

Again, all this may be true, but theimage of a country with total automationand people -less factories brings to mindthe anonymous quotation "They earned aprecarious living taking in one another'swashings."

Artificial IntelligenceJust how intelligent are robots right now?It's safe to say that they're pretty dumb:smarter than your dishwasher, but wellbelow your pet gerbil. Of course all thiswill change, because integrated circuitmanufacturers usually have chips on thelab table that are far ahead of anythingreleased commercially; it shouldn't belong until the next generation of microcir-cuits is unveiled for your amazement anddelight. Both American and Japanesefirms are hard at work on two functionswhich will vastly increase the capabilitiesof industrial robots; vision and speechrecognition.

A company in Windsor, Ontario,called Diffracto, Limited is making visionsystems for robots, and claims to be farahead of industry competitors. At the mo-ment, optical sensing devices used with

lasers or other light sources can performsuch jobs as sorting bolts, gauging the sizeof extruded wire, and checking for flawsin surfaces, but this is pretty basic stuff.On the drawing boards are moresophisticated devices that will recognizeobjects and sort them according to quali-ty, a natural for the canning industry.

General Electric has developed a sim-ple laser vision system for guiding weldingunits; it can continually observe the jointand weld "puddle" and make ad-justments as it moves. This again is fairlysimple, but it points the way to the visionsystems we can expect in the near future.There is no reason that a robot cannotscan an entire room with a television lens,recognizing objects by comparing themwith previously stored information, andmaking decisions based on its program.There are already security systems whichuse this method; at present they arelimited to simple intruder detection (itsimply detects any change in the scene -it's only suitable for empty rooms) but theonly limitation here is processing power.As computer systems get cheaper, there isno technical reason why robots couldn'thave vision as good as a human's; thechoices and decisions it makes with thatvisual input is quite another story.

This is where artifical intelligencecomes in. It's an elaboration on the morefamiliar computer programs, because therobot's computer will have a huge volumeof sensory inputs once vision and touchsystems become more elaborate. Thesense of touch, at the moment, is usuallyprovided by a series of microswitcheswhich tell the controller whether or not anobject has been successfully grasped, butsoon more refined methods such as con-ductive touchpads will allow betterdiscrimination; even subtle differences insurface textures could be easily detected.With so much information coming in, thecomputer needs to be able to do betterthan the familiar "if -then -else" logicstates; it needs to be able to make deci-sions which appear human for all intentsand purposes. A "thought" process in arobot's computer might go something likethis: "I have inserted 3,458 bolts, but thisnext one feels 1.5 millimeters too short.The others I have are the wrong colour.There is no answer from the inventoryrobot. The production -control robot saysI can't stop the line. A human is ap-proaching. It's Bob. He'll know what todo. I'll ask him."

This is somewhat beyond thecapability of a ZX81, even with the 64KRAM pack. The robot has made a simpledecision based on the yes -no aspects of theparts supply, but has had to recognize aperson and work out that the person couldsolve the problem. A robot that workstirelessly is one thing: robots that can fixunforeseen problems would be a produc-tion manager's dream.

OPTOELECTRONICS, INC.

CELECTRONICS

LIMITED

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MODEL K -7000 -AC 10 Hz to 550 MHz counter. 50 Ohm & 1Megohm inputs via BNC type connectors on rear panel. Thismodel is available in optional kit form.#K -7000 -AC counter assembled 115VAC/12VDC . . $266.00#Ni-Cad 70S internal Ni-Cad battery pack $43.30

MODEL LFM:1110 Low frequency multiplier. A frequencycounter accessory enabling tone frequencies to be countedfaster and more accurately. Has low pass filter for off -the -air.Tone -squelch measurements. BNC input/output.#LFM:1110 115VAC/12VDC $259.00

MODEL 7010-S 10 Hz to 600 MHz counter. 50 Ohm & 1megohm inputs via BNC type connectors on rear panel. ±1PPM TCXO standard ±0.1 PPM TCXO time base optional forgreater accuracy. 10 mV average sensitivity. Very compact 81/2 digit counter: Size 2" H x 4" W x 5" D, 1 lb.#7010-S 600 MHz counter 115 V AC/12 V DC...$395.00#TCXO-80 ± 0.1 PPM TCXO time base $129.95#Ni-Cad 76 Internal Ni-Cad Battery Pack $43.30

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MODELS 8007-S, 8010-S, 8013-S Deluxe series with frequencyranges of 10 Hz to 700 MHz, 1 GHz and 1.3 GHz. Standardfeatures include; external clock input/output, excellent sen-sitivity, sealed ± 1 PPM 10 MHz TCXO time base, 4 gatetimes, 9 digit resolution to 175 MHz, front panel power jackfor optional Broadband Preamp accessory, 115 V AC or 12 VDC operation, high quality compact construction housed inrugged aluminum cabinet. Optional features: internal Ni-Cadrechargeable battery operation, precision ±0.1 PPM TCXOor 0.05 PPM proportional oven (OCXO) time base. All timebase oscillators, including the standard TCXO, have 10 turncalibration adjustment accessible from rear panel. Size 3" Hx 71/2" W x 61/2 D. 23/4 lbs.#8007-S 700 MHz counter $619.00#8010-S 1 GHz counter $749.00#8013-S 1.3 GHz counter $880.00

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Robotics

Mr. AsimovIn the science -fiction classic, I, Robot,Isaac Asimov took a wild guess at thefuture state of robotics and came up withmechanical men located in the 21st cen-tury. It's interesting to note that he wasquoted in the press recently as saying thathe didn't think he would live long enoughto see the robotics industry as it is today.This shows rather well the dangers of thecrystal ball applied to technology; he 'wasright about the coming ultra -sophisti-cation of robots. Only the timing waswrong. On the other hand, he also for-mulated the Laws of Robotics: a robotshall not harm a human, a robot shallobey its orders and so on. This is where anaive belief in the reliability of machinerygot in the way. Murphy's Law overrulesAsimov's laws: even the smartest of ar-tificial intelligences is subject to the whimof wiring errors and malfunctioningmicrochips, and may, with the very bestof intentions, grab you firmly with itswaldoes and twist off your head under theimpression that you're a rear bumper foran '85 Toyota. People with defective wir-ing do this sort of thing all the time; it's inthe papers.

Robots will be dangerous, but so arecars and airplanes and sharp pointedobjects.

ForecastingIf Isaac Asimov can't predict the timing ofrobotics, it might be a good idea to passover the whole idea. Fortunately, otherpeople have gone out on a limb for us. Dr.Archie Bowen, Professor of Systems andComputer Engineering at Ottawa'sCarleton University, was quoted in theOntario government's Technology Newsas saying that since the capabilities ofsilicon chips seem to double every 18 mon-ths or less, we can expect speech recogni-

The Rumble equipment companyof Rexdale, Ontario, produceswelding packages using Hitachirobots. The robots are "taught"to weld complex shapes by using

an external keyboard.

tion by the middle of the decade and realartificial intelligence by the middle of thenext. The speech recognition will soonprogress from simple word commands tounderstanding sentences and sorting outmeanings according to context. The voice -operated typewriter will be a reality. Hegoes on to say that home robots will be thecat's pajamas by the end of the century,and no home will be complete withoutone; it all depends on breakthroughs inlow-cost artificial intelligence, abreakthrough that is being taken forgranted (we also need a breakthrough inlow-cost indexing motors and pulleys andsolenoids, but maybe we can get a robotto make these for us).

Professor Bowen then says "Whenyou get into a dialogue with a machine, itshakes your belief in your position on theplanet." This seems to say a lot aboutProfessor Bowen. The invention of thescientific calculator had everybody ga-ga,but soon it became just one more item toprop up next to the food processor thatyou didn't use as much as you thoughtyou would.

But this is frivolity. The real pointcomes when he says that artificial in-telligence will result in an equalization ofour intelligence and capabilities: "thegreatest contribution to maintaining oursocial structure will be from those whocan live creatively with our machines."

Hopefully those who can live crea-tively with the New Machinery will ar-range for a bit of input from those whocan't. Society doesn't reject people whocan't drive, for instance.

Safe ForecastingIt would be foolhardy to make a definitestatement about such spooky things as theuse of microsurgery to implant a humanbrain into a robot to produce science -fiction's "androids". On the other hand,

some things are self-evident. One of themwould be the use of robots by smallbusinesses as well as heavy industry. TheJapan External Trade Organization saidin their journal Industrial Robots, ". . .

robots will be used more and more bysmaller businesses . . . robots are gettingcheaper and skilled workers are gettingmore expensive and harder to find, mak-ing robots an attractive alternative even totiny cottage -type industries." Mind you,if robots will be displacing so many skilledworkers, employees shouldn't be hard tofind. In any case, this swing to robotics is

a natural extension of the changeover toautomated machinery of all types.

Another safe guess is that labourunions will not vehemently oppose the in-troduction of robots. Basil Hargrove ofthe United Auto Workers was quoted inCanada's Business Life as saying"(robotics is) desirable because we have toremain competitive in a worldwidemarket."

Companies will have to rethink theirentire manufacturing procedure beforebuying robots simply because they worklonger for less; otherwise the robots will

not be integrated into the flow of the pro-duction line. They may end up shelved ina back room somewhere.

There is general agreement from bothindustry and manufacturers that moreand more robots will be employed despitethe threat of displacing workers, becausemore jobs will be lost if robots aren't us-ed. The Ontario government has spottedthis trend, and has opened two specialcentres for guiding manufacturers; one isthe Robotics Centre in Peterborough, theother is the Computer AssistedDesign/Computer Assisted Manufactur-

ing (CAD/CAM) Centre in Cambridge.Universities will begin offering degree

courses in Robotics (Robotics 101: TheLaws of Robotics, Professor Asimov).This has started already; the Cranfield In-stitute of Technology in the UK is now of-fering a Master's Degree in robot science.

At this point, the home robots are lit-tle better than toys, and the large in-dustrial types are hidden away in fac-tories. All this is soon bound to change;remember that the same conditions ap-plied to the microcomputer a very shorttime ago.


Introduction to Fibre Optics

The technology of fibre optics hasgone from dopey novelty lamps tobeing the greatest thing to happento communications since thediscovery of copper.

by Robert G. Traub

THE FIELD OF land line telecommunica-tions represents one of the fastest chang-ing, and rapidly developing, hightechnology areas. The introduction of theintegrated circuit, and later, themicrocomputer, have enabled faster,more efficient information and data ex-change between telephone subscribers.Even so, the land line telecommunicationsfield still has some serious drawbacks.One of the major drawbacks is represen-ted by the speed restriction inherent in thesystem, through the use of copper wirecable. These cables restrict the bandwidthand thus the data rate at which informa-tion can be transmitted from one point toanother. As well, the copper wire systemis prone to static noise interference andcrosstalk, while presenting a lack ofsecurity and a shock hazard. To overcomethese and other limitations inherent in the

copper wire cable systems, many of theworld's telephone companies, such asSaskatchewan Telecommunications andNorthern Telecom Canada Ltd., are cur-rently involved in the development offibre optic cable systems.

The Basic IdeaFibre optic principles and theories havebeen understood by scientists since beforethe turn of the century. Experiments werecarried out and demonstrated in Britain in1870 by John Tydall, a noted physicist ofthe times. However, until recently thetechnology to develop the required hard-ware for their use was not available. Re-markably, in the past few years, many dif-ferent technical advances occurred atabout the same time, thereby making thedevelopment of systems and networkspossible. Necessary components, such as

high quality, low attenuation fibres, effi-cient light emitters, and high speed lightdetectors, all with a high degree of com-putability, have been developed. Otherimportant developments include reliablesplicing devices, and high quality, low lossconnectors. Connectors have been devel-oped for both simplex and full duplexsystems, along with a series ofsophisticated network connectors used toroute the light beam from a single fibre totwo or more fibres.

Employing fibre optic systems for thetransmission of data has shown a numberof advantages over the present method ofwire cables. First, optical fibres, becausethey transmit light and not electricity, of-fer complete electrical isolation betweencircuits, thereby eliminating hazardouselectrical ground loops. Further, thefibres do not present a shock or fire


hazard, allowing them to be used in areaswhere highly volatile liquids and gasesmust be processed. This also points outthe fact that there is no possibility of ashort circuit anywhere in the fibre opticsystem. Optic fibres are immune to radiofrequency interference and other elec-tromagnetic effects. This results in com-plete isolation from transient voltages(noise), and surges of harmful high cur-rent levels induced by lightning. Thefibres are smaller in diameter than theequivalent circuit carrying copper wire,and many more fibres can be placed in acable, offering even more circuits with alower total weight. Unlike their coppercounterparts, fibre optics are not subjectto 'crosstalk' from adjacent fibres, andare free from signal leakage. These twopoints show the additional security avail-able in the fibre optic, since they cannotbe tapped by induction devices as can cop-per wire.

Putting Them To WorkIt was not until the 1950s that an opticalquality glass fibre was developed. Theglass fibres of this era were very expensiveto produce, and exhibited a very high at-tenuation factor. These facts preventedthem from finding acceptance for com-mercial use, as the copper wire being usedat that time was easier to work with andmuch less expensive. About a decadelater, in the early 1960s, an economicalplastic optic fibre was produced. This typeof optical fibre did find its way into com-mercial use. However, they were restrictedto less technical areas such as ornaments,remote light sensing applications andnovelty items. In recent years, glass fibresmade from fused -silica have been produc-ed. Fibres of this type can be made at avery competitive cost, and their light -carrying ability is greatly improved overthe earlier versions. Fused -silica opticfibres consist of a small diameter, solidcore glass tube or rod, around which isbonded a second layer called 'cladding'.The cladding is constructed from a mater-ial which has a lower refractive index thanthe core material. This cladding is re-quired in order to increase the criticalangle of incidence, by reducing the dif-ference in refractive indices between thecore and outside world. A light ray strik-

ing the glass wall at less than the criticalangle of incidence will be refracted intothe air and lost. If it should strike at anangle greater than the critical, it will betotally reflected back into the rod. Thecritical angle depends on the refractive in-dex of the two materials; the glass rod andair, or the glass rod and cladding. In highquality optical fibres, the cladding is madeof glass, while in lower quality fibre, thecladding is made of plastic. The cladding,in either case, is very thin, and the actualphysical bond between it and the glasscore cannot be seen. In all cases, lightfrom a source will propagate in the opticalfibre only if it is either confined within theglass tube (called total internal reflection),or by refracting the light through manylayers of glass of different densities, eachhaving a refractive index less than thepreceding layer, with the layer of highestrefractive index at the centre. This secondmethod is called 'continuous refraction.'

In the case of total internal reflec-tion, the light must enter the glass fibre atan angle equal to, or greater than, thecritical angle of incidence. At angles lessthan this, the light will strike the glass sur-face and be refracted into the air and lost.At angles equal to, or greater than, thecritical angle of incidence, the light willstrike the internal wall of the fibre and bereflected back along the length of thefibre. This is the common method of lighttransmission used in `step -index' fibres. Inthe case of continuous refraction, the lightentering the fibre will gradually be bent asit passes through the many layers of dif-ferent refractive index changes, and willremain confined within the fibre itself.This system of light transmission isemployed in 'graded -index' fibres.

Basic TypesThere are many ways in which optic fibrescan be classified, depending on the phys-

a

ical properties involved. However, in rela-tion to the way in which they propagatelight, there are three main categories.These are known as multimode step -index, monomode step -index, and multi -mode graded -index. The 'mode' is relatedto the way in which light rays, which enterthe fibre at different angles, are pro-pagated. In the case of the multimodestep -index fibre, a light ray entering thefibre and striking the interior wall at ahigh angle of incidence will be reflectedfewer times than a light ray which entersthe fibre at the same time, but strikes theinterior wall at a lower angle. Due to thisfact, the ray of light striking the interiorwall at a high angle will travel along thefibre at a faster rate as a result of thereduced number of reflections. In fact, alight ray that enters the fibre parallel withthe fibre's axis (called the 'axial ray'),would not be reflected off the walls of thefibre at all (assuming no bend in thefibre), and have the shortest path;therefore it would reach the far end first.Each light ray of different angle is called a`mode', and the difference in time re-quired by each ray to reach the far end iscalled 'modal dispersion'. This dispersiondoes not effect the light gathering proper-ties of the fibre, but it drastically affectsthe rate at which a pulse of light can betransmitted. For instance, a very shortpulse will have all of its light rays enteringthe fibre at the same time, but at differentangles.


Fibre Optics

This action will result in one of therays reaching the far end ahead of another(with the axial ray being first), and so on,until all the rays of different angles havearrived. This will result in the sharp pulsesent being spread out over a period oftime, and thus badly distorted. The longpulse received at the far end will no longerrepresent the fast, short pulse originallysent. Multimode step -index fibre of thistype is the least expensive of all the opticalfibres. It is also the easiest to work withdue to its rather large diameter and goodlight -gathering properites, but has verybad modal dispersion characteristics. Oneway to combat the modal dispersion ofthe thousands of light waves that traveldown the length of the fibre is to make thefibre as small in diameter as possible. Thismethod is used in what are termed 'mono -mode step -index fibres'. Monomode step -index fibre was designed to minimize thenumber of different angles that the lightcould enter the fibre originally. As aresult, this type of fibre is extremely thin,expensive, and very hard to work with.However, it offers the least amount ofmodal dispersion by allowing only a single(mono) mode to propagate efficiently.This requires special contruction techni-ques where the cladding is of a refractiveindex only slightly less than that of thecore. The cladding is then increased indiameter in order to allow the extremelythin fibre to be handled. Monomode step -index fibres are very efficient, and can beused at high data rates over long dis-tances. Another method employed toreduce modal dispersion is by having aglass fibre which exhibits a higher densityat the center and gradually decreases indensity as it approaches the outer edge.The fibre constructed in this manner iscalled 'multimode graded -index fibre'.Multimode graded -index fibres offer alarger diameter than the monomode'fibres, while at the same time greatlyreducing the modal dispersion exhibitedby the multimode step -index fibre. Thistype of fibre is able to reduce the modaldispersion by forcing the axial rays totravel in a dense centre material, slowingthem down, while the reflected rays areconstantly being refracted by differentdensities, and actually travel at about thesame rate due to the time spent in the lessdense outer material. Multimode graded -index fibres offer excellent data rate anddistance properties. This type of opticfibre is used extensively in cable televisionsystems.

Lighting Them UpEach of these optic fibre types requires asmall light source using a narrow band offrequencies in order to reduce propaga-tion losses. An ordinary light emittingdiode cannot be used for anything otherthan short transmissions of a few feet, and

at slow pulse or data rates. OrdinaryLEDs disperse light in all directions, andare much larger than the fibre itself, whichintroduces severe power coupling loss.For these and other reasons, ordinaryLEDs are not an efficient light source foruse with optic fibres. To overcome the dif-ficulties displayed by the common lightemitting diodes, research was undertakenin recent years to provide new and bettertypes. Due to this concentrated research, anumber of special light emitting diodeshave been successfully developed. Onesuch diode, a planar heterojunction de-vice, is constructed using many layers of nand p material to form an "nnppnp" lightemitting diode. This, in turn, is coveredwith a small metal plate, with a tiny holeat the centre to allow the light to shinethrough. This type of construction offersa very brilliant light spot concentrated in avery small area in such a manner as to in-crease the coupling efficiency of the diodeto the fibre. The hole in the centre of themetal plate, has an extremely smalldiameter (the entire chip is about one halfthe size of a pin head), and requires asmall glass ball or `microlens' to be placeddirectly over it. The lens further directsthe light into a narrow beam, allowing thelight to be efficiently coupled to the fibre.This type of light source is usable for datarates up to about 80 MHz. For evengreater data rate, another diode, calledthe 'Burrus' or 'etched -well' diode, wasdeveloped. This special diode has an evensmaller light emitting area and can be usedto efficiently couple light to a very thinmonomode step -index fibre. Also, due toits special construction, designed todissipate the heat developed, it can beutilized at very high data rates. Anotherspecial light emitting diode was designedto emit light in a very small, directionalbeam. This is known as an 'edge emitting'diode. With this type of diode, the light isnot radiated out of the top of the chip asin the others, but rather is directed outone end of a special internal chamberwhich opens at the edge of the diode. Thistype of light emitting diode offers very ef-ficient coupling of the light source to theoptic fibre, and can be employed insystems that have a high data rate andlong distances. The edge -emitting diode isvery similar to the injection laser diode,and does not require a large currentsource. All of the special light emittingdiodes mentioned are, needless to say,much more expensive than the ordinaryplanar LED.

Getting It Out AgainTo receive the light at the far end of thefibre optic system, a photodiode, photo -transistor, or special 'receivers' can beemployed. For use in a very short distancesystem, a photodiode or phototransistorwould be sufficient. For distances bet-

ween 10 and 100 metres, a special receivercircuit can be employed. These receiversconsist of a photodetector, an amplifier,an automatic gain control, and a signalreshaper, all on one small chip enclosed ina TO -5 case. The case has a plastic cap toallow for easy press -fit alignment to thefibre. Low cost versions offer data ratesfrom between DC to 200,000 bits per se-cond. Receivers of this type are called`Fibre Optic Schmitt Detectors'. Fordistances greater than 100 metres, thereceivers employed are the same as theprevious one, with the addition of aspecial 'timing recovery' circuit. Again,all the circuits required are built on asingle small chip.

There are many areas that requirespecial consideration in the design of afibre optic system in order to minimizelosses. The system will exhibit a certainamount of loss at the coupling of the lightsource to the fibre, due to some of thelight being reflected off the polished sur-face of the fibre (fresnel loss), or improperangle of radiation causing much of thelight to be refracted, among other things.The optic fibre itself will cause a certainamount of loss due to absorption. Thefibre will also fail to carry the light if it isforced to bend around a very sharp cor-ner, as all the light will strike the surfaceat an angle less than the critical angle andwill be refracted into the cladding andlost. Each splice encountered in thesystem will also introduce loss, as will the

final coupling to the receiver at the farend. In the overall design of the system,the amount of power supplied by the lightsource, less all the losses incurred, muststill allow sufficient power for detectionby the receiver at the far end.

Each of the areas discussed, fibres,receivers, LEDs, couplers, and splicers,are currently undergoing rapid changes.Every day, it seems, brings newer, moresophisticated and cheaper fibre optic pro-ducts into the market place. With suchrapid development underway, the use ofthese high technology products will sooninvade every business and home that cur-rently sports a telephone or cable TV line.The telecommunications companies areconstantly breaking new ground in bothproduct design and application methods.

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Survey of 50 SystemsHEREIN we present 50 of the lower -costcomputers available in Canada. Asalways, we're sure it's complete andperfect; as always, the inevitable on -goingchanges in the market prevent this fromever happening.

A word about prices: they are themanufacturer's suggested list price,because various dealers sell at differentprices. Don't be surprised if they're dif-ferent when you get to the store.However, you can use them as a roughcomparison guide.

maimenfinit-iiiimmemmommisSystem: AVT Comp 2Operating System: BASICProcessors: 6502RAM: 64KPrinter I/O: 7 Exp SlotsDisk Drives Inc: Optional floppyScreen Format: 40x24Graphics: 280x193Sound:Colour:Key board:Software Included:Software Available:

Primary Market:Manufacturer:Available From:Price:Other:

YDetachableBasicFortran, COBOL, PASCAL,etcPersonal or BusinessAVT, SwitzerlandInteractive Micro Systems$1695.007 Apple compatible I/O slots

System: Acorn AtomOperating System: BASICProcessors: 6502RAM: 2KPrinter I/O: Opt S or PDisk Drives Inc: OptScreen Format: 32xI6Graphics: 256x192Sound:Colour: OptKeyboard: IntegratedSoftware Included: BASICSoftware Available: ExtensivePrimary Market: HomeManufacturer: Acorn ComputersAvailable From: GladstonePrice: $199.95Other:

System: ACE 1200Operating System: CP/MProcessors: 6502, Z80ARAM: 128KPrinter I/O: S, P & 3 ExpDisk Drives Inc: SS floppy disketteScreen Format: 40(80)x24Graphics: 280x192Sound:Colour:Keyboard: IntegratedSoftware Included: CP/M, Apple BASICSoftware Available: ExtensivePrimary Market: BusinessManufacturer: Franklin ComputersAvailable From: Local dealersPrice: $1399.00Other: Plug Apple compatible

System:Operating System:Processors:RAM:Printer I/O:Disk Drives Inc:Screen Format:Graphics:Sound:Colour:Keyboard:Software Included:Software Available:Primary Markel:Manufacturer:Available From:Price:Other:

ACE 1000BASIC650264K8 ExpOpt40x24280xI92NOptIntegratedApple Comp BASICExtensiveBusinessFranklin ComputersLocal dealers$1399.00Plug Apple compatible

System: AquariusOperating System: BASICProcessors: Z80ARAM: 4KPrinter I/O: 5

Disk Drives Inc: Opt or cassetteScreen Format: 40x24Graphics: 320x192Sound:Colour:Keyboard: Integrated, QwertySoftware Included: BASICSoftware Available: CP/M CompatiblePrimary Market: HomeManufacturer: Mattel ElectronicsAvailable From: Electronic PlayworldPrice: $199.00Other: Disk drive not available until late

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System: tari 1200XLOperating System: BASICProcessors: 6502RAM: 64KPrinter I/O:Disk Drives Inc: OptScreen Format: 40x24Graphics: 280x192Sound:Colour:Keyboard: IntegratedSoftware Included: BasicSoftware Available: ExtensivePrimary Market: Home or BusinessManufacturer: AtariAvailable From: Irwin ElectronicsPrice: $949.00Other: CP/M Opt

System: Atari 600XLOperating System: BASIC

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System: Coleco AdamOperating System:Processors: Z80ARAM: 80KPrinter I/O: S & 4 I/O portsDisk Drives Inc: Digital cassette (50 IPS)Screen Format: 36x25Graphics: High resSound:Colour:Keyboard: DetachableSoftware Included: Smartwriter, Smartbasic, gameSoftware Available: Atari games, Apple Basic Com-

patiblePrimary Market: Home or BusinessManufacturer: ColecoAvailable From: Consumers, Sears, Bay, EatonsPrice: $1200.00Other: Letter quality printer included


Smith -Corona introduces the first printerwith real character at the unreal price of $1095.*

The Smith -Corona DaisyWheel PrinterUntil now, if you wanted to include a reasonably -

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Not anymore. Now Smith -Corona* offers a daisywheel printer at such an incredibly low price, you can'tafford not to include it. That means that even thesmallest installation or business can now have letter qualityprinting capabilities at every work station.

The Smith -Corona printer operates with micro-processor -controlled daisy wheel technology, and isavailable with industry standard serial or parallel datainterfaces.

Best of all, it produces results identical to those of ourvery finest office typewriters - printing with real character.So it can be used to create letters or documents that haveto look perfect. As well as financial statements, inventoryreports, direct mail campaigns - anything that requiresquality printing.

And it's easy to use -just turn on the power, load thepaper and away it goes. (It works equally beautifully withletterhead bond or fanfold paper.) There are drop -in ribbon


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Computer Survey

System:Operating System:Processors:RAM:Printer I/O:Disk Drives Inc:Screen Formal:Graphics:Sound:Colour:Keyboard:Software Included:Software Available:Primary Market:Manufacturer:Available From:Price:Other:

Commodore 64Basic651064KS

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Dragon 32BASIC6809E32KP

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ExpanderCP/MZ80A64KS, P & 4 Exp51/4" or 8" floppy with CP/M40x24 colour80x72 colourYYIntegratedCP/MExtensiveBusinessCalifornia Computer SystemsOrion Electronics Supplies Inc.$1550.00Included floppy, IEEE diskcontrol

HP -75CBASICCMOS16KHP -ILCassette, built-in card reader32 character windowN/ANNTouch-typeBASICApplication SoftwareBusinessHewlett PackardHewlett Packard$1687.00Portable and battery operated

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System: Micro DecisionOperating System: CP/MProcessors: Z80ARAM: 64KPrinter I/O: 2 SDisk Drives Inc: One SS 51/4" floppyScreen Format: 80x24Graphics: N/ASound:Colour:Keyboard: DetachableSoftware Included: BASIC, Wordstar, Logicalc,

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System: Micro -ProfessorOperating System: BASICProcessors: 6502RAM: 64KPrinter I/O:Disk Drives Inc: Opt cassette or disk drivesScreen Format: 40x24Graphics: 280x192Sound:Colour:Keyboard: Integrated, QwertySoftware Included: BASICSoftware Available: ExtensivePrimary Market: BusinessManufacturer: Multitech Ind. Corp.Available From: Polytech Int. Canada Ltd.Price: $600.00Other: Portable


LX304 digital multimeter withautomatic decimal point, built inlow battery indicator andtransistor testing capability.,4138.00

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Model 216 Transistor Testerwith fast, automatic switchingfor instant good -bad analysis ofNPN's, PNP's, FET's, diodes andSCR's in or out of circuit.$182.00

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Computer Survey


M5BASICZ80A20KP

Opt cassette24x40 (TV)N/AYYIntegrated, QwertyBASICAvailable from SordHomeSordMicos Computer Systems Inc.N/APortable

System: Micro 48 Model IIOperating System: Apple CompatibleProcessor: 6502RAM: 48KPrinter I/O: OptionalDisk Drive: OptionalScreen Format: 40 x 24Graphics: Med. res.Sound: NoColour: NoKeyboard: IntegratedSoftware Inc.: BasicSoftware Avail.: ExtensivePrimary Market: Home or businessManufacturer: MicroAvailable From: GladstonePrice: $488.00

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System: PC 1500Operating System: BASICProcessors: C-MOSRAM: 2.6KPrinter I/O: Optional Printer -cassette inter-

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Home or BusinessSharpTotal Office Systems Ltd5299.95Battery operated, portable

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cassetteScreen Format: 40x24Graphics: 256x192Sound: ProgrammableColour:Keyboard: DetachableSoftware Included: BASIC, PASCAL, LOGOSoftware Available: ExtensivePrimary Market: Home or BusinessManufacturer: NABUAvailable From: Local dealersPrice: 8995.00Other: Portable, network

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miii011011111111111111111111111111111111111111111114

System: PC 8800Operating System: BASICProcessors: PD780C-1RAM: 64KPrinter I/O: P, S & 4 ExpDisk Drives Inc: 51/4" & 8" floppy interfacesScreen Format: 80x25Graphics: 640x200Sound:Colour: OptKeyboard: DetachableSoftware Included: Two BasicsSoftware Available: Extensive, CP/M compatiblePrimary Market: BusinessManufacturer: NECAvailable From: SGV MarketingPrice: 51795.00Other: Processor is Z80 compatible

System: PC -8201Operating System: ProprietaryProcessor: 80085RAM: 16KPrinter I/O: YesDisk Drive: NoScreen Format: 40 X 80 LCDGraphics: BlockSound: YesColour: NoKeyboard: IntegratedSoftware Inc.: BASIC, textfiles, Telecom, plus

cassette, etc.Software Avail.: LimitedPrimary Market: Home and businessManufacturer: NECAvailable From: Microcomputers of CanadaPrice: $1195.00

32-NOVEMBER-1983-ETI Continued from page 68

Now NRI takes you inside the newTRS-80 Model 4 microcomputer withdisk drive to train you at home as the

new breed of computer specialist!NRI teams up with Radio Shackadvanced technology to teachyou how to use, and

service state -of- e -artmicrocomputers...

It's no longer enough tobe just a programmer or a technician. With microcomputersmoving into the fabric of ourlives (over 1 million of theTRS-80m1 alone have beensold), interdisciplinaryskills are demanded. AndNRI can prepare you withthe first course of its kind, covering thecomplete world of the microcomputer.

Learn At HomeIn Your Spare Time

grammer gains practical knowledgeof hardware, enabling him to designsimpler, more effective programs. And,with advanced programming skills, thetechnician can test and debug systems

Now training includes either the TRS-80 Model 4Microcomputer with Disk Drive or TRS-80 ColorComputer with Computer Access Card; profes-sional D multimeter; the NRI Discovery Lab; andhundreds of demonstradons and experiments.(TRS-80 is a trademark of the Radio Shack division of Tandy Cap.)

quickly and easily.Only NRI gives you both kinds

of training with the convenience oflearning at home. No classroom pres-sures, no night school, no gasolinewasted. You learn at your convenience,at your own pace. Yet you're alwaysbacked by the NRI staff and your in-structor, answering questions andgiving you guidance.

TRS-80 Model 4 Plus DiskDrive To Learn On and Keep

NRI gives you hands-on trainingon the latest model in the most popularline of Radio Shack microcomputers:the TRS-80 Model 4.

You not only learn to programyour Model 4, you learn all about it...how circuits interact... interface withother systems...gain a real insight intoits nature. Under NRI's expert guidance,you even install a disk drive, verifyingits operation at each step.

You also work with a professional4 -function digital multimeter and theNRI Discovery Lab® performing over60 separate experiments.

The powerful, versatile TRS-80Model 4 microcomputer disk drive andother equipment you train with areyours to use and keep!

Same Training AvailableWith Color Computer

NRI offers you the opportunity totrain with the TRS-80 Color Computeras an alternative to the Model 4. Thesame technique for getting inside isenhanced by using the new NRI-developed Computer Access Card. OnlyNRI offers you a choice to fit yourspecific training needs.

The Catalog is Free.The Training is Priceless.

Get all the details on this excitingcourse in NRI's free, 104 page catalog.It shows all equipment, lesson outlines,and facts on other electronics coursessuch as Electronic Design, IndustrialElectronics, Video/Audio Servicing...12 different career opportunities in all.Keep up with the latest technology asyou learn on the latest model of theworld's'most popular computer. If cardhas been used, write to:

NRI SchoolsMcGraw-Hill Continuing

Education CenterAI r4 M 330 Progress Avenue

Scarborough, Ontario MIP 2Z5110111I or telephone 416-293-8787

We'll give you tomorrow.

NRI

REQUIRED OR ANY PURCHASE FROMALBERTA

F-

SO BUY FROM US ANDS AVE $NO SALE TAX* * 64K 6502 COMPUTER * *

..---,--- COMPLETELY ASSEMBLED Et TESTED - READY FOR USE

64K BYTE OF DYNAMIC RAM ON BOARD(W. BLANK EPROMS)

KEYBOARD WITH UPPER AND LOWER CASE FUNCTION - 4 x 4 NUMERIC KEY PAD INCLUDED -,--,...,

DELUXE PLASTIC CASE90 DAY WARRANTY ONLY $569

MITAC AD -151/4" FULLHEIGHT, QUIET Et PROVEN

DISK DRIVESPECIAL $325WITH CONTROLLERCARD $380\ 120 DAY WARRANTY

SPECIAL SP -1: 64K SYSTEM $1039 SP -2: 48K SYSTEM: $9891. 64K COMPUTER (SAME AS ABOVE) 1. 48K COMPUTER (DELUXE MODEL BELOW)

PACKAGE 2. DISK DRIVE MITAC AD -1 2. DISK DRIVE MITAC AD -13. DISK CONTROLLER CARD 3. DISK CONTROLLER CARD

DEAL 4. 12" ZENITH GREEN MONITOR 4. 12" ZENITH GREEN MONITOR

RF MODULATOR W/SOUND, 10 FT CABLE AND TV -COMPUTER SWITCH BOX FOR APPLE (TM) AND ITS COMPATIBLE: $20* * OUR BEST SELLING GOOD QUALITY BUT LOW PRICE 48K 6502 COMPUTER * *

COMPLETELY ASSEMBLED Et TESTED 48K BYTE OF DYNAMIC RAM ON BOARD ONLY $475 (HOUSED IN REGULAR ? LOOKALIKE CASE) 12K BYTE ROM (3 BLANK EPROMS INCL) KEYBOARD WITH UPPER Et LOWER CASE FUNCTION OPTION: SAME AS ABOVE BUT HOUSED IN DELUXE PLASTIC CASE

90 DAY WARRANTY WITH ADDITIONAL 4x4 NUMERIC KEYPAD: $515

6502 COMPONENTS1. 48K AEtT MOTHERBOARD (W. BLANK EPROMS) $3002. REGULAR KEYBOARD $ 903. KEYBOARD W. 4x4 NUMERIC KEYPAD $1004. REGULAR ? LOOK ALIKE CASE $ 805. DELUXE PLASTIC CASE $1056. SWITCHING POWER SUPPLY $ 98

DEALERS INQUIRY WELCOME ( HAR(;IA master chargeAEtT PERIPHERALS FOR YOUR APPLE('TM) I

DISK DRIVE CONTROLLERCARD $60

16K RAM CARD $59 Z-80 CARD $60

80 COLUMN CARD (1°41

PRINTER CARD $80 JOYSTICK (AUTO CENTERING).$30

MAIL ORDERSSend certified cheque or money order(allow 2 weeks for personal cheque).Mastercard and Visa welcome, pleasesend card no., expiry date, and name ofbank. Add 93 for shipping & handling.Always include your name and address.* No provincial sales tax required.

INNOVATIVE ELECTRONICS Et DEVICES145 SITKA DR., FORT MCMURRAY, ALTA. T9H 3C1Phone: (403) 791-4048 DAY, EVENING CALL 791-1164


FOR THE PROFESSIONAL

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CASES & BOXESWRITE FOR YOUR FREE CATALOGUE TODAY

Electronic Packaging Systems Ltd.P.O.BOX 481, KINGSTON, ONTARIO, K7L 4W5PHONE (613) 384-1142 TELEX 066-3243

WHY SPEND A FORTUNE ON ADIGITAL CAPACITANCE

METER?As a matter of fact you don't have to pay$200 to $500 and up anymore for a DigitalCapacitance Meter that is both depen-dable and rugged with good accuracy.The MC100A comes completely assembl-ed and calibrated and at $89.95 is anoutstanding value. The extensive range of30 pF to 9,999 uF (no external meters re-quired) and true hand held portable size(only 43/4" x 2V2" x 1'/i') make theMC100A an extremely practical and easyto use instrument for the hobbyist techni-cian or engineer.CHECK THESE OTHER FEATURES'Basic accuracy 2% (± one count) onpF, nF ranges, 5% (± one count) on uFrange.'Uses single 9V battery (not included).'Decimal points light up when battery islow or when capacitor is overrange.'Full 4 digit high efficiency LED displayuses special circuitry to save on batteries. Maximum conversion time for 9,999 uFis less than 6 seconds.'Constructed with a tough impact resis-tant plastic case. 90 day parts and labour warranty.

DAETRON935 THE OUEENSWAY. BOX 641TORONTO, ONTARIO MR 551(4161 499-7221DEALER ENQUIRIES INVITED

$89.95PLEASE SEND ME

(Quantity) MC100A(s) Cs $89.95Ontario residents add 7% PSTPostage - $1.85 (per instrument) (C.0.0. orders add $1.591rl I ENCLOSE CHEQUE I.: MONEY ORDER BILL MY VISAn VISA CARD NOEXPIRY DATE SIGNATUREImmediate shipping on orders with money orders. VISA or certified cheque.Personal cheques please avow 2 to 3 weeks for clearance.NAMEADDRESSCITY PROV. POSTAL CODE

TOTALS



MAIL TO DAETRON 935 THE OUEENSWAY BOX 641 TORONTO ONTARIO M8Z 5Y9


T next monthAt the time of going to press, the articles mentioned are in an advanced stage of preparation. However, circumstances may result in changes torte finalcontents of the magazine.

8 CHANNEL A TO DZX81

ETISPECTRUM

ZX81 Analog/Digital ConverterAn 8 -channel ADC with 8 -bit resolution to let your ZX com-municate with the Real World; careful though, ours got a tasteof freedom and ran off with a food processor.

dpnics Archaeitlf6W how they fi d oldcitijf pyramids da

J '2314 BC?''un history7i s.

y1.1ex pocket watches and stuff

ti em to Wednesday morning,explains the methods used in

Electronic MailRoger Allan investigates another technological

miracle: getting

the Post Office to work at the speed of light.

PLUS!!!Expanded Scale Voltmeter!

Laser Diodes!Playmate Part 2!

Odometer Project!

Which Battery?A car battery will run your Walkman for ages, but it'll gyou lower back pains. We look at how to suit the battery to thapplication for best performance and longer life.

FACTORYELECTRONICSGIVES YOU A BETTER REASON TOSHOP BY MAIL

IBM COMPATIBLE

BOARDSFROM 'THE LEGEND' J.L.S. COMPUTERS INC.

256K. $359W/RS232 PORT + 64K ON BOARD

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BARE BOARDS ARE AVAILABLE ATSPECIALLY REDUCED PRICES

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VISA MASTERCARD ACCEPTEDPRICES SUBJECT TO CHANGE WITHOUT NOTICE


PIE DISK DRIVE COMPANy PRODUCT DATA SHEP

Cumana disk -drives, the highly successful British product, is now available inCanada, exclusively by C&H Electronics Corp. Cumana has been selling plugcompatible drives in Europe for years. Now the same advance technology is of-fered to Canadians.This is a fully APPLETM compatible drive, fully tested with DOS 3.2.1, DOS3.3, CP/M and Pascal & feature track zero microswitches. The mechanics is aSiemens drive. Storage capacity is 143, 360 bytes w/DOS 3.3.

Christmas Special $300.00 (REG. $339.00)(1 year extended warranty)

DEALER INQUIRES WELCOME.

C&H ELECTRONICS PLUS23 Passmore Ave., Unit 11,

Scarborough, Ontario M1V 2J8(416) 292.0813 Telex: 065-25320 - C&H TOR


THE FIRSTChilhOlhil 5h -1 -ELUTE EHFDFEBRUARY 3,4,5 1984 VANCOUVER BCA three day exposition at Vancouver's Delta River Innfeaturing seminars, lecturers, wholesale distributors,leading manufacturers and more. All aspects of theSatellite Industry will be represented. To assure yourplace among the front runners in the field reserve now.The First Canadian Satellite Show

NElistributor of First Canadian Satellite TU Guide:caLaHy

minformation for the First Canadian Satellite EHpobooths aueileble now

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5330 IMPERIAL STREET BURNABY, B.C., CANADA V5J 1E6, TELEPHONE (604) 430-4040BRANCH OFFICES: MONTREAL, TORONTO, WINNIPEG, EDMONTON, SEATTLE

36-NOVEMBER-1983-ETI Circle No. 9 on Reader Service Card.

WE'RE HERE AT LAST! NOW OPEN DIRECTLY TO THE PUBLIC

L

C H ELECTRONICS PLUS MAIL ORDER DEPARTMENT

Call 9 to 5 Mon. to Fri. - 10 to 2 p.m. Sat.

NOT ONLY DO WE HAVE MORE TO OFFER, BEING A NATIONAL WHOLESALER ACROSSCANADA, ALL OUR PRODUCTS HAVE A FULL 180 DAYS WARRANTY (UNLESS STATEDOTHERWISE). WE CARRY ONLY THE BEST QUALITY MERCHANDISE AT THE LOWEST PRICESAROUND. PLUS FREE DELIVERY ANYWHERE IN CANADA! (NO MORE PARKING

HEADACHES OR FRUSTRATING LINE UPS)

NO FA CY OR EXPENSIVE DISPLAYS - JUST GOOD PRICES & EXCELLENT SERVICE

COMPUTERS

SOURCE 9000*Well built 48K compatible (to you

know what!), numeric keypad, ABSCase, heavy duty power supply, 8 expan-sion slots, U/L case $595.00

(REG. $699.00)

SOURCE 6400*The only hassle free -with APPLE -

computer. Multi -System 64K memoryboard, 9 expansion slots andunrestricted memory. No ROM and fix-able language. Therefore allowing userto create/operate any language withover 50 different expansion cards on themarket.

*Includes numeric keypad, heavy dutypower supply, U/L case, 25 functionkeys, card to run APPLEIm and more!

*No legal worries with APPLE on thisone! $795.00

(REG $849.00)

SOURCE 2000*The ultimate computer with both

6502 and Z-80 CPU's, 64K expandable to294K, built in disc printer interface, 40/80column selectable, U/L case, 25 functionkeys, numeric keypad, heavy duty swit-ching power supply LED reminder onboard and (2) volume controlledspeakers $995.00

(REG. $1149.00)*Surfboard beware*

Apple Ile "Starter System"*Inclues 64K, 80 column card,

drive/controller, Apple III monitor andstand $2495.00

(REG. $2795.00)

**COMING SOON IBM CLONES **Source Cards16K $65.00Z-80 $65.0080 column $79.00Disc Controller $65.00Freeze Play $99.00(Wildcard emulator/disk/documenta-tions)192K Disk RAM $499.00(Virtual Disc Card with (2) software pkgs)Grappler/printer $79.00

Perisoft CardsMessenger $119.00(Dual/ink RS232C, built in firmware, 1

year warranty)Timelink $109.00(Built-in firmware, alarm clock, 1 yearwarranty)

Wizard Cards16K $109.0080 column $229.00IPI Printer $89.0016K Buffer card $199.00(Above all 2yr warranty)

ACCESSORIESFlip 'n File $32.00(Holds 50 diskettes)Kraft Joysticks $58.00Apple Stands $39.00(Fits 2 drives/monitor)Printer Stands $35.00(5" high, paper feed slot)Muffin Fans $50.00(dual outlets)Siemens Fans $95.00(Surge supression/filter/outlets)Paper $39.00(2100 sheets, 91/x11 perforated)Printer Ribbons $CALLRibbon Re -Inking $CALL(Saves on new ribbons)Plott II Graphics Table $129.00Light Pen/I nterface/Sf twr . $369.00

DISKETTESGenerics $23.00BASF $29.00Dysan $33.00Maxells $35.00 All box in 10's & SS, DD

Send us any diskettes and a list of particular soft -wares you want & for $10.00 ea. we will have it mailedto you. (Providing its on our list)($25.00 CLUB REGISTRATION FEE)

PERIPHERALSCUMANA "Rainbow I" Disc Drive $319.00

Siemens drive, direct from U.K., (REG. $339.00)If you thought Quentin was good try this drive!

CUMANA "Rainbow II" Disc Drive $379.00'IBM, D.D. Drive, Siemens based.

Slimline Drives $319.00

Zenith green screen monitors $129.00

NOTE: Call for quotes on hard disc drives, ambermonitors or whatever you can't find.

C-ITOH PRINTERSProwriter I (Parallel) $609.00Prowriter II (Parallel) $1009.00Starwriter F-10 $1775.00(40 cps letter quality)F-10 Tractor option $399.00OKI-DATA 160 cps PrintersMicroline 92 $839.00(U.S. hottest printer, prints 160 cps dot matrix, 40 cpsletter quality)Microline 93 (15" Carriage)Microline 82AMicroline 83A (15" Carriage)Microline 84P (200 cps)Microline 84S (200 cps)

EPSONFX-100 $979.00FX-80 $879.00FX-80 FT $699.00NEC 8023A $699.00Toshiba P1350 $2279.00(Top of the line)Introducing: The RIteman P.P.

Epson FX-80 emulator, 120 cps, 9x9 dot matrix,true 1:1 dot ratio, bi-directional, slimilne $599.00

SMITH CORONA TP-1, letter quality $625.00SMITH CORONATP-2, New Model, letter quality $750.00

$1599.00$669.00$999.00

$1599.00$1859.00

*IF YOU DON'T SEE IT! ASK!*MAIL ORDERS: Send certified cheque/money order. Ontario residents mustadd 7% PST Visa card accepted: cardno., name, signature, exp. date and bankname please!

C & H ELECTRONICS PLUS ATTENTION: Clubs, schools, and co-op purchaserscall for our special pricing catalogues

23 Passmore Ave., Unit 11, Scarborough, Ontario. M1V 2J8.(Just (1) light North of Finch right side of Kennedy Rd.)

(416)292-0813 - TELEX 065-25320 C&H TOR

Dealer inquires welcomed!Contact: Rob Laver


Product ReviewFluke 70 Series DVM

WHAT? ANOTHER handheld? Ho hum,send me a couple of dozen; the kids canbuild play -houses with 'em. Oh, it's reallynew, you say? Okay, let's have a look here. . . hmmm, no mess of buttons down theside, and what's this? An analogbargraph? An automatic display latch?Put all my calls on hold, I'm going in theworkshop for a couple of hours to playwith this thing.

First ImpressionsIf you're trying to get a circuit workingagain, and everything is going wrong atonce, the last thing you need is test equip-ment that wants special attention; itshould just do its job transparently, asthey say in computer -speak. For thisreason, I've never been partial to thoseDVMs that require puzzling out a row ofpushbuttons whenever you want tochange functions or ranges. Fluke hassolved the problem by using a large rotaryfunction switch conveniently mounted tofall under your left thumb, and it includesautoranging to minimize control -fiddling.

The next thing you notice when youpick it up is the.remarkable solidity of thecase; it's supposed to survive a lengthydrop onto a hard surface, and it certainlyfeels rugged enough to do just that. In-cluded with the Model 77, and optional onthe others, is a rubbery holster that servesas either an upright stand or a belt clip; in-serted into this holster, the meter feels asif you could drive concrete nails with it.The holster also includes a neckstrap; aflexible clip on the end of the holster letsyou sit the meter horizontally on yourbelt, freeing both hands for testing. Theprobe leads can be inserted into holdersinto the back of the holster.

The ModelsThree versions are offered: the 73, 75 and77. All models feature autoranging, ananalog bargraph, a continuity beeper, and31/2 digits. The basic differences betweenthem are the accuracy specification andthe manual range function. In a nutshell:The Model 73 at $125 has 0.7% DC ac-curacy and autorange only. The Model 75at $145 has 0.5% DC accuracy, auto andmanual ranging. The Model 77 at $185 has0.3% DC accuracy, auto and manual

The DVM has been re -thought.Bill Markwick looks at Fluke's new

70 Series handhelds.

ranging, plus Touch Hold, a marvelousdisplay latch which I'll get to in amoment.

The DisplayIt isn't really accurate to call them 31/2digit meters. As you can see from thephotograph, the half -digit goes up tothree. This gives you 3200 counts perrange, and extends the ohms range to 32megohms. The digits are updated 2.5times per second, and the 30 -segmentbargraph 25 times per second.

The FunctionsThe usual: AC volts, good for 3% on the73 and 2% on the others with a frequencyresponse of 45 Hz to 1 KHz. DC volts asmentioned above, including a 300 mV

range with a resolution of 0.1 mV. Ohmsto 32 meg, and a continuity beeper whichalso displays the forward voltage ofdiodes. Moving the test leads will give youAC and DC milliamperes up to 300, andmoving them once again extends the cur-rent range to 10 amperes.

The BargraphHave you ever tried to trim some sort ofcalibration level with a digital meter flipp-ing and flashing and trying to make up itsmind where to settle? The analogbargraph is just the ticket here; its rapid25/sec updating means that you can getsome idea of what's happening with less -than -ideal signals. Another use would bewhen two signals beat together to causesome low -frequency swaying of the level;


the bargraph at least clues you in that thedigital display isn't having fits. The 30segments don't give you the best possibleresolution, but after all, you're dealingwith a compromise.

Touch HoldIn a previous life as a technician, I alwaysseemed to be working upside down withmy head stuck in somebody's equipmentconsole trying desperately to make areading and watch the meter at the sametime. Maybe my whole career would havechanged if I had owned a Fluke 77; it in-cludes the best feature of all, the remark-able Touch Hold. In this mode, you touchthe probes to the test point, and the meterpeeps to let you know that it's foundsomething out. You then casually crawlout from under the equipment rack,straighten your tie, and read the display atyour leisure. The reading will be held untilyou re -apply the probes; it will then auto-matically update itself.

I think Fluke will have a warehousefull of 73s and 75s once people try the 77'sTouch Hold feature.

AccessoriesAll kinds of them: a case, deluxe leads,temperature probes, RF probes, HV pro-bes, high -current clamps. The only optionI missed was a True-RMS function; theFluke designers felt that this was a special-ty feature which would raise the cost ofthe meter. Maybe somebody will developa little add-on box.

MiscellaneousAs you've probably gathered by now, Ithought using the meter was a delight; thedisplay was updated quickly and solidlywith no blurring of digits. The digits, bythe way, quietly go away after an hour ifyou should leave the meter and forget toturn it off; they return to life if youoperate the rotary switch. A nice touch,though you get better than 2000 hourswith an alkaline battery anyway.

Other stuff: all voltage ranges havegreater than 10 megohms input im-pedance; overload is 1000 VDC or 750VAC, or 500 V on the Ohms range. Theranges on the 75 and 77 are changed bypressing the range button; each press stepsthe decimal point one place.

I suppose to make this an objectivereview, I should find something wrongwith it, but I'd have to be awfully picky.The meter does everything it's supposedto, and superbly at that.

And Finally . . .

The Fluke 70 Series, and all other Flukeequipment, is available across Canadafrom Allan Crawford Associates Ltd.,with branches in Mississauga, Montreal,Ottawa, Halifax, Vancouver, Calgary,and Edmonton.

MEMORY SPECIAL4116 150nS MOT $1.994116 200nS NEC $1.754164 150 or 200 Fujitsu or Oki$6.992708 1 Kx8 $5.552716 2Kx8 Hitachi,NEC $4.502732 4Kx8 NEC $6.992764 8Kx8 Mitsubishi $9.506532 $7.502532 $7.652114 200nS (Hitachi) $1.752128-2 $7.99

Japanese Parts SpecialistsPARTS 100% GUARANTEED

CPUZ80 $5.99Z80A NEC . $6.756502A 2M Hz $6.996502 $6.506845 CRT Controll-er (Hitachi) . $8.996522 $6.998088 $24.50

A. 5 1/4 " MITAC DISKDRIVE (NEW MODEL)

$339.00c/w controllercard

$279.00without controller card

Peripherals8748D NEC .$24.508741 NEC $32.508251 NEC . $5.998253-5 NEC . $9.008257-5 NEC $9.25

TTLLS323LS132LSO8LS11LS107LS257LS151LS194LS139LS283LS367LS166LS377LS368LS86

B. 51/4" TEAC SLIMDRIVE $319c/w controller cardSPECIAL $379without controllercard.Panasonic Direct Drive

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Japanese precision 90 day warranty (operation manualincluded) Guaranteed run V: track programs. Items A &B for your Apple II use.

1.40-80 Column Switch2. Color R.F. Modulator3. Joystick (Self -centering)two adjustable controlsa) Parallel Printer Cardb) 16K RAM Cardc) 80 Column Cardd) Disk ControllerCarde) Z80 Cardf)Communication Card

$7.50$14.00$39.00

$69.00$59.00$79.00$55.00$60.00$67.00

A. 6502 48K KIT or (A&T) $499.00B. 6502 64K KIT or (A&T) $539.00C. 6502 64K built in Z80 or (A&T) $699.00ITEMS A,B & C Comes with case andnumeric keypad, gold (hydro approved 5amp power supply)D. 5 amp Teapo Black PowerSupplyQuality IC SocketsDouble Side 24/pin

We repair Power Supply and 6502 Boards

$99.00

GOLD Switching PowerSupply(+5V, 5 AMP, +12V, 2.5AMPS, - 5, % AMP, -12V-' AMP). Heavy duty.Hydro approved. Run 2drives and lots ofperipherals.90 Days Warranty.

Service Centre and Retail Outlet, 4051 Sheppard Avenue East (at Kennedy), Agincou t, Ontario MIS 1S8 (416) 298-3280

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Mail Orders: Send a certified chequeor money order plus $3.00 for shipp-ing and handling. For SpecialDelivery, please add $1.00 extra. On-tario residents add 7% P.S.T. Visa &Mastercard accepted.

Will the real Buck Rogers pleasesit down? Plans are afoot to

build weapons normallyassociated with Hollywood sci-fi.Roger Allan separates the reality

from the wishful thinking.

WITH THE Reagan Administration an-nouncement some months ago that theUnited States was to embark on a massivemilitary upgrading program, an embarka-tion which is to include development ofparticle beam and laser weapons systems,a veritable panoply of articles and com-mentary has descended on the unsuspec-ting public. The possibility of BuckRogers type warfare is dealt with, on ascale previously unimagined. As withmost such Star Wars articles, a great dealhas been written which is essentiallynonsense, better confined to the pages ofsecond-rate science fantasy articles thanto the quality publications in which suchmaterial so frequently appears. Theseparation of the fantasy from the fact, inthe public's mind, has become increasing-

ly difficult as more and more supposed ex-perts vent their opinions on subjectswithout really explaining what they mean,how much is reality, how much is poten-tially possible and how much is justwishful thinking. When one digs into theprimary data on this subject, however,one finds that it is quite easy to separatethe wheat from the chaff, as it were, and itmostly turns out to be chaff.

To begin at the beginning. Thedevelopment of a laser -damage weaponsystem was felt by the military to havesome particularly attractive features. Forexample, since light travels at a speed of186,000 miles per second, the lethal fluxwould arrive at the target almost instan-taneously, and there would be no require-

ment to lead the target, except at very longranges. It takes six millionths of a secondfor laser light to travel one mile, and inthat time, a supersonic airplane travellingat twice the speed of sound will travel onlya little more than one -eighth of an inch.Also, a laser weapon could be used toselectively attack and destroy single enemytargets in the midst of a host of friendlyvehicles or equipment.

Laser BasicsBut first a laser of sufficient power had tobe developed, one which could producepower in the range of megawatts.Although many different lasers werediscovered in the 1960s, none was suitablefor high energy applications. In themid -60s, a discovery led to efficient laserswhich generated their energy in the in-frared portion of the spectrum. A con-


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Multiflex products and designs arecopyright of Multiflex TechnologyInc.

Exceltronix319 College StreetToronto, lant.MST 152

REE1,1OROSIO,

OSI A1110M51 1 2. ?HOSE:

( 416)9 4941.

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Prices and specificationssubject to change

without notice

HERE WE GROW AGAINIEITIONOTTAWA, ONTARIO

RETAIL OUTLET -PICK UP ONLY(613) 225-0029

EXCELTRONIX2 - Exceltronix Catalogue 1983

Microprocessor ChipsRCA COSMAC SERIES1802185218541855

8 -bit CPU (CMOS)8 -bit I/O port (CMOS)UART (CMOS)Multiply/Divide Unit

$ 10.504 25

10.0016.75

1856 Bus Separator/Latch 4 151858 Address Latch/Decoder 4 151861 Video Dipslay Controller 5 651862 Colour Generator Controller 4 40

6500 Series6502 8 -bit CPU (1 MHz) 6 956502A 8 -bit CPU (2 MHz) 8 506522 VIA Versatile Interface Adaptor 7 996532 RIOT (128x8 RAM, I/O, Timer) 9.756545 CRT Controller 16.506511 ACIA Async. Comm. Interface Adaptor . . .9.75

6800 Series680068B00680968B096809E68B09E

8 -bit CPU (1 MHz)8 -bit CPU (2 MHz)8/16 -bit CPU (1 MHz)8/16 -bit CPU (2 MHz)8/16 -bit CPU c/w external clock (1 MHz)8/16 -bit CPU c/w external clock (2 MHz)

6 507 25

15.7526.75

. . 20.95

. . 33.256810 128x8 static RAM 4 006821 FIA Periphrial Interface Adaptor 3 696840 Programable Timer 8 406844 DMA Controller 14.006845 CTRC controller 11.996847 Video Display Generator 20.996850 ACIA 4 096852 Syncronous Serial Data Adapter 5 996860 0-600 Baud Modem 15.90

68000 Series68999L8 16 -bit CPU (8 MHz) 89.0068000L10 16 -bit CPU (10 MHz) 139.0068008 16 -bit CPU (8 bit data path) 109.9968230 Parallel Interface Adapter 24.7568450 16 -bit DMA Controller 368.0068451 Memory Management Controller 144.99

8080 Series8080 8 -bit CPU 5 508085 8 -bit CPU 7 758212 8 -bit I/O Port 2 508214 Priority Interrupt Controller 5 258216 4 -bit Bidirectional Bus Driver 2 508224 Clock generator for 8080/8085 3 458226 Inverting Bus Driver 2 50

All prices areIn Canadian

funds, FederalTax included.

8228 System controller for 8080/8085 4 758251A Programmable Communications

Interface 6 508253 Programmable Interval Timer 8 508255 Programmable Interface Adapter 7 958257 Programmable DMA Controller 6 508272 Programmable Floppy Disk Controller . . . 45.758275 Programmable CRT Controller 49.85

8086 Series8086 16 -bit CPU 46.508088 16 -bit CPU c/w 8 -bit data bus 36.508087 Math Processor 289.008089 I/O Processor8282 Octal Latch 8 998283 Inverting Octal Latch 8 998284 Clock Generator for 8086/8088 7 508288 Bus Controller 19.508289 Bus Arbiter 49.99

Z80 SeriesZ80A-CPU 8 -bit CPU (4 MHz) 6 99Z80B-CPU 8 -bit CPU (6 MHz) 17.99Z80A-P10 Parallel I/O 6 50Z80A-CTC Counter Timer 625Z80A-DART Dual Asyncronous Receiver Transmitter .11.99Z80A-DMA Direct Memory Access 18.25Z80A-S10-0 Serial I/0 ver. 0Z80A-S10-9 Serial I/O ver. 9

Misc. Microprocessors and Periphrial ChipsAY3-1015 UART (Single 5V Supply) 8 25AY5-1013 UART 6 89S1602 UART 4 75TMS9918 Sprite Graphics Generator 46.45TMS99532 FSK Modem 47.99COM5016 Dual Baud Rate Generator 18.10COM8116 Dual Baud Rate Generator

(5V supply only) 16.75KR3600 Keyboard Encoder 16.50MSM5832 Real-time Clock 18.10MSM58321 Real-time ClockSN D5037 CRT Video Timer Controller 32.25WD2143 4 -phase Clock Generator for Floppy DisksFDC1771 Single Density Disk Controller 29.00FDC1793 Double Density Disk Controller 56.50FDC1795 Double Density/Sided Disk Controller .. . 84.75FDC2793 Dbl. Density Disk Controller c/w precomp. 55.00FDC2795 DDDS Disk Controller c/w precomp. 59.95FDC9216 Floppy Disk Data Separator 18.65

FOR QUANTITYPRICES CONTACTUS FOR REALLYSUPER PRICES

Exceltronix Catalogue 1983 - 3

Cxceltronix

TTL IC'S7400 Series TTL 74500

Series TTL7400 Quad 2 input NAND gate .34 74143 Counter/latch/decoder/driver 4 857401 Quad 2 input NAND gate 0/C .34 74144 Counter/latch/decoder/driver 4.85 74S00 Quad 2 input NAND gate $ .447402 Quad 2 input NOR gate .34 74145 BCD to decimal decoder/driver .89 74S02 Quad 2 input NOR gate .447403 Quad 2 input NOR gate 0/C .34 74147 10-4 priority encoder 1 89 74S03 Quad 2 input NOR gate 0/C .447404 Hex inverter .37 74148 8-3 priority encoder 1 34 74SO4 Hex inverter .497405 Hex inverter 0/C .37 74150 16-1 multiplexer 1 57 74S05 Hex inverter 0/C .497406 Hex inverter buffer/driver .89 74151 8 channel digital multiplexer .67 74S08 Quad 2 input AND gate .447407 Hex inverter buffer/driver .89 74153 dual 4-1 multiplexer .67 74S09 Quad 2 input AND gate 0/C .447408 Quad 2 input AND gate .34 74154 4-16 decoder/demultiplexer 1 57 74S10 Triple 3 input NAND gate .447409 Quad 2 input AND gate 0/C .34 74155 Decoder/demultiplexer .67 74511 Triple 3 input NAND gate 0/C .447410 Triple 3 input NAND gate .34 74156 Decoder/demultiplexer .87 74S15 Triple 3 input AND gate 0/C .447411 Triple 3 input NAND gate 0/C .37 74157 Quad 2 input multiplexer .74 74S20 Dual 4 input NAND gate .447412 NAND gate inverter .44 74159 4-16 decoder/demultiplexer 0/C 1 95 74S22 Dual 4 input NAND gate 0/C .447413 Dual Schmidt trigger .49 74160 Decade counter with async. clear 89 74S30 8 input NAND gate .447414 Hex Schmidt trigger .54 74161 Sync. 4 bit counter .89 74S32 Quad 2 input NOR buffer .577416 Hex inverter buffer/driver .49 74162 Sync. 4 bit counter .89 74S37 Quad 2 input NAND buffer 1.237417 Hex buffer driver .49 74163 Sync. 4 bit counter .89 74S38 Quad 2 input NAND buffer 0/C ... 1.237420 Dual 4 input NAND gate .34 74164 8 bit serial shift register 89 74S40 Dual 4 input NAND buffer .497421 Dual 4 input NAND gate .44 74165 Parallel load 8 -bit shift 74S74 Dual D flip flop .667422 Dual 4 input NAND gate 0/C .49 register 1 09 74S85 4 bit magnitude comparator 1.947423 Dual 4 input positive NOR 58 74166 8 bit shift register 1 09 74S86 Quad 2 input XOR gate .757425 Dual 4 input NOR .44 74167 Sync. rate multiplier 3 64 74S109 Dual JK positive edge triggered7427 Triple 3 input NOR .44 74174 Hex D flip flop with clear .72 flip flop 1.657428 Quad 2 input NOR buffer .58 74175 Quad D flip flop with clear .72 74S112 Dual JK flip flop .877430 8 input NAND gate .37 74176 Presettable decade counter/latch ...1.06 74S113 Dual JK negative edge triggered7432 Quad 2 input NOR buffer .44 74177 Presettable binary counter/latch .1.06 flip flop .877433 Quad 2 input NOR buffer 0/C .44 74178 4 bit universal shift register 1.67 745114 Dual JK negative dge triggered7437 Quad 2 input NAND buffer .44 74179 4 bit parallel access shift register .1.67 flip flop .877438 Quad 2 input NAND buffer 0/C .44 74180 9 bit odd/even parity generator/ 74S124 Dual VCO 3.157439 Quad 2 input NAND buffer 1.47 checker .99 74S132 Quad 2 input Scmitt trigger7440 Dual 4 input NAND buffer .44 74181 ALU 2 74 NAND 1.697442 BCD -to -decimal decoder .62 74182 Look ahead carry generator 1 17 74S128 3-8 decoder/multiplexer 1.177445 BCD to decimal decoder/driver 1.65 74184 Code convertor BCD to binary 2 75 74S139 Dual 2-4 decoder/multiplexer ... 1.177448 BCD to decimal decoder/driver 1.65 74185 Binary to BCD convertor 2 74 74S140 Quad line driver .787470 Edge triggered JK flip-flop 44 74190 Sync. up/down counter BCD 1.01 74S151 8 channel digital multiplexer 1.177472 JK master/slave flip flop .49 74191 Sync. up/down counter binary 1 01 74S153 Dual 4-1 multiplexer 1.357473 Dual JK flip flop with clear .49 74192 Binary up/down counter .42 74S157 Quad 2 input multiplexer 1.357474 Dual D flip flop .49 74193 Binary up/down counter .42 74S158 Quad 2 input multiplexer 1.347475 4 bit bistable latch .54 74194 4 bit bi-directional shift 74S160 Decade counter with async.7476 Dual JK master/slave flip flop .49 register .96 clear 3.727480 Gated full adder .82 74195 4 bit parallel access shift register.....96 74S161 Sync. 4 bit counter 3.447482 2 bit binary full adder 1 81 74196 Presettable decade counter 1 17 74S162 Sync. 4 bit counter 3.727483 4 bit binary full adder .89 74197 Presettable binary counter 1 17 74S163 Sync. 4 bit counter 2.757485 4 bit magnitude comparator .89 74198 8 bit shift register 1 75 74S168 4 bit up/down sync. counter 5.447486 Quad 2 input XOR gate .50 74199 8 bit shift register 1 75 74S169 4 bit sync. counter 5.137489 64 bit RAM 2.78 74221 Dual Monostable multivibrator 1 09 74S174 Hex D flip flop with clear 1.567490 Decade counter .54 74251 Tri-state data selector 74S175 Quad D flip flop with clear 1.567491 8 bit shift register .78 multiplexer 1 10 74S181 ALU 3.947492 Divide by 12 counter .54 74259 8 bit addressable latch 2 58 74S182 Look ahead carry generator 2.007493 4 bit binary counter .54 74265 Quad complementary output 74S189 16 x 4 RAM 3.877494 4 bit shift register elements .91 74S195 4 bit parallel access shift

(parr. in, ser. out) .89 74273 Octal D flip flop 258 register 1.977495 4 bit right/left shift 74276 Quad JK flip flop 3 16 74S196 Presettable decade counter 3.16

register .72 74278 4 bit cascadable priority register .3.44 74S197 Presettable binary counter 3.167496 5 bit shift register async. 74279 Quad S -R latches .96 74S201 256 bit RAM 6.95

preset .79 74283 4 bit binary full adder 1 67 74S240 Octal line driver 2.247497 Sync. 6 bit binary rate 74285 Tri-state 4 bit multiplexer 4 49 74S241 Octal line driver 2.24

multiplier 2.37 74290 Decade counter 1 09 74S244 Octal line driver 3.0974100 8 bit bistable latch 1.81 74293 4 bit binary counter 1 09 74S251 Tri-state data selector74104 Gated JK master/slave flip/flop 1 34 74298 Quad 2 input multiplexer 1.09 multiplexer 1.5174105 Gated JK master/slave flip/flop 1.34 74351 Dual 8-1 multiplexer 309 74S260 Dual 5 input NOR gate .9374107 Dual JK flip flops with clear .58 74365 Hex bus drivers .75 74S274 4 x 4 binary multiplier 17.8974109 Dual JK positive edge triggered 74366 Hex bus drivers inverting .75 74S275 7 bit slice wallace tree 17.89

flip flop .58 74367 Hex bus drivers 75 74S283 4 bit binary full adder 3.4474110 AND gated JK master/slave flip flop ....67 74368 Hex bus drivers inverting 75 74S289 16 x 4 RAM 4.1074111 Dual JK master/slave flip flop .82 74376 Quad JK flip flop 85 74S299 8 bit universal shift74116 Dual 4 bit latch 1 81 74390 Dual decade counter 1 57 storage register 7.8474120 Dual pulse syncronizer/driver 1 81 74393 Dual 4 bit binary counter 1 99 74S373 Octal D latch 2.7474121 Monostable multivibrator .54 74S374 Octal D latch 2.7474122 Retriggerable monostable

multivibrator .7274123 Dual retriggerable monostable

multivibrator .7474125 Tri-state quad bus buffer .7274126 Tri-state quad bus buffer .7274132 Quad 2 input Schmitt trigger NAND ....7474136 Quad 2 input XOR gate .7474141 BCD to decimal decoder/driver 1 5374142 Counter/latch/decoder/driver 485

4 - Exceltronix Catalogue 1983

74L500 Series TTL74LS00 Quad 2 input NAND gate $ .3474LS01 Quad 2 input NAND gate 0/C .3474LS02 Quad 2 input NOR gate .3474LS03 Quad 2 input NOR gate 0/C .3474LSO4 Hex inverter .3474LS05 Hex inverter 0/C .3474LS08 Quad 2 input AND gate .3474LS09 Quad 2 input AND gate 0/C .3474LS10 Triple 3 input NAND gate .3474LS11 Triple 3 input NAND gate 0/C .3474LS12 NAND gate inverter .3474LS13 Dual Schmidt trigger .5474LS14 Hex Schmidt trigger inverter .6274LS15 Triple 3 input NAND gate .5074LS20 Dual 4 input NAND gate .3474LS21 Dual 4 input NAND gate .3674LS22 Dual 4 input NAND gate .5074LS24 Quad 2 input NAND Schmidt

trigger .7874LS26 Quad 2 input positive NAND gate .4474LS27 Triple 3 input NOR gate .3474LS28 Quad 2 input NOR buffer .5074LS30 8 input NAND gate .3474LS32 Quad 2 input NOR gate .4474LS33 Quad 2 input NOR gate 0/C .5074LS37 Quad 2 input NAND gate .4474LS38 Quad 2 input NAND gate 0/C .4474LS42 BCD to decimal decoder .5874LS47 BCD to 7 segment decoder/

driver .8674LS48 BCD to 7 segment decoder/

driver 1.1774LS49 BCD to 7 segment decoder/

driver 1.0574LS51 And/or invert gate .3474LS54 4 wide and/or invert gate .3474LS55 2 wide 4 input and/or invert gate . .3774LS63 Hex current sensing switch 2.5874LS73 Dual JK flip flop with clear .4474LS74 Dual D flip flop .4974LS75 4 bit bistable latch .5474LS76 Dual JK master/slave flip flop .5474LS77 4 but bistable latch .8274LS78 Dual JK flip flop preset,

common clear .5574LS83 4 bit binary full adder .7174LS85 4 bit magnitude comparator .8974LS86 Quad input XOR gate .4974LS90 Decade counter .6774LS91 8 bit shift register .6774LS92 Divide by 12 counter .6774LS93 4 bit binary counter .6774LS95 4 bit right/left shift register .8774LS96 5 bit shift register async. preset .8774LS107 Dual JK flip flop with clear .4974LS109 Dual JK pos. edge triggered

flip flop .4974LS112 Dual JK edge triggered flip flop .5474LS113 Dual JK edge triggered flip flop .5474LS114 Dual JK edge triggered flip flop .54

74LS122 Retriggerable monostablemultivibrator

74LS123 Dual retriggerable monostablemultivibrator

74LS125 Tri state quad bus buffer74LS126 Quad 3 state buffer74LS132 Quadruple 2 input NAND Gate ..74LS133 13 input NAND gate74LS136 Quad XOR gate74LS137 3 of 8 decoder/demultiplexer74LS138 3 to 8 decoder/multiplexer74LS139 Dual 1 of 4 decoder/demultiplexer74LS145 BCD to decimal decoder/driver74LS147 10/4 priority encoder74LS148 8 to 3 line priority encoder74LS151 8 channel digital multiplexer ....74LS153 Dual 4/1 multiplexer

.61

.91

.58

.58

.7258

.54

.58

.62

.62

.911.612.08

.67

.67

74LS154 4 to 16 decoder multiplexer 1.75 74LS260 Dual 5 input NOR gate .5574LS155 Decoder/demultiplexer .91 74LS266 Quad 2 input XNOR 0/C .5474LS156 Decoder/demultiplexer .91 74LS273 Octal D flip flop 1.1774LS157 Quad selector/multiplexer .58 74LS275 7 bit slice Wallace tree 5.5574LS158 Quad 2 input multiplexer 74LS279 Quad S -R latches .58

(inverting) .62 74LS280 9 bit odd/even parity checker/74LS160 Decade counter with async. generator 2.30

clear .81 74LS283 4 bit binary full adder .7574LS161 Sync. 4 bit counter .91 74LS289 64 bit RAM 5.1274LS162 Sync. 4 bit counter .91 74LS290 Decade counter .9574LS163 Sync. 4 bit counter .91 74LS293 4 bit binary counter 1.0374LS164 8 bit serail shift register .88 74LS295 4 bit shift register 1.2074LS165 Parallel load 8 bit shift 74LS298 Quad 2 input multiplexer 1.09

register 1.17 74LS299 8 bit storage register 2.4584LS166 8 bit PISO shift register 1.81 74LS319 64 bit RAM 0/C 5.1474LS168 Up/down decade counter 1.33 74LS320 Crystal oscillator 3.7374LS169 4 bit sync. binary counter 1.33 74LS321 Crystal oscillator 3.7374LS170 4 x 4 register file 1.75 74LS322 8 bit shift register 6.5374LS173 4 bit tri state register .77 74LS323 8 bit bidirectional universal74LS174 Hex D flip flop with clear .62 shift 4.8574LS175 Quad D flip flop with clear .67 74LS348 8 to 3 priority encoder 1.1774LS181 4 bit ALU 2.74 74LS352 Dual 4 bit multiplexer 2.1974LS182 Look ahead carry 1.75 74LS353 Dual 4 bit multiplexer 1.1774LS183 Dual carry/save full adder 4.15 74LS354 Data selector multiplexer 1.1774LS189 64 bit RAM 4.71 74LS355 Data selector multiplexer 3.6574LS190 Sync. up/down counter BCD .96 74LS356 Data selector multiplexer 3.6574LS191 Sync. up/down counter binary ... .96 74LS357 Data selector multiplexer 3.6574LS192 Binary up/down counter .91 74LS365 Hex bus driver tri state .61

74LS193 Binary up/down counter .91 74LS366 Hex bus driver74LS194 4 bit bi-directional shift (inverted output) .61

register .72 74LS367 Hex bus driver .61

74LS195 4 bit shift register .79 74LS368 Hex bus driver74LS196 Decade counter 1.24 (inverted output) .61

74LS197 Presettable binary counter 1.19 74LS373 Octal transparent latch 1.34

74LS219 64 bit RAM 4.71 74LS374 Octal dual flip flop 1.34

74LS221 Dual monostable multivibrator 1.19 74LS375 4 bit bistable latch .67

74LS240 Octal inverting bus driver 1.09 74LS377 Octal D register 1.34

74LS241 Octal bus driver 1.09 84LS378 Hex D register 1.17

74LS242 Quad inverting transceiver 1.09 74LS379 4 bit register 1.17

74LS24374LS244

Quad transceiverTri state octal driver

1.091.17

74LS38074LS381

Multi function octal generator .4 bit ALU

10.483.43

74LS24574LS22774LS24874LS249

Octal bus transcieverBCD to 7 segment decoder driverBCD to 7 segment decoder driverBCD to 7 segment decoder driver

1.341.531.531.53

74LS38474LS38674LS39074LS39374LS395

8 bit multiplierQuad 2 input XOR gateDual decade counterDual 4 bit binary counterTri state shift register

7:88.61

1.341.171.34

74LS251 Tristate data selector 74LS396 Octal storage register 2.07multiplexer .68 74LS398 Quad D flip flop 2.7374LS253 Dual 4 bit multiplexer .67 74LS399 Quad 2 input multiplexer with74LS257 Quad 2 input multiplexer .67 storage 1.7574LS258 Quad 2-1 multiplexer .67 74LS629 Voltage controlled oscillator 2.6074LS259 8 bit addressabe latch 1.17

...

Due to current severeparts shortage, pricesare subject to change

without notice. Contactus for current pricing. wehave excellent stock andwill try to keep prices ascompetitive as possible.

Contact us forOEM pricing.


C xceltronix

Linear109 1A +5V regulator 8.38124 Quad op amp 3.95139 Quad comparator 3.95148 Quad op amp 6.40300 General purpose op amp 4.10301 General purpose op amp .40305 Voltage regulator 1.15306 Improved voltage comparator 2.05307 Op amp .50308 Super beta op amp 1.70309 + 5V regulator 2.27310 Voltage follower 3.38311 Voltage compatator .70317 3 terminal adjustable regulator 3.10318 Precision high speed op amp 1.89319 High speed dual comparator 2.55323 3A +5V regulator 7.95324 Quad op amp .60337 3 terminal negative regulator 2.23339 Quad comparator .60348 Quad low -power 741 .99350 3A 3 term. positive adjust. regulator 7.60355 FET input op amp 1.75356 Monolithic J-FET input op amp 1.74357 Monolithic J-FET input op amp

(uncompensated) 1.74358 Dual version of 324 .65380 2W audio amp 1.20393 Dual version of 339 .65398 Sample and hold amplifier 6.20555 Timer .43556 Dual timer .88558 Quad timer 2.95567 Tone decoder 1.20709 Op amp .93710 Differential comparator 1.23711 Dual channel differential comparator 1.30714 Precision op amp 3.95715 High speed op amp 5.40723 Voltage regulator .60725 Instrumentation op amp 2.55726 Temperature controlled differential pair .. 38.95727 Temp. controlled differential preamplifier . 57.85733 Differential video amp 1.30739 Dual high performance op amp 2.15741 Operational amplifier .44747 Dual op amp .88748 Op amp .75749 Dual audio preamplifier 3.10759 Power op amp 3.19760 High speed differential comparator 10.95776 Multi -purpose programmable op amp 1.75796 Modulator/demodulator 3.101372 RF modulator 4.301436 High voltage op amp 4.491458 Dual op amp 1.701488 Quad RS2321ine driver .85

148914951496152415581595159618001889390026LS2926LS3026LS3126LS3226LS33347034863487764777647876489

8T268T28TL070TL071TL072TL074TL075TL080TL081TL082TL083TL084TL497ULN2002ULN2003ULN2004XR200XR205XR210XR215XR240XR320XR1310XR2206XR2207XR2208XR2209XR2211XR2212XR2213XR2240XR2242XR2567XR4739XR14412

Quad RS232 line receiver .85Multiplier 5.25Modulator/demodulator 3.10Pulse width mod. reg 15.35Dual op amp 2.89Four quad multiplier 7.78Modulator/demodulator 5.49Demodulator 6.25Video modulator 6.25Quad op amp 0.95Quad RS423 line driver 5.49Quad RS422/4321ine driver 3.95Quad differential line driver RS422 2.70Quad differential line driver RS422 2.70Quad differential line driver RS422 3.95Floppy disk read amplifier 5.35Quad RS422/423 line receiver 3.35Quad line driver RS422 3.35A log complex sound generator 5.00Analog complex sound generator c/w amp . 6.90Microprocessor cont. complex soundgenerator 8.30Quad tri-state bus transceiver 1.70Quad tri-state bus transceiver 2.59Low noise bifet op amp .79Low noise bifet op amp .69Low noise bifet op amp 1.09Low noise bifet op amp 2.10Low noise bifet op amp 3.10General purpose bifet op amp .60General purpose bifet op amp .53General purpose bifet op amp .99General purpose bifet op amp 1.66General purpose bifet op amp 4.00Switching voltage regulator 2.757 segment transistor array 1.357 segment transistor array 1.357 segment transistor array 1.75Multifunction I.C. 67.75Monolithic waveform generator 8.10FSK modulator/demodulator 5.95Phase lock loop 5.95PCM repeater 11.95Monolithic timing circuit 1.64Stereo demodulator 1.25Monolithic function generator 4.95Voltage controlled oxcillator 3.45Operation multiplier 3.45Precision oscillator 3.45FSK demodulator/tone decoder 3.90Precision phase locked loop 5.45PLL/tone decoder 5.45Programmable timer counter 1.99Long range timer 2.25Dual monolithic tone decoder 2.40Dual low noise op amp 1.55FSK modem system 9.39


CMOS4000 Dual 3 input NOR gate .25 4081 Quad 2 input AND gate .254001 Quad 2 input NOR gate .25 4082 Dual 4 input AND gate .254002 Dual 4 input NOR gate .25 4086 Expandable 4 by 2 AND/OR invert gate .974006 18 static shift register .78 4093 Quad 2 input NAND Schmitt trigger .504007 Dual complementary pairs/inverters .25 4094 8 stage shift/store register 1.744008 4 bit full adders .78 4097 Diff 8 channel analog mux/demux 2.304009 Hex buffer/converter (inverting) .53 4099 8 bit addressable latch 1.134010 Hex buffer/converter .53 4501 Industrial control unit .444011 Quad 2 input NAND gate .25 4502 Strobex Hex inverter/buffer 1.054012 Dual 4 input NAND gate .25 4503 Hex tri state buffer 1.104013 Dual D Edge triggered flip flop .45 4504 Hex level shifter 2.004014 8 bit static shift register .78 4506 Dual Expandable A01 gate 1.374015 Dual 4 bit static shift register .78 4508 Dual 4 bit latch tri-state 2.074016 Quad bilateral switch .45 4510 BCD up/down counter .954017 Decade counter/divider .67 4511 BCD to 7 segment latch/decoder/driver .954018 Presettable divide by N counter .88 4512 8 channel data separator .804019 Quad and/or select gate .60 4514 1 of 16 decoder/demultiplexer 1.904020 14 stage binary/ripple counter .78 4515 1 of 16 decoder/demultiplexer 1.904021 8 bit static shift register .88 4516 Binary up/down counter 1.104022 Divide by 8 counter/divider .97 4518 Dual BCD up counter .754023 Triple 3 input NAND gate .25 4519 4 bit AND/OR select gate .754024 7 stage binary counter .67 4520 Dual binary up counter .904025 Triple 3 input NOR gate .29 4521 24 state frequency divider 2.594026 Decade counter/divider 1.75 4522 BCD divide by N counter 1.104027 Dual JK flip flop .54 4526 4 bit binary divide by N counter 1.104028 BCD to decimal decoder .75 4527 BCD rate multiplier 1.104029 Presettable up/down binary/decade counter .91 4528 Dual retriggerable/resettable monostable 1.104030 Quad XOR gate .50 4529 Dual 4 channel mux 2.304033 7 segment decaded counter 1.76 4530 Dual 5 input majority logic gate 1.654034 8 stage universal bus register 2.03 4531 12 bit parity generator/checker .964035 4 stage PISO shift register 1.15 4532 8 bit priority encoder 1.104038 Triple serial register 1.75 4534 Real time 5 decade counter 9.354040 12 stage binary/ripple counter .79 4536 Programmable timer 5.554041 Quad true complement buffer 1.17 4538 Dual precision monostable multivibrator 1.754042 Quad clock D latch .75 4539 Dual 4 channel digital multiplexer .954043 Quad tri state NOR R/S latch .82 4541 Quad 2 input analog mux 2.104044 Quad tri state NAND R/A latch .924046 Micropower phase locked loop 1.24 4553 3 digit BCD counter 5.054047 Low power monostable/astable multivibrator .... 1.00 4555 Dual binary 1 of 4 decoder .904049 Inverting hex buffer .44 4556 Dual binary 1 of 4 decoder .904050 Hex buffer .53 4557 1-6 bit shift register 5.154051 Single 8 channel multiplexer/demultiplexer .75 4558 BCD to 7 segment decoder 2.304052 Dual 4 channel multiplexer .75 4560 NBCD adder 4.854053 Triple 2 channel multiplexer/demultiplexer .75 4561 9's complimenter 2.084054 4 segment display driver 1.75 4562 128 bit static shift register 6.344055 BCD to 7 segment recorder/LCD driver 1.75 4556 Industrial time base generator 3.154056 BCD to 7 segment recorder/LCD driver 1.75 4568 Phase comparator/programmable counter 5.604060 14 stage binary counter/oscillator .82 4572 Hex gate .904066 Quad bilateral switch .47 4573 Quad programmable op amp 3.434068 8 input NAND gate .25 4575 Quad programmable comparator 3.854069 Hex inverter .25 4580 4 x 4 multiport register 6.984070 Quad 2 input XOR gate .25 4581 4 bit A/U 5.054071 Quad 2 input OR gate .25 4582 Carry look ahead generator 1.754072 Dual 4 input OR gate .25 4583 Dual Schmitt trigger 2.184073 Triple 3 input gate .25 4584 Hex Schmitt trigger .674075 Triple 3 input OR gate .25 4585 4 bit magnitude comparator .974076 4 bit D register 1.17 4702 Programmable bit rate generator 9.954078 8 input NOR gate .33

MemoriesFor current pricing on memory check our ad each month in ETI

STATIC RAMS DYNAMIC RAMS EPROMS ?2101 250nS 256x4 22 PIN 4.69 4116 200nS 1.95 16Kx1 2708 1Kx8 450nS 8.002102L 250nS 1Kx1 16 PIN 2.19 4116 300nS 1.70 16Kx1 2716 2Kx8 450nS 5.75

2114 450nX 1Kx4 18 PIN 1.49 2118 200nS 7.85 16Kx1 2716 2Kx8 350nS 7.50

2114L 200nS 1Kx4 18 PIN 2.59 2118 120nS 9.50 16Kx1 2732 4Kx8 450nS 8.952149-045 45nS 1Kx4 18 PIN 15.75 SINGLE 5V 2732A 4Kx8 350nS 9.95

2016 150nS 2Kx8 24 PIN 9.95 SUPPLY 2532 4Kx8 450nS 9.95

6116 150nS 2Kx8 CMOS 24 PIN 10.95 4164 200nS 8.95 64Kx1 2764 8Kx8 450nS 10.99

6116L 150nS 2Kx8 CMOS 24 PIN 14.95 4164 150nS 9.50 64Kx1 2564 8Kx8 450nS 28.954164 120nS 12.00 64Kx1 27128 16Kx8 450nS

TTL PROMS listed in TTL above. 41256 150nS 256Kx1


OxceltronixT-aterin

TRANSISTORS TRANSISTORS

DEVICE PRICE POL. BVceo Icmax ft or Pdiss hfe CASE DEVICE PRICE POL. BVcso Icmax It or PdissWe2N697 .57 NPN si 60V 1A 100 MHz 120 max TO -5 2N4416 1.75 N-JFET si 30V 10ma ---2N706 .65 NPN si 25V 200mA 400 MHz 60 max TO -18 2N4853 UJT si 30V 50ma ---2N720 1.74 NPN si 120V 1A 50 MHz 100 typ TO -18 2N4856 2.30 N-JFET si 40V 50ma ---2N760 .70 NPN si 45V 100mA 50 MHz 100 typ TO -18 2N4871 2.15 UJT si 35V 1.5V -2N915 NPN si 50V --- 250 MHz 250 max TO -18 2N4891 1/5 UJT si 30V 1.0A -2N918 1.10 NPN si 15V 50ma 500 MHz 40 max TO -72 2145143 40 PNP si 20V 500ma 100 MHz 50 typ2N930 .45 NPN si 45V 30ma 30 MHz 600 max TO -18 2115172 19 NPN si 25V 100ma 120 MHz 500 max2N964 PNP Ge 7V 300ma 300 MHz 20 typ TO -18 2115195 2.83 PNP si 80V 4A 40W 80 max2N1040 PNP Ge 50V 3A 20 W 200 max TO -5 2N5210 34 NPN si 50V 50ma 30 MHz 600 max2N1303 PNP Ge 25V 300ma 3 MHz 50 typ TO -5 2115232A 1.26 NPN si 50V 100ma 375 typ2N1304 3.30 NPN Ge 25V 300ma 5 MHz 70 typ TO -5 2N5245 .67 N-JFET si 30V 50ma2N1379 PNP Ge 25V 200ma --- 200 typ TO -5 215307 77 NPN si 40V 200ma 60 MHz 2000 min2N1893 .62 NPN si 120V 500ma 50MHz 35 max TO -5 215356 PNP si 25V 300ma 250 MHz 375 typ2N2102 1.50 NPN si 65V 1A 60 MHz 120 max TO.5 2N5369 .35 NPN si 30V 500ma 250 MHz 175 typ2N2219A .60 NPN si 40V 800ma 250 MHz 300 max TO -5 2N5400 .25 PNP si 120V 600ma 100 MHz 180 max2N2221A .34 NPN si 40V 800ma 250 MHz 120 max TO -18 2N5401 .30 PNP si 150V 600ma 100 MHz 240 max2N2222A2N22392N22702N2369A

.34

.94

.34

NPNNPNNPNNPN

sisisisi

40V40V45V15V

800ma1A1A

200ma

300 MHz---100 MHz500 MHz

300 max30 min

200 max120 max

TO -18TO -37TO -5TO -18

2N54152N54472N5457215458

2.35.40.57.57

PNPPNP

N-JFETN-JFET

sisisisi

200V25V25V25V

1A 15 MHz500 MHz200maa

10m1Orna

68 typ300 max

===2N24282N2432A

PNPNPN

G3si

12V45V

100ma100ma

1.2 MHz20 MHz

130 max50 min

TO -1TO.18

2N54592N5485

.65

.70N-JFETN-JFET

sisi

25V25V

10ma10ma ---

2N2483 NPN si 60V 50ma 60 MHz 120 max TO -18 215525 1.74 NPN si 40V 220ma 200 MHz 5000 min2N2484

.41NPN si 60V 50ma 60 MHz 500 max TO -18 215550 .39 NPN si 140V 600ma 100 MHz 250 max

2N2614.40

PNP Ge 40V 50ma 4 MHz 110 typ TO.1 215770 .27 NPN si 12V 50ma 900 MHz 40 min2N2641 NPN si 45V 30ma 30 MHz 300 max TO -99 215771 .45 PNP si 15V 50ma 850 MHz 35 min2N2646 1.30 UJT si 30V 2A .75 max TO.18 215772 .34 NPN si 15V 300ma 350 MHz 30 min2N2647 1.38 UJT si 30V 2A --- .82 max TO -18 2N5881 3.94 NPN si 60V 15A 160W 20 min2N2904 .59 PNP si 40V 600ma 200 MHz 120 max TO -5 215962 .37 NPN si 45V 50ma 100 MHz 450 min2N2905 .60 PNP si 40V 600ma 200 MHz 300 max TO -5 2N6027 .43 PUT si 40V 150ma -2N2906 .34 PNP si 40V 600ma 200 MHz 120 max TO -18 2N6028 .43 PUT si 40V 150ma2N2907A .38 PNP si 40V 600ma 200 MHz 300 max TO -18 216059 7.23 NPN si 100V 12A 150W 18000 max2N2920 4.98 NPN si 60V 30ma 60 MHz 600 max TO -99 2N6657 8.47 N-VFET si 60V 2A 25W ---2N2983 NPN si 60V 700ma 60 MHz 250 max TO -5 2N6658 10.00 N-VFET si 90V 2A 25W ---21,13014 1.66 NPN si 20V 200ma 350 MHz 120 max TO -52 MJ802 8.22 NPN si 90V 30A 200W 100 max2N3019 .75 NPN si 80V 1A 100 MHz 300 max TO -5 MJ2955 PNP si 60V 15A 150W 70 max2N3053 .57 NPN si 40V 700ma 100 MHz 250 max TO -5 MJ3701 PNP si 40V max2N3054 1.54 NPN si 55V 4A 25W 100 max TO -66 MJ4502 PNP si 90V 30A 200W 100 max2N3055 1.25 NPN si 60V 15A 115W 70 max TO -3 MJE340 1.76 NPN si 300V 500ma 20W 240 max213117 88 NPN si 60V 50ma 60 MHz 900 max TO -18 MJE520 NPN si 30V 3A 25W 25 min2N3227 NPN si 20V 500ma 500 MHz 300 max TO -18 MJE702 PNP si 80V 4A 40W 750 min2N3250 .43 PNP si 40V 200ma 250 MHz 150 max TO -18 MJE802 NPN si 80V 4A 40W 750 min2N3391A .22 NPN si 25V 100ma 90 MHz 375 typ TO -98 MJE1093 PNP si 80V 5A 70W 750 min2N33942N3415

.48

.15NPNNPN

sisi

25V25V

100ma500ma

80 MHz 82 typ360 typ

TO -98TO -98

MJE1102MJE1103

NPNNPN

sisi

80V80V

5A 70W5A 70W

750 min7_50_m_i n

2''3440 1.50 NPN si 250V 1A 10W 80 typ TO -5 MPF102 .57 N-JFET si 25V 10ma2N3442 3.20 NPN si 140V 10A 115W 38 typ TO.3 MPF105 N-JFET si 25V 16ma ---2N3565 .57 NPN si 25V 50ma 40 MHz 300 typ TO -106 MPS5172 .19 NPN si 25V 100ma 120 MHz 500 max2N3566 .57 NPN si 30V 50ma 40 MHz 300 typ TO -105 MPS6514 .17 NPN si 25V 100ma 390 MHz 300 max2N3567 .57 NPN si 40V 500ma 60 MHz 70 typ TO -105 MPS6515 .17 NPN si 25V 100ma 390 MHz 300 max2N3568 .91 NPN si 60V 500ma 60 MHz 70 typ TO.105 MPS6516 .18 NPN si 40V 100ma 270 MHz 100 max2N3569 .61 NPN si 40V 500ma 60 MHz 175 typ TO -105 MPS6519 .20 NPN si 25V 100ma 420 MHz 500 max2N3638A .57 PNP si 25V 500ma 150 MHz 130 typ TO -105 MPSA05 .17 NPN si 60V 500ma 100 MHz 50 min213641 .88 NPN si 30V 500ma 150 MI-lz 70 typ TO -105 MPSA06 .26 NPN si 60V 500ma 100 MHz 50 min2N3642 .59 NPN si 45V 500ma 150 MHz 70 typ TO -105 MPSA09 .17 NPN si 50V 50ma 80 MHz 600 max2N3643 ,43 NPN si 30V 500ma 250 MHz 140 typ ,T0-105 MPSA13 .26 NPN si 30V 500ma 125 MHz 10000 min2N3644 .63 PNP si 45V 500ma 200 MHz 140 typ TO.105 MPSA14 .26 NPN si 30V 500ma 125 MHz 20000 min2N3645 .63 PNP si 60V 500ma 200 MHz 140 typ TO.105 MPSA18 .20 NPN si 45V 200ma 100 MHz 1500 max2N3703 .17 PNP si 30V 200ma 100 MHz 75 typ TO -92 MPSA20 .20 NPN si 40V 100ma 125 MHz 400 typ2N3704 .17 NPN si 30V 800ma 100 MHz 300 max TO -92 MPSA42 .38 NPN si 300V 500ma 50 MHz 40 min2N3705 NPN si 30V 800ma 100 MHz 150 max TO -92 MPSA43 .38 NPN si 200V 500ma 50 MHz 50 min2N3725 1.30 NPN si 50V 1A 250 MHz 150 max TO -5 MPSA55 .26 PNP si BOV 500ma 100 MHz 50 min2N3773 4.00 NPN si 140V 30A 150W 30 typ TO -3 MPSA56 .32 PNP si 80V 500ma 100 MHz 50 min2N3819 .60 N-JFET si 25V 10ma TO -92 MPSA65 .32 PNP si 30V 300ma 175 MHz 20000 min2N3820 .69 P-JFET si 20V 10ma --- --- TO -92 MPSA70 .27 PNP si 40V 100ma 125 MHz 400 typ213904 .22 NPN si 40V 200ma 300 MHz 160 typ TO -92 MPSA92 .35 PNP si 300V 500ma 50 MHz 25 min2N3905 .28 PNP si 40V 200ma 200 MHz 100 typ TO -92 MPSUO5 NPN si 60V 2A 150 MHz 125 max2N3906 .22 PNP si 40V 200ma 250 MHz 160 typ TO -92 MPSUO6 NPN si 80V 2A 150 MHz 155 max213947 .97 NPN si 40V 200ma 300 MHz 160 typ TO -18 MPSU10 NPN si 300V 500ma 60 MHz 25 min2N4036 1.19 PNP si 65V 1A 7W 76 typ TO -5 MPSU51 .79 PNP si 40V 2A 50 MHz 50 min2N4037 1.15 PNP si 40V 1A 60 MHz 110 typ TO.5 MPSU55 .82 NPN si 60V 2A 100 MHz 160 typ2N4062 .45 PNP si 30V 30ma 170 typ TO -92 MPSU56 .85 NPN si 80V 2A 100 MHz 160 typ2N4112 NPN si 60V 5A 30W 140 typ TO -3 MPSU60 1.69 NPN si 300V 500ma 60 MHz 25 min2N4123 .20 NPN si 30V 200ma 250 MHz 150 max TO -92 PN2222A .17 Electrically Equivalent to 2N2222A2N4124 .20 NPN si 25V 300ma 300 MHz 360 max TO -92 TI P29B .69 NPN si ,BOV 1A 30W 40 min2N4125 .20 PNP si 30V 200ma 200 MHz 150 max TO -92 TIP29C si 100V 1A 30W 40 min2N4126 .20 PNP si 25V 200ma 250 MHz 360 max TO -92 TIP30C .70 PNP si 100V 1A 30W 40 min214208 .85 PNP si 12V 50ma 700 MHz 60 typ TO -18 TIP31C .70 NPN si 100V 3A 40W 25 min2N4222 2.24 N-JFET si 30V 15ma --- --- TO -72 TIP32C .75 PNP si 100V 3A 40W 25 min2N4248 .75 PNP si 40V 100ma 40 MHz 1000 max TO -106 TIP33C 1.54 PNP si 100V 10A 80W 100 max214250 .95 PNP si 40V 100ma 50 MHz 800 max TO -106 TIP34C 1.80 PNP si 100y 10A 80W 100 max2N4339 N-JFET si 50V 15ma --- --- TO -18 TIP35C 2.92 NPN si 100V 25A 125W 50 max2N4400 .22 NPN si 40V 600ma 200 MHz 150 max TO -92 TIP36C 3.07 PNP si 100V 25A 125W 50 max2N4401 .22 NPN si 40V 600ma 250 MHz 300 max TO -92 TIP41C 1.01 NPN Si 100V 6A 75 max2N4402 .22 PNP si 40V 600ma 150 MHz 150 max TO -92 TIP42C 1.08 PNP si 100V 6A 65W 75 max2N4403 .22 PNP si 40V 600ma 200 MHz 300 max TO -92

CASETO -72TO -18TO -18TO -92TO -92

TO -106TO -9277-03TO -92TO -98TO.92TO -92TO -98TO -92TO -92TO.92TO.5TO.92TO-92

TO -92TO.92TO -92TO.92TO -92TO -92TO -92TO -3TO -92TO -92TO -92TO.3TO -3TO -3TO -3TO -3TO -66TO -377-0377-0377.0377.0390-0590-05

1900- .0952

TO.92TO.92TO -92TO -92TO.92TO -92TO -92TO -92TO -92TO.92TO.92TO -92TO -92TO -92TO -92TO -92TO -92TO -92TO -92TO -92152-02152.02152.02152-02152-02152.02152-02

TO -220TO -220TO -220TO -220TO -CP-3CP-3CP-3CP-3TO -220TO -220


TransistorsDEVICE PRICE POL. BVcoo Ictnax it or Poiss hte CASE DEVICE PRICE POL. BVceo Icmax tt or Pdiss hte CASE

TIP47 .91 NPN si 250V 1A 40W 25 min TO -220 TIP142 3.15 NPN si 100V 10A 125W 500 min CP-3

TIP48 .97 NPN si 300V 1A 40W 25 min TO -220 TIP146 PNP si 80V 10A 125W 500 min CP-3

TIP49 1.02 NPN si 350V 1A 40W 25 min TO -220 TIP2955 1.26 PNP si 60V 15A 90W 500 min CP-3

TIP50 1.02 NPN si 350V 1A 40W 25 min TO -220 TIP3055 1.15 NPN si 60V 15A 90W 15 min CP-3

TIP110 .89 NPN si 60V 2A 50W 500 min TO -220 TIS43 UJT si 30V 50ma - --- TO -92

TIP111 .89 NPN si 80V 2A 50W 500 min TO -220 TIS58 N-JFET si 25V 10ma - --- TO -92

TIP115 .78 PNP si 60V 2A 50W 500 min TO -220 TIS59 N-JFET si 25V 10ma --- --- TO -92

TIP120 .99 NPN si 60V 5A 65W 1000 min TO -220 TIS62 NPN si 12V 30ma 500 MHz 30 min TO -92

TIP121 .99 NPN si 80V 5A 65W 1000 min TO -220 TIS73 N-JFET si 30V 50ma - --- TO -92

TIP122 1.01 NPN si 100V 5A 65W 1000 min TO -220 TIV4 N-JFET si 30V 50ma _ --- TO.92

TIP125 .94 PNP si 60V 5A 65W 1000 min TO -220 TIS75 N-JFET si 30V 50ma --- TO -92

TIP127 1.14 PNP si 100V 5A 65W 1000 min TO -220 TIS84 NPN si 30V 50ma 100 MHz 45 typ TO -92

TIP140 2.75 NPN si 60V 10A 125W 500 min CP-3 TISB6 NPN si 30V 50ma 500 MHz 200 max TO -92

TIP141 2.99 NPN si 80V 10A 125W 500 min CP-3 TIS87 NPN si 45V 50ma 500 MHz 150 max TO.92

ZenerDiodes

Vz V, Watt 1.0 Watt 5 WattVOLTS IN52XX IN47XX IN53XX2.42.52.72.83.0

21

22232425

3.3 26 28 333.6 27 29 343.9 28 30 354.3 29 31 364.7 30 32 375.1 31 33 385.6 32 34 396.0 33 406.2 34 35 41

6.8 35 36 427.5 36 37 438.2 37 38 448.7 38 459.1 39 39 4610 40 40 4711 41 41 4812 42 42 4913 43 43 5014 44 51

15 45 44 5216 46 45 5317 47 54

VzVOLTS

20c

1/, WattIN52XX

25c $1.85

1.0 Watt 5 WattIN47XX IN53XX

18 48 46 5519 49 5620 50 47 57

22 51 48 5824 52 49 5925 53 6027 54 50 61

28 55 6230 56 51 6333 57 52 6436 58 53 6539 59 54 6643 60 55 6747 61 56 6851 62 57 6956 63 58 7060 64 71

62 65 59 72

68 66 60 7375 67 61 7482 68 62 7587 69 7691 70 63 77100 71 64 78110 72 79120 73 80

20e 25c $1.85

OUTPUTCURRENT

CASESTYLE

VOLTAGE50 2KBP005 DBPC1005 KBPC6005 100J BO5L 250J BO6L

$0.95 $1.46 $2.18 $3.25 $3.25100 1DMB10 100J B1L 250J B1L

$0.60 $3.25 $3.35200 1DM B20 2KBP02 KBPC102 KBPC602 100J B2L 250J B2L

$0.65 $1.25 $1.55 $2.35 $3.38 $3.45400 1DM B40 2KBP04 KBPC104 KBPC604 100J B4L 250J B4L

$0.69 $1.50 $1.70 $2.53 $3.51 $3.58600 2KBP06 KBPC106 KBPC606 100J B6L 250J B6L

$1.65 $1.87 $2.85 $4.55 $4.75

Bridge Rectifiers1.0A 2.0A 3.0A 6.0A

D-43 D-44 D-45 D-46

10.0A 25.0A

.\

SCR'S, DIAC'S & TRIAC'SSCR's2N5061 800mA 60 TO -92 .67 DIACS2N5062 800mA 100 TO -92 .75 D3202Y2N5063 800mA 150 TO -92 .79 D3202U 2A2N5064 800mA 200 TO -92 .85 2A2N6333 2A 50 TO -39 1.972N6334 2A 100 TO -39 2.05 TRIACS2N6335 2A 200 TO -39 2.31 PART # Im PIV CASE2N6336 2A 300 TO -39 2.51 TIC206B 3A 200 TO -220 1.38

2N6337 2A 400 TO -39 2.73 TIC206D 3A 400 TO -220 1.47

TIC106B 5A 200 TO -220 0.79 TIC216B 6A 200 TO -220 1.69

TIC106D 5A 400 TO -220 0.85 TIC216D 6A 400 TO -220 1.75

TIC116B 8A 200 TO -220 1.59 TIC226B 8A 200 TO -220 1.64

TIC116D 8A 400 TO -220 1.65 TIC226D 8A 400 TO -220 1.69

TIC116M 8A 800 TO -220 3.66 TIC236B 12A 200 TO -220 1.76

TIC126B 12A 200 TO -220 1.75 TIC236D 12A 400 TO -220 1.82

TIC126D 12A 400 TO -220 2.25 TIC263B 25A 200 3.04

TIC126M 12A 600 TO -220 3.68 TIC263D 25A 400 3.96

Contact us forQuantity Pricing


Oxceltronix

CapacitorsCERAMIC PLATE CAPACITORS100VDC

PARTNUMBER (pF)

TOLERANCE PARTNUMBER (p F)

TOLERANCE

638 09188 1.8 ± 0 . 2 5 p F 638 58151 150 ± 2%638 09228 2.2 ± 0.25pF 638 58181 180 ± 2 %638 09278 2.7 ± 0.25pF 638 58221 220 ± 2 %

638 09338 3.3 ± 0.25pF 638 58271 270 ± 2 %

638 09398 3.9 ± 0.25pF 638 58331 330 ± 2 %638 09478 4.7 ± 0.25pF 630 03391 390 ± 10%638 09568 5.6 ± 0.25pF 630 03471 470 ± 10%638 09688 6.8 ± 0.25pF 630 03561 560 ± 10%638 09828 8.2 ± 0.25pF 630 03181 680 ± 10%638 10107 10 ± 2% 630 03821 820 ± 10°/0638 10129 12 2% 630 03102 1000 ±10%638 10159 15 ± 2 % 630 03122 1200 10%638 10189 18 ± 2% 630 03152 1500 ± 10%638 10229 22 ± 2 % 630 03182 1800 10%638 10279 27 ± 2 % 630 03222 2200 ± 10%638 10339 33 ± 2 % 630 03272 2700 ± 10%638 10399 39 ± 2 % 630 03332 3300 ± 10%638 10479 47 ± 2 % 630 03392 3900 ±10%638 10569 56 ±2. 630 03472 4700 ± 10%638 10689 68 ± 2% 63 V 0 C638 10821 82 ± 2 % 629 03103 10 000 -20% + 80%638 10101 100 ± 2 % 629 03223 22 000 -20% +80%638 10121 120 ± 2%

All Philipsceramic capacitors

12c each.

Disc CeramicCERAMIC DISK CAPACITORS (1000 VOLTS)ALL VALUES IN PICO-FARADS

3.3 5 6 6.8 7.5 8

10 12 15 18 20 22

24 25 27 30 33 39

47 50 51 56 68 75

82 91 100 120 130 150

180 200 220 240 250 270300 330 350 360 390 400470 500 510 560 600 680750 820 910 1000 1200 1300

1500 1600 1800 2000 2200 25002700 3000 3300 3800 4000 43004700 5000 5800 6800 7500 8200

All Values 9 cents each

VOLTAGE REGULATORSPOSITIVE NEGATIVE:7805 + 5V 1A .75 7905 -5V 1A .8578L05+ 5V .1A .43 79L055V .1A .7578H054- 5V 5A 9.44 7906 -6V 1A .8578P05+ 5V 10A 14.97 7912 -12V 1A .857806 + 6V 1A .75 79L1212V .1A .7578L06+ 6V .1A .43 7915 -15V 1A .857812 + 12V 1A .75 79GUIC Adjust. 1A 1.6578L12+ 12V .1A .43 79HGASC Adjust 5A ....... 17.9978H121- 12V 5A 10.957815 +15V 1A .757824 +24V 1A .7578GUIC Adjust. 1A 1.3378HGASC Adjust. 5A 11.4778S40 Switching regulator 3.84

Electrolytics.47uF1.02.23.34.7

16V

.13

25V 35V 63V

.18

.18

.18

6.8 .1810.0 .13 .18 .2015.0 .1822.0 .16 .2733. .16 .20 .3547.0 .16 .21

68100 .27 .24 .50150 .48220 .41 .49 .74330 .55 .58 .84470 .45 1.02 .78 .88680 .49 .781000 .50 .78 .98 1.701500 1.08 1.16 2.102200 .99 1.1 1.30 2.983300 1.42 2.114700 .99 2.11 2.69

Please specify axial or radial leads when ordering

TantalumCapacitors

DIPPED TANTALUM CAPACITORSuF WORKING VOLTAGE (V)

3 6.3 10 16 25 35.1 - - - - - .27

.15 - - .27.22 - - - - .27.33 - - - - .27.47 - - - - .27.68 - - - - .271.0 - - - - .27 .271.5 - - - - .27 .342.2 - - - .27 .30 .373.3 - - .27 .30 .37 .414.7 - .27 .30 .37 .41 .546.8 - .30 .37 .40 .51 .6010 .27 .34 .40 .51 .64 .7815 .34 .40 .48 .52 1.10 1.7322 .37 .48 .52 .71 1.50 2.1733 .40 .53 .71 1.19 2.22 3.3447 .48 .53 1.10 1.91 3.33 4.5068 .58 .75 1.91 2.20 4.82


Resistors5% TOLERANCE EIA STANDARD VALUES

Ohms Ohms Ohms Ohms Ohms Ohms Ohms Ohms Meg.2.7 16 100 620 3.9K 24K 150K 910K 5.13 18 110 680 4.3K 27K 160K Meg. 5.63.3 20 120 750 4.7K 30K 180K 1 6.23.6 22 130 820 5.1K 33K 200K 1.1 6.83.9 24 150 910 5.6K 36K 220K 1.2 7.54.3 27 160 1K 6.2 K 39K 240K 1.3 8.24.7 30 180 1.1K 6.8K 43K 270K 1.5 9.15.1 33 200 1.2K 7.5K 47K 300K 1.6 105.6 36 220 1.3K 8.2 K 51K 330K 1.8 11

6.2 39 240 1.5K 9.1K 56K 360K 2 126.8 43 270 1.6K 10K 62K 390K 2.2 137.5 47 300 1.8K 11K 68K 430K 2.4 158.2 51 330 2K 12K 75K 470K 2.7 169.1 56 360 2.2K 13K 82K 510K 3 1810 62 390 2.4K 15K 91K 560K 3.3 2011 68 430 2.7K 16K 100K 620K 3.6 2212 75 470 3K 18K 110K 680K 3.913 82 510 3.3K 20K 120K 750K 4.315 91 560 3.6K 22K 130K 820K 4.7

1% RESISTORS ARE AVAILABLE ON REQUEST

PricesIN STORE1-99 100 -up

MAIL ORDER1-99 100 -up

1/4W .03 .02 .06 .051/2W .06 .05 .08 .06

1W .10 .08 .15 .122W .30 .27 .35 .305W .35 .30 .40 .35

10W .60 .50 .70 .60

SIP (single in -line package)

PART PINS COMMONPIN

6-1-XXX 6 1 0.798-1-XXX 8 1 0.90

10-1-XXX 10 1 0.95 XXX = Value

DUAL INLINE PACKAGE 898-1-;21(Ay

PART PINS DESCRIPTION 'WICKMAN4114R-001-XXX 14 7 ISOLATED RESISTORS 1.254114R-002-XXX 14 13 RESISTORS, PIN 14 COMMON 1.254114R-00 3XXX 14 24 RESISTORS, DUAL TERMINATOR 1.254116R-001-XXX 16 8 ISOLATED RESISTORS 1.254116R-002-XXX 16 15 RESISTORS, PIN 16 COMMON 1.254116R-00 3XXX 16 28 RESISTORS, DUAL TERMINATOR 1.25

PotentiometersValues Available

OHMS250 5.0K 50K 750K500 7.5K 75K 1.0M750 10K 100K 1.5M1K 15K 150K 2.0M1.5K 20K 200K 2.5M2K 25K 250K 5.0M2.5K 35K 500K 10M

All $1.25 musjSpecify Linear or Log track.

Trim PotsP.C. MOUNT MULTITURN TRIMPOTSRESISTANCE10 500 10K 200K20 1K 20K 500K50 2K 50K 1M100 5K 100K 2M200

TRIM POTSRESISTANCE

$1.65 ea.

100 1000 10K 100K 1M250 2500 25K 250 K 2.5M500 5000 50K 500K 5M

OPEN CASEENCLOSED CASE

35c85c

Check ourads in ETI

each month

The Exceltronix Bulletin BoardIn addition to our electronic cataloguewe will also shortly have in operation anumber of computer bulletin boards (alloperating on MULTIFLEX products)which can be accessed by the public.These bulletin boards will allow users toswap technical advice, software techniques, and public domain software. Aswell computer clubs are invited to use

this bulletin board to leave informationon their clubs, such as time and place ofnext meeting, cancellations, notice ofspecial events, etc. MULTIFLEX ownersmay also wish to consult this board fromtime to time since a special file will beset up for machine language programsand subroutines which will run on theMULTIFLEX Z-80, U of T 6809 board and

the new 68000/8086 computer. There willbe no charge for the use of this systemhowever maximum connect times maybe established to allow a maximumnumber of users access to the system.When the system is running the phonenumbers will be published in our ad inETI.


Sxceltronix

optoCouplers

TRANSISTOR OUTPUTMCT26 .964N28 .854N26 .85MCT2 1.024N38 1.164N37 1.164N25 .854N27 .854N35 1.164N36 1.16

DARLINGTON OUTPUT4N31 1.164N29 1.134N30 1.134N32 1.164N33 1.16

TRIAC DRIVER OUTPUTMOC3011 1.81MOC3020 1.37MOC3030 2.04MOC3031 2.68

SCR OUTPUTMOC3002 1.81MOC3003 2.60

OPTOTI 1/4 Flashing LED .95

JUMBO LED

RED .25GREEN .30YELLOW .35ORANGE .35

TI 1/4

RECTANGULAR .45ROUNDEDRECTANGULAR .45

7 SEGMENT DISPLAYS

DL1416 34.7 1

FND500 2.04FND507 2.04FND501 2.04FND508 2.04TIL313 1.85

10 ELEMENT LINEAR DISPLAYRBG - 1000 RED 4.50OBG - 1000 HIGH EFFICIENCY RED 4.50YBG - 1000 YELLOW 4.50GBG - 1000 GREEN 4.50

All prices arein Canadian

funds, FederalTax included.

SWITCHESMINIATURE TOGGLE

SwitchesSOLDER PRICE P.C. PRICE FUNCTION ACTIONTAIL MOUNTPART# PARTN4030 2.50 SPST ON -OFF4031 2.70 4331 4.10 SPDT ON -ON4032 3.40 4332 3.80 SPDT ON -OFF -ON4033 4.10 4333 6.10 DPDT ON -OFF -ON4034 3.95 4334 5.50 DPDT ON -ON4231 2.90 4431 4.10 SPDT ON -(ON)4232 3.10 4432 4.15 SPDT (ON) -OFF -(0N)4233 4.50 4433 6.55 DPDT (ON) -OFF -(0N)4234 4.50 4434 6.55 DPDT ON -ION)4235 3.50 4435 4.25 SPDT ON -OFF -(ON)4236 5.10 4436 6.85 DPDT ON -OFF -(0N)

MINI -MINI TOGGLE SWITCHES

PART# ACTION4050 SPST 1.90 RATED 3A4051 SPDT 1.95 AT4052 DPDT 2.20 125 VAC

DIP SwitchesDIP SWITCHESSTANDARD AND RECESSED ROCKERSNO. OFROCKERS SPST

1

2

3

4 $2.506 $3.008 $3.2510 $3.5012

TOGGLE SWITCHNO. OFROCKERS SPST1

2

3

46 $3.008 $3.2510 $3.5012

CrystalsMICROPROCESSOR QUARTZCRYSTALSHC-33IU CASE

1.000000 MHz 1.843200 MHz2.000000 MHz 2.097152 MHz2.457600 MHz 3.276800 MHz3.579545 MHz 4.000000 MHz4.194304 MHz

HC -181U CASE

1.000000 MHz 2.457600 MHz3.276800 MHz 3.579500 MHz4.000000 MHz 4.194304 MHz4.915200 MHz 5.000000 MHz5.017600 MHz 5.068800 MHz5.120000 MHz 5.185000 MHz5.714300 MHz 5.990400 MHz6.000000 MHz 6.144000 MHz6.400000 MHz 6.553600 MHz8.000000 MHz 10.000000 MHz10.240000 MHz 11.000000 MHz11.674000 MHz 12.000000 MHz14.318180 MHz 16.000000 MHz18.000000 MHz 18.432000 MHz20.000000 MHz 20.480000 MHz22.118400 MHz 24.576000 MHz28.356900 MHz 48.000000 MHz

REAL-TIME CLOCK CRYSTALS32.768 kHz

All Crystals $5.30 each

Watch for ourregular specials

featured inour ads InETI eachmonth

Check ourads In ETI

each month


ConnectorsPin Connectors (Dual Row Hooded Headers)

PINS SOLDER TAIL MALE WIRE WRAPSTRAIGHT RIGHT ANGLE STRAIGHT

20 2.09 2.09 2.9726 2.69 2.69 3.6534 3.50 3.50 4.2940 3.97 3.97 4.8350 4.76 4.76 5.6360 5.75 5.75 6.78

MALERIGHT ANGLE

2.973.654.294.835.636.78

RIBBON CABLEFEMALE

2.703.424.445.226.508.16

IC Sockets

8 14 16 18 20 22 24 28 40

SOCKETSSOLDERTAIL 16c 28c 32¢ 36c 40c 44c 48c 56c 80c

SOCKETSWIRE WRAP 65c 89c 1.11 1.17 1.49 1.69 1.75 1.89 1.98

LOW PROFILEMACHINE CONTACT 1.69 2.50 2.75 3.50 3.89 4.00 4.75 4.75 5.95

COMPONENTSPLATFORM 1.99 2.50 3.39 5.85

DIP HEADER2.35 2.75 3.50 5.60

D -Shell Connectors-SHELL CONNECTORS

RACK/PANELCONNECTORS

SUFFIX (XX-Z) RP -P RP -S

PINS PART#9 DE-9-XX-Z 3.63 3.67

15 DE-15-XX-Z 4.95 4.9525 DE-25-XX-Z 6.50 6.5037 DE-37-XX-Z 6.95 11.0050 DE-50-XX-Z 9.00 14.95

SUFFIX NOTES:RP = STANDARD SOLDERTAILID = RIBBON CABLEPC = PRINTED CIRCUIT MOUNT (RIGHT ANGLE)

P = PLUGS = SOCKET

INSULATIONDISPLACEMENT

PRINTED CIRC.MOUNT

ID -P ID -S PC -P PC -S

5.287.129.50

12.35

5.707.689.50

13.4810.50

D -SHELLS

6.858.50

PART#

SH-9-X 3.75SH-15-X 2.05SH-25-X 2.05

Edge Card Connectors P.C. Mount

100 Contact SpacingNo of Contacts105086100



4.00 228.68 505.75 86

3.364.726.167.159.66

10.85

6.657.158.19

13.30

THE EXCELTRONIXBULLETIN BOARD

In addition to our electronic cataloguewe will also shortly have in operation anumber of computer bulletin boards (alloperating on MULTIFLEX products)which can be accessed by the public.These bulletin boards will allow users toswap technical advice, software techni-ques, and public domain software. Aswell computer clubs are invited to usethis bulletin board to leave informationon their clubs, such as time and place ofnext meeting, cancellations, notice ofspecial events, etc. MULTIFLEX ownersmay also wish to consult this board fromtime to time since a special file will beset up for machine language programsand subroutines which will run on theMULTIFLEX Z-80, U of T 6809 board andthe new 6800018086 computer. There willbe no charge for the use of this systemhowever maximum connect times maybe established to allow a maximumnumber of users access to the system.When the system is running the phonenumbers will be published in our ad inETI.

Store HoursMon -Wed 9.00-6.00Thurs, Fri 9.00-9.00Saturday 9.00-6.00

We carry a widerange of

electronic andcomputer booksincluding Sams,Tab, McGraw-Hill,Babani, Hayden,

Osborne,Prentice -Hall,

Sybex andDilithium Press.


Oxceltronix

monitorsBMC BM-12AU: 5125A 12" green phosphour monitor with a12 MHz bandwidth, which is ideal forthe APPLE computers (in either 40 or80 column mode).

ZENITH ZVM-123: $139A 12" green phosphour monitor with a15 MHz bandwidth and a 40/80 col-umn screen width selector switchworks with just about any homemicrocomputer on the market today.

AMDEK COLOUR -1: 5569A 13", medium resolution, compositevideo colour monitor with a built-inspeaker, which gives a great colourpicture with just about any computer.

ZENITH AMBER ZVM-122: $219

AMDEK AMBER 300A: $269

5" Green ScreenMonitors. $59

Open frame.Requires 12V.Ideal for 6502computers.

Requires SyncSeparator Board

Kit $9.95

Contact us forcustom design and

manufacture ofcomputer products

ModemsHAYES SMARTMODEM: $399 NOVATION AUTO -CAT: 5399This is an RS232C, 300 baud, directconnect, intelligent modem. It cananswer calls, dial numbers, receiveand transmit data and disconnect ...all automatically. The SMART -MODEM is also a true direct connectmodem - that means that it plugsdirectly into a modular telephonejack, not a specialized telephone.Thus much less noise and morereliable reception.

HAYES MICROMODEM II: 5499This unit has all the features of theHayes SMARTMODEM, but on asingle card which plugs directly intoone of the expansion slots of an AP-PLE 11/1I+ /Ile computer. It comescomplete with software to allow youto use the modem as soon as youplug it in, or develop your own ap-plications software.

NOVATION APPLE -CAT: 5569An intelligent modem which plugsright into your APPLE II/11+ /Ile com-puter. All auto functions are sup-ported, as well as an RS232 port. ABSR x10 controller, a telephone hand-set and an extra board to enable 1200baud service are all options for thisunit. It also comes complete withself -prompting software.

A truly automatic direct -connectmodem using a state-of-the-art, all -digital, crystal controlled design. Allyou need to do is plug it to your com-puter and a modular telephone jackand away you go!

NOVATION ACOUSTIC CAT: $249(300 BAUD)

ECONO MODEM300 baud, acoustic coupler, attrac-tively packaged, (uses + 5, + 12, -12voltages from your computer).Limited time offer only: $59

EMP 310 Modem $109300 Baud

Novation J -Cat $189

Diskettes51/4" Diskettes Boxes of 10Maxell MD -1Maxell MD -2VerbatimCDCDysan3M-Ectype (with library case$4.95)2 Ectype Diskettes in abinder sheet

36.0064.0034.0026.9538.4438.44worth27.44

plastic5.89

SPECIAL Free calculator when youpurchase 5 boxes of 3M diskettes.

(Time Limited Offer)

JoysticksEcono Model

Self -CenteringWith two adjustable controlsSuper offer

Kraft Joystick $74.00TG Joysticks $79.00DeLuxe Model

TG Paddles $64.95De Luxe Model

$19.95

$39.95

Deluxe Table Top Model$59.00


SA200SA390SA400LSA455TM100-1TM100-2TM100-4SA801SA851SA860TM848-1TM848-2

41/4" Single sided slimline disk drives 5249.0051/4" Single sided bare disk drive . . . . 219.0051/4" Single sided disk drive 249.0051/4" Double sided slimline disk drive 299.0051/4" Single sided disk drive 325.005,/4" Double sided disk drive 469.005,/4" Double sided TPI disk drive 620.008" Single sided disk drive 649.008" Double sided disk drive 869.008" Double sided slimline disk drive . 795.008" Single sided slimline disk drive . 749.008" Double sided slimline disk drive . 830.00

Shugart 31/2" Disk DrivesSingle Sided, Double Density. 400K formatted. Thedrive of the future $299

Hard Disk DrivesSeagate 5,/4" ST50610 Megabyte $1395

Shugart 51/4" slimline 10 Megabyte SA712 $950(Interface Card available at nominal cost)


C xceltronix

APPLE

Academic APPLE $14.95An APPLE for kids 10.95An APPLE in the classroom 8 50APPLE BASIC 16.95APPLE BASIC made easy - for beginners

cartoons 20.95APPLE Files 19.95APPLE Logo: Activities for turtle graphics 26.00APPLE machine language 19.95APPLE machine language: A

programming guide 26.50APPLE Pascal: A programming guide 26.50Applesoft BASIC Toolbox 21.95APPLE II disk guide 9.95APPLE II Users Guide 11.95A -W Book of APPLE Software 25.95Basic APPLE BASIC 18.95BASIC/APPLE II: A programming guide 24.95BASIC/APPLE Ile: A programming guide 24.95Database Urgent for the APPLE 18.95Discovering APPLE Logo 20.95Executive Visicalc for APPLE II 20.95Fancy Programming in Applesoft 19.95Graphics Cookbook for the APPLE 14.50I Speak BASIC to my Computer 16.95Interface Projects for the APPLE II 16.95Kids and the APPLE 14.50Ready, Set, Run for my APPLE 23.95Some common BASIC Programs

(APPLE ed.) 27.9532 BASIC Programs for the APPLE

Computer 27.95Turtlesteps (An introduction

to APPLE Logo) 20.95Using 6502 Assembly Language with an

introduction to Sweet 16 26.00Visicalc Book (APPLE ed.) 19.95Your APPLE II needs you 22.95

ATARI

Advanced Programming Techniquesfor your ATARI 17.95

ATARI - A Beginners Guide 16.95ATARI BASIC 18.95ATARI Pilot for beginners 19.95ATARI Programming . . . with 55 Programs 18.95ATARI Users Guide 20.95A -W Book of ATARI Software '84 25.95Compute's 1st Book of ATARI 19.95Compute's 2nd Book of ATARI 19.95Compute's 3rd Book of ATARI 19.95Compute's 1st Book of ATARI games 19.95Compute's 1st Book of ATARI Graphics 19.95Computers for people 10.95400/800 Disk Guide 9 95I speak BASIC to my ATARI 16.95Inside ATARI BASIC 16.95Inside ATARI DOS 27.95Kids and the ATARI 26.00Mapping and the ATARI 19.95Programming your ATARI Computer 16.95Rainy Day Activities for the ATARI 16.95Stimulating Simulation for ATARI 9 50The ATARI Assembler 19.95Visicalc Book (ATARI ed.) 19.95

BASIC

Advanced BASIC 17.50APPLE II BASIC 16.95Armchair BASIC 21.95BASIC and the Personal Computer 20.95Basic BASIC 17.50Basic BASIC - English Dictionary for

APPLE, PET, TRS-80 11.95


BooksBasic Computer Programming for kids 15.95BASIC from the Grid up 18.95Basic Microsoft BASIC 22.95Beginning BASIC 19.50Bit of BASIC 11.50CBASIC Users Guide 18.95Computer programs in BASIC 14.95Implementing BASIC: How Basics work 19.95Introduction to BASIC 17.95Little book of BASIC style 11.95Making BASIC work for you 11.95Microsoft BASIC 22.50Practical BASIC Programs 19.95Secrets of Better BASIC 22.95Simple BASIC Programming for Business 19.95Some Common BASIC Programs 19.95The BASIC Conversion Handbook for

APPLE, TRS-80, PET 12.95The BASIC Cookbook 14.9525 Graphic Programs in Microsoft BASIC 14.95

BUSINESS

BASIC Computer Programs for Business . . 17.95Business Guide to the UNIX System 25.95Computer BASIC: A Guide for

Business Applications 9.95Computers for Profit 19.95Data Bases, a users guide 16.95Data Base Guide 23.35Data Base Management Systems 19.95From the counter to the bottom line 23.50How to buy a business computer

& get it right the 1st time 19.95How to choose your small business

computer 13.95How to microcomputerize your

small business 10.95How to use Supercalc 27.95How to use Visicalc 27.95Microcomputers for accountants 19.951983 Canadian Business guide to

microcomputers 9 95Small Business Computer Primer 20.95The Tenderfoots guide to wordprocessing 13.95

COMMODORE

Commodore 64 User's Guide 19.95Compute's 1st book of PET/CBM 19.95Compute's 1st book of the Commodore 64 . 20.95Compute's 1st book of VIC 19.95Cosmic Games for Commodore VIC-20 7 95Elementary Commodore 64 19.95Elementary VIC 19.95How to use the Commodore 64 5 95How to use the VIC 5 95Interface Projects for PET/CBM 14.94I speak BASIC to my PET 16.95I speak BASIC to my VIC 16.95Kids and the VIC. 26.00Mapping the Commodore 64 21.95Mapping the VIC 21.95More than 32 BASIC programs for

the Commodore 64 computer 27.95PET BASIC 19.95PET/CBM BASIC 16.95PET/CBM basics 10.95PET Games & Recreations 16.95Programming the PET/CBM 36.95Sprite graphics for the Commodore 64 20.95Stimulating Simulations for the VIC 9.5025 advanced games for the PET/CBM 16.95Using the Commodore 64 in the home 14.95VIC BASIC - A friendly users guide 19.95VIC games 18.95VIC Revealed 18.95VIC graphics 18.95

Zap! Pow! Boom! 16.95PET Fun & games 17.95PET/CBM Personal Computer Guide 21.95PET Personal Computer Guide 20.50VIC 20 Users Guide 19.95

MICROPROCESSORS

Basic Microprocessors & the 6800 23.95HPX 88 Book 16.95MC68000 16 -bit Microprocessor

user's manual 19.95Programmers Guide to the 1802 18.95101 projects for the Z80 17.95S6800 family 25.95The 8086/8088 Primer 19.95The 8086 Book 19.956502 Assembly Language Programming 22.956502 Assembly Language Subroutines 22.956809 Assembly Language Programming 23.956800 Assembly Language Programming 23.9568000 Assembly Language Programming 23.95Z80 Assembly Language Programming 23.95Z8000 Assembly Language Programming 23.958086 Assembly Language Programming 22.954 & 8 bit Microprocessor Handbook 26.9516 bit Microprocessor Handbook 26.95Z80 Assembly Language Subroutines 20.956502 Software Gourmet Guide & Cookbook 18.956800 Software Gourmet Guide & Cookbook .18.958080 Software Gourmet Guide & Cookbook 18.95Z80 Software Gourmet Guide & Cookbook 18.95Z80 Instruction Handbook 18.95Using and troubleshooting the Z8000 19.95Z80 Users Manual 20.9516 Bit Microprocessors 19.95The 6800 Microprocessor 13.95

GENERAL INTEREST

Are you computer literate 13.95A.B.C.s of microcomputers 10.95Computer anatomy for beginners 14.95Computer Bridge 14.50Computers for everybody 10.95Digital Image Processing 19.95Excuse me, what was that? 6 95Genesis II - creation and

recreation with computers 33.00Home Computer Basics 11.95Home Computers can make you rich 11.50Income from your home computer 16.95Its BASIC, the ABC's of compute

programming 11.95Microcomputes and the 3 R's 15.95RS232 made easy 20.95Simplified Guide to Microcomputers 25.95Understanding computers 25.95What to do after you hit RETURN 25.95

HARDWARE

Designing Microcomputer Systems 17.50How to read & interpret schematic

diagrams 19.50Interfacing to the S-100/IEEE 696

bus handbook 16.95Handbook of microcomputer

interfacing 15.95Microprocessor systems engineering 41.95The S-100 Bus handbook 22.50Troubleshooting and repairing

personal computers 16.958080 Microcomputer Subroutines 19.50

IBM P.C.

A -W Book of IBM sot tware '84 25.95

More BooksAssembly language programming for PASCAL Supercalc: the book 22.95

the IBM Personal Computer 26.00 Visicalc applications book 22.95Executive Visicalc for the IBM P.0 20.95 Pascal: A considerate approach 12.95 Visicalc disk guide 9 95Graphic Programs for the IBM Pascal 17.95 Visicalc made easy 19.95

personal computer 20.50 Pascal from BASIC 17.95 Wordstar made easy 16.95Handbook of BASIC for the IBM-PC 20.95 Pascal for IBM-PC 20.95 Wordstar with style 19.95How to work an IBM program 19.95 Pascal with style 13.95 Using microcomputers in business 18.95IBM BASIC 20.95 Pascal sourcebook 26.00IBM BASIC for business & home 19.95 Personal computing with theIBM data files - a basic tutorial 19.95 UCSD Pascal System 22.95IBM Display Writer user's guide 16.95 Speaking Pascal 18.95 TIMEX/SINCLAIR

IBM-PC Assembly LanguageIBM-PC Disk guideProgramming the IBM Personal Computer

26.009 95

UCSD Pascal: A considerate approach 16.95Basics of Timex Sinclair 1000

- ZX81 BASIC 14.95

ROBOTICS- Fortran 77Programming the IBM Personal Computer

24.95Making the most of your ZX-81Mastering machine code in your ZX-81

14.9516.95

- UCSD PascalProgramming the IBM Personal Computer

- BASICProgramming the IBM Personal Computer

24.95

24.95

Pattern RecognitionRobots on your doorstepThe year of the robot

21.5013.9512.50

Timex Sinclair InterfacingThe TS 2000 Book of gamesThe ZX-81 pocket book30 games for the Timex Sinclair

14.9512.9514.95

- Wordstar 24.95 computer 6 95RADIO SHACKITRS-80Software solutions for the IBM

Personal Computer 19.95 Explore computing with the TRS-80 15.95

The Visicalc book for the IBMPersonal Computer 20.95

Hardware interfacing with the TRS-80How to write a TRS-80 program

18.9519.95 TI.99/4A

Using the IBM Personal ComputerYour IBM-PC

19.9517.95

Interface projects for the TRS-80Programming for the TRS-80

pocket computer

16.95

11.95

Compute's 1st book of TI -99Get personal with your TI -99/4A

19.9513.95

TRS-80 Assembly Language 12.95 How to use the T1 -99/4A 5 95

LANGUAGES TRS-80 Assembly LanguageSubroutines 12.95

Kids & the TI -99Programmers reference guide

26.00

APL: An introduction 18.50 TRS-80 Cobol 22.95 to the TI -99/4A 18.95

Basic FORTRAN 15.95 TRS-80 Colour Computer Graphics 19.95

Beginning FORTRANCOBOL with styleForth

22.5012.8023.95

TRS-80 Extended Colour BASICTRS-80 Model IIITRS-80 Colour Programs

16.9519.9527.95

VIDEO ELECTRONICS

FORTRAN Fundamentals 9 30 Beginners handbook of IC projects 16.95Introduction to C Programming 28.95 OSBORNE Cabelmania cable television sourcebook 12.95Microsoft FORTRAN 22.50 Complete guide to reading schematicProgramming in C 24.95 Osborne business applications 23.95 diagrams 9 95Programming the language C 26.95 Osborne user's guide 19.95 Digital IC's: How they work andSprites, a turtle, and TI Logo 19.95 Osborne word processing & applications .19.95 how to use them 10.95Starting Forth 22.95 Using the Osborne I computer 19.95 Electronic troubleshooting handbook 9.95Statistical Programs in FORTRAN 22.95 Video fundamentals 16.95Turtle Sourcebook 29.00 SOFTWARE APPLICATIONS Video Invaders 7 95Z80 Assembly Language Subroutines 22.95

All about 1-2-3 13.95BASIC computer programs for the home ....17.50

EDUCATIONAL WORD PROCESSINGCreate word puzzles with yourmicrocomputer 21.95

C.A.I. Sourcebook 15.95 D -Base II user's guide 38.00 Affordable word processing 14.95

Computer Aided Instruction Dr. Dobbs Journal Vol. 1 33.50 Choosing a word processor 16.95

(as used in the classroom)Computer Playground1,2,3 My Computer and Me

16.9519.9514.95

Dr. Dobbs Journal Vol. 2Dr. Dobbs Journal Vol. 3Dr. Dobbs Journal Vol. 4Dr. Dobbs Journal Vol. 5

33.5033.5033.5033.50

Getting the most out of yourword processor

Mastering English skillsfor word processing

12.95

7.95

Dr. Dobbs Journal Vol. 6 33.50OPERATING SYSTEMS Everyman's database primer:

featuring D -Base II 19.95

An Introduction to CPIM Game Playing with BASIC 16.95for the beginner 19.95 Getting the most from Wordstar

A programmer's notebook:utilities for CP/M-80 22.95

and MailmergeHow to build and program

19.9527.95 Watch for our

A user friendly guide to CP/M 2.2CPIM Assembly Language Programming ....

19.9516.95

How to design and use questionnairesIntroduction to computer animation

13.9514.50 regular specials

CP/M Database Management SystemsCPIM Disk Guide

27.959.95

Last word on WordstarSargon: a computer chess program

26.5025.50 featured In

CP/M RevealedDatabase Management Systems

19.9526.95

Take AIMThe Illustrated CP/M & Wordstar

27.95 our ads InHow to get started with MS-DOS 19.50 Dictionary 19.95 ETI eachInside CP/MPractical Guide for CP/M

33.0020.95

The power of MultiplanThe power of 1-2-3

19.9519.95 month

Programmers & Users Guide The power of Supercalc 19.95

to the UNIX system 23.95 The power of Visicalc Vol. 1 19.95

System programming under CPIM 80 20.95 The power of Visicalc Vol. 2 19.95UNIX Programmer's manual Vol. 1 48.95 The power of Visicalc Real Estate 19.95UNIX Programmer's manual Vol. 2 48.95 The power of Visiplot-Visicalc-Visifile 19.95UNIX Quick Reference Guide 16.95 The practical Wordstar book 23.95Using the UNIX system 20.95 32 Visicalc worksheets 27.95


MultiflexZEICIA

$33wZ80 Computer Kit

Assembled and Tested $389OPTIONS PRICE

64K dynamic RAM kit forCPU board (kit) $88.00Piggyback board (kit) $120.00RS232C port for motherboard(kit) $25.00DC -DC converter (kit) $19.95Extra S100 connector $5.95

MULTIFLEX's Z80 computer is a versatile and ex-pandable stand-alone computer system designedand built right here in Canada. It uses the newesttechnology to provide the user with the mostcapabilities for the smallest price -tag. Its adap-tability to any situation and extremely low costallow it to be used in many applications rangingfrom a trainer to a complete CP/M-based computercomparable to the best on the market, at a fractionof the price.

The actual layout of the system is a two boarddesign. One board (the "motherboard") contains a24 -line parallel I/O chip for interfacing to the exter-nal world, an RS232C serial port with baud ratesselectable from 110 to 9600 baud, a hex addressand data display, a hex keypad, 14 monitor func-tion keys, 2 user definable keys, a 40 -chip wirewrap area with full access to all the bus signals,on -board provision for regulators so that the boardcan be supplied with standard S-100 voltages, anEPROM programmer which will handle 2708(1Kx8), 2716 (2Kx8), 2732 (4Kx8) 2532 (4Kx8), 2764(8Kx8) and the brand new 27128 (16Kx8) EPROMs,a DC -to -DC converter to supply the programmingvoltage to the EPROM programmer and four (4)slots for IEEE S-100 compatible boards for furtherexpansion. This is an extremely useful and impor-tant feature as it allows expansion of the systemwith all boards using this industry -standard busstructure, which are available from MULTIFLEX,as well as from hundreds of manufacturers world-wide.

The other board is the CPU card. This cardplugs into one of the S-100 slots on the mother -


A HLF,nC21 190

board and is IEEE 696/S-100 compatible with thefull 24 -bit address path to allow up to 16megabytes of memory to be addressed. The pro-cessor used is the Z80 (running up to 6 MHz) andthere is provision on -board for 64K of dynamicmemory (using 4164 chips) which will operatewithout wait states. Provided for as well is a 2K to32K (selectable in 2K blocks) common residentarea in memory for use with multiple memorybanks. There are also 4 sockets on board whichwill handle 2732 (4Kx8) or 2764 (8Kx8) EPROMs orthe new 6116/2016 (2Kx8) static RAMs (all of whichcan be software deselected if desired) to allow theuser complete versatility in setting up the board tomeet his own specifications. Also on board is 1

parallel port with 24 lines of I/O and 3 16 -bitcounter/timers for applications which require theunit to keep track of real time. Another feature ofthe CPU board is that it was designed by ourengineers to run the CP/M 2.2 disk operatingsystem so that if a floppy disk controller board isadded to the system a fully configured CP/Mmachine can be set up for a very low cost asdescribed on page 13.

The monitor software that comes with the kitis a well -written extensive package which allowsthe user to have complete versatility in machinelanguage programming and execution as well ascontrol of all the features on the board. Themonitor functions include: examine/modifymemory locations, memory block moves, compare2 blocks of memory, examine CPU registers, ex-

amine I/O ports, load and save from cassette,calculate relative branch offsets, set breakpoints,single step programs, execute programs, and pro-gram EPROMs. Each of these processes is invok-ed by a single keypress. Also available to the userare 2 spare keys definable for special functions asrequired by specific applications and applicationprograms.

Available as an option, there is a piggybackboard which attaches to the CPU board and givesthe user a real-time/time-of-day clock with batteryback-up, memory management for up to 16M ofmemory in 4K blocks, 2 RS232C ports which haveindependent software selectable baud rates, vec-tored interrupts for the onboard I/O and clockdevices, and a general interrupt controller design-ed to handle multiple interrupts for up to 7 otherboards.

All these features make this a very impressivestand-alone unit and, when combined with otherS-100 boards either from the MULTIFLEX line orfrom most other manufacturers, give the user thepotential for a very powerful microcomputersystem.

The standard kit includes the CPU board witha Z80A (4HMz) processor, 2K of RAM (a 6116), and4K of EPROM (a 2732) as well as the motherboardwith all the features mentioned above except theRS232C port and the DC -to -DC converter. Alsosupplied are sockets for all IC's and 1 S-100 con-nector.

Multiflex Super System

All this for an incredible $1195 *Nowhere in Canada, can you find acomputer value such as this one. TheMULTIFLEX Super System is theideal computer for the person whowants to get the most for his systemdollar.

The package consists of: theMULTIFLEX Z80 Computer Kit c/w64K of dynamic RAM, the MULTIFLEXEconomy Video Board, theMULTIFLEX Floppy Disk ControllerBoard, 1 5 1/4" disk drive (either aSA400L or an SA200), and CP/M com-plete with the MULTIFLEX BIOS. Allof this makes a fully expandableCP/M-based IEEE 696/S-100 system,that is on par with any on the market,but which costs much, much less.

The MULTIFLEX Z80 ComputerKit is the heart of this powerfulsystem. Its special features includean EPROM programmer (which willhandle any EPROM from a 2716 up toa 27128), 4 S-100 slots, a 40 -chip wire -wrap area, 2 built-in parallel ports, upto 3 optional RS232 ports. a hexkeypad, 16 function keys, a hex ad-dress/data display, a Z80 processor(and which can run at 4 MHz), 64K ofdynamic RAM, optional memorymanagement, an optional real-timeclock, and room for up to four IEEE696/S-100 cards.

The MULTIFLEX Economy VideoBoard gives the user an 80 characterdisplay on a standard compositevideo monitor. The board emulates astandard terminal, which allows theuser to configure his software to runextremely easy on his system. A

number of attributes, such as inversevideo, highlighting, underlining, andblinking characters. There is enoughon -board RAM to allow for up to 3 1/2pages of text to be stored on theboard, making local editing a breeze.A keyboard also contained on theboard for easy interfacing of justabout any ASCII keyboard.

The MULTIFLEX Floppy DiskController Board is a full featuredfloppy disk controller board. It allowsuse of 8" or 51/4" drives, whether theybe single or double density or singleor double sided, in any combination(up to a maximum of 4 drives total).The board is based on the WD2793disk controller IC and the FDC9216Bintegrated disk data separator IC,which makes this board extremelyreliable and versatile.

The other items in the packageinclude a 51/4" single -sided, double -density disk drive (either an SA400Lor an SA200) and the CP/M 2.2operating system complete with theMULTIFLEX BIOS. This BIOS allowsthe user to mix and match his diskdrives and even read (or write) theOSBORNE 51/4" disk format, whichgives the user a more extensive selec-tion of software.

The MULTIFLEX Super System isideal for the computer enthusiast,hobbiest, educational institutions orthe serious computer user who islooking for a low-cost way to enterthe world of CP/M computing, with anexpandable and versatile system.

111111111111Pit ,toppw: -mirr

* BASIC EXTRAOPTIONS

Multiflex Keyboard (with duplicatednumeric keypad) $120Keyboard (without numeric keypad) . $99Keyboard Case (for either of above) . $35Power Supply (5V 6A,+15 3.7A, -15V3.7A) includes case and RF filter. Idealfor this system. $139Zenith 12" Green Monitor (10% off thisprice if purchased with system) ....$139

Huge Selection ofOptions Available

Hardware1. Piggyback board with 2 serial portsand real time clock (kit) $120.002. Economy RS232 expansion board(kit) $35.003. DMA (kit) $29.004. High resolution graphics board.Details on request5. DC -DC convertor for programmingEPROMs $19.95

Plus Many More - Runs Virtually allS-100 Cards.

Software1. BASIC (running under CP/M)2. WORDSTAR (Word Processor)3. SUPERCALC (Spread Sheet)Plus Many More.


xceltronixMulti,'lex ProductsMultiflex

Econoram KitThe MULTIFLEX Econoram kit is a lowcost way to add 64 Kbytes of RAM to yourIEEE 696/S-100 Z80 -based system. Theboard uses 8 150 or 200ns 4164 64K x 1dynamic memory chips, refreshed by thesignal supplied by the Z80, which allowsthe chip count to be kept to an amazing25!! Since the chip count is so low, thereis room on the board for a 28 chip wire -wrap area for custom user circuits. A latchaddress at I/O port FFH (supplied on eachboard) allows up to 16 such boards to beused in a system for a total of 1 Mbyte ofmemory. These boards may be used in amemory -mapped I/O 'system due to the in-clusion of a phantom line which disablesthe board when activated. The other im-portant feature of the board is that it re-quires only a +8V (jumperable to +5 ifyour power supply is already regulated)power supply. This board is superb for theperson who wants to add extra memory,but doesn't want to spend extra money.

Kit $179A&T $250

Multiflex 64K/StaticRAM Card Kit

This is one of the new high technologyboards in the MULTIFLEX line of IEEE696/S-100 compatible computer boardkits. Using the new 2K x 8 static RAMchips, the user can have 64K worth ofRAM in his system without having toworry about the timing problems causedby refreshing. In the standard kit the user

is supplied with CMOS 6116 chips so thatwith the optional battery backup circuit,memory can be retained up to one yearafter a power down situation occurs.Other features include a deselect featurefor each 2K chip (in the range C000H toFFFFH) so that the RAM card does notconflict with system EPROMs and the factthat any RAM chip can be replaced by astandard 2716 EPROM. A battery chargercircuit is provided for the batteries used inthe power down back-up circuit. Also, theboard may be disabled during memory -mapped I/O operations by use of the S-100"phantom" signal. This board is a very in-expensive way to add 64K worth of RAMto your S-100 system.

Kit with 16K 5249Kit with 32K $319Kit with 64K $395A&T with 64K 5459

A ComprehensiveMiniRange of

Multiflex Boardsto expand your

Computer

Remember,we maintain aprofessionalservice staff

Multiflex RAM 11 KitThe RAM 1 kit from MULTIFLEX is the firstin a series of IEEE 696/S-100 RAM cards.Based on the 8202 Dynamic Memory Con-troller chip, which minimizes wait statesand allows on -board refresh, each boardcan hold up to a maximum of 64K bytes of200nS 4116 memory chips (ie. 32 chips).The board has a software bank -selectfeature allowing up to eight (8) full boardsto be used in a single system. If the useruses a slightly modified addressingscheme, any microprocessor can accessup to 512 Kbytes of memory. To maximzeflexibility, hardware jumpers are used toselect certain functions on the board,allowing for variations in user applica-tions. Firstly, the refreshing of thememory chips may be done internally bythe 8202 (this is transparent to thesystem) or externally if the proper signalsare available from some other board in thesystem. Secondly, the memory map on theboard may be defined in 16K blocks byuse of jumpers. This feature is used main-ly with partially populated boards,however it may also be used as a limitedwrite protect feature. As with all otherboards in the MULTIFLEX line, the S-100bus is fully buffered. All these featuresmake this board an excellent way to addmore memory to your S-100 system.

Kit with 16K 5295Kit with 64K 5350A&T with 64K 5450

Econoram Kit

64K Static RAM Card Kit

tt!...refr!!!!!YTiM:rftletf

RAM 1 Kit

Multiflex EconomyVideo Board

This is yet another of the exciting newIEEE 696/S-100 compatible products fromMULTIFLEX Tech. Inc. This board is an in-telligent, I/O mapped, 80 x 24 VideoDisplay Board. Based on the 8275 pro-grammable CRT controller, the 8257 pro-grammable DMA controller, and a Z80 pro-cessor, this board has many extremelyuseful features that are extremely simplefor the user to implement. Provided onboard is 8K of static RAM which gives theuser 31/2 screens of text. With simple com-mands, the user can easily scroll aroundin this buffer, clear the present page andhome, home on the present page and goto the beginning of the buffer. There arealso 4 field attributes (blink, reverse video,underline, and highlight) which can beturned on and off by software. Other soft-ware commands include a carriage return,line feed, clear to end of line; transmit cur-sor location; transmit character at cursorlocation; position cursor; disable controlfunctions; reset control register; as wellas all the standard functions such as tabreturn, line feed, and backspace. Also in-cluded in the software is a debug/setupprogram which completely tests the boardand allows the user to set up variousparameters on it. The output from theboard is in either composite video or avideo signal with separate horizontal andvertical sync signals (either normal or in-verted). All this makes this board a superbvalue in an S-100 video board.

Kit 5295A&T 5349


Floppy Disk Controller Kit

Nog CPU Card Kit

Economy Video Board

Zilog CPU Card KitMULTIFLEX is pleased to announce itsnew IEEE 696/S-100 based processor cardkit using the ZILOG series of processorsand support chips. The Z80 processor canbe jumper selected to run at 2 or 4 MHz.Also selectable, on 4K boundaries is thereset/power-on jump. There are 2 Z80 -P10parallel port chips on board which provide32 fully programmable I/O lines. One (1)RS232 port and 1 TTL-level serial port arealso provided for by use of a Z80 -DART In-tegrated circuit. If the user wishes to havesyncronous serial data transfer, he cansimply replace the Z80 -DART with aZ80 -S10/0 and he will have all the standardfeatures of the DART along with syn-cronous data transfer. There is no RAMprovided for on -board, however there is aspace for an EPROM which can beselected to be either a 2716 (2K x 8) or a2732 (4K x 8). Also, the board takes full ad-vantage of Z80 vectored interrupts andpriority arbitration.

Kit $275A&T $350

With every Multiflex Kityou get 2 hours free

service.

Multiflex Floppy DiskController Kit

The MULTIFLEX floppy disk controller is astate-of-the-art IEEE 696/S-100 compatibleboard. It allows the user to interface.simultaneously, up to four (4) 8 inch or 51/4inch disk drives in any combination to hissystem with the flexibility of single/doublesided and single/double density opera-tion. If desired, all operations can be doneusing DMA techniques with the optionalon -board controller or under processorcontrol. Latest technology has been usedin this design. The board is designedaround the FD2793 controller chip foreasy use under any operating system.However, this board is especially design-ed for easy use with the CP/M or MP/Moperating system (available as an option)and the MULTIFLEX Z80 computer kit.With all these features and its reasonablecost, this board is one of the best buys ina floppy disk controller board on themarket today.

Kit $295. A&T $350DMA Kit $29.00

CP/M (with BIOS) $169

1111111Millt MULTIFLEX VIDE

The MULTI FLEX Video Character DisplayBoard is the first in a line of IEEE696/S-100 compatible video displayboards. With its own Z80 microprocessorand 6845 CRT controller, this board usesonly 2 I/O ports with full handshaking andinterrupt capability. There are 12 Kbytesof on -board RAM for screen buffering,with bus arbitration built in. This meansthat the on -board processor can accessthe screen RAM at any time without in-terfering with the display (or without en-countering wait states), which make ex-tremely rapid screen updates possible.There is provision for up to 16K of pro-gram EPROM (using a 27128), so the usercan customize his software to his re-quirements. A standard keyboard connec-tor is furnished for addition of an ASCIIkeyboard. A 4K EPROM charactergenerator containing 128 ASCII symbolsand 128 block graphic symbols is one ofthe standard features of the board. Aswell, a 4K RAM bank is set aside for theuser to program up to 256 customcharacters and symbols in software. Thisallows a choice of up to 512 displayablecharacters to be in the system (and on thescreen) at any one time. Four displayableattritibutes are available to be used in anycombination for any character on thescreen. These are inverse video, blinkingvideo, underlined and a 4 bit grey -scalewhich will give either bright or dimcharacters. The 4 -bit grey -scale can beturned into colour if the optional pig-gyback board (described later) is added.

This board was developed to give the

maximum flexibility so the user can meethis display requirements. To this end,there are numerous software selectablefeatures. There are four selectable modesfor screen display, which are 24 lines of 80characters, 48 lines (interlaced) of 80characters, 24 lines of 132 characters, or48 lines (interlaced) of 132 characters.Also selectable is the character size. Itcan either be 5 x 7 pixels in a 6 x 10 blockor 7 x 9 in an 8 x 12 block.

On a board with these superb texthandling capabilities, one would not ex-pect bit -map graphics. The MULTIFLEXVideo Character Display does have thatcapability! The user can software selectone of three modes: 320 x 240 pixels in 1bit -plane; 256 x 192 pixels in 2 bit -planes;or 176 x 132 in 4 bit planes. Each bit -planeoan either be used as part of a grey -scale(ie intensity, or colour select if the userhas the piggyback board option) or as aseparate screen of single Intensity bit -map graphics.

Available as an option for the boardis a piggyback board which gives the usersome enhanced features over the stan-dard unit. 2K of RAM is located on thisboard for the user to add his own customsubroutines to the software included inthe board. This RAM can be loaded direct-ly from the S-100 bus. Another 2K isavailable for use in a print spooler bufferwhich will allow the main processor in thesystem to perform more of the functions itwas designed for and not be tied up doingmundane I/O chores. this print spoolarea is connected to a standard

Centronics -type parallel printer port.Three (3) 16 -bit counter -timers providesoftware selectable baud rates for a com-plete RS232C serial interface (which alsoincludes extension connector), as well asreal-time clock interrupts. When the pig-gyback board is added to the VideoDisplay Board, colour then becomesavailable to the user. On the piggybackboard are 16 12 -bit registers which allowthe user to software select 16 coloursfrom the 4096 possible colours. An RGBcolour monitor and NTSC-encoded UHFRF-modulator output are both provided forattachment of different monitors or evenan unmodified TV. A light pen optionis also built onto the board and this aswell as all other devices have interruptcapability in the system.

All these features! But that is still notall! The MULTIFLEX Video CharacterDisplay Board also can be used as astand-alone Intelligent terminal withdefault set up parameters, set up byjumpers. The board can also be used as aterminal emulator in an IEEE 696/S-100system with complete control commandsand local editing. That's just one morething which adds up to show that theMULTIFLEX Video Character DisplayBoard is one of the best on the market,especially in its price range.


Multiflex ProductsMultiflex Economy

Video DisplayTerminal Kit

Now available from MULTIFLEX is aneconomy video display terminal. Original-ly designed as a low cost access unit forour soon to be operational computerizedmail -ordering and bulletin board system,this terminal is a semi -intelligent systemwhich is controlled by a Z80Amicroprocessor and a 6845 CRT controllerchip. The keyboard is fully ASCII encodedand the character generator contains thefull 128 -character set as well as a128 -character alternate set both of whichare in the 5x7 dot matrix format. Thescreen display is 80 characters by 24 linesif the unit is hooked to an external monitor(not included) or 64 by 24 if run through anRF modulator to a TV. There are 3 soft-ware selectable attributes (dim, reversevideo, and alternate character set) whichcan be chosen one at a time for the wholescreen. This attribute can then be switch-ed on and off for each individualcharacter. A 2K buffer is provided for nor-mal operation. However when the optional6K memory upgrade is purchased, 4screen pages can be loaded from the hostmachine, edited localy, and thendownloaded back to the host again savingon connect time and phone line bills. Alsoincluded are 2 RS232 ports: one for amodem and one so that a printer can beattached to the terminal. The baud rateson these ports are software program-mable and can range from 110 to 9600baud. The MULTIFLEX Video Display Ter-minal has provision for an on boardmodem freeing a serial port. With all thesefeatures, you would expect to pay a lot forthis kit, but all this is available to you,complete with a case, for an extremelylow price.

Kit $259Kit & Case $289A&T plus case $369

U of T6809 Single Board

ComputerThe 6809 Single Board Computer, design-ed at the University of Toronto anddistributed exclusively by EXCELTRONIX,is a compact hardware unit which wasdesigned originally as a lab board forteaching students about microprocessorsystems. Its many features, however,make it an ideal unit for stand-alone con-trol applications or software developmentsystems as well.

The system is designed around theMotorola MC6809 microprocessor. This isan 8 -bit processor with full 16 -bit internalarchitecture, 2 index registers, 2 stackpointers, 2 8 -bit or 1 16 -bit accumulators, adirect page register and a wide range ofaddressing modes, including a program -counter -relative mode. This mode allowsthe user to write completely position in-dependent software, important insystems software development.

There is provision for up to 48K bytesof dynamic RAM on -board. The refreshingof this RAM is controlled by an 8202Dynamic RAM Controller. This chip allowsfor completely transparant refreshing ofthe RAM (ie. no wait states to slow thesystem down). There is also provision forup to 12K of EPROM using either 2532 or2716 chips.

There are 4 complete I/O circuits builtonto the board. 2 of them are serial(RS232); one is used for a terminal (whichis required for use of the board with thesupplied monitor software), and the otherone is user defineable, but it is set up to

6809 Board

Multiflex Terminal

communicate with either a modem or aprinter. Also on -board are 2 6522 VIAchips. These provide 2 parallel ports perchip along with 2 16 -bit timer/counters.One of the parallel ports and one of thetimers are use by the monitor software toprovide a cassette interface (whichoperates at 300 baud). The second parallelport on that chip is wired into a connectorwhich is ideal for interfacing a parallelprinter or keyboard. The 2nd VIA is not us-ed at all and is completely free for theuser. For further expansion of the system,a fully buffered version of the CPU signals(data, address, control lines and a signalindicating whether or not the current ad-dress is located on the board) is availableat a cable connector.

The software provided with thesystem is in a 2532 EPROM and allows theuser to: test the memory; dump blocks ofmemory; examine and modify singlememory locations; read or write from thecassette port; set and examine break-points; single step and/or executemachine language programs and set andexamine the processor registers. All thisis accomplished through a 9600 -baud ter-minal interface (one of the serial ports)Included is a full screen editor/assemblerwhich allows the user to work in 6809assembly language rather than machinelanguage. All this makes this board anideal trainer, control unit or softwaredevelopment unit for just about anyone.

Kit with 16K $369A&T with 48K $499

Special Pricing is available when both items on this page are purchased together

MEMMultiflem 68000 System

FEATURES:*Works with either of the two major16 -bit microprocessors: the MC68000or the 8086.*Speed from 2-12 MHz.*Maximum of 16M bytes of memory.*4 serial ports on -board.*24 -bit counter/timer on -board.

BasicKit

$695CPU CONTROL

0.1 F,.*.

MC68000or

8086

*Centronics printer interface.*Cassette interface.*Full floppy disk controller.*82x25 text display.*320x256 pixel, 4 colour graphics.*RGB or composite monitor interface.*Various operating systems available(CP/M-86, XENIX, MS-DOS).

DIRECTCONNECTMODEM

FCC DOT .,w-

280 DART 280 DART MC68230

Price and rspecification may c.1<CDchange withoutnotice. MC68451 MMU ADDRESS

DECODE

GRAPHICS PLANE 128Kbyte

(320 x 266 x 2 bit pixel)

DRAM 16K or 64K chips

GRAPHICS PLANE 128Kbyte

(320 x 256 x 2 bit pixel)

DRAM 16K or 64K chips

EXPANSION BUS

L

F01797

FDC

5- er 5 1/4-0 0

MODULATOR

5

VIDEO

DRIVER

and

CHARACTER

PLANE

128Kbyte

RAM

EPROM

Imiwk4

5-100 BUS INTERFACE Permanent MasterTemporary MasterSlave

The MULTIFLEX 68000/8086Single Board Computer allows theuser to enter the exciting new worldof 16 -bit computing at an impressive-ly low price, with the option of makinghis system very powerful very easily.

The most important feature ofthis system is the processor, or ratherthe choice of processors. There is achoice of two: a Motorola MC68000 orthe Intel 8086. Both of these pro-cessors run at speeds ranging from 2- 12 MHz. This choice allows the userto pick the processor to fit hisspecific needs.

The 68000 is Motorola's ventureinto the world of 16 -bit micro-processors. The 17 internal registersare divided into two groups; a groupof 8 32 -bit data registers (which canbe used in 8, 16 or 32 bit segments)and a group of 7 address registersand 2 stack pointers. There are twostack pointers so that the systemsoftware and user's software can

maintain separate stack and not in-terfere with one another. A separate16 -bit data path and 24 -bit addresspath are built into the 68000, so thatno external de -multiplexing isnecessary, which help keep thethroughput of the processor high.This allows this microprocessor to beused in a multitasking or high-levellanguage environment with greatease.

The 8086 microprocessor is anupwards -compatible member of the8080 series of microprocessors. Thismeans that there is software com-patibility (at the source code level)between this 16 -bit unit and theearlier 8 -bit microcomputers. Theregister layout of this machine issimilar to the 8080, but the registersare 16 -bits wide instead of 8 -bits.Directly, with its multiplexed ad-dress/data bus, the 8086 can addressup to 1 Mbyte of memory.

The basic system comes with a

comprehensive 68000 monitor inEPROM which creates an ideal basisfor the user, who wants to learn howto use a 16 bit system and who wantsto eventually expand it.

A full 16 Mbytes of memory canbe addressed by the combination ofthe processor and the 68451 MemoryManagement Unit. Of this memory,there are 7 sockets (each of 16K bytessize) which can be set up for eitherRAM or EPROMs. Also 5 of thesesockets can be strapped to programEPROMs. The maximum on -boardRAM is 300K bytes. The fully extend-ed S-100/IEEE 696 bus on the boardallows for another 15M bytes worth ofmemory. All of this memory give theuser complete flexibility for whateverapplication he has in mind.

This board also has an amazingassortment of I/O features. Fourserial ports are included on the board,each with individually programmablebaud rates. Two of these ports aresetup with RS232 drivers, one with aRS422 driver, and one is set up for anoptional onboard direct connectmodem. Also onboard is a parallelport controller that is wired up as aCentronics -type printer port and alsohandles a cassette interface. A 24 -bitprogrammable timer is also includedso that user timing functions (such asa real time clock) can be set up. Alsoincluded on -board is a full -featuredfloppy disk controller. This controllerwill handle up to 4 drives (either 8" or51/4") in either double density orsingle density modes with either dou-ble or single density drives.

The video section on theMULTIFLEX 68000/8086 Single BoardComputer is another very impressivefeature of this system. An RGBmonitor, a composite video monitor,and an RF modulator are all providedon -board. For text display, the usergets an 82 character by 25 line screen(41 x 25 through the RF modulator).All characters on this display canhave up to 4 attributes (Inverse video,Highlight, Underline, and Blink) andeach character be in one of 4 colours.The character generator for allcharacters is in RAM, so that userdefined characters are a breeze tocreate and use. Also supported arefull 4 -colour graphics with a 320 x 256pixel resolution. There is anASCIIparallel keyboard interface on theboard as well.

All of these features make theMULTIFLEX 68000/8086 Single BoardComputer Canada's leader in the new16 -bit computer technology.


Oxceltronix

Multiflex ProductsMultiflex Single Board Computer

FEATURES:*Full IEEE S-100 bus for easy expan-sion.*Up to 256K of on -board dynamicRAM.*Processor speed 4 MHz.*Memory management for up to 16Mbytes of memory.*3 16 bit timer/counters.*2 RS232C serial ports.*24 line parallel port.*Real time (time -of -day) clock.*Floppy disk controller.*80x24 video display.*512x512 bit -map graphics*Print spooler.*Optional RF modulator.*Priority interrupts.*Fully CP/M compatible.*Many jumper -selectable hardwareoptions.

The MULTIFLEX Single BoardComputer is among the new breed ofstate-of-the-art Canadian computerproducts. With a Z80 seriesmicroprocessor, 64K of dynamicRAM, a full featured floppy disk con-troller and a 80x24 video section, allon the board, this unit makes an ideallow-cost system for the CP/Moperating system.

The memory section has anumber of unique features rarely tobe found on any other machine. Thecircuitry is provided on -board for upto 256K of dynamic RAM (using 416464K x 1 chips). Jumper options allowthe user to select one of three optionswith regard to wait states (no waitstates, wait states on operation codefetches, or wait states on all memoryaccesses) so that the user can con-figure his system to his requirements.Four jumper -configurable sockets arefurnished as well. Any mix of6116/2016 (2K x 8 RAM); 2716 (2K x 8EPROM); 2732 (4K x 8 EPROM) or 2764(8K x 8 EPROM) can be placed in thissocket, which can be enabled toshadow any other memory whichwould be addressed in these loca-tions. It is also possible to disablethese sockets in software, if the userwishes to do so. Full memorymanagement is available on theboard which can turn the Z80's stan-dard 64K address space into the full16 Mbyte 24 -bit address space allow-ed by the S-100 bus standard. Thismemory management applies to the256K RAM on -board, all other on-board memory, and all memory on theS-100 bus.

Kit with 64K $599A&T with 64K 5795

CP/M (with BIOS) 5169

The board also contains a full -featured floppy disk controller. Basedon the WD1793 IC, this section willhandle any combination of 8" or 51/4"drives, whether they be single or dou-ble density or single or double sided.The newest technology was also us-ed in designing the data separator cir-cuit. This circuit is all -digital, allow-ing extremely reliable use in the dou-ble density mode. The floppy con-troller is fully compatible with bothCP/M, giving the user full flexibility asto what operating system he wants torun.

For interfacing to the real world,the user is again given the flexibilityto configure the system to his ownneeds. Supplied are 3 independantsoftware and/or hardware controlled16 -bit timer counters, 2 of which areused to generate the baud rates forthe 2 on -board RS232C serial ports.Both of these ports are program-mable for either syncronous or asyn-cronous operation. A full 24 -line soft-ware controlled parallel port and areal time (time -of -day) clock, whichcan be backed up with batteries if theuser so wishes.

The real-time clock, the floppycontroller, the timers, and any other


MuItiflex Single BoardI/O port can be chosen to operate in asoftware selectable priority interruptscheme. A second interrupt controllerallows the on -board interrupts to bevectored with and other interruptsfrom external S-100 bus boards in ajumper selectable priority.

There is a full video section onthe MULTIFLEX Single Board Com-puter as well. A second Z80 processoris used along with a 6845 CRT con-troller, giving the user a variety offeatures. Up to 8K of EPROM can beused to control the section, allowingemulation of a variety of terminals orroom for custom display routines. 8Kof static RAM is also provided for,this being used for the display buffer,

the Z80's work area, and a print buf-fer. The print buffer can be used forthe built-in Centronics -type printerport in the section. An ASCIIkeyboard port is also provided. Thecharacter generator on the board pro-vides up to 256 characters and sym-bols, which are user -programmablesince they are in a 2732 EPROM. Thevideo output is available in two forms:a composite video signal, and theseparate sync and video signals,allowing the board to be used with avariety of monitors. As well, circuitryfor an optional RF modulator is pro-vided on -board, for easy connectionto a TV set. The actual display formatin text is 80 characters by 24 lines.

But, a 192 by 256 pixel graphics modeis also made available to the user.The resolution of this graphics modecan be changed by the user by pro-viding additional software. A full,general, graphics interface (forjoysticks, digitizing tablets, touchpanels, etc) and a light pen input areprovided so that user-friendly soft-ware is easy to implement on thesystem.

Overall, the MULTIFLEX SingleBoard Computer, with its numerousfeatures can be many things to manyusers, from a full -featured Z80development system to a very power-ful CP/M based computer.

Multiflex 51/4" & 8" Systems.We, at MULTIFLEX, are pleased

to announce two new assembled andtested configurations of our newSingle Board Computer systems.These systems are based on theMULTIFLEX Single Board Computer,a description of which is given onpage 11.

THE TRAVELLING SYSTEM:The first configuration is a portable,unit. It will provide for two slim -line51/4 inch double -sided, double -densitydisk drives, mounted side -by -side ver-tically, a nine inch video monitor inthe middle, and internally at the otherend, room for an optional S-100backplane which can plug into theSingle Board Computer (it is ter-minated in a S-100 female card -edgeconnector). The backplane can holdup to 4 additional S-100 boards (extramemory, A/D + D/A, colour video,etc.). A switching power supply canbe mounted internally and a hingedexternal keyboard along the front ispart of the package. All this will resultin a portable system which runs CP/Mand all its compatible software.

51850THE BUSINESSMAN'S SYSTEM:The second system is a full configura-tion business system. Included is afully configured Single Board Com-puter complete with 256K bytes ofRAM, a 4MHz Z80A processor, and allof the other exciting features of thisremarkable system, including theCP/M operating system. Also includ-ed are two 8" slim -line double sided,

double density disk drives (SA860)and a powerful switching power supp-ly. External connectors are providedfor an ASCII keyboard, an externalvideo monitor, extra external diskdrives, two RS232C ports, and aCentronics -style printer connector.All of this gives the serious systemuser all the advantages of a fully load-ed CP/M system in one smallpackage. $2895THE SYSTEMS INTEGRATORPACKAGE:This configuration is suitable forsystems developers or hobbyistswanting a powerful packaged system.

It consists of three of our S100 cards:CPU Board with 64K of RAM onboard, economy video board, floppycontroller board and our six slotbackplane. It also includes akeyboard and CP/M and a portable12" Zenith green screen monitor. Itcomes complete with two 8" doublesided, double density disk drives, anda very powerful switching power sup-ply.This system allows the user todevelop and test easily what ever cir-cuitry he wants within his system. Allthe standard external connectors areprovided, so that expansion and con-nection of external devices is simple.

52950Exceltronix Catalogue 1983 - 25

CxceltronixCheck out these Super BargainsFuller details elsewhere in this catalogue

Gemini 10X Printer $369Wizard Intelligent Printer Interface $89Wizard Buffered Parallel Output $179Multiflex Apple Compatible Disk Drive $259 *Multiflex Apple Compatible Slimline Disk Drive,

DS DD $345* *Quentin Disk Drive $299 * *Micro Sci Disk Drive $299 * *

*One year warranty * *90 day warrantyZenith ZVM-123 Monitors $139Amdek Colour Monitors $395Multiflex 16K RAM Card $55Wizard 16K RAM Card $79PDA 232 Serial Interface $109Multiflex EPROM Programmer for Apple

(for 2716, 2732, 2732A and 2764) $69Multiflex 280 Card (No CP/M software inc) $55Multiflex 80x24 Video Card

(Runs CP/M and Pascal) $79Wizard 80 Column Card $199

Multiflex Products for the IBM PCRAM Card (256K) with serial and parallelinterface, real time clock and optionalmodem interface. Incredible bargain . . .Call for PricesSA455 Slimline Disk Drive DS, DD . . . $299Multiflex Disk Drive for the VIC-20 or

Commodore 64 with power supplyand intelligent interface $389

Multiflex 300 and 1200 Baud Modem $299XR Modem Kit (as advertised in Byte) $225VIC-20 $169Commodore 64 5359


Hioki Test Gear3207 Digital Pocket

Hi Tester$189

Full Autoranging DMM

3208 CalcuHi Tester

$350

Calculator and DMM Capability

autoranging A multimeter with a function calculatorLo power ohms for in -circuit resistance

AC/DC 10MS2 Input Impedance

High sensitivity with 200mV range

Alarm provided for continuity test work

Diode check range Zero adjust function

DMM display with one -touch keying -in ofthe calculator

Lo power ohms for in -circuit resistance AC/DC 10MS2 Input Impedance

Alarm provided for continuity test work Alarm indicates range selection and func-

tion selection

Diode check range

Specifications 3207/3208DC Voltage:

Input Impedance:AC Voltage:

Input Impedance:

AC DC Current:

Resistance:

Range: 200m 2 20 200 1000V10MS2Range: 2 20 200 600V10MclFreq.: 40 - 500 Hz

Range: 20m 200mARange: 0.2 2k 20k 200k 2000ki2

Ranging: Automatic & ManualSample Rate: 2 samples per secondDimensions, Weight:

3207:150Hx6OW x 12D mm, Approx. 120g3208:170H x 76W x 20D mm, Approx. 250g

Calculator: Separate Entry/Func-tion keys

Display: 8 digits sign or 5 mantissaand 2 exponent with sign

Accessories: Test Leads,3207: Soft Case3208: Carrying CaseFuse (0.3A)

The Multiflex LSA

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Multiflex Low -CostLogic State AnalyzerYou've just completed a microprocessorsystem, and it doesn't work. What next?You can use an oscilloscope to check forclock signals and the like, but ifeverything appears to be in order youcan't go much further withoutsophisticated equipment. In these situa-tions, professionals turn to their logicstate analyzers, each of which costthousands of dollars. MULTIFLEX has theanswer for all those people who don'twant to take a mortgage on their housejust to get a computer working. TheMULTIFLEX Logic State Analyzer has allthe essential features of those more ex-pensive units at a fraction of the cost.This is a high -quality piece of test equp-ment, suitable for industrial or scientificuse, but its price is well within the pricerange of a hobbyist.

Easy to understand and operate, theLogic State Analyzer allows you tomonitor 16 points in a digital system (ie.data and/or address bus, or control lines)which carry continually changing signals.You can select a bit pattern you expectwill appear at these points. Once the pat-tern appears the Analyzer will trigger andrecord ("freeze") the next 1023 bit pat-terns so that they can be examined stepby step even though data is no longeravailable in the unit being examined. Forsoftware development the Analyzer is in-valuable, especially in dedicated systems.If you design a microprocessor system fora specific function, and you have nomonitor, assembler or other such soft-ware, the best and often only way todebug the system is to use a logicanalyzer. It will let you look closely at thedata flow as a program is executing, ormonitor the address lines to make surethat the instructions are being executed inthe proper sequence. The various controllines such as memory read and write,DMA, interrupts, or enable and disablesignals can also be examined. You can, ofcourse, monitor any combination of thesesignals, such as the data bus and half ofthe address bus, or half of each plus 4control lines. The combinations areendless.

A special feature of the MULTIFLEXLogic State Analyzer is that any number ofunits can be interconnected for dealingwith larger input words. With twoAnalyzers, you can monitor the addressand data bus of an 8 -bit processor at thesame time and have 8 spare signals tomonitor the control lines, I/O signals orsignals from external devices. Anyonewho will be doing any systems debuggingshould take a close look at this unit, sinceits features and low price tag make it anasset.

Kit with case $295A&T $395


28 - ExceltronixCatalogue 1983

exceltronix

PRINTER SPECIALSEpsonFX80 $84581/2" Dot Matrix with enhanced Graftrax 160CPS.

MX100 $109515" Dot Matrix with Graftrax - 100 CPS

FX100 $99515" Dot Matrix with enhanced Graftrax 160CPS.

8155 Serial Interface $190with 4K Buffer

Letter QualityTTX 15" DAISY WHEEL PRINTER 16 CPSbidirectional and logic seeking. Manysoftware features - reverse line feed; stan-dard feature parallel and serial inputs.One of the best printers on the market atan affordable price of

BMC Printer80 CPS Dot Matrix

04'

Gemini 10X $369- 9x9 Dot Matrix ow- 120 CPS 4 Print sizes- max. paper width:

10"- dot addressablegraphics

user definablecharacter set

Gemini 15 9x9 Dot Matrix 100 CPS- 4 Print Sizes- max. paper width:

15"

$599- dot addressable

graphics- proportional

spacing

RF Mods $14.00Applesoft Tutorial $14.44DOS Manuals $25.00Printer Manuals also available

Oki DatamL 82AmL 9270001301Serial Interface

$639$759

PaperControl Data 91/2" x 11" plain -500 sheets $10.44Box 2400 sheets long 151/2" x 11" $45short 81/2" x 11" $55Mailing labels - Multicopy formsavailable $14

InterfacesWizard $184AppleTM compatible WizardBPO-16 16K Parallel BufferPrinter Card

Wizard BPO-32 $22432K parallel buffer printer card

Wizard $84IPI parallel intelligent printer interface

Microtek AppleDumpling $170Multiflex printerinterface $69

We will make cables for any computeron the market min. $35

New Exceltronix ProductsMULTIFLEX QUAD

The MULTIFLEX QUAD is theleast expensive way to add a fullfeatured multifunction board to yourIBM-PC. This board contains 256K ofparity -checked RAM, a real-timeclock/calendar, a RS232 serial portand a parallel printer port. all of thisallows you to expand your PC to newheights of usefulness and func-tionality in one great leap, for onceyou have the QUAD you can ask thecomputer the time (and have it reply),or talk to other machines, and neverrun out of room while using that im-portant program. All of this isavailable to you for an unbelievablylow price.

MULTIFLEX HARD DISKSTORAGE SYSTEM:

Are you constantly running outof disk space on your APPLE, IBM orS-100 computer? Are you tired ofwaiting while your DOS tries to findthat important file on the disks? Thenyou should get the MULTIFLEX HardDisk Storage System. The systemconsists of a 10M byte 51/4" hard diskdrive, a full featured hard disk con-troller (that will handle up to 4 harddisk drives), a host adapter boardwhich fits the particular computeryou are using, and a new diskoperating system for the computerwhich allows you to use the hard disksystem in your system. The systemwill be available in 3 versions: one forthe APPLE II, one for the IBM-PC, andone for an S-100 based system suchas the MULTIFLEX super system.

MULTIFLEX DRIVE FORVIC-201C-64:

The MULTIFLEX drive for theVIC-20/C-64 is a low cost alternativeto the COMMODORE 64 computers. Itis completely compatible with all pro-grams and data now prepared onCOMMODORE equipment and usesthe same commands for accessingthe data on the diskette. All of thesefeatures and many more are availableat a substantial savings from theoriginal equipment.

MULTIFLEX INTELL-MODEM:The MULTIFLEX Intell-Modem is

a 300 or 1200 baud direct connectmodem with intelligence. This in-telligence allows interactive controlof the modem from your computer orterminal. It allows you to auto -dialphone numbers (and redial if thenumber is busy), automaticallyanswer the phone, and automaticallyselect the correct baud rate to com-municate at. It also has a front panelbank of LEDs to give the status of themodem and communications line at aglance. And you get all of this andmore for an incredibly low price.

Multiflex 256K -Byte RAM Card KitThis is a brand new product from theMULTIFLEX line of state-of-the-art IEEE696/S-100 compatible boards. This boardgives the user up to 256K of dynamic RAMwith full 24 bit addressing which cantransfer data on an 8 bit wide path and inthe new IEEE 16 bit method for 16 bit pro-cessors. The standard board includes 8150 or 200ns 4164 64K x 1 dynamic RAMchips (ie. 64K of memory) which will runcomfortably at 4 MHz and in some casesmay be good up to 6 MHz. However, if it isintended to use this RAM Card solely at 6MHz, we strongly recommend that you,when you order, specify 120ns 4164's,which can be supplied at a slight addi-tional charge. The refreshing of the RAMcan either be handled externally (if youuse a Z80 processor) or internally. If norefresh signal is available on the bus (dueto wait states or use of a processor thatdoes not supply a refresh signal) the inter-nal refresh acts as a fail-safe, by supply-ing the refresh signal to protect the con-tents of your memory. Wait states can bejumper selected in, so that memory notcapable of running at the speed of the pro-cessor can be used if desired. Another im-portant feature of this board is its com-patibility with both the CP/M and MP/Moperating systems and a bank -selectfeature for use of more than one of theseboards in the system. There is also a writeprotect option which allows the user toload something (eg. an operating systemkernal) into memory and then protect itagainst accidental erasure.

Kit with 64K $295A&T with 64K $395

MULTIFLEX EPROMPROGRAMMING SYSTEM:

This new product fromMULTIFLEX is a superb EPROM pro-gramming system. It programs up to 8EPROMS at a time and can handle2716, 2732, 2732A, 2764, 27128, 27256,2532, and 2564 chips. Based on an Z8processor, this system can be used tolocally enter and edit data, as well asdownload from a RS232 serial port. Asocket for master EPROMs makes co-pying a breeze, and that master neednot be of the same type as the copys(ie. you can copy from a 2732 to a2532, etc.). All of these features andthe many more make this EPROM pro-grammer the one to have.

MULTIFLEX 212AMODEM DESIGNERS SYSTEM

This 212A compatible modem is bas-ed on the EXAR series of modemchips. The XR2123 CMOS modulator/demodulator required for 212A com-patibility and the XR2120 provides the1200 and 300 baud filtering. Based onthese CMOS/LSI components we canoffer a modem completely compati-ble with the BELL 212A standards atan extremely low cost with enhancedreliability since the LSI circuitsreduce the number of active com-ponents and the space to housethem.

With the addition of theMULTIFLEX Intelligent Modem Con-troller you receive a smart modem,which is software compatible withother popular modems on the markettoday.MULTIFLEX MODEM DESIGNERS

KIT (A&T) $349.95MULTIFLEX INTELLIGENT MODEM

CONTROLLER$ 149.95BOTH TOGETHER $449.95

Contact us forpackage deals

As these are new products, call us for prices or followrelease dates and pricing in our ads in ETI magazine.


xceltronix

Slimline Disk DrivesThe MULTIFLEX Slim -line Disk

Drive for the APPLE II series of com-puters is a double -sided drive whichgives the user double the storagespace of a regular APPLE -compatibledisk drive. It is still, however, APPLEcompatible with all the various AP-PLE software, so that programs thathave already been developed for thecomputer can be run under their ownDOS.

$35980 -Column Card

FEATURES:*Gives 80 columns and upper/lowercase on your APPLE II/11+ /Ile com-puter.*Works with PASCAL and CP/M.*Auto -switch between 40 columnsand 80 columns.*Full inverse video.

The MULTIFLEX Video -80 cardallows the user of an APPLE 11 com-puter to have an 80x24 text displaywith upper and lower casecharacters. This board allows theuser to switch from a 40 columndisplay to a 80 column display, andrun PASCAL, CP/M and show AP-PLESOFT programs in 80 columns.

579

16K RAM Card $55Expand your 48K APPLE to 64K. The MULTIFLEX16K RAM Card allows other languages to beloaded into your APPLE from disk or tape. t,Allows APPLE CPIM users to run CP/M 56.

Multiflex Z-80 CardThis card allows the user to run

Z80/8080 programs on his APPLEII/11+ /Ile computer. Specifically, itallows him to run the CP/M operatingsystem, with all its attendant soft-ware, such as word processors, ac-counting packages etc. $55(CP/M not included)

Multiflex Semi DiskFEATURES:*Fully compatible with APPLE com-puters*256K of fast dynamic RAM.*Works like 2 disk drives.

The MULTIFLEX SEMI DISK is adisk emulator board for the APPLE 11range of computers. With its 256Kbytes of RAM, it looks to the com-puter like two very fast disk drives.This makes the use of various database programs, and other softwarethat use more than one drive extreme-ly easy because the wait time untilthe next module is loaded is minimal,thus increasing the productivity ofthe user immensely.No software

included

$379

Multiflex Drive for AppleFEATURES:*SA390L base drive.*APPLE compatible.*Complete with case.*One year warranty.

The MULTIFLEX APPLE -compatible disk drive is a standardShugart SA390L which has beenmodified to work with the APPLEII/11+ Ile computers. It is compatibleand handles all the special protectiondisk operating systems that are inuse (including those that use "half -tracking"). This drive, in a case, com-plete with a year's warranty isavailable with or without a controllercard

Drive with controller 5349Drive only 5269

Multiflex EPROMProgrammer

FEATURES:*EPROM programmer for APPLEcomputers.*Programmes 2716, 2732, 2732A,2764.*ZIF socket for the EPROM.*Complete with software.*Built-in programming supply.

The MULTIFLEX EPROM Pro-grammer Card for the APPLEII/11+ /Ile computers allows the userto create his own software and thenstore it on an EPROM for use inanother system. This card, with itson -board programming supply, canprogram 2716 (2K x 8), 2732 or 2732A(4K x 8), and 2764 (8K x 8). Includedwith the card is a disk full of soft-ware, which using menus allows theuser to program or verify EPROMs,check if they are blank, set pointersanywhere in memory, and save orload memory ranges to/from the diskdrive, making this unit a very versatilepiece of hardware for the hardwaredeveloper or the hobbiest. 599

Apple II Printer CardsMICROTEK APPLE DUMPLINGCARD: $170This card gives the user full control of his printerdirectly from his APPLE 11/11+ /Ile keyboard, in-cluding graphics and text screen dumps. It comescomplete with a cable for a printer with a standardCentronics -style interface.

ORANGE MICRO GRAPPLER +: $235The Grappler + interface is uniquely capable ofperforming a wide range of both text and graphiccommands, such as: Dual Hi -Res graphics;keyboard programming; DIP switch printer selec-tion; Inverse, Rotated, or double sized graphics;skipover-pert; Left and right margin variation; andVariable line length.

PURE DATA PDA-232 SERIAL CARD: $95The PURE DATA PDA-232 is a complete serial cardfor the APPLE II/11+ /Ile computers. Its on -boardsoftware allows to make the APPLE into a dumbterminal, allows the APPLE to be accessedremotely or as a simple I/O device to allow connec-tion to a printer, modem etc. It also allows for soft-ware and/or hardware baud rates and charactertypes.

Check with our ads in Electronics Today and Computing Now!or call us for information on availability.


Apple® Ile$1795

FEATURES:*Upgraded version of the APPLE II + .

*64K of RAM now standard.*Full upper and lower case keyboard.*High -resolution graphics.*Wide software and hardware sup-port.*All standard APPLE features.*Built-in self -tests.

The APPLE II + was one of theworld's most popular homemicrocomputers. The brand new AP-PLE Ile is a redesigned and upgrad-ed version of this computer. Some ofthe features common to both com-puters are: a 40x24 text display,290x192 high resolution graphics in 6colours, 40x48 low resolutiongraphics in 16 colours, a 6502microprocessor, built-in keyboard,composite video output, built-incassette interface, a joystick/paddleinterface, and a full set of I/O bus con-nectors. It is all of these featuresthat made the APPLE II + so popular,and it is this that make the APPLE Ilecompatible in all ways to the oldmachine.

The new features of the APPLEIle are 64K of RAM on -board (insteadof 48K), a full 64 -key upper/lower caseASCII keyboard with auto -repeat thatputs out all 128 ASCII codes and has6 new keys (DELETE, "open -apple","closed -apple", TAB, "up-arrow", and"down-arrow"), all logic circuitry built

Apple Disk IIThe APPLE DISK II is a mass -

storage floppy disk drive for any ofthe APPLE II series of computers.Each unit stores up to 124K bytes ofuser information per diskette (underDOS 3.3) using a single sided, singledensity diskette. It will run any pro-gram written for the APPLE II/11+ /Ilecomputers. The DISK II can be sup-plied in one of two forms: as a firstdrive (c/w DOS 3.3 controller card,DOS 3.3 diskettes, and DOS 3.3manual), or as a second drive (just thedrive itself). Each APPLE Disk Inter-face Card can control two of theseDISK II (or equivalent units).

Drive with $795controllerDrive only $750

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into 3 custom IC's allowing for easierservice and lower power consump-tion, 16K of firmware including a setof self -test routines and new videohandling routines, an AUX connectorwith virtually every useful computersignal available for use by peripheraldevices, an internal "power -on" lightto remind you not to connect ordisconnect anything inside the corn-

puter while the power switch is on,and a redesigned back panel thatgives the user better control of thecables coming out of his computer.

Even with all of these remarkablefeatures, the APPLE Ile still remainsfully compatible with the old APPLEII + , and any software that was writ-ten for the APPLE II + will run on thenew machine.

Hardware for Apple®APPLE ][ + c/w 48K $1195.00 Videx videoterm 80 -columnAPPLE ][e $1795.00 Card 495.00MULTIFLEX Disk Drive c/w Videx Enhancer II 199.95controller $349.00 Videx Function Strip 109.95MULTIFLEX Disk Drive $269.00 Hayes Micromodem II 495.00MULTIFLEX 16K RAM Card . .$55.00 Novation Apple -Cat II 539.00MULTIFLEX Z80 Card $55.00 T.G. Joystick 65.00(No software included) T.G. Paddles 60.00MULTIFLEX EPROM Programmer Mountain Computer CPSCard $69.00 Multifunction Card 330.00Pure Data PDA-232 Serial Orange Micro Grappler +Card $109.00 Card 220.00Microtek Apple Dumpling PrinterCard 170.00

Apple Is a trade mark of Apple Computer Inc.


CxceltronixApple SoftwareGAMES

AVALON HILLEmpire of the Overmind 44.95The Sorceress

AVANT-GARDEDeath Race '82 27.95Federation 41.95Hi-res Computer Golf 39.95Zero Gravity Pinball 33.95

BRODERBUNDA.E 44.95Choplifter 44.95David's Midnight Magic 44.95Labyrinth 39.95Sea Fox 39.95Serpentine 44.95Snoggle 28.95Star Blazer 39.95The Arcade Machine 64.95Track Attack 39.95

BUDGE CO.Raster Blaster 39.95

CALIFORNIA PACIFICUltima I 48.95

DATAMOSTCrazy Mazy 39.95Missing Ring 37.95Pig Pen 37.95Snack Attack 39.95

44.95Vortex 37.95

DATASOFTCanyon Climber 39.95Fathom's 40 45.95Micro Painter 45.95Tumble Bug 39.95Zaxxon 51.95

ELECTRONIC ARTSAxis Assasin 51.95Hard Hat Mack 51.95Pinball Construction Set 51.95

EPYX (AUTOMATED SIMULATION)Crush, Crumble & Chomp 37.95Curse of Ra 24.95Jumpman 52.50Temple of Apshai 52.50Upper Reaches of Apshai 24.95

GEBELLIPhasar Fire 34.95Horizon 44.95

SIERRA ON-LINECannonball Blitz 47.95Crossfire 39.95Frogger 39.95Hi-res Cribbage 34.95Hi-res Football 46.95Hi-res Soccer 38.95Jawbreaker 37.95Laffpack 44.95Lunar Leeper 37.95Maurader 44.95Mouskattack 44.95Mystery House 32.95Pest Patrol 28.95Sabotage 31.95Soft -porn Adventure 39.95Threshold 49.95Ultima II 68.95Wizard and the Princess 44.95

28.95

SIRIUSApple Cider 44.95Autobahn 36.95Bandits 44.95Beer RUn 43.95Blade of Blackmore 48.95Critical Mass 42.95Epoch 42.95Escape of Rungistan 36.00Flip Out 35.95Free Fall 41.95Gamma Goblins 38.95Gorgon 49.95Hadron 42.95Kabul Spy 39.00Minotaur 43.95Orbitron 39.95Sneakers 37.95Space Eggs 37.95Wavy Navy 44.95

SIR TECHStar Maze 45.95Wizardry 62.95Wizardry II 44.95

SOFT IMAGESBlack Jack Strategy 81.95Pandemonium 48.95

STRATEGIC SIMULATIONSBattle for Normandy 52.95Battle of Thiol 52.95Bomb Alley 81.95Cartells & Cutthroats 52.95Computer Air Combat 52.95Computer Ambush 69.95Computer Baseball 52.95Computer Conflict 52.95Computer Quarterback 52.95Epidemic 48.95Fighter Command 62.95Galactic Adventure 81.95Galactic Gladiators 52.95Germany, 1985 52.95Guadacanal Campaign 81.95Napolean's Campaigns(1813-1815) 81.95North Atlantic 1986 81.95Operation Appocalypse . 81.95President Elect 52.95Pursuit of the Graf Spee 81.95RDF 1985 81.95Road to Gettysburg 81.95S.E.U.I.S. 52.95Southern Command 81.95The Cosmic Balance 52.95The Shattered Alliance 81.95The Warp Factor 52.95Tigers in the Snow 52.95Torpedo Fire 81.95

SUBLOGICA2-FS1 (Flight Simulator)A2-PB1 (Night Mission Pinball)Airsim-1

44.9542.9542.95

SYNERGISTICAdventure to Atlantis 47.95Complete Adventure 42.95Crisis Mountain 41.95Microbe 65.95Nightmare Gallery 44.95Procyron Warrior 39.95

BUSINESSARTSCIMagic Window II 119.95Magic Window II 189.95Magic MailerMagic Words

ASHTON-TATED -Base II 810.00

APPLEApplewriter II + 119.95Applewriter Ile 209.95ACCOUNTING PLUSAccounting Package. 1365.00

General LedgerAIR, A/PInventory

BPIGeneral Ledger 499.95Accounts Receivable 499.95Accounts Payable 499.95Inventory 499.95Canadian Payroll 479.95

BRODERBUNDBank Street Writer 89.95

HAYDEN6502 Disassembler 62.95Orca/M 189.00Elefacts 49.95Microtyping II 35.95How to Program inApplesoft Basic 72.50

INFORMATION UNITED SOFTWAREEasy Writer 149.00

MICROPROCalcstar 180.00Datastar 365.00Infostar 610.00Mailmerge 310.00Spellstar 310.00Supersort 310.00Wordstar 610.00Wordstar & Mailmerge 795.00Wordstar & Spellstar 850.00Wordstar & Mailmerge

& Spellstar 1050.00

MICROSOFTMulti -plan Electronic

Worksheet 318.00Multi -tool Expert SystemsMulti -tool Financial StatementMulti -tool BudgetBasic Compiler 468.95Cobol Compiler 879.95Fortran 80 CompilerApplesoft CompilerSort FacilitymuLisp/muStar 232.95MUSEAddress book 57.95Data Plot 69.95Form Letter Module 119.95Super Text 40/80 199.95

ON-LINELisa 2.5 104.50Lisa Educational Pak 157.00Screenwriter II 170.00

PEACHTREEPeach Text 350.00


Apple SoftwareList Manager 350.00Spelling Proof Reader 220.00Peachcalc 220.00Series 40 Sale Pak:

G/L, A/R, A/P 575.00

SILICON VALLEYWordhandler 259.95List Handler 116.95

SOUTHWESTERN DATA SYSTEMSASCII Express II 78.50Bezare 45.95The Correspondent 78.50Disk Library 65.50Merlin 84.50Printog rapher 65.50

STONEWARED.B. Master 289.00D.B. Master Stat Pak 125.00D.B. Master Utility Pak 125.00

VISICORPBusiness forecasting Model 150.00Desktop Plan II 370.00Visicalc 325.00Visidex 330.00Visifile 330.00Visilink 330.00Visiplot 260.00Visischedule 404.00Visiterm 128.00Visitrend/Visiplot 404.00

UTILITIES & EDUCATIONALAPPLEApple Fortran 249.00Apple Logo 345.00Apple Pascal 199.95Dos Tool Kit 98.00

DOLPHIN SOFTWAREMaster Math 39.95Multi Maze 39.95Multi Targets 39.95Catch a Falling Star 39.95

COMPUTER ADVANCED IDEASMaster Match 52.95Master Match:

Basic Skills 26.50Science & Math 26.50Math & Social Studies 26.50Foreign Languages 26.50

The Game Show 52.95The Game Show:

Win with Words I 26.50Win with Words II 26.50People, Places & THings 26.50Movie & Television 26.50

Tic Tac Show 52.95Tic Tac Show:

Fun with Facts I 26.50Fun with Facts II 26.50History 26.50Sports Facts 26.50

EDUWAREAlgebra 1 52.50Algebra 2 52.50Algebra 3 52.50Algebra 4 52.50Compu-math 65.00Compu-read 3.0 39.95

Compu-spell System Disk 39.95Compu-spell Data Level 4 26.50Counting Bee 39.95Edu-ware Decimals 62.95Edu-ware Fractions 62.95Spelling Bee Games 39.95Spelling Bee/Reader Primer 49.95

INSOFTGrafforth 86.00

KRELLLogo 128.95

LEARNING COMPANYBumble Plot 75.00Bumble Games 75.00Gertrude's Puzzles 95.00Gertrude's Secrets 95.00Juggle's Rainbow 56.95Rocky's Boots 56.95

MICROSOFTALDS 165.95TASC 199.95Typing Tutor 32.95

MILLIKENAl ienpower/Faceflash 45.95Battling Bugs/Concentration 45.95Frenzy/Flip Flop 45.95Golf Classic/Compubar 45.95Gulp/Arrow Graphics 45.95Jar Games/Chaos 45.95

MUSEThe Voice 49.95

HAYDENAlibi 35.95Championship Golf 35.95Crime Stopper 49.95Final Conflict 49.95Klondike 2000 35.95Sargon II 49.95Shuttle Intercept 49.95Tetrad 35.95Wargle 49.95

INFOCOMDeadline 63.95Starcross 51.95Suspended 61.95The Witness 47.95Zork I 53.95Zork II 48.95Zork III 48.95

INSOFTZargs 39.00

I.D.S.I.Juggler 45.95Pool 1.5 45.95Shuffleboard 39.95Trick Shots 49.95

LIGHTNING SOFTWAREMaster Type 58.95

MICROLABJigsaw 33.95Miner 2049er 44.95Mings Challenge 33.95Peeping Tom 41.95

MICROSOFTAdventure 38.95Olympic Decathalon 32.95

MUSEABM 32.95Castle Wolfenstein 37.95Caverns of Frietag 37.95Robotwar 48.95Three Mile Island 45.95

ODESTACheckers 64.95Chess 89.95

PENGUINPie Man 33.95Spy's Dance 33.95Thunder Bombs 24.95

PHOENIXAdventure in Time 37.95Queen of Phobos 39.00

PICADILLYFalcons 38.95Star Blaster 39.00Succession 33.95

SENSIBLEQuadrant 6112 34.00

SENTIENTCongo 75.00Gold Rush 44.95

OMEGA MICROWARELocksmith 122.95The Inspector 84.95Watson 74.95

PHOENIX SOFTWAREZoom Graphix 56.95

QUALITYBag of Tricks 46.00Beneath APPLE DOS 26.00

SENSIBLESuper Disk Copy III 38.95DOS Plus 28.95Image Printer 42.95

SOUTHWEST EDPSYCH SERVICESMath Wars 51.95Spelling Sorcery 39.95The Math Machine 101.95The Spelling Machine 62.95SPINMAKERDelta Drawing 92.95Facemaker 44.95Hey Diddle Diddle 39.95In Search of the Most

Amazing Things 50.95Kindercomp 39.95Rhymes & Riddles 39.95Snooper Troopers 1 54.95Snooper Troopers 2 54.95Story Machine 42.95

VIDEXApplewriter/Videoterm Pre -boot . 27.95Visicalc/Videoterm Pre -boot .... 64.95


C xceltronix

EDMULTIPLEX Z80

UCATIONAL SYSTEThe Multiflex Z80 Educational

computer is an ideal trainer systemfor the teaching of microcomputertechniques to students. When thissystem is expanded using the op-tional peripheral components it canalso be turned into a full-fledged, ex-tremely powerful CP/M based com-puter system, making it flexableenough to allow the teaching of com-puter concepts from basic digitalelectronics to microcomputer soft-ware on the operating systems level.

The basic unit (which is describ-ed on p. 20 of this catalogue) is idealfor a course in digital electronics or inelementary computer hardware. Themonitor software that is included inthe basic unit allows the input of sim-ple machine language programs tocontrol the hardware, or direct con-trol of the I/O ports so that interfacingtechniques can be learned quitesimply. There is a 40 -chip wirewrap/prototyping area on the motherboard with easy access to all the bussignals so that custom interfacingcan be learned. The cassette inter-face allows programs, once properlyworking to be saved for future use ormodifications. An EPROM program-mer is also built into the system sothat the most commonly usedsubroutines can be built into perma-nent memory and used over and overagain. Also available are 2 24 -bitparallel ports, 3 16 -bit counters andan optional RS232 serial port for in-terfacing external peripherals to thecomputer.

With the addition of the floppydisk interface and the video monitorinterface and a floppy disk drive, theMULTIFLEX Z80 Educational Systemturns into a full blown CP/M-basedoperating system. This gives you allthe advantages of the basic unit plusadditional software capabilities forexposing the student to the industrystandard operating system. With thissystem the student can learn aboutassembly language programming,and other aspects of the softwareends of computer such as word pro-cessing and higher level languageslike BASIC, Pascal and "C". It alsogives flexability for the teaching staffto set up demonstrations and ex-periments on disk prior to the lab34 - Exceltronix Catalogue 1983

period so that less time is wasted onsetting up the equipment and morepractical time is gained. A full in-teractive monitor can also be obtain-ed so that all functions of the basicmonitor are handled through thekeyboard and video interface. Withthis monitor and CP/M, both the soft-ware and hardware aspects of inter-facing equipment to a microcomputercan be demonstrated effectively andefficiently.

A sample course based on thisunit might include the followingtopics:* Introduction to Z80 machine lang-

uage programming

M

* Introduction to Z80 assembly lang-uage programming (if using theenhanced system)Serial I/O communication

* Parallel I/O communication* Hardware interfacing (eg. a hex

keypad)* Interrupts

Subroutines Tables and Lists Operating systems programming

(with the enhanced system)* Human Interface p-ogramming

(with the enhanced system)* Custom circuit design and inter-

facing

MULTIPLEX 6809EDUCATIONAL SYSTEM

The MULTIFLEX/U of T 6809Educational system is the idealsystem for the teaching of microcom-puter interfacing and software. Thepackage consists of the University ofToronto 6809 computer, theMULTIFLEX Intelligent Terminal, anda 12" monitor. Included with the 6809board is a full-screen/editorassembler package that wasespecially designed by the Universityof Toronto for use by students in lear-ning the basics of microcomputerhardware and software. Some of thefeatures of this software (which iscontained in 12K ROM on -board) arefull breakpoint/single-step capabilityfor program debugging, a telecom-

munications mode which allows com-munications and information transferbetween computer systems, registerexamine and set, and many more. Thesoftware also handles file transfer toand from the built-in cassette inter-face.

EducationalInstitutionsAccountsWelcome

Leader Test Gear2Miis SweepFunction Generator

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$949

FUNCTION GENERATORDC Wit? OUTPUT

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The LFG/1300S is a general-purposesignal source with a broad range ofresearch, design and serviceapplications. Outputs include sine,square, triangle, ramp and pulsesignals. Pulse symmetry is variableover a 9:1 range and, unlike manyother instruments, changing thesymmetry does not appreciably affectthe output frequency. Linear andlogarithmic sweep frequency outputsare available with sweep widths upto 1,000:1. Output level is controlledby a calibrated 70 -dB attenuator(10-dB/step) with continuousadjustment between steps. The outputmay be frequency or amplitudemodulated by an external signal. Alevel control also provides suppressedcarrier outputs. The LFG-1300S ishoused in a sturdy metal housing witha "human -engineered" front panel forconvenient, simple operation.

General Purpose 'ScopesThe LBO -310A is a compact, generalpurpose instrument designed to providelong, reliable service in production test,repair, and educational applications. Itssimple front panel with a minimum ofcontrols makes it ideal for use byproduction personnel, students, andnon -technical operators. Its low costopens up many applications wherewaveform monitoring might otherwisebe economically prohibitive. Sensitivityis 20 mV/division. Sweep frequenciesrange from 10 Hz to 100 kHz.

$349

LBO -51 OA

The LBO -510A is a best buy generalpurpose oscilloscope. Ideal forservice, education andcommunications. Solid State designdelivers H MHz vertical bandwidthplus 20 mVp-p/Div verticalsensitivity. Bright, easy to readdisplay - use multiple units formonitoring several phenomenasimultaneously.

$529

SPECIFICATIONSDC Voltage

100p y - 1000 V 5 rangesAcCUraCy

]%r09 +1 Ogt(100AV - 200 V) 6% rOg 1 Oct (200 V - 1000 V)

AC Voltage nl1011,V - 1000 V 5 ranges 0 5% reig 2 Mgt

(101:50/ - 200 V)061,00 1091 (200 - 1000 VI

DC Coirent1m A - 2A 4 rangesAccuracy 0 iletrcig +2001+ 1 5% rdg 2 091

AC Current1m A - 2A rangesaccuracy18% rag 3 Ogl

Resistance0 1 ohm - 20 Kt ohm 5 rangesacC,AaCytOrerdg +2021

101- 2 AI ohm)6%rclig 2 091

(2 ohm - 20 M ohm)

Compact, rugged and accurate; theLDM-853 is uniquely suited for bothlaboratory and field work with eitherAC or battery power. Operation iseasy and straightforward. The LDM-853 features high accuracy of 0.3%(D.C.V.) and employs 0.2V rangeswhich are capable of 10Oµ Vresolution. Current measurement to2 amp on both AC and DC ranges.Automatic polarity and automaticzero are also provided for yourconvenience $359


xceltronix

Leader OscilloscopesLBO -518 LBO- 514A

w * A 3

This is a 100MHz, 5mV/div oscilloscope (500uV/div at x10 MAG) and maximum horizontalsweep speed is 2 n -sec at x10 MAG. Its applica-tions cover not only production and servicemaintenance but also research/development.

$3589LBO- 524/524L

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CRT: 150mm, Rectangular, Internal-graticule (8 x10div: 1div = 1cm), Post -acceleration (7kV), Flat -face,Metal -back, Dome -mesh, % Scale, Scale Illumina-tion, Beam Rotation. Delayed Sweep (Continuous/Triggered) WideBandwidth: 35MHz (5mV, 8div Ref.) Max. Sensitivi-ty: 500uV (MAG x 10, 5MHz) Max, Sweep Speed:2Ons/div (MAG x 10) TV -V, TV -H Sync. Separation ALT Trigger Hold -off Variable X -Y Operation PRESET Synchronization Linkage of FrequencyCounter Using CH -1 OUT, TTL Level Z MOD. Themodel LBO -524L offers a signal delay line which per-mits viewing the leading edges of pulses.

LBO -524 $1695L130 -524L 51939

CRT: 130mm Round, Stabilized Acceleration1.8kV, High Brightness & Clear Sharp Trace, Flat -face, Beam -Rotation Wide Bandwidth: 15MHz (5mV, 6div Ref.) Max. Sensitivity: 1mV (MAG x 5, 6MHz) Max. Sweep Speed: 10Ons/div (MAG x 5) HF-REJ trigger for stable display which includesHF-noise & TV -Vert. X -Y Operation TTL Level Z MOD. $919

LBO -522

CRT: 150mm, Rectangular, Internal-graticule (8 x10div: = 1cm), Post -acceleration (7kV), Flat -face,metal -back, Dome -mesh, % Scale, Scale Illumina-tion, Beam Rotation Wide Bandwidth: 35 MHz (5mV, 8div Ref.) Max.Sensitivity: 500uV (MAG x 10, 5MHz) Max. SweepSpeed: 2Ons/div (MAG x 10) TV -V, TV -H Sync. Separation ALT Trigger Hold -off Variable X -Y Operation can be controlled Manually & byREMOTE PRESET Synchronization Linkage of FrequencyCounter Using CH -1 OUT. TTL Level Z MOD. $1049


Hameg Oscilloscopes

SpecificationVertical Deflection IV)Baedwidth of Coin charm.,DC 20 MHz (r3d0). DC 28 MHz I -Pee)Also tome 17 5 its land°. )

Overshoot 1% (maximumlWAND. eaellluenly 12 calibr steps

5.1//cm 20V/cm (1. 25 sequenCelatculacy better Than = 3%.lapel leopedaeco 1 Megohm II 25 pfInput couplong °CAC GNDInput voltage max 5000 IDG + peak ACI

Ogieretleg nooksChannel I Channel II. Channel land IIalternate or chopped (approx 120kH1IX y Operation sensitivoty ratio 1 1

TimelineTime caitacienlar 18 calotoraterl steps.0 5 us/cm-0 2 s/crn 11-2-5 sequenCe)wan variable control uncalthr to 200 ns/cM.wan magnifier e5 uncalibr to IOns/crnaccuracy better an ± 3% (in cal pOSOon)Ramp Putout 5V (PRY°. I

Trigger SystemModes automata or variable trigger levelSources Channel 1 Ch II. lone external

Slope ploSolive a negativeCoupling AC or TV lowpas.folierSensitivity ont 3mm. ext 0 7St tapprrox

Bandwidth 30 Hi (auto). 5 Hi (IMOup to at least 30 MHz

Horizontal Deflection IX)B andwidth. DC -2 MHz 1-3081Input v. Channel),for other data see Y detlectOn specT phase thherence 3' up to 100 010

MiscellaneousCeltiediHreo Mee'. 130 5%831 13 cmAcceleo ding potenhal 20008Caiitorald Squarerwave periodic)! 1 601

0 20 rir 1%. ha probe COmPerHati.Trace rotation apustable at Boni panelReoulated DC prim supplies: all operatingvoltages including the ENTLine voltages 110. 125. 220. 240V ACLine liucluabon jr 10% (mammon)Line Irequency range' 50r60 HzIoM cesseieeliee: 36 Watts 1300100 I

Weight 6 kg (approximately)D imensions (mm) H 145. W 285. 0 380Finish dark greyWith handle and till stand

Supert to change

5750

HM204

fllllal 2. 201.1Hr max 2mVrom

Component Teem,

104, Rectangular CRT

SpecificationVertical Deflection (Y)Bandwidth: DC to 10MHz (-3dB).

DC to 15MHz (-6dB).Risetime: approx. 35ns.Overshoot. max. 1%.Deflection coefficients: 12 calibr. steps,5mV/cm to 20V/cm in 1-2-5 sequence.accuracy better than ±5%.Input impedance: 1MS2//25pF.Input coupling. DC -AC -SD.Input voltage max. 500V (DC + peak AC).

TimebaseTime coefficients: 18 calibrated steps,0.51as/cm to 0.2s/cm in 1-2-5 sequence.with variable control uncalibr. to 0.21as/cm,accuracy better than ±5% (in cal. position)Normal length of baseline approx. 6 cm.Trigger SystemSource internal or external.Slope positive or negative.Modes. Manual Trigger level control,

Automatic Triggering (AT).Sensitivity: 3mm (2Hz to 30MHz).

external. 0.5-5V, AC only.

Horizontal Deflection (X)Bandwidth: 1 Hz to 1 MHz (-3dB).Deflection coefficient: approx. 0.75V/cm.Input impedance approx. 1M4//25pF.

Timebeew 20namm r 2 slcm

In Trigger Bandwidth 50 MR:

lath Delayed Sweep 10Ons -

.204 ..f1,4. 1.e W..... ."

'cows RR CRT Ns ale. asicmoovanwaceumm retoRtene+canom, cativo. Ron e 0.144, IPS Rope. recn7.rve

RIR*, einem et sh. w00%. .1

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....is wRR CRT *awnIce R0200 ms. dm& sm. Ts* nom )*Ron.

$1145

Component TesterTest voltage: max 8.6 V rms (open circuit).Test current: max. 28 m A rms (shorted).Test frequency: 50 resp. 60Hz.Test circuit grounded to chassis.

General InformationCathode-ray tube: 3RP1A, 7cm dia.Accelerating potential. approx. 1kV.Built-in square -wave generator 1kHzfor probe alignment (0.2V ± 1%).Electric regulation for all importantsupply voltages incl, high voltage.A.G. Supply voltages: 110.127,220. 237V AC.Maximum A.C. Supply: fluctuation: ± 10%A.C. Supply frequency: 50 to 60 Hz.Power consumption: approx. 24W.Weight. approx 8V. lbs.Dimensions: 4.5" x 8.3" x 12".Finish: dark grey.With handle and tilt stand.

Subject to change

$489

SpecificationVertical Deflection (Y)sandwich of both cnanne,s0C-701.111 (r3d13). DC.90/4. (1418)Pocono ppm 5nsOvershoot maximum 1%WOKS. Coellicleirts: 12 caltd steps5mV/cm-20VDm (1.2-5 sequence)wan variable control II 2 5) to 2m8/cm.Accuracy wilhon 3% in cal posmon1noul lispelience: 1 MegoOm II 25 00Input Coupling DC -AC -ONOInput collage ma= 5008 IDC peak ACIOverscannong Indication by 2 LEDsMay Line: to Herr leading trigger edge

Operating ModesChannel I. Ch II. Ch I and Ch II.

alternate or cnoppediapprox I MHz'Aigebroc Addition Ch 1 + IL CH -1 IIDIterence with Channel I invertedOrY display' X Ha CP Ile yea Ch t

TininessTime Criefficients: 23 caul steps50 nsr cm 1 s/cm 11.2-5 sequence).MIR Variable contrd (2 5 11 to 2 5s/cmWoln monsoon .10 lo 500cre.Accuracy within 3% in cal positionRamp Output approx 58 Doglivergang)

Trigger SystemModes Automata or Normal TriggeringSources Ch 1 or H. alt 1/11 line eel

Slope Positive. Or negativergoing edgeCoupling AC. DC. HF. LFSensitirtty: .n1 5mm ext approx 0 5VBandwidth DC to al teas! 70 MHz

Bandwidth DC to al least 70 MHzTrigger Action !Waded by LEOSingle sweep. Songle.aeSet buttons with LEDHeide, Heroic 10 1 varoade control

Sweep DelayHenget. 7 decade steps 100 its 0 Isman venal* control 10 1 to 15I Delay time measured< with IDebaSeModes normal search delayed 1LED nolo I

Zee Triggering "DM OW.'with tarots). lave, pos or neg slopeml or exi dosconnectoble to 'tree run

Horizontal Deflection (Stflandieldte. DC-5MHz 13681Input via chance IIX I Phase Stull <31 up to max 1006110(01ner values see Vertical Detiedoon

MiscellaneousCethedo-Pay redo 014.654 (P31 or 871.rectangular screen wolf Internal gratoculeTotal Accelerate. Voltage: 1468race Holman adi on front panel

1-Medeloticsi Input pos TTL.DvelScale Illumonabon 11,1110.(10511.0115W1101

Caliblate, square -wave generator0 2V 4- 1%. approx 1 kHz lot

Probe compensatoonModeled Pew Sappy nogn voltage

AC Power Source 110. 125. 220. 2408Line Fluctuaton maximum ± 10%Line Frequency 501060 HzPoser Consuatelion: approx 42WWeight appro. 1069.°monsoons Imml W 212. II 237. D 380Finish dark grey Wits handle and liltstandAccessories Ind.. Manual. 2 probes X10/%1

Supect to change

$1595Exceltronix Catalogue 1983 - 37

0 xcel tron ixComponents & Computing Inc.

Order Form

319 College Street, Toronto, Ontario, Canada M5T 1S2 (416) 921-8941.Telex: 06524218 (EXCELINC)

Address . _ ...

Date Name.. .. ..

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For office use Catalog Number Quantity Description Price Each TotI Price

The minimum prepaid order is $10.00. Please include sufficient for postage and ship-We insured Please

Total for goodsping.* normally ship via parcel post. note any other routing required:All orders are subject to the Conditions of Sale in our current Catalogue.

Shipping

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We accept Visa, Mastercard and American Express credit cards in respect o any order of$10.00 or over. In order to use your card you simply complete the details requested below. It is

master cttaris important that all questions are answered, if this is not done, or your signature is not added,...... i---... we are not permitted to accept the order.Mastercard CI Visa G Name of the bank on the cardAmerican Express 0

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number .

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ALL PRICES ARE IN CANADIAN FUNDS F.S.T. INCLUDED.

Please feel free to photocopy this order form.

ORDERING POLICYPAYMENT:

CHEQUES:

TAXES:

PRICES:RETURNS:

WARRANTY'

REFUNDS:

MINIMUM:SHIPPING:

- Cheque or Money Order- VISA- Master Card- American Express- Diners Club

All non -certified cheques will be held for ten (10) business days for clearancebefore any items can be shipped.

All of the prices include F.S.T. Ontario residents must include 7% P.S.T. withtheir order, unless proper exemption forms are supplied with the order.

All prices and specifications are subject to change without notice.

Any merchandise to be returned to EXCELTRONIX must have prior writtenapproval, and be accompanied by the assigned RMA number. Please contactour mail-order department for more information.

Warrantied items will be repaired within a reasonable period of time. Refundswill not be issued in lieu of repairs.

A 15% restocking charge will be applied to all items returned for refundunless prior written approval is obtained.

$10.00 for all orders.

All items will be shipped via UPS or other suitable courier (if possible). Pleaseconsult the rate chart below and enclose the appropriate amount whenremitting your order. If in doubt, please call our mail order department.

By Mail:Exceltronix Inc.,319 College St.,Toronto, Ont.,M5T 152Attn: Mail Order

Weight0 to 5 pounds5 to 10 pounds

10 to 20 pounds20 to 30 poundsOver 30 pounds

HOW TO ORDER:By Phone:Call (416) 921-8941or 1-800-268-3798

For repairs:(416) 921-1067

SHIPPING RATES:Charge$12.00$16.00$20.00$24.00please call

By Telex:06524218(EXCELINC)

By MODEM:(416) 921-4013

ExampleComponentsDisk DrivesPrinters, MonitorsSystems?????

The above rates reflect ground shipping via courier. Please contact us for air rates. If you wish, yourorder can be sent by Canada Post. There is a minimum charge of $5.00 for this method. Pleasecontact us for further rate information.


Versadigital SignsEvery business needs attention. In today's com-petitive marketplace you need to get thecustomers' attention and you need to get yourmessage across - as boldly and as dynamicallyas possible.

Two versions are available, single and dou-ble row. Each row holds up to 21 standardcharacters and can be expanded to up to 42characters. The LED (Light Emitting Diode)display is available in red (standard or extrabright), green and yellow. Standard, wide (2",upper and lower case) and bold tall (4", uppercase) come with the display. All can bedisplayed normally or in inverse (blackcharacters on a lit background) image format.You can even program your own characters andgraphic symbols. As well as the standard LEDdisplay, larger, brighter incandescent light bulbdisplays can be built to your specifications. Allprogramming features are retained, and thestandard LED display is included for ease ofprogramming.

A wide variety of features allow you tocatch the public's attention - choose fromWipe -On and Wipe -Off, Spell -On, Flash andBlink, Shift left and right, Scroll up and Down- in any order and at individually selectablespeeds.

Up to six different events can be displayedsimultaneously within dynamically selectableboundaries. Up to 128 labelled messages can bestored within the units memory for display atany preselected time and date and in any order.12,288 character memory is standard on theVersadigital Display. This can be expanded to36,864 with optional external read only memorymodules.

Text can be entered through the Display'sown keyboard, from an ordinary cassetterecorder, from optional external memorymodules, or optionally over telephone lines,radio or infra -red link or over AC wiring. A com-prehensive set of commands allow completecontrol over the display's facilities. A powerfulword processor type editor lets you easily write,edit, run, save (on cassette) and transmitmessages.

Use It Alone ...Using the Display's own keyboard, you canenter messages, or modify old ones, any timeyou wish. You can create messages weeks in ad-vance and store them on cassette for subse-quent use.

You can program, say, a set of storespecials to appear at selected times throughoutthe day and then just leave it alone. TheDisplay's internal clock does the rest. You caneven program it to turn itself off at night andback on in the morning. The VersadigitalDisplay's optional voice capability ensures thatyour messages will be noticed as they come up.

... Or Use a Lot SimultaneouslyAn optional link enables additional displays toecho a single central display, at distances of upto 4,000 feet. You can disperse displays arounda bus terminal, shopping plaza or throughout atrain and update them all by simply updatingone.

Unprecedented Programming Flex-ibilityVersadigital offers a variety of methods for pro-gramming your Display. Aside from standardkeyboard and cassette interface, the Displaycan be programmed (by means of an RS -232port) via telephone lines, infra -red or radio linkor over AC wiring. Ideal for multibranch use asit allows updating across the city, or across thecountry.

The sign that also talks

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VERSADIGITAL DISPLAY

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CASSETTERECORDER

The Versadigital Modular Display System

°monadPROGRAMMER

11,1:00 characterMEMORY MODULE

OPRoaalRD F32

INTERFACE

OptionalTEMPERATURE

SENSOR

Optional Programinable External MemoryModules expand the Display's internal memoryand allow preprogramming weeks in advance.Unlike audio cassettes, these require no specialreader, but can be plugged directly into theDisplay. One module can be added withoutmodification, two more plus an options boardexpand the Versadigital's memory to a whopp-ing 36,864 characters. Modules can be readdirectly by the Display, or programmed via anoptional programmer module. Modules can beprogrammed weeks in advance and then mailedout to branches for displaying.

The modules are completely re -usable andare erased by a half hour's exposure toultraviolet light.

The Sign That's PortableThe Versadigital Display can be optionally runfrom any 12 volt automobile supply. Take it onthe road! To outdoor rallies, fairs and otherevents. Anywhere you can go, you can take theVersadigital Display with you.

The Sign That Can Sell Your Pro-ductResearch has shown that digital displays can in-crease sales by up to 30%. The VersadigitalDisplay virtually assures that figure by increas-ilg the readers' involvement. An optional inter -

A revolution in sign technologyface allows up to 128 switches to be connectedto the Display, enabling customers to selectspecific messages without having to wait forthe sign to cycle through its repertoire.

The optional External Accessory Interfaceallows you to write messages that actuallypoint to the product being discussed. Atselected points within your message you canprogram the Display to turn on an external lightor a bell. Thus your message might be saying"You won't find these shoes anywhere else. . " and the Display will then activate a lamphigh -lighting the product. Up to 128 externaldevices can be controlled in this fashion. Thisfeature alone makes the Versadigital Displaythe most effective sales tool you can have.

The Sign That Protects YourMessageIn the event of a power failure, the VersadigitalDisplay's memory back-up keeps the Display'smemory intact for six hours. The Display willalso keep proper time. With this feature, youcan unplug your sign to move it without losingany messages.

We believe that the Versadigital Display isthe most advanced digital sign available today.It has all the features and capabilities you'llever need in an electronic sign, and if it doesn't,tell us, and we can build to your specifications.

Versadigital Technology also manufac-tures Time and Temperature displaysand can build dynamic plaza maps toyour specifications. Our extensiveengineering experience enables us todesign to a wide variety of situations.Whether It is modifying a current pro-duct, or designing new equipment, tellus what you need, we can deliver!

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comitant discovery was that flowing thelaser gas through the optical cavity at highspeed could solve the waste heat problemand greatly increase the power output ofthe laser. The next step was to invent away to generate the energy required tooperate the laser in an efficient and up-wardly scalable manner. The required in-vention was made in 1967, and consistedof the carbon dioxide gas dynamic laser,or CO:GDL.

The energy required for operation ofthe CO2GDL is generated by combustionof carbon monoxide with an oxidizingagent such as nitrous oxide. This combus-tion produces energetic molecules of CO:capable of releasing photons. This ener-getic state is maintained by dynamic ex-pansion of the hot gases through a bankof supersonic nozzles; this also providesthe conditions of flow necessary for ex-traction of the photons with good beamquality. The optical energy is extractedfrom the energetic CO: molecules withmirrors looking across the flow field justafter the flow leaves the nozzles. Thephotons extracted move across the flowfield, picking up other photons as they go.The photons leave the laser cavity as anintense beam of energy at a wavelengthdictated by the type of molecule giving upthe energy; 10.6 micrometers since themolecule is CO:. Subsequently, upwardlyscalable lasers include the electricdischarge laser, the chemical laser, the ex-cimer laser and the free electron laser.

A laser system is expected to handle alarge number of targets even if the targetsare coming from all directions. For each"shot" the laser takes, relatively smallamounts of fuels are used to generate thebeam. Thus, there is the potential for stor-ing a large number of shots per installa-tion (or a large magazine per weapon).Finally, since the beam is steerable bymoving mirrors, the laser weapon has thepotential to move rapidly from target totarget over a wide field of view.DisadvantagesBut simply spitting a laser ray in the direc-tion of a target is not enough. A suc-cessful laser engagement occurs when thebeam burns through the target surfaceand destroys a vital component such as itsguidance system, or ignites a fuel orwarhead. Thus, since the energy isdelivered instantaneously, the laser mustdwell on the target to destroy the target.Furthermore, jitter of the focussed spotover the target smears the energy in thebeam over a larger effective spot size, in-creasing the time required to damage thetarget. Thus the beam's control subsystemmust hold the beam steady on the targetaimpoint. To do this, the target trackingand beam point functions must be espec-ially accurate.

A second difficulty with such aweapons system is the effect the at -

LASERFUELS

FLOW CONDITIONING OREXPANSION NOZZLES

LASER BE A

PLENUM ORCOMBUSTOR

CAVITYMIRROR

CAVITYMIRROR

DIFFUSER

EXHAUSTIOR

ECIRCUL A T EDIGAS

Basic diagram of a high-powered laser

mosphere has on the laser beam. As afunction of the wavelength of the laserenergy, the atmosphere absorbs some ofthe energy being propagated, causing thebeam to "bloom" or defocus, and addsthe above -mentioned jitter to the beam.Interactions between the high power beamand the atmosphere effectively increasethe spot size on target, lowering the peakintensity and thereby increasing the dwelltime. The next effect is that for a givenrange there is a critical power level beyondwhich intensity on target decreases as the

"The separation of fantasy fromfact has become increasingly

difficult as experts vent opinionswithout explaining how much

is reality."

power radiated by the weapon increases.This effect is most pronounced when theline of sight to the target is fixed (as is thecase where the attacker is headed directlyat the laser and the wind velocity is low).In bad weather or in the presence ofclouds or aerosols such as smoke, more ofthe energy in the laser beam is absorbed,effectively limiting the rage of the laserweapons.

In the vacuum of space, the laserbeam does not have to contend with thedegradations caused by the atmosphere,and space has often been referred to as the"natural" environment for laser wea-pons. In this vacuum, potential applica-tions include anti -satellite, counter -air,and ballistic missile defense. Some haveargued that the potential exists to create adamage limiting ballistic missile defensesystem with space -based laser weapons; inthe vacuum of space, one could achieve

the very long weapon ranges of operationneeded to contend with the vast volume ofnear earth space. At long ranges, thestressing requirement to point accuratelyis ameliorated somewhat by the lowangular tracking rates required. However,at ranges typical of space engagements, itis necessary to lead the target.

In response to Congressional re-quests, a report on the subject of spacelaser weapons was made in May of 1981,and a space laser program approved bythe Secreatry of Defense was forwarded toCongress in June of 1982. This plan pro-vides for continuing development ofnecessary technology and concomitantsystem effectiveness and mission utilityanalysis over the next few years, leading toa decision in the later 1980s whether toproceed with an in -orbit demonstration ofan integrated battle station for some mis-sion application. Such technology devel-opment for the next few years is necessarybecause of significant uncertainties, notonly in the technology for the proposedspace battle station itself but also in targetdamage and vulnerability, potential targethardening, command and control,surveillance and warning, and launch andsupport.

Development of laser weaponsystems had previously hissed and sput-tered through the 1960s, dying out in1971. In 1973, it was determined that theSoviet Union was devoting significantresources to the development of laserbeam weapons. Their high energy pro-gram, even today, is three to five times theUS effort. It began in the mid -1960s,when they commenced pursuing chemicallaser development, and later, work on thegas dynamic laser and the electricdischarge laser. The Soviets also pursuedrelated technologies such as the develop-ment of efficient electrical power sourcesand the capability to produce high quality

Continued on page 72


Computer ReviewA sales success in theUK, the Dragon 32 at-tempts the same inCanada. Bill Markwicktries out this arrivalfrom Wales.

THE DRAGON IS the national symbol ofWales; the actual animal is a bit rare thesedays, except for the one that's recently ar-rived at a large number of departmentstores and computer retailers. The makershope it will be as popular as its namesakeis scarce.

On unloading the computer from itsstyrofoam box, you'll find it rather largeat about 38 x 33 cm. There's a proper full-size keyboard, and the usual string of con-nectors around the edges for connectingperipheral equipment. The power pack,which by the way is rivetted shut, is theusual separate lump in the middle of theline cord, and the on/off switch danglesfrom the cord as well. The reason for thisis that they stole the computer's powerswitch to use for the TV channel -select forthe North American version. You canswitch the RF output from channel 3 tochannel 4; a handy thing if you have an in-terfering local station on channel 3.

If you prefer a video monitor to a TVset, there's a five -pin DIN socket withvideo and audio available. You would ex-pect a much better image on a propermonitor, but this isn't the case. The col-our output makes for very low contrast ona monitor, and the display is much morereadable when a TV is used; the longerpersistence of the TV phosphor seems tomake everything much clearer. Incidental-ly, you won't find anything in the manual

about connector pinouts; they assumeyou'll just go and buy all the proper stuffand plug it in. We found the ground pinwas the middle one of the DIN, and thevideo was on the pin at the 9 -o'clock posi-tion (the one at the end, going clockwise).

On powering it up, you'll be inform-ed that it has a 16K BASIC interpreter byMicrosoft. This is good news, as it's oneof the most popular BASICs around, andyou'll be able to use a lot of the publishedprogram listings. When you look thekeyboard over, you'll find that the fourarrow keys are not cursor keys at all. Infact, it doesn't have any. This is bad news.If you should make a mistake, and catch itright away, there's a backspace key whichdeletes anything it backs over; that's all,folks, no other cursor control.

EditingNaturally, you'll want to know what to doin case of a major mistake, especially oneembedded in your BASIC program whichjust took you an hour to type in. Evenmore bad news. It has the MicrosoftEDIT function that you'll find on some

-other computers as well, surely one of themost awkward ever invented. If youshould boo-boo on a computer such as aCommodore, you cursor up to the mis-take, correct it, and press RETURN (orENTER). That's it; if you're nervous, youcan type LIST to be sure that the correc-tion has been entered.

On the Dragon, and others using thisMicrosoft editor, you type EDIT and theline number. The offending line isdisplayed with the line number repeatedbelow it. As you press the space barrepeatedly, the line appears againcharacter by character. When you come toa part that you don't like, you type a "D"to delete, or an "I" to insert. There areother commands, such as "X" to movethe cursor to the end of the line, and "S"to search for specific characters. Whenyou've corrected the mistake, ENTERsends the corrected version to the pro-gram.

Now, this function might be useful ifthey had added it to sensible cursoringand editing, but on its own, it gives you asense of despair. It's the same sort offrustrating feeling you get when youspend three hours re -assembling a com-plex appliance, only to find a part leftover after tightening the last of seventeenscrews.

It's particularly irritating to picturedesigners in Wales selecting this cumber-some editor because they couldn't bebothered changing it; the idea seems to bethat you'll only be running pre-packaged


software and won't need programmingfunctions, which makes the inclusion of a16K interpreter a puzzle.

Getting StartedThe manual starts you off with simplearithmetic and string manipulation tofamiliarize you with basic BASIC basics.The computer starts you off by not prin-ting characters if you type too fast. Thereason for this lies in the keyboard. Thecontact is made when the key is presseddown for only a tiny part of its travel; dur-ing fast typing it's inevitable that severalkeys will be down at once, and the firstkey down plugs up the works until it'sreleased. There should be a properrollover function; a buffer should storethe keystrokes and march them out to thecomputer in a nice orderly way.

Once your fingers get the hang of thekeyboard, though, there are a wealth ofnifty features provided by the BASIC. Ithas all the usual functions provided byMicrosoft: strings, arrays, easily -used ran-dom number generation, loops, andothers.

In the text mode, that is, the normalmode available on power -up, the screen isdivided into a 32 x 16 grid with each in-tersection having a number. This providesyou with the PRINT@ feature; you caneasily specify where you want text printedon the screen. It's like the "tab" feature

on a typewriter, but with control of thevertical as well. The character set, by theway, is upper-case only.

More BASICIn addition to the expected commands,such as FOR -NEXT and GOTO, you canalso use RENUM to renumber a programwith any number series you'd like. This ishandy should you fill up the available linespaces with additions; the RENUM willreset the lines to larger numbers.

When you run the program and bugsappear, you can track them down with theTrace function. This is the same as theApplesoft version, except that you enterTRON for "trace -on". The program willthen run, displaying the number of eachline it's doing at the moment. Nice forcatching those little lapses of logic.

More HardwareNow that we're right into the program-ming, let's look for those little touches weall like on computers, like auto -repeat.Press the key down . . . hmmm, no re-peat. There must be a separate key,Apple -style. No, there isn't. Maybe it's aControl key function. Let's see . . .

where's the control key? There isn't one!What? I'll go through the manual again;those things that look like cursor keysmay be control keys . . . Nope, two ofthem print brackets, one is an exponent

function, and the other is the backspace.At least there's a BREAK key to get youout of those endless loops. How aboutRESET? Ah, there it is, down at the side.I'll just get a loop going here . . . there weare, now press the button. What do youknow, it stopped printing and cleared thescreen. And it didn't even dump thememory; LIST brought it all home again.PerifsPeripherals shouldn't be a problem;there's the usual raft of connectors: anine -pin power plug, which speaks wellfor adding things which need voltagesother than 5 V; the above -mentionedmonitor DIN plug; TV RF; Reset; left andright joystick DINs, a cassette DIN; amysterious DIN labelled SI/O which isn'tmentioned in the manual, but seems to bea hastily -added serial port. There's also a20 -pin Centronics -type printer port and aROM pack connector, but no memory ex-pansion port as such.

The manual doesn't mention disks,and glosses over printers, but has infor-mation on joysticks and cassettes. There isa good section on writing programs to suitthese; cassette motors, for instance, canbe controlled by MOTOR ON or OFF,and there's a section on how the computerpicks up and responds to the joystick posi-tions. Incidentally, the cursor -keys -that -aren't can be made to come to life usingthe joystick routines.

VIEW FROM ALTA VISTA COMPUTERSSPECTRAVIDEO SV318

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32K RAM - Expandable to 256K CP/M Compatible Built-in 16 Colours - Joystick on board User Define Functions Micro Soft BASIC Built-inIN STOCK NOW! $399.00

Converts Standard ANSIkeyboard to an additional 91Function Keys.EASY TC $69.00IN

ULL SIZE SHUGART DRIVE1 YR. WARRANTY!

100% APPLE COMPATIBLEONLY $309.00

EPSON HX-20 Portable Computer

11 x 81/2"Digital Screen

Printer Cassette Drive 16K Expandable to

32K RAM Clock, Sound,

RS232, Serial 20 Programs & Word

Processor included

Externally Printers &Drives

ONLY $1089.00EXTERNALLY PRINTS & DRIVES

GRAND MASTER

Automatic Movement of Pieces by Computer Unlimited Skill Levels Auto Replay Function to Review Game Auto Mode Computer Plays Itself Hint Function. Computer shows right move.

THE ULTIMATE CHESS CHALLENGE $749.00

ZEUS 2001PROFESSIONAL COMPUTER

64K RAMCPU 6502, CP/MFAN BUILT INPOWER SUPPLY286 FUNCTIONKEYS!

ASK FOR SYSTEM PRICES $749.00

SUPER 400 64K RA Dual microprocessors on board Colour graphics, high resolution Fully Applesoft. Call for price!

Computer furniture YJE Monitors

Amber Wizard Cards Novation Modems

103 Smart Cat $389.00 Vectrex Arcade System $199.00 APPLE COMPATIBLE COMPUTERS

CALL FOR BEST PRICES!

$165.00$185.00

Alta Vista Computers586 tliamplp2,tic I)f. Dosk ns ie%%. (Iilari() \13J 2(.3

1-4 1 6-6 13-200 I

MAIL. ORDERS: Please send certified cheque or money order. Weaccept VISA and Mastercard. Send card number. expir) date, nameof bank and signature. Add 53.00 to cover shipping and handling.Ontario residents add 7.), P.S.T. DO NOT SEND CASH. Shippingis added to order - add Pio to cover estimated cost. ANY EXCESSVS II I RE CREDITED.

VISA

Circle No. 5 on Reader Service Card. ETI-NOVEMBER-1983-43

This last item points out a bit clearlythat the Dragon 32 is aimed at the tailor-made software market; the cursor keysappear only under software control.

More HardwareThe Dragon runs under the control of a6809 CPU addressing 32K of RAM. Likeall computer makers, they don't 'fess upthat not all of the RAM is available to theuser; some of it gets corralled to run theoperating system. Sneaky devil that I am,I used the MEM commend to return thefact that there are 24,871 bytes free onpower -up. This is a goodly bit of RAM,even for long programs.

As mentioned, you won't findpinouts or wiring diagrams in the manual.In fact, you won't find any technical helpwhatsoever. The appendices consist onlyof ASCII codes, graphics stuff, and amemory map. There's a one -page in-troduction to machine language whichrefers you to other books on the subject.

GrafsGraphics can be invoked in either low- orhigh -resolution modes. The low-res modeis the 32 x 16 text format, and uses blockcharacters for making simple outlinesmixed with text. In the hi-res mode, thestandard of living increases to 256 x 192pixels. There are several grades of resolu-tion in between; the finer resolutionmodes naturally use up more memory.Text is verboten in hi-res unless youdesign your own character set.

There are nine colours available; theAmerican Microsoft spells it COLOR andthe British manual spells it both ways, justlike ETI (we're working on a standard;hang in there). There is a LINE commandwhich links any two pixels, and PAINT,which fills any enclosed shape with aspecified colour. CIRCLE draws, guesswhat, circles or parts of circles. TheDRAW function is similar to LINE, butjoins the co-ordinates specified by a


string; it draws much more versatileshapes on the screen.

There isn't room to cover all thevaried graphics functions; in this respect,the Dragon is very impressive.

SoundsEverybody got sound, man; pick up thatcomputer and just, like, blow. Well, sortof. After typing in a quarter page of sym-bols, we got it to buzz out "Clementine"("found a pea -nut, found a peaaaa-nut

There are two ways of gettingtoots and beeps out of the Dragon. One isthe PLAY command. This one takes theoutput of the tone generator and nicelydivides it up for you into an approxima-tion of the tempered scale. You can enternote names rather than numbers, andspecify which of five octaves you want.There are also sub -commands for length,tempo and volume. There's only one tonegenerator, so no fair asking for chords.The quality of the note produced is full ofharmonics that don't sound properlyrelated, kind of an electronic flatulence.Most small computers sound like this.

The Dragon is being advertised by alocal dealer as having "speechcapability". It won't do any speech as itis; an external program would be re-quired.

SummaryOn the plus side, you get lots of memoryand a very comprehensive BASIC, goodgraphics capabilities and a soundgenerator. The computer is well -made,and there is much software availablethrough Dragon dealers on cassettes andROM packs.

On the negative side, the price tag of$399 puts it in the same league asmachines like the Commodore 64 (allow-ing for Commodore's package -deal pric-ing) or the Spectravideo SV318. Thesemachines give you a decent editor andproper cursor control, have more I/O

Quick ReferenceDragon 32Mfg: Dragon Data, Wales, UKPrice: $399CPU: 6809RAM: 32KUser RAM: 25KROM: 16K Microsoft BASICScreen: 32 x 16 text, various graphicsmodes up to 256 x 192Connectors: TV, audio/video DIN, 2joysticks, cassette, serial port, Centronicsparallel printer port.Other Features: Comprehensive BASICand graphics, sound generator.

ports, more sophisticated sound genera-tion, and control keys. You might arguethat the SV318 has rubber keys, but thefull keyboard on the Dragon is also a bitdifficult to get used to if you type rapidly.The manual included with the Dragon iscertainly a good one as far as MicrosoftBASIC goes, but lacks the technical sup-port you get with other documentation.You never know when you'll want to adda non -Dragon peripheral or cable, and it'snice to know those pinouts.

The Dragon 32 is said to be one of thebest-selling computers in the UK. Thismay speak more for aggressive marketingthan it does for the computer itself. Whilenot exactly a bow -wow, we had expectedto find more features on a computer inthis price range.

CO3

Parts PERIPHERAL CARDSIBM PCTMLOOK -A -LIKE CASE

Maice your Appletm or 6502 machine look like an IBMPC m. This attractive metal case with ABS front bezellooks just like you -know -who, but is punched internallyto take all the 6502 Mother boards, power supplies etcthat are now sold. Our black beauty power supply fits injust right with the power connector and switch ac-cessable at the right hand side. In addition the caseholds 2 standard disc drives (4 slim lines) with all holespre -punched. There is also a cut-out for a 4'/. inch muf-fin fan inside. Look at the photo, it really looks good

$159.95 Keyboard Case $ 29.95

ELECTRONICCOMPUTER

Galore316 College St., Toronto. M5T 1S3(416) 925.1105 (416) 925.8291

OUR 6502 BOARDNow only $24.95, still withall the versatility of theoriginal and a full 8 slots.

SOLID ABCASENUMERIC$49.95STANDARD$39.95

UNITRON 2200CASE

An attractive case and keyboard combination that givesthat modern look to your 6502 machine. The case fits theolder numeric keyboards and the PCB goes into thecase just fine. Comes in an attractive carrying carton.Case and KB case together $ 89.95Case only $ 69.95KB Case only $ 29.95Keyboard and KB case $119.95

UNITRON 2200PCB

A great new PCB, with Z-80, Disc controller, 64K and softswitch on board. Made to run with CPM systems underZ-80 control. Fits into the 2200 case above and use the2200 KB and case listed. Bare PCB $ 44.00

ASCII KEYBOARDSallitirmasammasaaste as

tjaramsaansampasraintitiruirmarini

Our ASCII keyboards are by ALPS, a famous Japaneseswitchmaker and feature high quality debounced swit-ches. Full upper and lower case capability. Direct plugin compatible with all 6502 boards and 'SURF' board.Available in numeric and std style.(a) Standard KB $89.00(b) Numeric KB $99.00

New low prices.

A) Z-80 Wired n tested ....$59.95..Bare PCB $12.95B) 80 Col. Wired n tested ..$74.95..Bare PCB $12.95C) 16K Wired n tested ....$59.95..Bare PCB $12.95D) Disc Wired n tested ...$69.95..Bare PCB $12.95E) Shamrock 13/16 sector disk Wired n tested $79.95F) Appletm Prototype card, all WW holes $12.95G) Appletm Prototype card, power bussed $14.95H) Wildcardtm, Wired n tested.$59.95.Bare PCB $12.95I) 128K Wired n tested, no IC's $69.95

With 64K .$149.94, 128K .$239.95, PCB $24.95J) IBM PCtm Prototype board, WW only, has a DB-25

footprint and a DB-9 footprint on end for I/O, all theremaining area is WW holes on .1" $34.95

K) IBM PCtm Memory prototype board, same as abovebut a 256K/1024K memory (for 4164 Or 41256 IC's)has been laid out at the inboard end with all the bitsbussed as 4 separate banks of 64K/256K with parityand babk select isolated, saves a lot of work in WINmemory design $44.95

L) IBM POI' Mother board, a powered 6 slot Motherboard that allows the use of our CP I/O 8088 plus ourmonochrome video/memory board to make a fullyIBM compatible system. Note this is a 62 pin bussedMother board similar to S-100 Mother boards in con-cept, it thus allows you to plugin any IBM peripheralboards to make your own PCtm clone along with ourCPU board $34.95

M) IBM PCtm Our newest and most exciting product forthe PCtm market. Our designer looked at the pastsuccess of the S-100 design and took apart an IBMPC and relaid it out as two standard IBM plug incards. One is the main CPU with Disk Controller I/O,8087, 8088, keyboard I/F onboard and the other is astd monochrome video board with 256K of memory.The ROM bios has been completely rewritten so asnot to infringe any IBM copyright and since theBasic and DOS are available on the legal market,you can make a fully compatible system that is alsofully legal software -wise.SEND FOR COMPLETE DETAILSPrice ...Main CPU board, wired n tested $695.00

Video board, 64K $475.00128K $545.00192K $625.00256K $695.00

Power supply, our new power supply is not readyyet, however the black beauty power supply will runa minimum system with 2 standard floppy drives.

N)

POWERSUPPLY

Our Famous "BLACK BEAUTY" power supply, nowreduced in price but not in quality. Our ratings are 5V -5A;12V -2.5A; -5A-1/2A; -12V-1/2A for real. Make sure that anyother power supply that lays claim to this rating actuallydoes so. Labels are cheap and we have seen many of theold silver power supplies unchanged except for thelabel. Easily beats all the rest $99.95

GREATDEAL

THE GREAT DEALCARRIES ON FOREVER AND GETS BETTERWe made an even better buy on over 1000 sets of powersupply, 6502 board, numeric keyboard and numeric ABScase (solid coloured ABS All the way through, not justpainted plastic) and can now offer the great deal withnumeric case and keyboard for the amazing price of

$275.00along with any 4 of the peripherals listed above as abare pcb with parts layout. The price is the same fornumeric or non -numeric styles of KB and case for thisgreat deal. Please specify numeric or non -numeric whenyou order, Except 128K, wildcard.

SYSTEMSAVIOUR

Hot and getting hotter??? Got an older power supply???Then you need a SYSTEM SAVIOUR. This is not areligious object, it is a nicely packaged 31/2" muffin fanin a molded plastic housing that fits against the slots onthe side of our 6502 computer case and draws out thehot air. Widely used by all major political parties,especially the NDP, now at a new low -low price. Com-plete with 2 grounded 3 wire switched sockets, pilotlight, surge protector and on -off switch to turn off yoursystem and two plugged in items $55.95

MAIL ORDERSWe accept; Personal Cheques, Postal Money Orders,Certified Cheques, Travelers Cheques, Visa, AmericanExpress, Mastercard, Bank Draft. We ship C.O.D. only byCANPAR and Truck. We do not use Canada Post C.O.D.We will send your goods via CANPAR or Canada Postunless you say otherwise. You will be charged a min$3.00 for delivery and handling or more if your goods areheavier than the $3.00 weight or if you specify anotherdelivery service that charges more. All Ont res + 7%sales tax. We sell wholesale to any retail store or otherreseller with a sales tax exemption M. as long as arealistic quantity is bought. We ship within a week if instock and we will cancel any backorders over 4 weeksunless otherwise instructed. 20% Restocking Charge.


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CLASSIFIEDADVERTISINGETI's classified advertising sectionallows you to reach about 30,000Canadian readers nation-wide for $1.00per word. For as little as $20 per inser-tion (there's a 20 word minimum) youcan promote your business from coast -to -coast.

WHAT DO YOU DO?Send us your typewritten or clearlyprinted words, your permanent ad-dress and telephone number and yourmoney (no cash please). Make your

cheque or money order payable to 'ETIMagazine'. We're at Unit 6, 25 OverleaBlvd., Toronto, Ontario, M4H 1B1.

WHAT DO WE DO?We typeset your words (and put thefirst word and your company name inBOLD capital letters). If we get yourmessage by the 14th of the month, itwill appear in ETI 11/2 months later. Forexample if we receive it by Octolier14th you (and thousands more) will seeit in the December issue.

PLANS to build your own backyard satellitedish and pay -TV decoders. Send a S.A.S.E. to:J.C. SYSTEMS INTERNATIONAL, Dept.306, 7305 Woodbine Ave., Markham, Ont.L3R 3V7 for free information.

HYDROGEN GAS GENERATOR plans andstarter kit, $12.PRAIRIE POWERRESEARCH AND DEVELOPMENT, P.O.Box 8291, Edmonton, Alberta. T6H OLO.

WSI RADIO - SWL Radios - Ham radios 18Sheldon Avenue North, Kitchener, OntaricN2H 3M2. Tel. (519) 579-0536. Write for 1983catalogue, $2.00 (VE3EHC).

J&J ELECTRONICS Ltd., P.O. Box 1437E,Winnipeg, Manitoba R3C 2Z4. Surplus andSemiconductor Specialists. Do you get ourbargain flyer? Send $1.00 to receive the currentliterature and specials and to be placed on themailing list for future publications.

CORONET ELECTRONICS, 649A NotreDame W., Montreal, Que. H3C 1H8,Catalogue IC's, Semi's, Parts, send $1.00 tocover postage. Monthly specials at crazy prices.

FOR $10 per kit $2 handling, receiv; free flyerand any of the following. #1: 1000 asst'd pcs,choke - capacitor - resistor - transistor - hard-ware - etc. Capacitor specials: #2: 200 asst'dceramic - #3: 100 asst'd silver mica - #4: 100asst'd mylar - #5: 50 asst'd tantalum - #6: 50asst'd electrolytic - #7: 50 asst'd feed -through-#8: 50 asst'd metallic silver mica (Elmenco)-#9: 25 asst'd variable. All new material. Un-conditional guarantee. SURPLUS ELECTROQUEBEC, 2264 Montee Gagnon, Blainville,Quebec J7E 4H5.

NEW catalogue of components available. Geton our mailing list for regular bits and bytesspecials. M.O. ENTERPRISES, Box 2066E,Bramalea, Ontario. L6T 3S3.

ZX81 EXPERIMENTERS. Now you can easi-ly build those projects you need. Three slot ex-pander plugs into rear connector, and hassockets for two Radio Shack or Vectorwirewrap boards, plus RAM, printer, etc.$29.95. Included, information on wire wrap-ing, parts and project reprint buylines. JDC,5-14 Sentinel Rd., Downsview, Ont. M3M2Y5. Include $2.00 o&h.

HAS your DMM or frequency meter TALKEDTO YOU lately? If not, then you needFREQUENTALKERTM! Imagine: you don'thave to look up while measuring. It tells you inplain English what's on the display. Easy inter-facing to any digital equipment (please specifywith order). Send $129 to microNOVAELECTRONICS, P.O. Box 1284N, Halifax,N.S. B3K 5H4.

SAVE money on breadboard, LED's, resistorsand much more. Send for your free flyer. P &0 DISTRIBUTORS, P.O. Box 1293, Stn. E,Victoria, B.C. V8W 2W3

VIC20 4K RAM kit; $39.95, 8K kit, $59.95(case included). Assembled and tested 8Kcartridge with battery back-up circuitryand 30 day warranty $89.95 (Ont.Res. add 7% P.S.T.) CANADIAN MICROPERIPHERALS, Box 123, Waterloo, Ont.N2J 3Z9.

CONVERT your voltmeter into a measurementlab! MULTIPAKS plug in for capacitance, fre-quency, audio, automotive, much more. Latestcatalogue: plans, kits - $1.00. ERNSTENGINEERING LTD., Box 1184, Stn. B,Oshawa, Ontario. L1J 5Z1.

TRS-80 Model 111 with interface laboratory.Also, stock and commodity programs. Writefor details. INPHOTECH, Box 113, Oakville,Ontario. L6J 4Z5.

STUDENT discounts on resistors, capacitors,I.C.'s, semiconductors. Pick up your freeHOBBILT catalogue at the store: 7454Langelier, St. Leonard. Tel: (514) 259-5581. Ormail your name and address to HOBBILTELECTRONICS, 7303A Dumesnil, St.,Leonard, Que., H1S 3A7.

ZX-81 Joystick kit, $24.95. Full size keyboardplans, $2.95; "Mastering Your TimexSinclair", new 208 page book $6.95; Gold ZXEdge Connectors, $8.95. Send stamp for freecatalogue. PORTER ELECTRONICS, 17Harper Way, Thornhill, Ontario L3T,5A4.

DISKETTES SS/DD $26.95 per 10; $125.00per 50 bulk; $225.00 per 100 bulk. Withenvelopes, write protect labels. Money backguarantee. Insurance postage, and handlingadd $6.00/100, $4.00/50, $3.00/10. VISA &Mastercard. BINARY PRODUCTS, 284 CreekRoad, St. Davids, Ont. LOS 1PO (416)262-4135.

PRINTED circuit boards for ETI Projects andHam Radio Projects. ZX81 Interface - $4.95;digital capacitance meter - $5.50. Full listfree. Boards from ARRL Handbook 1983 alsoavailable. Post & Pack $1.00. Ontario tax 7%.B -C -D ELECTRONICS, P.O. Box 6326 Sta.F, Hamilton, Ontario L9C 6L9.

DUPLICATE your software as backup againstmachine/human error. RAMCRACKERPLUS has duplication circuitry plus 16K RAMon one card to upgrade your Apple II or II + to64K. Invaluable for debugging programs.$175. (B.C. add 6% sales tax) certified chequeor moneyorder. POLYCARD INDUSTRIES,Box 278, Pitt Meadows, B.C. VOM 1PO.

COMMODORE 64 owners. We offer a fineselection of programs. Send for free catalogue.SANDISON SOFTWARE, Box 1403,Chatham, Ont. N7M 5W8.

APPLE CLONES: first ever detailed circuitand hardware description. Over 100 pages withfull schematics, waveforms and tutorials. Idealfor all owners. Essential for servicing, repairand interfacing. Send $18.95, cheque or moneyorder, to MICROTRONICS ENGINEERING,Box 358, Pinawa, Man. ROE 1LO.

PORTABLE Am, Fm, and Shortwave boosterAntennas. Tested Speakers, surplus tubes andother parts. List/order form: ELDON ELEC-TRONIC ENTERPRISES, 10653 - 137AStreet, Surrey, B.C.; Canada V3T 4J7.

CLOSE-OUT! Everything must go! I.C.'s-7400 - 15/$2.; 7404 - 12/$2.; 7413 - 18/$2.;Assorted I.C.'s, house numbered with data-100/$8.; LED's - Jumbo Red - 6/$1.;Assorted (Red, Green, Yellow) - 50/$5.; ACLine cords -10/$5.; Capacitors - Electrolytics-20/$2.; 1000 of - 25V. - 10/$5.; .1 - 250V.Mylar - 50/$10.; Epoxy Caps - 1000/$6.; ColorVideo Games (uses LM1889) for parts or? -$24.each - 2/$40.; All items new. Add Postage plus50' handling. No personal cheques. CloseoutFlyer - $1. -ELECTRONICS, P.O. Box 68,Whitecourt, Alberta, TOE 2L0.

REPRODUCTION of PCB's 30C a squareinch. Drilling, IC sockets and tinning of PCB'sare included. Write for additional information.EGD ELECTRONICS, Box 298 Youville,Montreal H2P 2V5.

MULTIFLEX owners: Screen orientedoperating system, editor and software develop-ment tools for Z80A system. Canadian madevideo terminals also available. ZEMOSSYSTEMS LIMITED, 7225 Woodbine Ave,Suite 110, Markham, Ontario L3R 1A3.TIMEX-SINCLAIR Software and Hardware.Brand name products at incredible prices! Sendfor FREE catalogue -price list. TORONTOSOFTWARE WORLD, Box 84, Dept. E,Agincourt, Ontario. MIS 3B4.

TECHTRONIX Plug -ins for series 530 & 540scopes. Dual trace, 24 meg. 53/54 C /$60; 545CA/$65 unchecked - checked add $30. Othertest equipment available; also 6502 computers.Cheque or money order. INFOTECH 2000,4693 Lacombe; Montreal, Quebec. H3W 1R4.

VIC20 owners! - Say goodbye to 'OUT OFMEMORY' messages! Memory Module 16Kfor $59; or expand your system to its full RAMcapacity with Module 32K for $99. Send tomicroNOVA ELECTRONICS, P.O. Box1284N, Halifax, N.S. B3K 5H4.


Compressor/LimiterWhen it comes to compres-sing those troublesomesignals that are prone tooverload, this ETI projectreally does the job.

COMPRESSORS and limiters have manyuses in professional recording and broad-casting, and they can also be pretty usefulto the amateur. Perhaps the single mostimportant use is for overload protection:the limiter is set up so as to remain inac-tive until a signal occurs which wouldoverload following circuits (perhaps aradio transmitter or power amplifier), atwhich point gain reduction cuts in and,without being very noticeable about it, theunit prevents blown fuses, gross distortionor worse.

The circuit described here has beendesigned to be capable of both the com-pressing and limiting actions - it alldepends on the signal size you apply andthe gains you set in the circuit. With thecomponent values shown, the specifica-tion of this unit is very similar to devicescurrently in use in stereo radio broad-casting.

On the AttackIn this circuit the attack has been madevery fast indeed, the time constant being220 microseconds: hence the time takenfor the limiter to react fully to an overloadabove the limiting threshold is approx-imately 500 microseconds. The decay timewas chosen to be 330 milliseconds; hence

If ow it N ksThe left and right channels of the unit areidentical, so this description will be confin-ed to the left-hand channel.

ICI forms a buffer, and its gain is ad-justable by PRI so that it can be used to setthe input sensitivity. The variable gain cellis made up from IC2 and IC7a and theirassociated components. The configurationused is slightly unusual: IC2 forms a con-ventional inverting amplifier, its gain beingdetermined by RFB RIN in the usual way.However, while RIN is simply R2, RFB ismade up from R4 and IC7a which, as anoperational transconductance amplifier,can be used as acurrent-controlled resistor.With the addition of a voltage -to -currentconverter to drive the control input of theLM13600, a complete VCA is formedwhich will produce a gain inversely propor-tional to the control voltage.

The first stage of the gain -control sidechain is a full -wave rectifier made up fromIC3a and IC6a. Q1 boosts the output cur-rent drive capability of the rectifier in orderto produce a fast attack characteristic whencharging C11.

From Cl! onwards until the finalvoltage -to -current converters for the VCA,the two side chains are combined into onechannel, the highest of the left or right in-put signals being registered on C11. In thisway stereo ganging is achieved, and thisprevents the stereo image from wanderingfrom side to side during gain reduction (if

the overload signal is in one channel only).The adjustment of the decay time andlimiting threshold for both left and rightchannels is achieved easily and equally byR32 and PR5. IC8b is used as a high im-pedance buffer for the control voltage heldon C11, which is discharged by R31. Theoutput of this buffer is fed to PR5, whichcontrols the side chain gain and hence thelimiting threshold.

The only problem with the particularVCA configuration chosen is that shouldthe control voltage (and hence control cur-rent being fed to IC7a) fall to zero, the gainof the VCA will increase to the open -loopgain of IC2, probably resulting in the VCAoutput reaching one of the supply raisl (as isusually the case when an IC amplifier losesits feedback). In order to prevent this fromhappening, the control voltage Vc isprevented from going below OV5 by zenerZD1 and preset PR6. Thus the higher ofeither VMIN or the output of PR5 is passedviaDll or D12 to the law -shaping amplifierIC8a.

The diode D13 and resistors R35, 36are configured to make up for the voltagedrop across D11 and D12, and maintain atight compression ratio, typically 10:1. Theoutput of the shaping amplifier provides alow source impedance to drive the voltage -to -current converter IC9a and Q3 (note thatthe left and right channels split again at thispoint).

TABLE 1Measured performance of the prototype. Tracking between channelsGain: 0 dB (adjustable) during gain reduction: better than 0.3 dBBandwidth (3 dB points): 10 Hz and 30 kHz

approximately Distortion at 1 kHz:Input impedance: 22k Input Output DistortionOutput impedance: 100R -8 dB -8 dB -66 dB (.1%)Limiting threshold: 0 dB (adjustable) 0 dB -1 dB -60 dB (.1%)Compression ratio for signals + 10 dB 0 dB -58 dB (.13%)exceeding threshold: 10:1 Distortion at 100 Hz:Crosstalk with non -speaking channel terminated with 600R (left -to - Input Output Distortionright or right -to -left): -8 dB -8 dB -58 dB (.3%)

100 Hz 1 kHz 10 kHz 20 kHz 0 dB -1 dB -45 dB (.6%)-70 dB -70 dB -68 dB -65 dB +10 dB 0 dB -38 dB (1.3%)

Noise with input terminated as above: -70 dB(this is the gain required to make noise at the output peak to 0 dB ona standard broadcast peak program meter, ie this is the peak noise.Should a measurement be made with an RMS reading meter, thismeasurement may improve by as much as 6 dB).Control voltage breakthrough onto non -speaking channel with 20dB of gain reduction occurring on the other channel:

100 Hz 1 kHz-68 dB -68 dB

NB. These figures for 100 Hz distortion were measured with arecovery time constant of 100 milliseconds (total recovery time ap-proximately 220 milliseconds), hence a certain amount of distortiondue to the compression of individual waveforms is to be expected.Incaeasin the recovery time constant as in the final design will im-prove the low frequency distortion measurements, until for longrecovery times (greater than 3 seconds) they will approach the valuesobtained for 1 kHz.


PRI475

C247p

NOTE:IC1,24,5 ARE TL071IC3,6,8,9 ARE TL072IC7 IS LM1380001,2 ARE 2N390403,4 ARE 2N3905D1-15 ARE 1N4148ZD1 IS 5V6 400mW ZENER

C747p

Ce R16u 22. ,

c-11-Nw-=IC4

R1020k

D

R1820k

R17150

R2547k

R1920k

R2020k

+15V

C10100p

RIGHTOUTPUT

R2110k

RV5k6

C547p

D3

R2220k

cs47p

D8

+15V

GI

R1410k

15V

R2915k

14

39OR

+15V

R2310k

12

16

+15V 0

OV

C16100n

15V 0

C17100n

IC1,2,4,5 IC3,6,8,9PIN 7 PIN 8

IC1,2,4,5PIN 4

IC7PIN 11

IC3,6,8,9 IC7PIN 4 PIN 6

R15220R De

R24220R D10

R35

IC8a

C1347p

14R38013

470k < 470k

1C14014 47p

R377k5

0 15V

C

R387k5

IC9a

IC16

D15

103b

47p

R3210k

;,1)}

+15V

R31330k

R33 R34470R 457

5V6 C1102u

PR510k

011

PR6150

1 012

VMIN

Fig 1. The schematic diagram of the stereo Compressor/Limiter.

full recovery takes place approximately700 milliseconds after the overload hasbeen removed from the input. Thisrecovery time was chosen after much sub-jective assessment, and is the fastest possi-ble without undue distortion of low fre-quencies (this being a common problem inall compressor/limiters). However, as thisis a simple one -resistor adjustment it iseasy to experiment and find the best com-promise for different uses.

Shaping UpThe need for the shaping amplifier builtaround 1C8a arises because the side chainis, like most professional designs, an openloop system deriving its input from the in-coming program material, not from theVCA output. This has the advantage thatthe limiting threshold and other dynamiccharacteristics may be altered easily.

Before installing the VCA ICs andpowering up, it would be wise to check the

side chain components; a fault whichresulted in no control current to IC7 coulddamage the LM13600. Remove ICs 2 and5; apply power and measure the currentinto pins 1 and 16 of IC7. This shouldread in the region of 65 uA. Vmin shouldbe OV5, and there should be no signalpresent.

The setting up procedure is very sim-ple indeed. PR6 should be adjusted sothat Vc is held at OV5 with no input


Compressor/Limiter

Fig 2. The component overlay.

ti

41.

Fig 3. The printed circuit layout, foil side.


signal. PR1 and PR3 should then be ad-justed to give the required gain from eachchannel (usually 0 dB). That concludes thestatic setting -up, except for PR2 and PR4which should be adjusted for zero offsetat the output of the VCA. This ensuresminimal control voltage breakthrough on-to the audio output during gain reduction.

To set the compression threshold, ahigh level signal (for example, + 10 dB)should be applied to the input, and PR5adjusted to give 0 dB at the limiter output.

If the above sequence is followed, thelimiter will act as a normal unity -gainamplifier for all signals below 0 dB, andwill reduce the gain of all signals abovethis threshold such that the output at notime exceeds 0 dB. Should the limitingthreshold need to be reduced to, say, -10dB to be more compatible with domesticequipment, then all that is required is anincrease in the gain of the side channel bythat amount. This is easily achieved by in-creasing R13 and R22 from 20k to, say,47k. Should an indication of gain reduc-tion be required, this is easily provided bybuffering off Vc, the control voltage, bylkO or so to prevent any fault on themetering equipment affecting the opera-tion of the limiter (or this metering equip-ment could consist of a simple bargraphdriver and LEDs).

Parts ListResistors (all V4W, Ph)R1,16 22kR2,25 47kR3,26 100RR4,27 5k6R5,7,28,30 390RR6,29 15kR8,17 1k0R9-11,13,18-20,22 20kR12,14,21,23,32 10kR15,24 220RR31 330kR33 470RR34 4k7R35,36 470kR37,38 7k5

PotentionmetersPR1,3 47k miniature horizontal

trim potPR2,4 220R miniature horizontal

trim pot

PR5

PR6

CapacitorsC1,6,11C2,4,5,7-9,13-15C3,10C12C16,17

10k miniature horizontalpreset1k0 miniature horizontalpreset

luO polycarbonate

47pF ceramic100pF ceramic10uF 16 V tantalum100nF polycarbonate orceramic

SemiconductorsIC1,2,4,5 TL0711C3,6,8,9 TL0721C7 LM13600 (National)Q1,2 2N3904Q3,4 2N3905D1-15 1N4148ZD1 5V6 400 mW zener

PCB, suitable case, etc.

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Designer's NotebookSwitch Capacitor Filters Part 2

Last month, we looked at someof the new switched capacitorICs. This month, Tim Orr getsdown to some circuits usingthem.

Seven -Octave Audio AnalyserThe R5606 is a single octave filter. EachR5606 is clocked with a square wave gen-erated by a seven -stage binary divider, sothat successive filter break-points arespaced at exactly one octave intervals. Theresulting circuit is very simple and may beused as a real-time audio analyser or as anaudio equalizer with a steep filter roll -off.Half -octave or even '/3 octave resolutioncould be obtained by using the R5605 orthe R5604 respectively. The output signalis filtered by a simple single -pole low-passfilter to remove the effects of the samplingand the residual clock breakthrough. Asimple anti-aliasing filter can also be usedat the input to each filter, but this may notbe considered necessary. A dynamic rangeof about 76 dB per channel should be ob-tained.

AUDIO INPUTO

CLK54013

SINGLE POLERECOVERY

FILTERS14.0 F.)

1014 1 OCTAVE0 8 kHz BANDWIDTH

z510pRESOLUTION

104.--A/0/-0 4 kHz

/47104

2 kHr5.06

104

5038 --0VW1--0 1 kHz

2n2

10k54306 500 Hz-1ArVi--C)

8n2

r7)77

OS cc

612 13110

10k----1,11V-0 .5406 50 Hz

15n

4cmutV bid

6" OUT

MASTER OSCILLATOR

SET CLK TOFREQUENCY

100n

4.10V OV -10VTO ALL 5406 UNITS

SET CLK TO872 kHz

CLK

le 1E4 /0 126 Hz33n

CLOCK GENERATOR AND DIVIDER

BINARY OUTPUTS

2

100n. 11 _

Audio ConverterWith Tracking FilterThe R5609 is a steep low-pass filter whichcan be used as an anti-aliasing filter andrecovery filter in an audio converter, suchas digital delay line. If the clock for thefilter is derived from the system clock andthe A -to -D converter, then the low-passfilter frequency will track any changes inthe conversion speed.

INPUT (3-0.

ANTI -A LIASINGFILTER

R5609LOW PASS

.CLK

ADC MEMORYDAC

SYSTEMTIMING

GENERATOR

RECOVERYFILTER

4.0 OUTPUT

R5609.LOW PASS

CLK

32 F.

CONVERSION FREQUENCY = F.

),,tf VARIABLECONVERSION

SPEED

The R5609 has a rollo11 Mop. of 100 dB/octavo

32.FSystem. bandwidth -E00 0.32 F,

1

Ma.,mum theorznocal bandwnt1b. as predicted by Gk. urnolong thoorom 0.5 F.


Low -Pass ResponseUsing the MF10The frequency responses of second,fourth and sixth order maximally -flat low-pass filters are shown in the graph. Thesecan be realized by cascading second orderlow-pass filter sections together. The tableshows the break frequencies and Q factorsfor both maximally flat (Butterworth) and3 dB ripple (Chebychev) responses. Themaximally flat responses are easy torealize because all stages use the sameclock frequency. The 3 dB ripple responserequires awkward clock frequencies. Asimple design example will illustrate howto use the filter.

The figure shows a design for afourth -order 2 kHz maximally -flat low-pass filter with an oferall gain of 1 in thepass band. From the table, the first stageshould have a Q of 0.54 and a frequencyof 2 kHz, the second stage, a Q of 1.306and a frequency of 2kH. Mode la is themost simple realization of the secondorder low-pass filter. For the first sectionlet R3 = 10k. Then R2 = 18.48k (15k +3k6 would do). For the second stage let R2= 10k, then R3 = 13.06k (9k1 + 3k9 isnear enough). Both clock pins can be tiedtogether and driven with a single 200 kHzclock (pin 12 grounded gives a clock -to -filter frequency ratio of 100 to 1).

LOW-PASS FILTERRESPONSE

1st STAGE 2nd STAGE 3rd STAGE

to 0 to a to 0

2nd ORDER BUTTERWORTH(FLAT RESPONSE)

2nd ORDER CHEBYCHEV(3dB RIPPLE)

1.0 F 0.707

0.84 F 1.304

4th ORDER BUTTERWORTH

4th ORDER CHEBYCHEV

1.0 F 0.54 1.0 F 1.306

0.443 F 1.076 0.95 F 5.58

6th ORDER BUTTERWORTH

6th ORDER CHEBYCHEV

1.0 F 0.518 1.0 F 0.707 1.0 F 1.931

0.298 F 1.044 0.722 F 3.46 0.975 F 12.78

Band -Pass ResponseUsing The MF10A simple band-pass filter can be con-structed using the circuit shown as mode 1in the first article on switched capacitorICs, and shown again to jog yourmemory! For a Q of 10, R3 = 100k, andR2 = 10k. To give the filter unity gain atresonance, RI = R3 = 100k. The exter-nal clock frequency determines the reso-nant frequency. By cascading two filterswith a Q of 10, a very sharp resonancecurve is produced as you can see in thegraph below, If the Q factor of each filteris increased further, then an even sharperresponse can be obtained, although thismay result in a double peak if the relativeresonant frequencies of the two filtersdeviate.

NA

VIN

SA/B,6

S

MODE 1

-10-12

P -10

-20

t -22-24-a

-3022

-3430

100 1k

For the equivalent highpass response, use the sameQ factor but use the reciprocal of the frequency multiplier.

-3 de POINT

2nd ORDERROLOFF -12L dll/OCT

4th ORDERROLLOFF -24 de/OCT

FREQUENCY (110

10k

LOW-PASSRESPONSES

VIN

.45V100

TTL CLK200 IcHT

OUTINS 0.5411.. 2 WU

YAF 10MODE 14

113/112 0.541

0-1.706

5MF10MODE 14

143/52 1.306

LPA LP,

"A BP.

N/AP/HPA N/AP/HP6

INVA INVB

"A SIBMFIO

EA/B AGM)

VA. VA

yOUT

-DV

BPA LPA

11201

o-

-5

10

s -15

O12 -20

-25

--30

-35

45

PERFORMANCE OF THE MF10,IN THE BAND-PASS MODE

INPUT -1w

I

0= 10 411. 0= 10 -a. OUTPUT

MEASURED RESPONSE,DOUBLE TUNED

0 = 10

THEORETICALRESPONSE 0 = 10

MEASUREDESPONSE 0'10

10 100 1k 10k 100k

FREQUENCY IHz)


1

2

3

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Designing Micro SystemsPart 3

A computer never forgets -provided the information isstored in ROM. Owen Bishopexplains the different types andthe different applications.

WHEN THE structure of a computer wasdescribed in Part 1, 'memory' was con-sidered simply as a section of the circuitresponsible for storing information (in-structions or data). Part 2 showed howthis information is in the form of a se-quence of binary code groups, each usual-ly containing eight bits (one byte).

The first point to consider is why acomputer needs memory. Although theMPU has internal programming whichmakes it perform a given operation (suchas adding together the contents of tworegisters) when it receives a machine codeinstruction on the data bus, there isnothing inside it to tell it what operation itis to perform next. The operations it per-forms automatically are very simple ones.Adding together two single -byte numbers

ex-amples are incrementing a number by one,decrementing a number by one, transferr-ing the contents of one register to anotherregister, logically ANDing the contents oftwo registers and so on.

Simple Sums,Complex SequencesIt takes a fairly long sequence of thesefundamental operations to perform eventhe simplest of calculations. For example,to add two numbers which are alreadystored in memory and to display the resulton the monitor screen, the MPU has to: Read one number, already stored inmemory location X, and store it in its ac-cumulator Read the other number, stored inmemory location Y, and add it to thenumber already in the accumulator Refer to a table of data already storedin memory to convert this number to itsequivalent in the ASCII code. The ASCIIcode (of which more will be said in a laterissue) is a special code used in the majorityof computers for representing letters,numbers and punctuation marks in binaryform. It takes the MPU several operationsto find the ASCII code, and then it has to: Find out in which screen position theanswer is to be displayed and work outwhich byte of memory the code group

must be stored in to achieve this. Finally itmust: Transfer the ASCII group along thedata bus to that byte of the videomemory, so causing the answer to bedisplayed on the screen in the correct posi-tion.

The procedure above may soundcomplicated but it is a gross over-simplification of what the MPU has to do.For instance, we have assumed that thetwo numbers are stored as single bytes,but a single byte can take values only from0 to 255. Most micros store integers asdouble -bytes (allowing values from -32768to + 32767). They require four bytes forfloating-point numbers (seven -figureprecision) or eight bytes for 16 -figureprecision. To add two such numberstogether, the MPU must work with thepairs of bytes in turn (one from eachnumber), adding in any carry-over digitfrom one addition to that of the nexthigher pair of bytes. It is clear that eventhe simplest of mathematical operationsrequires a long sequence of operations bythe MPU. Since the MPU can accept andact on only one instruction at a time, thesequence of instructions is set out in apro-gram, which is held in memory.

ROM And RAMAt this stage we must distinguish betweenthe two kinds of memory that may be usedfor instructing the MPU. In physicalterms, both kinds of memory consists ofarrays of integrated circuits, as will bedescribed later. When you type a programinto the computer, or when you load aprogram from a cassette tape or a floppydisk, it is stored away in a part of RandomAccess Memory (RAM for short). We sayit is 'written into' RAM. The informationis stored in memory cells (bit -storing sub -circuits), hundreds of thousands of whichgo to make up the circuitry of each RAMIC. With RAM you can, if you wish, sup-ply the MPU with a different programevery time the computer is used. When aprogram is run the MPU 'reads' the pro-gram from RAM. When you switch offthe computer, or type NEW, the programis lost. RAM will be the subject of nextmonth's article but, to sum up its mainfeatures, we can say its contents mayreadily be changed, and it loses its con-tents when the power supply is cut off.

By contrast, the contents of ReadOnly Memory (ROM, for short) cannot bechanged or, if changeable, can be altered

only as the result of a special procedure,and are not lost when the power supply iscut off. The fact that the contents are notreadily changeable is reflected in the name`Read Only'. In other words, this kind ofmemory is intended only (or primarily) tobe read from, not to be written into.

Kinds Of ROMObviously, there must be a way of writinginstructions into ROM, otherwise it wouldcontain no instructions and would betotally useless. There are several differenttypes of ROM with different ways ofwriting instructions into them. To beginwith we will look at the type known as themask -programmed ROM.

Each memory cell (each bit) is pro-grammed at the manufacturing stage.Typically, the cell consists of a transistorwith its gate either connected to ground oropen -circuit. A connection to groundmeans that the output from the cell is 1;open -circuit gives an output 0. Before theROM is made, the program which is to bestored in it is very carefully tested to en-sure that it is free from error. The masksused for making and linking the com-ponents on the slice of silicon are drawnout accordingly. Cells which are to store a1 have the gate of the transistor grounded.When the ROM is in use and the MPU ad-dresses a particular cell by applying theappropriate combination of voltages tothe address terminals of the ROM IC, thecell's output is gated to one of the datalines. This output may then be read by theMPU. Thus the program is permanentlybuilt into the structure of the IC and can-not be altered after manufacture.

High Volume Equals Low CostAs might be expected, this procedure is anexpensive one, due to the high cost ofpreparing the special masks. Only if hun-dreds or thousands of ROMs are to bemanufactured with exactly the same pro-gram does the cost fall to a reasonablelevel. This is the type of ROM generallyused for holding the monitor program ofa computer and perhaps a resident lan-guage, as explained later. Mask -program-med ROMs are made with capacities bet-ween 1 kilobyte and 8 kilobytes.

The advantage of the mask -program-med ROM is that once the program hasbeen finalized, it is possible to manufac-ture identically programmed ROMs inlarge quantities very cheaply. For pro-totyping and for applications in which it is

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Designing Micros

known that only a few ROMs with a givenprogram are likely to be required, we needa ROM that does not depend on mass -production for cheapness. For this pur-pose we use a different type of IC, knownas a programmable ROM, or PROM forshort. There are several kinds of PROMs,as will now be described.

Fusible -link PROMsIn a typical version of this kind of PROMthe gate of the transistor of each cell isjoined to ground by a fusible link. This isa connection which can be destroyed bypassing a high current through it. Tobegin with, all transistor gates are ground-ed so all the cells in the PROM are set withoutput 1. When a particular cell is ad-dressed by putting the appropriate com-bination of inputs on the address lines ofthe IC and a high voltage is applied to aspecial terminal of the IC, the link is`blown'. From then on, that cell gives a 0output when addressed. Fusible -linkPROMs are usually programmed byspecial electronic PROM programmerswhich may operate under the control of acomputer. The controlling computerholds the program which is to be writteninto the PROM and coordinates the pro-cesses of applying address and 'blowing'the links. Once the PROM has been pro-grammed it can not be reprogrammed, forit is possible only to convert 1 to 0, but not0 to 1. If only a part of it has been pro-grammed, the remainder still being all Is,the remainder can be programmed on alater occasion. An example of a fusible -link PROM is the Intel 3624, which stores512 bytes (1/2K).

A photomicrograph of a typical mask -programmed ROM chip.

NEGATIVELY CHARGEDISOLATED GATE

TO Vss

CONTROL GATEELECTRODE

INSULATING LAYER OFSILICON OXIDE

n -TYPE CHANNEL INDUCEDBY POSITIVE IONSIN SILICON OXIDE

CONNECTION TOCONTROL GATE

TO VDD

-ELECTRONS

Fig. 1 Diagram of a memory cell in a UV -erasable EPROM. The gate is an N -channeldepletion -type MOSFET; here the gate isshown with its negative charge depleting theN -type channel by repelling the electrons in it.

The Ubiquitous EPROMAn erasable PROM can be erased andreprogrammed. The most frequently usedEPROM is that which is erased by expos-ing the chip to ultraviolet light. You canrecognize this kind of IC by the windowof quartz, through which the chip itselfcan just about be distinguished as agreyish object about 4 or 5 mm square.Quartz must be used rather than glass,since glass is not transparent to ultravioletradiation. The UV -erasable EPROMstores information by making use of theextremely high electrical insulation pro-perties of silcon oxide. Insulating layerscan be readily formed on the surface ofthe substrate simply by oxidizing it. Ineach memory cell, the gate of the tran-sistor has a control gate situated close toit, but separated by an insulating layer(Fig. 1). The gate itself is left unconnectedand floats with whatever charge it may ac-quire.

After manufacture, the gate has nocharge, so each cell gives a '0' output. Inprogramming, a high voltage (about 25 V)is applied to the control gate (Fig. 2).Some electrons in the control gate gainsufficient energy to cross the insulatinglayer and charge the gate of the transistor.Once the gate has been charged, thecharge remains for decades, and the cellgives a '1' output. The only way of rapidlyremoving the charge is to expose the gateto a highly energetic radiation, such asshort-wave ultraviolet radiation. This ismaking use of the photoelectric effect.

A Wavelength That WipesThe amount of energy carried by a photonof radiation depends on its wavelength;the shorter the wavelength, the greater theenergy. In the UV range, only short-waveUV photons carry enough energy each todislodge and electron from the floatinggate. Photons of visible light and UV oflonger wavelength each carry too littleenergy so they have no effect whatever.

Radiation of shorter wavelength such asX-rays and gamma rays (which are emit-ted by certain radioactive elements andproduced by a nuclear explosion, for ex-ample), are also able to erase EPROMsthough these radiations are not in normaluse for erasing!

After an exposure to short-wave UVlasting a half an hour or more, the gates ofall cells on the IC become discharged. TheEPROM is then ready to be programmedagain. In this way it has a great advantageover the fusible -link PROM and is widelyused in microprocessor systems. Althoughthe EPROM has to be removed from thecomputer and placed in a special EPROMprogrammer device (which may be undercomputer control) the programming, eras-ing and reprogramming of EPROMs is astraight -forward matter. Naturally, it ispreferable for the program to be correctto begin with and have no bugs, but if anyerror is discovered in the program, it canbe replaced by a corrected version in anhour or so.

An EPROM is a PROM which is readfrom most of the time, but which can bewritten into occasionally. The operationof writing generally takes rather longerthan the reading operation. For thesereasons some people refer to EPROMs asread -mostly memories (RMMs).

EEROMs And EAROMsWhen an EPROM is erased, the ex-ceedingly small size of the memory cellsmakes it impossible to pick out any onecell or group of cells for treatment. It isnecessary to erase the whole EPROM andprogram it all again. There are other kindsof PROM which can be erased electrical-ly, known as EEROMs and EAROMs.The EEROMs, or electrically erasableROMS, are similar to EPROMs in thatthe whole array of cells must be erased,but erasing is achieved by passing a cur-rent through the device. EAROMs, orElectrically Alterable ROMs allow us todischarge the gate by a signal applied tothe control gate. In this way we can alterany one or more memory cells without af-fecting the state of the others.

An example of an EAROM is theGeneral Instruments ER3400. Most of


FROMADDRESS BUS

DATA BUS

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A51

A41

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EA8}E A9FROM ADDRESS BUS

E v, (+25V, USED IN PROGRAMMING ONLY)

E CS (CHIP ENABLE, USED IN READING)

E A10 FROM ADDRESS BUS

tB PD/PGM

2 D7

D6

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E D4

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LOGICAL 1 PUT HERE PROGRAMSADDRESSED CELL

these devices employ NMOS transistors,and while they are relatively expensive atpresent, their cost is beginning to fall andthey will soon be very competitive with theUV -erasable ROMs. It takes so little timeto erase and reprogram these devices thatit is feasible for their programming to becarried out while they are still plugged into the computer circuit. The usual powersupply at + 5 V is required for reading,and supplies at other voltages such as -12V and 30 V are required for programming.We now have the possibility of the com-puter with appropriate power supplies be-ing able to alter its ROM during thecourse of running a program; the distinc-tion between ROM and RAM becomesmore clouded, though there remains the

fact that ROM is permanent (if we want itto be), while RAM is not.

Using ROMBefore going on to discuss how ROM isused, we will discuss why ROM is neededin a computer. Why not just use RAMwhich is so flexible and can be readilyaltered at will? To answer this, let usfollow the sequence of events when a com-puter is first switched on. First of all theMPU is reset. This is usually done auto-matically by a capacitor connected to thereset input, so that the voltage there isheld low for a fraction of a second afterall other inputs have reached 5 V. In addi-tion, most computers have a reset buttonto allow manual resetting - this is

Fig. 2 The pin connections of the 2716, acommonly -used 2K EPROM. During program-ming the data bus is used to input the requiredbytes.

particularly useful if the computer latchesup in some otherwise interminable cycleof operations, as it may well do if there isa bug in the program.

When the reset input is made low,either at power -up or by manual resetting,one of the most important results is thatthe program counter of the MPU is set toa fixed value. In the Z80 and 8505, theprogram counter is cleared to address0000. We must make sure that there is aninstruction there for it to execute, other-wise it will never be able to do anything. Itwill be no good typing instructions at thekeyboard or trying to load them from tapeor disk. Until the MPU has been told toscan the keyboard for input, or to registerthe signals coming in at the tape or disksockets, you will be unable to com-municate with it. What it needs as aminimum is a short program to allow it toacquire instructions through the key-boards, or from tape or disk, and storethese instructions in RAM (they cannot goin ROM, of course, because ROM cannotbe altered). ROM is essential for holdingthe initializing program which tells theMPU how to get information from thekeyboard, tape or disk.Next month, we look at how a"bootstrap" start-up begins reading datain and out of the CPU.

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CHARLESWHEATSTONEA multi -talented Victorian scientist and inventor.

by Ian Sinclair

ONE OF THE curious facts about theway we remember Charles Wheatstone isthat the measuring system that bears hisname, the Wheatstone Bridge, was not, infact, his invention, nor did he ever lay anyclaim to it!

Charles Wheatstone was born in 1802at Gloucester, and seems to have beeneducated at rather undistinguishedschools, because we have no record of hisprogress in these days. There seems tohave been little about his early life to con-nect him to electrical engineering, and thefirst impression he made on the world wasin 1829, when he invented, of all things,the concertina, that miniature accordianwhich became the traditional accompani-ment of singing sailors in the Victorianera. His interest was at that time intenselydevoted to sound waves, and he is creditedwith the discovery that sound travelsfaster in glass or metal rods than in air.

In 1834, his research efforts wererewarded by his appointment as Professorof Experimental Philosophy at Kings Col-lege, and he continued his researches intosound. It was at this time, incidentallythat he coined a new word:"microphone" - though he didn't inventthe device. His most important achieve-ment, however, was the measurement ofthe speed of electric current along cables.

Not many details of the experimentsurvive, but from the hints that remain,we can reconstruct the method.

Two spark gaps were connected inseries, one at the start of a very longlength of cable, and the other at the end ofthe cable. The idea was that when a highvoltage (he seems to have used a capacitorcharged from a Wimshurst Generator) isapplied to one end of the cable, sparks

will be produced across both gaps - butthe spark at the far end of the cable willoccur slightly later than the one at thestart.

A Space In TimeThe time difference is not large, however.If we assume, as we know now, that thespeed of the current wave in the cable isaround 200 million metres per second, or200 m per microsecond, then it takes a 200m length of cable to cause a delay of onlyone microsecond. That's not a lot even bytoday's standards, and it was unimagin-ably small in those days. Wheatstone used

Fig. 1 The 'Wheatstone Bridge'; (a) a simplepotential divider; (b) Two dividers connected ina bridge formation.

L'"IN Ibl OUT

Fig. 2 Cable capers; (a) a long cable can berepresented as a set of inductors, capacitorsand resistors; (b) their effect is to smooth outpulse waveforms, and this limits the speed oftransmission of information.

a method which had already been used tomeasure the speed of light -a revolvingmirror.

The mirror was small, and turned at avery high, steady, measurable speed. Thelight from the first spark would reflectfrom the mirror, and so would the lightfrom the second spark - but in the shortinterval between these sparks, the mirrorwould have turned so that the reflectedimages, which would coincide if the mir-ror had not turned, seemed to separate.The faster the mirror was rotated, thegreater was the separation. From theseparation of these images, Wheatstonecould work out the angle through whichthe mirror had turned and, knowing therotating speed, he could also find the timeit had taken to cover this angle. This wasthe time between the two sparks, andfrom this he could find the speed of thecurrent in the cable.

The method worked (using severalkilometres of cable) and Wheatstone wasable to announce a value for the speed ofelectric current in a cable.

This work on the speed of current,however, led Wheatstone to become in-terested in sending signals through cables,the work which was to occupy him for therest of his life. He was elected a Fellow ofthe Royal Society in 1836, at a time whenhe was working with William FothergillCooke on a telegraph system which was tobe standard on railways all over the worldfor more than a century.

Getting The NeedleWheatstone's aim was to produce atelegraph signalling system which could beused by relatively unskilled operators, butwhich could handle a lot of information.His first efforts used a 6 -wire systemwhich operated three needles (using elec-tromagnets), but this was quickly super-


seded by a 6 -wire, 5 -needle system.Each of the five needles was operated

by an electromagnet which was connectedbetween one of the five signal wires andthe sixth (ground return) wire. Current inone direction would turn the needleclockwise, current in the opposite direc-tion would turn the needle anticlockwise;the needles were spring -loaded to ensurethat they returned to the central positionwhen the magnets were not energized, andalso that the angle of deflection was pro-portional to the current passing throughin the electromagnet. The principle wasthat a digit could be selected by pointing aneedle at it, and a letter could be selectedby pointing two needles so that they in-tersected. It may look slow and clumsy,but remember that it only needed lookingat to receive the message and Morse code,which in any case needs a trainedoperator, was still a thing of the future.

Wheatstone and Cooke's telegraphsystem was eagerly adopted by railways allover the world as the railway boom of the1840-1860 period got under way and, inBritain at least, the name of Wheatstonebecame almost synonymous with tele-graphy. Wheatstone then became deeplyimmersed in submarine telegraph - theuse of underwater cables - and this in-volved the measurement of largeresistance values. The solution that headopted actually was an invention bySamual Christie to be known as the"Wheatstone Bridge."

The principle, like that of so manygood inventions, was simple. If we con-nect two resistors in series, the voltageacross one resistor depends on the ratio ofits resistance to the total resistance of thepair. If we use two pairs of resistors, thenthe voltages at their junctions (Figure 1)are equal when the ratios of the resis-tances are equal. Since this equality,which determines that no current will flowbetween the points, is easy to detect, andcan be detected using very sensitive in-struments, it forms a much better systemfor measuring high -value resistors thanthe use of Ohm's law. The delightful pointabout the bridge system is that no measur-ing instrument is needed. All we need is asensitive galvanometer (which need not becalibrated) to read zero when the voltagesare equal, and some resistors of knownvalue.

From Cables To TVWheatstone's use of the bridge circuit wasanother step forward in telegraph tech-nology and led to the first successful tran-satlantic cable being laid in 1866. This wasa remarkable event, not simply because itlinked the telegraph systems of two majorcontinents, but because of the other ad-vances which it sparked off. During hiswork on high resistance measurements,Wheatstone had used the elementselenium as a resistor material, and foundthat its resistance value altered according

to the brightness of the light striking it.This discovery set off the research on im-age transmission that led to TV. In addi-tion, the integration effect of capacitance,inductance and resistance in a long cable(Figure 2) led to the analysis, by OliverHeaviside, of the effect of capacitanceand inductance on signals and particulalryon pulses, in cables - work which waslater to be of inestimable value in radarengineering.

Wheatstone was knighted in 1868, ajust recognition of his pioneering effortswhich covered a huge range of activies notmentioned here. One of these was thestereoscope, which allowed the viewer tosee three-dimensional pictures. Anotherwas the use of electromagnets as fieldmagnets in dynamos, a developmentwhich changed the dynamo fromlaboratory device to engineering plant,and led to the large-scale use of electricity(a power source regarded at the time withas much superstitious dread as nuclearpower is now).

Wheatstone also amused himself withciphers, cryptographs and his first love,music. He died in Paris in 1875, too soonto see some of the most exciting results ofhis work, but with the satisfaction ofknowing that he had made a lasting con-tribution to many fields.

UNLOCK MASTERAPPLE DISK COPY CARD

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UNLOCK MASTER is a hardware interface card that is slot independent, users can copy and examine programsthat were inaccessible due to all the locking schemes currently used. UNLOCK MASTER does not copy theoriginal disk track by track, rather it copies the program executing in memory. Minimum requirements are an Ap-ple II or any Apple compatible computer with one disk drive and a 16K RAM card.

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UNLOCK MASTER is intended to be used for making back up programs only. Apple II is a registered trademark of Apple Computer Inc.

Circle No. 23 on Reader Service Card. ETI-NOVEMBER-1983-63

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OTTAWA (613) 238-7007 111

Playmate Continued from page 11

Fig. 4 The LM13600 as an expander.

Fig. 5 Here the LM13600 is configured as a compressor.

0

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R1100k

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R210k

IC2,4 ARE 13600IC3 IS TL084IC4 IS T L08201,2 5 ARE BC212L03,4 ARE BC182L06 IS BD13207 !SSC/131D1-4 ARE 1N4148

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Fig. 6 Circuit diagram for the Playmate.

How it WorksThe gain of the input buffer ICI is set by R2and R3 at 48. RI determines the input im-pedance while Cl provides DC blocking.The output from this device goes to thedynamic range compressor IC2a and itsbuffer IC3a. This part of the circuit alsoprovides control signals for the expandercircuit and, if required, for the wah wah ef-fect. The buffered output from the com-pressor then goes via C4 to the first part ofthe fuzz effect circuitry constructed aroundaround IC3b. Here an inverted half -wave -rectified version of the input signal is pro-duced by the action of DI and D2 in thefeedback network of IC3b. This is appliedto RV1 from which a portion is selected andmixed with a little of the original signal. Asthe half -wave -rectified signal at this pointof the circuit is twice as great as thestraight -through signal, by varying the set-ting of RV1, amounts of distortion varyingfrom none to virtual frequency doublingcan be selected.

The mixture of signals obtained aboveis now applied to IC3c where they areamplified. The amount of amplification isdetermined by the setting of SW1. In posi-tion 3 minimum gain is provided and in factthe whole fuzz section is bypassed. Position2 gives the same gain, allowing the firstdistortion stage to be effective. The finalposition connects D3 and D4 via C5 andR19 into the feeback circuit of IC3c insteadof R18. This has the effect of greatly in-


+VE

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creasing the small signal gain but causingthe output to limit sharply, thus clippingand squaring the output. This facility isavailable on whatever output is comingfrom IC3b.

The output from the fuzz stages nowpasses to the wah wah. This effect is pro-duced by the current controlled statevariable filter used in a band-pass mode.The filter is realised by using a LM13600device with a controlled bias current pro-viding the variable centre frequency. The'Q' factor is controlled by a dual gangpotentiometer, half of which is used to con-trol the 'Q' factor while the other half com-pensates for the effective gain change asthis is altered. In this type of circuit the fre-quency range is determined by the values ofC7, C8, R24 and R26, while the actual cen-tre frequency is controlled by the amplifierbias current. If the bias current is allowedto become too small it is sometimes foundthat a thump is heard at the output; in orderto prevent this R34, R35, D5 and R33 areused in the control circuitry to keep the cur-rent above this threshold.

SW2 selects between the control op-tions for the wah wah circuit. The 'offposition bypasses the circuit altogether, the'pedal' position makes access to an externalfoot pedal if fitted, while the 'auto' posi-tion connects to an output from the com-pressor stage. This control signal is a cur-rent which is proportional to the amount of

signal compression being applied to the in-put signal. The magnitude of this currentincreases as the input signal increases. Theresult of this is that when the input signal isloud, the wah wah centre frequency is highand as the input decays, the wah wah fre-quency decreases with it. The effect of thisis to make a wah sound automaticallywhenever a string or chord is played.

The output from this section is buf-fered and adjusted in level by IC3d. Afterthis the signal passes to the signal expansionstage built around IC2b. C23 provides DCisolation and R36 converts the input voltageto a suitable drive current for the IC. Forthis application the linearising diode cur-rent is held constant while the amplifier biascurrent is varied. Q1 in the compressor cir-cuit provides the control current for thisstage allowing a good match in the attenua-tion/gain characteristics of the two stages.SW3 selects either the output from the ex-pander or bypasses it as required to givenormal or sustain on the effects channel.

A dual gang potentiometer RV4 allowsmixing between the original signal and theeffect -modified signal. This is followed by avolume control RV5 to set the output soundlevel.

After the volume control, IC5a buffersthe signal before applying it to the tone con-trol circuit around IC5b. The configurationused here is a very common type of feed-back arrangement. As an approximation,

the gain of an op -amp with feedback istaken as -(feedback resistor value)/(inputresistor value). If we replace the feedbackand input resistors with variable im-pedances, we find that when the feedbackimpedance is greater than the input im-pedance then the overall gain is greater thanunity, and vice versa. As impedances varywith frequency, the gain at each frequencywill tend to be different. The only time thegain does not vary is when the input andfeedback impedances are equal whatevertheir magnitude. This is the general princi-ple on which the tone control networksoperate.

The final section to be considered is thepower amplifier stage. Voltage amplifica-tion is provided by IC6 and the output fromit drives two complementary compoundDarlington pairs, Q4/Q6 and Q5/Q7.Quiescent current through the outputdevices is set by RV8 in conjunction withQ3, R54 and C19. R59 and R60 aid in main-taining bias stability and provide some pro-tection to the output transistors in the eventof a fault. R61 and C20 compensate forload impedance variations at high frequen-cy and C18 reduces the high frequency gainof the power amplifier to reduce thepossibility of RF oscillation. The largecapacitors C21-25 are to reduce the effectsof aging batteries and prevent low frequen-cy oscillation or intermodulation distor-tion.

The construction details, parts list and overlays will appear next month. OM


Computer Survey

System: Pied PiperSystem: Panasonic HHCOperating System: Snap

Operating System: CP/MProcessors: Z80A

Processors: 6502

RAM: 8K

RAM: 64KPrinter I/O: P

Printer I/O: Peripheral Connector

One 51/4" floppyRAM Modules available

Disk Drives Inc:Disk Drives Inc:

Screen Format: 40x24 (TV)Screen Format: 26 Char LCDGraphics: 159x8

Graphics: 10 Graphic Characters Sound: N

Sound: N Colour: N

Colour: N Keyboard: Qwerty

Keyboard: Integrated Software Included:Software Included: BASIC, Perfect Software Available:

Snap

ar Panasonic software availableWriter/Speller/Filer/Calc Primary Market: Home or Business

Software Available: Extensive Manufacturer: PanasonicPrimary Market: Home or Business Available From: Computer book & supplyManufacturer: Semi -Tech Microelectronics center

Price: $549.00Available From: To be announced in Sept.Price: $1900.00 Other: Built in rechargable batteriesOther:

System: PC -4

Operating System: BASICProcessors: ProprietaryRAM: 5KPrinter I/O: $109.95Disk Drives Inc: Cassette $54.95Screen Format: 12 charater LCDGraphics: N/ASound:Colour:Keyboard: QwertySoftware Included: BASICSoftware Available:Primary Market: Business or homeManufacturer: TandyAvailable From: Radio ShackPrice: $99.95Other: I K RAM module

System: PC -IOperating System: ProprietaryProcessor: ProprietaryRAM: 1.9KPrinter I/O: Radio Shack onlyDisk Drive: NoScreen Formal: 24 char. LCDGraphics: NoSound: NoColour: NoKeyboard: Calculator styleSoftware Inc.: BASICSoftware Avail.: LimitedPrimary Market: Home and businessManufacturer: TandyAvailable From: Radio ShackPrice: $159.95

uts ILL Ili NO.

.1.1 LIU W.V. Is. 114. 14. II la IS1\ tail WI

W.Li. 1.11. us. is lia it IS

Us Us {Iii t7 i uk. ut, u. u. U. IS In IIIU.sa. ut. Us. IR

System: PC -2

Operating System: BASICProcessors: ProprietaryRAM: 2.6KPrinter I/O: All -in -one printer/plotter/dual

cassette interface $299.95Disk Drives Inc:Screen Format: 7x156 LCDGraphics:Sound:Colour:Keyboard: QwertySoftware Included: BASICSoftware Available: ExtensivePrimary Market: Home or businessManufacturer: TandyAvailable From: Radio ShackPrice: $269.95Other: 4 or 8K RAM module available

System: Super 400

Operating System: DOS

Processors: 6502

RAM: 48KPrinter I/O: S, P & 8 Exp.Disk Drives Inc: Opt. DiskettesScreen Format: 40x24

Graphics: 192x180

Sound:Colour:Keyboard: IntegratedSoftware Included: DOSSoftware Available: ExtensivePrimary Market: Home or businessManufacturer: Arcomp, MontrealAvailable From: Chen KollPrice: $650.00

Other: Apple Compatible

14111111k


4032BASIC650232KP & IEEE

40x25128 Graphic CharactersYNIntegratedBASICExtensiveTeaching toolCommodoreLocal dealers$1095.00

System:Operating System:Processors:RAM:Printer I/O:Disk Drives Inc:Screen Formal:Graphics:Sound:Colour:Keyboard:Software Included:Software Available:Primary Market:Manufacturer:Available From:Price:Other:

8032BASIC650232KP & IEEE

80x25128 Graphic CharactersNNIntegratedBASIC

Business or homeCommodoreLocal dealers$1395.00

System: Oric 1Operating System: BASICProcessor: 6502RAM: 48KPrinter I/O: YesDisk Drive: YesScreen Format: N/AGraphics: Med. res.Sound: YesColour: YesKeyboard: IntegratedSoftware Inc.: BASICSoftware Avail.: LimitedPrimary Market: PersonalManufacturer: Oric, U.K.Available From: GladstonePrice: $399.00


There's Nothing Like Electronics Today As AGift For The Canadian Electronics And

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Projects: Each issue of ETI contains three or more projects forthe do-it-yourself builder; they cover audio, computers, testequipment, and various useful gadgets for the home and car.Each project features a complete how -it -works approach,printed circuit or perforated board artwork, concise construc-tion details and parts lists. Give them an ETI project; they'll beout of your hair for hours.

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Computers: Coverage of both ends of your computer: col-umns and articles from the user's point of view, including soft-ware listings and novel ideas, as well as the hardware approachto how it works and how to make it do more. Computerreviews that let you in on the performance of the latest modelsavailable in Canada. News and reviews of peripheral equip-ment. Everything except how to pay for it.

General: News of the latest products and happenings intechnology; in-depth coverage of technical stories that tend tobe over -simplified by the popular media. Stories to stimulateawareness of Canadian science. A series of articles and col-umns on both analog and digital circuit design. Cartoons andhumour to tickle your circuitry.

And It's Canadian! When trouble arises trying to locate thatspiffy little computer card made in California, ETI listsdomestic sources and prices, and, of course, has advertisingthat is largely Canadian. Beauty.Subscriptions! You save $14.05 over the single -copy price bysubscribing, and gift subscriptions save even more through theWintario Half -back program, of which you'll find details onanother page. Get your teeth a brighter, sparkling white, andthen subscribe to ETI!

Sec ronicsToaaySuite 60125 Overlea BoulevardToronto, Ontario M4H 1B1

HOLIDAY GIFT SUBSCRIPTION CREDIT NO. 1460Send my one-year gift of Electronics Today to the person named below andbill me later for only $18.95. I save $14.05 off the $33 single -copy cost.

Credit to the Account E XACTLY _L 4 0 8:5 L tr::!;B1335/

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City State Zip City State ZipEl In addition to my gifts, please renew or E Bill me later. E Payment enclosed.

start my own subscription for only $18.95MAIL TO:

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El In addition to my gifts, please renew or El Bill me later. E Payment enclosed.start my own subscription for only $18.95

MAIL TO:25 Overlea Boulevard,Suite 601Toronto, OntarioM4H 1B1

tit lut&Iceb_JAuthorized Signature

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IIIKKV62'7001;0011°411114*teliK__.tirsogro::0/111111*-1"'

latla

System:Operating System:Processors:RAM:Printer I/O:Disk Drives Inc:


SV 318BASICZ80A32KPeripheral & Exp. BusOpt. floppy, cassette, or cartridge

YYIntegrated, QwertyBASICExtensiveHomeSpectravideo, Hong KongSpectravideo5379.75Built-in cursor control Joystick

System: Multiflex SystemOperating System: CP/MProcessor: Z80RAM: 64KPrinter I/O: YesDisk Drive: Yes

Screen Format: N/AGraphics: NoSound: NoColour: NoKeyboard: OptionalSoftware Inc.: NoneSoftware Avail.: ExtensivePrimary Market: BusinessManufacturer: ExceltronixAvailable From: ExceltronixPrice: $994.00

System:Operating System:Processors:RAM:Printer I/O:Disk Drives Inc:Screen Format:Graphics:Sound:Colour:Keyboard:Software Included:

Software Available:Primary Market:Manufacturer:Available From:Price:Other:

SuperPETBasic6502 & 680996KS & IEEE

80x25128 Graphic CharactersN

NIntegratedWaterlooAPL/BASIC/COBOL/ FOR-TRAN/PASCALExtensiveTeaching toolCommodoreLocal dealers$1795.00


TK 8000Basic650248K7 Board ConnectorOpt cassette or drives40x.24280xI92YYIntegratedBASIC (integer and Applesoft)ExtensiveHome or BusinessChen EnterprizeC & H Electronic's Plus5699.00CP/M Opt

111

Ns oil di Ili


TRS MC -10BASIC68034KS

Optional cassetteTVBlockY

YIntegrated, QwertyBASICExtensiveHomeTandyRadio Shack5199.95Printer available, expandable to20K

System:Operating System:Processor:RAM:Printer: I/O:Disk Drive:Screen Format:Graphics:Sound:Colour:Keyboard:Software Inc.:Software Avail.:Primary Market:Manufacturer:Available From:Price:

TRS-80 Model 100Proprietary800858KYesNo40 X 8 LCDBlockYesNoIntegratedBASIC, telecom, textfiles, etc.LimitedHome and business portableTandyRadio Shack51099.00

System: TRS-80 Colour ComputerOperating System: BASICProcessors: 6809ERAM: 16KPrinter I/O:Disk Drives Inc: Optional disks or cassettesScreen Format: I6x32Graphics: 192x256Sound:Colour:Keyboard: IntegratedSoftware Included: BASICSoftware Available: ExtensivePrimary Market: HomeManufacturer: TandyAvailable From: Radio ShackPrice: 5449.00Other: Optional Joystick, Mouse, &

Multipack Interface

Um

MINPRIS

System: Tiger 4000Operating System: DOSProcessors: 6502 & Z80ARAM: 64KPrinter I/O: 8 slotsDisk Drives Inc: CassetteScreen Format: 40x24Graphics: 280x192Sound:Colour:Keyboard: IntegratedSoftware Included: Spreadsheet, word processorSoftware Available: ExtensivePrimary Market: Home or BusinessManufacturer: TEO ComputersAvailable From: TEO ComputersPrice: 5849.00Other: Apple compatible, CP/M

upgradable

System:Operating Sys em:Processors:RAM:Printer I/O:Disk Drives Inc:


TPC 8300Ext BasicCMOS6KP

Printer -plotter -cassette intefaceavailable48x2 LCD255 Graphic CharactersNNQwertyExtended pocket BASIC10 free programs includedBusinessTEO ComputersTEO Computers5499.00Portable, battery or adaptorpower


Computer SurveyN.7.2 200

System: T199 4A Chen Koll, 3987 Chestwood Dr., Downsview, On -Operating System:Processor:

BASICTMS9900 I6 -bit

tario, M3J 2R8. (416) 636-2116.®le asRAM:Printer I/O'

16KNo

. ilia il6 OkAO lir 411111111ft ta C & H Electronic's Plus, 23 Passmore, Unit 11, Scar-DiskADrive: No

ago A an we wr if8 it Sit wow borough, Ontario, M1V 2V8. (416) 292-0813.Screen Format: 32 X 24

---,----=--Graphics: Block Computer Book & Supply Center, 253 Eglinton Ave.System: VZ 200Sound:

Colour:NoNo

West, Toronto, Ontario. (416) 489-3625.

Keyboard: Integrated Operating System: BASIC

Software Inc.: TI BASIC Processors: 6502 Dragon Data (Canada) Ltd., Continental Bank

Software Avail.:Primary Market:

TI ROM PacksPersonal

RAM: 4KPrinter I/O:Peripheral expansion bus

Building, 130 Adelaide St. West, Suite 1818, Toronto,Ontario, M3H 3P5. (416) 947-9052.

Manufacturer:Available From:Price:

Texas InstrumentsLocal dealers$499.95

Disk Drives Inc: cassetteScreen 1632Format: x

Graphics: I28x64Sound: y

Electronic Playworld, 1726 Avenue Rd., Toronto,Ontario, M5M 3Y6. (416) 789-3596.

Colour: Y

Keyboard: Moving -key rubberSoftware Included: BASIC

Essna Services Ltd., 31 Progress Court, Unit 1, Scar -borough, Ontario, MIG 3V5. (416) 438-8060.

<!,1'..* 11 \

Software Available: Extensive by Video TechnologyLtd.

Primary Market: HomeManufacturer: Video Technology Ltd

Exceltronix, 319 College St., Toronto, Ontario,MST 1S2. (416) 921-8941.

Available From: Rocelco Inc.Price: $179.50Other:

Franklin Ace Computers, 1941 Leslie St., Don Mills,Ontario, M3B 2M3. (416) 449-9339.

,..

,,,,:,.4.,, , Gladstone Electronics, 1736 Avenue Rd., Toronto,

Ontario, M5M 3Y7. (416) 787-1448.

,,.:, \\ . Hewlett Packard, 6877 Goreway Drive, Mississauga,Ontario, L4V 1M8. (416) 678-9430.

v`, Interactive Micro Systems, 22 Strathearn Ave., Unit 6,

Brampton, Ontario. (416) 791-0543.System: UnitronOperating System:Processors:

MSDOS6502 System: VIC 20

Irwin Electronics, '165 North Queen St., Etobicoke,Ontario. (416) 626-6600.

RAM: 48K Operating System: BasicPrinter I/O: 8 Exp. slots Processors: 6502 Micro Bazaar, 23 Westmore Dr., Unit 5, Rexdale, On -Disk Drives Inc:Screen Format:

Opt. cassette or floppy80x25

RAM: 5KPrinter I/O: S

tario, M9V 3Y7. (416) 745-4740.

Graphics: Medium Res. Disk Drives Inc: Opt cassette or cartridgeSound: Y Screen Format: 22x23 Micos Computer Systems Inc., 1295 Eglinton Ave.Colour: Y Graphics: 178x184 East, Cooksville, Ontario, L4W 3E6. (416) 624-0320.Keyboard: Integrated Sound: Y

Software Included: MSDOS Colour: Y Micro Computers of Canada Inc., 3410 MidlandSoftware Available: Extensive Keyboard: Integrated Ave., Unit 6, Scarborough, Ontario. (416) 293-3885.Primary Market: Business Software Included: BASIC, gameManufacturer: Unitron Computer Corp. Software Available: ExtensiveAvailable From:Price:

Unitron Computer Corp.$1349.00

Primary Market: HomeManufacturer: Commodore

Orion Electronics Supplies Inc., 40 Lancaster West,Kitchener, Ontario, N2H 4S9. (519) 576-9902.

Other: Apple Compatible Available From: Local dealersPrice: $319.95 Polytech Int. Canada Ltd., 1262 Don Mills Rd., SuiteOther: 92, Don Mills, Ontario, M3B 2W7. (416) 445-4270.

Radio Shack Computer Centre, 329 Bay St., Toronto,Ontario. (416) 365-7207.

SGV Marketing 1520 Trinity Dr. Unit 16, Mississauga,Ontario, L5T 1T6. (416) 673-2323.

geirg"3"11i-ratan% VP VII MOtek "I "''' - .4.1e, tri rlik Isre VS tri I''''' Ms rill III°

Pet Tr la, 01111MIS ak't' Ifik CO ill til

tivell

Spectravideo, 2913 Lakeshore Blvd. West, Toronto,Ontario, M8V 1J3. (416) 252-4550.

Spiral Computers, 473 Church St., Toronto, Ontario,M4V 2C5. (416) 927-8440.

Teo Computers & Peripherals Inc., 218 YorklandBlvd., Willowdale, Ontario, M2J IRS. (416) 493-8558.

System:Operating System:

UR PortabrainCP/M

Total Office Systems Ltd., 1050 McNicoll Ave., Unit

Processors: System: ZX81 14, Scarborough, Ontario, M1W 2L8. (416) 493-3575.RAM: 64K Operating System: BASICPrinter I/O:Disk Drives Inc:

2 S & P51/4" floppy, RAM disk (192K)

Processor: Z80RAM: 1K

Unitron Computer Corp., 298 Dundas St., London,Ontario, N6B 1T8. (519) 672-3806.

Screen Format: N/A Printer I/O: Sinclair onlyGraphics: N/A Disk Drive: NoSound: N/A Screen Format: 32 x 24 ET1Colour: N/A Graphics: BlockKeyboard: N/A Sound: NoSoftware Included: CP/M & Communications Colour: No

Package Keyboard: MembraneSoftware Available: Extensive Software Inc.: ZX BASICPrimary Market: Business Software Avail: ExtensiveManufacturer: Universal Research Primary Market: PersonalAvailable From: Micro Bazzar Manufacturer: Sinclair/TimexPrice: $1495.00 Available From: various dealersOther: Portable Price: $69.95


8502 COMPUTERSPECIAL SALE

(THIS MONTH ONLY)PACKAGEISSK Klt 5500.00

o8K A 6 T Mother Board (wlblenk Eprome)Keyboard enumerle keypad and OIL casecaseSwitching Power Supply

PACKAGE II486 Computer KitDisk Drive (Quentin)Controller CardZenith 12" Monitor

ntie.00

1. VZ200 Compute...Complete $169.952. 16K Exp. Module $19.953. Printer Interface $39.054. Colour DOT Matrix Printer/Plotter $299.055. Joystick (Pair) $39.95S. Light Pen 1129.957. Data Recorder 510.95

Many Software Cassette Available at $13.95 each

AUDIO KITS

Bulit.in Selectable Switch !or Hign PowerMono Amp. or High Ouality Stereo Amp. On.board Power Supply end Dellay-On, speakerprotector

. All Pare including Power ire. and Heatsinksare Mounted onboardRequired Power Transformer 4133/CT.72vCT,5.10A /7777A Kli 599.50

A67 51213.50

LED Bar Graph or DOT Display with Responseto Freq. front 30HZ - 18 KHZDirect Connects to Preamp. or Power Amp.OutputLeft or Right Ch. Display SelectionInput Level ControlComplete with all Electronic Parts, Trans.I ormer and Pre -drilled Rack Mount Cabinet.STA2930 6119156.60

A8.71206.50

ELECTRONIC KITS

STEREO SPEAKER PROTECTORProtects your speakers and Power Amp. fromDamage due to Accidental Shorted Output cit.vit. Overloading and Excessive Output D.C.

oltageWith Delay on and LED IndletionA must foam D.C. OCL Power An..eMS038 Kit 912.50

A87110.50

PACKAGE III64K Computer KitDisk Drive (Quentin)Controller CardZenith 12" Monitor

51040.00

PERIPHERAL CARDS (ASSEMBLED &TESTED)

1. Language Card 372.002. 16K RAM Card 555.50J. ZOO Card 570.004. BO Column Card $44.505. Disk Controller Card $50.00B. RS232C Serial Card $72.007. EPOS°. Writer Card 510.008. Communication Card $85.009. Parallel Card with Cable $67.00

ACCESSORIES1. R.F. Modulator2 Joystick3. Disk Drive (Cotentin)4. Zenith 12" Monitor5 Verbatim Datalife Diskette

p.3.0.0. soft boxMelo box

6. Light Pen SYetrn0225.00

515.00524.00

3340.00$137.00

533.00535.00

iip..7 Graphic Table$149.00

120W MOSFET POWER AMP.

Based on ETI Design. Australian issue. Jan.1951High Speed High Reliability Moslet Output -The latest Trend In Power Amp. DesignSuperb Sound ReproductionRequired Power Transformer 80CT SAsTA477 $ 51.50

AST 1109.60

100W MOSFET POWER AMP.(Based on Haller Design)P.C. Board and Trs. Package 559.50

150W MOSFET POWER AMP.(See ETI Sept. 1ee2 issue for details)Transistors Package 546.50

COLOUR LIGHT CONTROLLER

Features Light Chaser and Colour OrganFunctionsLight Chaser in 3 Different Flashing Sequencewith Speed Control3 Channels (Treble. Midrange It Bass) ColourOrgan each with individual Input Level COMtrOlIdeal for Disco. Amusement Park, CommercialSigns and Special Light Effect - Handles upto 1,000W Light Power

Kit 579.50AST 599.50

Ideal lot Hobbysits, Experimenters and Shoal Pr'acts.

1 Touch on/off switch with Relay $11.5e

2. Light Activated Switch with Rally MAO3. Electronic Lock with Relay 111.50

O. Sound Activated Switch with Relay 15.505. Electronic Timer with Relay.

0.3.100 Sec 312506 F M Mike with Cigarette fee WM/7, High Sensitivity Homer F.M. Mike

vocase $12.508. A.C./D.C. 12D Quarts Green

Digital Clock $15.509. 12V D.C. Red Digital Clock $12.5010. Single Channel Color Oren 113.50

11. SoundlLight Activated Switch wIlleley $11.5012 infra Red Control Switch wiealay $24.5013. LED Panel Meter $42.50

SEMICONDUCTORSHITACHI Hostel 25(134, 2S.149 512.95 ea.MJ15003, 51J15001 MOO..2113055. MJ2955 30.75 en2SA1051A. 2SC2481A 515.00es

lee ea_01.80e.

265550.265401265415. 263x40, BF470, BF489

SCREW TYPE CHASSIS PUNCHING TOOLSET

For 18,18, 20, 25,30, M.M. Holes 533.50

TEST EQUIPMENT

12 STEP "PEAK HOLD" POWER LEVELINDICATOR

44 Aveiv=iir'ennow 'eg*. .......

SO

Connects direct to Power Amp Output3 Color LED 2 Ch. Indicationtor Power Amp. up to 10055Operates on DC 542Videal or Horne and Auto HI-FI SystemsComplete with Plastic Case and Front Panels1Y.2313 Kit $2950

AST 539.50

PAINI.LAB

M1h/it/Function and Multi.Purposelesinse Tester,Including Field Strength Indicator. A.F./R.F. sign.'Generator, Resistor/Condenser Substitution andNeer SupplySSE -400 595.00

"HELPING HAND."

Holds work in any pOsition - Free your lendsforce. $10.50

8502 COMPONENTS1. 18K AST Mother Board

(wfblank Estoril $300.002. 641( A It T Mother Board

(w/blank Euro.) 6345003. Numeric Keyboard $1007034 Case 580.005. Delue Case 5105.00B. Switching Power Supply 508.507. Numeric Keyboard . Case 5180.00

B. Numeric Keyboard Deka Case 6205.009. Numeric Keyboard + Case

Switching Power Supply $275.0310. Numeric Keyboard 3 Deli. Case

.1- Switching Power Supply $300.0011. Linear Power Supply Kit. 529.5012. Power Transformer $20.0013. Linear Power Supply Kit

and Power Transformer. $449.50

We repair 6502 Mother Boards at reasonablecharge,.

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RF output to TV and Video output tomonitorComplete with AC Adaptor, DemonstrationProgram. All Required Cables, T.V.Transformer/Switch. and 3 Manuals.

$169.95

D.C. FET SUPER CLASS A PREAMP.

High Quality High Output Direct Coupling EMIPreamp. with exceptional Low Noise Leveland Wide Dynamic Freq. Response RangeOnboard Regulated Power Supply and Delay,on Systemkeel Partner for any High Quality High PowerAmplifierI1A2200 Kil USN

AST 585.00Power Transformer, 72VCT, 2A 1610

BAR/DOT AUDIO LEVEL DISPLAY

some Leery. eery ST -

71-1TiT

20 Step BAR/DOT Mode Audio Level Display- Range horn -570$ to 0 DBCompatible with any Power Amp.Ideal Ior Power Output Indication and addsExciting Sight to your SystemOn -board Power SupplyOperates also on 120 DC Car BatterysTY.45 KIt 042.50

AST $57.50

10 BAND EQUALIZER PREAMP.

Combination of a Stereo Preemie. and A 10Band Slide Control Graphic Equaliser in a 19"Low Profile Pre -drilled Rack Mount CabinetTransformer, Instruction and all ElectronicParts Included./TA -2500 KR 01211,50

AST $179.50

SOLID STATE STEREO REVERBERATIONAMP.

Adds Depth and Exciting "Hall Effect" to yoursystem - "Bucket Bridgate Device'. Ulllileedas Delay ElementLED Reverberation Level DisplayToole Reverb. Control.Depth, Delay and Elliot- Compatible with any Preamp and PowerArno - Complete with all ElectrOnIC Palls,Transformer and Pre -drilled Rack MountCabinet.IOTA -2100 KIt .131.50

AST e1ee.10

POWER SUPPLY KITS(Power Trynelormer not included)1. 0353. 2.50 Regulated Variable Voltage Power

Supply1176.503 Kit $14 50

AST 020.502. a 50 70V. 0.2A, DC Servo Circuit and

Regulator for Powder Stage. Ideal for HighQuality Power Amp.ITR.747 Kit 025.50

AST $35.503. 15-18V, 0.IA Power Supply for Pre -Amp.

SMS9090 KIt $7.10AST $10.50

4. 2 Regulated Power Supply for StereoPreamp. and Ricer Amp.IMS9191 Kit $39.50

AST $49.505. 0.300, IA Variable Voltage Power Supply

CmAdletal Wiese. Meters and Transformer11711.8815 Kit 564.50

AST 064.59

MULTIMETERS

0101 U-10 U-20

U-101 DG 10K/V, AC 4K/v $37.50010 AC/DC 214N 1119.50U 20 DC 106N. AC 4 514/V $24.50

LOGIC PROBE 021.10

For quick servicing and checking of Islegryted logic systemUnique mult/lemp readoutsFeatures pulse detectionMax. input freq. Displayed:30 MHZMM. Detectable pulse width,20 yeInput Overload Protechen

DESOLDERING TOOLS

DT.200 512.50

1111111111r.14.819f

07.500

SIP IC EXTRACTION TOOL&tractile. LSI, MSI and Set DevicesSome lo 40 Pins $250

LOGIC PULSER $33.50

tsr-so'5.1A Valuable Tool for Troubleshooting DigitalEquipmentTo inject Pulses into Circuit nodes withoutcutting Traces, or Removing ICsAn EffectNe Method of Locating Faults inLogic, Connections or, Components

AUTOMATIC WIRE STRIPPER

licznimmimstPower Transformer.1. 54VC7.0.5A 55.702 110VCT. 0.5A 513.503. 30VCT, 2A $9.504. 18VCT, 5A

BRIDGE RECTIFIERS1. 200V 25A 5.3.502. 2000 BA $1.953. 2000 3A 01.25

RACK MOUNT CABINETS TOOLS

LED AUDIO SPECTRUM ANALIZER

Blank Anodised Aluminum Front Panel with SteelBoa, Hardware, Ventilation Slots and Instruction.

Panel sue(inch) Box size (inch) Price19 x 7 ' 17 x 6.5 x 20 87.5019 x 6 17 x 5.5 x 14 45.5019 x 7 17 x 6.5x 12 43.5019 x 6 17 x 5.5 x 12 42.5019 x 5 17 x 4.5 x 12 39.5019 x 4 17 x 35 x 12 38.5019 x 3 17 x 2 5 x 10 33.5019 x 2.5 17 a 2 x 10 32.5017 a6 15 5 x 55 .9 37.5017 a 4 155 x3.5 x9 32.5017 x 2 15 5 x 15 x9 30.5012 a 6 II 5 a 5 5 a 7 28.5012 a 0 115x3547 22.5012 x 2 I I 5 a 175 x 7 21.50

MINI -DRILLOperates on UM 3 e 4 or A.G. Adaptor 8120, M..15V.2A

410

Speed, 2200 RPM. ideal for drilling and grinding p.c.Ward. aluminum and copper sheets, etc.

Drill $23.50Stand $22.50

ELECTROLYTIC CAPACITORSI 33,000 MFD 50V 012.502. 10.000 MFD 1000 $10.003. 10,000 MFD 80V 115.004. 10,000 MFD 50V $9.50

S 3.300 MFD 50V toesS 2,200 MFD 50V $3.257 I.000 MFG 50V $1.00

ILLUMINATED SWITCHESI Locker on/off 125V 150 53.502. Push onioll 125V 10A $2.80

SELECTOR SWITCHES) tit Gang Push Switch with ROWNIKnote $4.50

Rectangular Knobs $5.002. Rotary Switch, W. Shaft SPI IT, 2P2T 2P5T,

2PEIT.3P4T,4P3T.6P31 See.

VARIABLE RESISTORSA. 50KD 16MM Double Gang PotB. Semi V.R.

3K, 5K, 50K, 2506500K es ea.

FUSESA 05 x 20MIA

0 5/3.1A, 2A. 3A, 40 or 5/3 Pug 10/505

5 06 a 30MM0 5A.1A,2A.3A.4A,5ASA or i OA Pup 10/505

AUDIOVISIONCOMPUTING/ELECTRONICS

Parts, Kits and Accessories

Toronto Store:578 Marlee Ave. (just Westof Glencairn subway),Toronto, Ont. M6B 315 Tel.(416) 781-3263Western Canada:

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diamairn

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Mall Order:Certified cheque, money order, Visa,Mastercard plus 5% delivery charge.Ontario residents add 7% P.S.T. Wesend Canada Post or Purolator col-lect

Military Lasers Continued from page 41

optical components in quantity. Theyhave developed a rocket driven magneto -hydrodynamic (MHD) generator whichproduces 15 megawatts of short term elec-tric power, a device which has no counter-part in the West. The Soviets have com-mitted to development moderate -powersystems capable of short range ground -based applications such as tactical airdefense and antipersonnel weapons. It isbelieved that by the latter half of thisdecade, it is possible that the Soviets couldproduce laser weapons for several otherground, ship and aerospace applications.

In response to the perceived threat,the US re -introduced studies in highenergy weapons systems (includingparticle -beam weapons) under the aegis ofthe Defense Advanced Research ProjectsAgency (DARPA). Simultaneously, thethree forces commenced studies of theirown. While complementary in some re-spects, these were being designed for dif-ferent end -user functions.

Army -Navy GameThe Army, for instance, has two weaponsystems under research and development:one, a lower power system, is designed to"craze" the optical and infrared sensorsof missiles and divert them from theirtargets. The other, a higher -powered

ELECTRONICS KITS FM Wireless Mike Music Synthesizer for Alarm, etc.Digtal TachometerDigital Auto -lock Key Motion Alarm Sensor Sensor Training Kit

EMI

$18.9519.9529.9549.9524.9616.95

ASSEMBLED a TESTEDP C. BOARD UNITS

Power Supply with Transformer±5-±15V, 150mAc 2. Adjustable 3r20V,1200mA. Adjustable - - 39.95

Mini Audio Amplifiers5Watts RIM Output 10.952Watts BIAS Output 8.95

ICL8038 Function Generator 36.95 Digital Capacitance Meter

10pF.999uF 42.95 Digital Panel Meter Or399.9mV ----- 49.95Digital Frequency Counters 89.95

6 -digit LED, 114. 2501114rBCD Code DigitM Read OutHigh Sensitivity 30m11 rms

P.C. BOARD HANDICRAFT KIT - 12.00

PARTS;CPU Chips, Memories, Relays, Pots,Registers, Capacitors .

Plus $3.00 each item for postage $ hondlingcharge, except $5.00 for Power supply unitsand PC board handicraft kit. Plus provincialsales tax. C.O.D. mail order accepted.Ask for catalog. NNW inquiries welcome.

KAIENTAI ELECTRONICSP.O. BOX 69126 STATION 'K'VANCOUVER, B.C., CANADA V5K4W4

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system, would destroy helicopters on theNATO front. The Army's success to date,at least publicly, was the destruction ofwinged and helicopter drones at theRedstone Arsenal, Alabama, in 1976.

The Navy's perception of the utilityof such weapons is primarily point defenseof ships, whereby a single laser (codenames Sea Lite) would be computer con-trolled to focus and aim a beam and keepit steady until a series of targets had beendestoryed. As such, the primary thrust oftheir research has been in perfecting thecomputer controlled sub -systems. DAR-PA, in general, needs a similar capabilityfor the space -based laser fire -control andtracking system in order to knock out bat-ches of oncoming intercontinental ballis-tic missiles long before they have reachedearth orbit and are able to release theirweapons. Their major public success todate was when a chemical laser ofmoderate power developed by DARPA,combined with a Navy developed pointer/tracker, successfully engaged and de-stroyed in flight a TOW antitank missilelaunched by a crew of Army technicians.This test was part of the Unified NavyField Test Program conducted at SanJuan Capistrano, California, at a site nearCamp Pendleton in 1978.

It is the Air Force, however, undertheir newly created Space Command,which has done most of the non -DARPAwork. Their efforts have been to develop away to prevent vibration aboard an air-craft when a laser is shooting photons at apower level of more than 1 million watts.Vibration upsets the alignment of the mir-rors that focus and reflect the laser's beamand keep it steady until a series of targetshad been destroyed. As such, the primarythrust of their research has been in perfec-ting the compuer controlled sub -systems.They have two published successes. Thefirst was in 1971, when they used a highenergy gas -dynamic laser of moderatepower and an on -gimbal telescope toshoot down a winged drone at the SandiaOptical Range at Kirtland AFB, NewMexico. Most recently, in July of thisyear, the Air Force used an airbornelaboratory aboard a converted NKC-135plane to successfully destroy fiveSidewinder missiles travelling at 3,000km/hour fired at it by an A-7 fighter-bomber.

Space LasersNext to Air Force expenditures, thelargest proportion of the almost halfbillion dollars being spent in 1984 on HighEnergy Laser (HEL) research is beingspent by DARPA for its space battle sta-tion. Their main interest is in the develop-ment of a space battle station for strategicpurposes. One of the main problems theyface is the optical tracking and locking -inprocess, code named Project Alpha in

general, with the tracking unit known asTalon Gold. Talon Gold has shownenough promise that it is expected to betried aboard the space shuttle some timein 1986 or 1987.

DARPA officials are optimistic thatthe laser battle station they are planningwill be able to shoot down enemy satel-lites, submarine launched missiles orflights of bombers. But such objects willbe sitting ducks compared to counteringland -based intercontinental missiles whichcould be launched by the hundreds orthousands at the US and must be destroy-ed in the early moments of flight. The costof such a shield would be enormous, in-volving at least several tens of such battlestations and "at least 200 billion dollars",according to Pentagon sources. To reducethe cost, there is some thought that DAR-PA should abandon its chemical laserwork and concentrate on developingX-ray or free -electron lasers, work that iscurrrently being pursued at Avco Corpand at the Defense Department's Law-rence Livermore and Los Alamos Labora-tories. Because free -electron lasers areable to transmit power at shorterwavelengths than gas dynamic or chemicallasers, they should permit the design ofsmaller weapons, but to generate power,they need vast amounts of either electricalor nuclear energy. Moreover, short wave-


length lasers also need very precise opticalsubsystems that are not now available.

Reality Steps InYet when all is said and done, it appearsthat while the Army can knock down heli-copters and the Air Force Sidewindermissiles, the potential for a space battlestation to actually work is almost negli-gible. There are two main reasons. Thefirst is atmospheric interference, evenallowing for the considerable problems ofstoring and generating enormous bursts ofenergy, aiming the weapons and verifyingthat the target has been hit. Moreover, ef-fective countermeasures against lasers areknown, and it is likely that they could bedevised for future weapons of this genre.

However, the most effective counter-measure against satellites, whether battlestations or communications satellites, isalso the most chilling form of space war-fare, namely the detonation of a nuclearweapon in space. Such explosions are ex-pressly prohibited by the 1963 Partial TestBan Treaty, but military analysts havenonetheless become anxious about the ef-fect of nuclear explosions on satelliteweapons systems.

Gamma rays and other forms of highenergy radiation from a nuclear explosionwould expel electrons from the metal skinof a satellite and thereby generate an elec-

GAS DYNAMIC LASER - GDL

NEATN2

002}\.CIV

CO; --40 CO2 +-W-0.I0.6µ

ELECTRIC DISCHARGE LASER - EDL

CHEMICAL LASER - CL

DISCHARGEINITIATION SMAINTENANCE

CW/REPETITI VE PULSE

CO; c02+-/N.,rf-s-w.10.6p

VARIANT: CO Sp + OTHER MOLECULES

02 OR H2

CW

(HE( 3. 8 µ

HF)DF.. OF

2.7p.

Three types of lasers used in weaponry.

tric field inside the satellite, the potentialof which could reach a million volts permetre. The electric field would disrupt ordestroy the electronic circuitry of thesatellite. The effects of a one -megaton ex-plosion would extend through a sphericalvolume of space 50,000 kilometres indiameter. Any unprotected satellite in thisrange, but not in the radiation shadow ofthe earth, would be made useless by the

explosion (see Military Communication:The Chaos Factor, ETI, Aug. 1983).

Unless these two problems can beovercome, which is highly unlikely, Presi-dent Reagan's hope that lasers and otherparticle -beam technology can be employ-ed by the end of the century to renderstrategic nuclear weapons obsolete seemsjust so much chaff.

IBM PCTM CAPABILITY

Now availablewith the Parts Galore

Venture 88, a bare 16 bit PCB

forth can be built into a system thatwill run any program compiled

fo te IBM PC using the powerful 8088 Intel microprocessor.

1) 8088 Mother boardwith 5 slots, accepts all IBM hardware and

all for the low price of only ........................$119.95

2) 64K memory board,expandable to 256K, with RS -232 port (IBM

compatible), an excellent PCB at .................. $ 89.05

3) Manual only (costcredited to Mother board purchase) $ 24.95

To see more, buy the manual, wewill credit the full cost of the

manual against thepurchase price of the Mother board within

3 months. See ourad on page 45 for

nice case etc for this PCB.

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5)Please note that we do not provide aM proprietary soft-

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IBM, IBM PCTM Registered TrademarkIBM Canada Ltd

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331 Queen St. W.,(416) 598-0752



by Bill Markwick

THIS MONTH Steve Rimmer is occupiedwith his duties as editor of ComputingNow! magazine. He'll be returning tothese pages in the next few months, aslong as he promises not to use the word"ginchy" more than five times per page.We present instead a short overview ofFORTH, a fascinating computer languagethat is slowly becoming more popular aspeople find out about its unique charac-teristics:1. Reverse Polish Notation, surely themost efficient way to do calculations.2. Speed approaching assembly code.3. A "dictionary" which stores whatevercommands you define.

The language was originally createdby Charles Moore as an aid toastronomers who needed simple rapidcontrol of instruments, but it soon spreadinto the world for general-purpose use.There have been many versions over theyears, each change making the languageeasier to use or suiting it to a specific com-puter, but there are enough similarities toallow a generic approach.RPNLet's start with the RPN. You'll befamiliar with this if you have a Hewlett-Packard calculator. Any numbers youenter will be held in the "stack", a last -infirst -out storage register. The HP stackcan hold four numbers for later manipula-tion, but for most purposes, FORTH canbe considered to have a bottomless pit. Asyou perform operations, usually betweenthe top number and the one under it, thestack pops out the answer, or stores it,and moves up the next next number to thetop. What makes RPN so efficient is thatthe mathematical operators are enteredlast; this eliminates the pesky "equals"sign, and removes any need for keepingtrack of nested parentheses. Here's asample calculation:

20 30 40 + -. RETURN-50 OK

The three numbers were pushed into thestack, with 40 being last in; this puts it atthe top. The plus sign added 30 and 40 togive 70, and then subtracted 70 from 20.The dot command means "display stack -top", and it displayed the answer.

This may seem more trouble than it'sworth; there isn't any great advantageover algebraic calculation at the moment.Where it really shines is in long equationssuch as network analysis or impedancecalculations. It becomes such a delight touse that you'll never want to see the"equals" sign again.

As far as speed goes, FORTH ac-complishes its rapidity by being halfwaybetween an interpreter and a compiler.When you enter something, a section cal-led the interpreter checks to see if it's astring, i.e., an instruction. This inter-preter is a bit different from the BASICtype, which converts each instruction tomachine code by performing little subrou-tines ("print", for instance); instead, thedictionary is checked to see if the com-mand is there. If so, it's performed. Ifnot, a section which handles numbers iscalled in, and the numbers put on thestack. If it isn't either, an error code isprinted.Dictionary DefinitionsThis brings us to the most fascinatingaspect of FORTH, the dictionary func-tion. It allows you to define commandsand store them; they become part of thelanguage, and each user then has his ownpersonalized FORTH. Here's an example.Suppose you often need to square somenumbers. Squaring is not a command inthe FORTH dictionary, so you'd have toadd it yourself. A colon tells FORTH thatyou're defining a new word. Call it"SQR".

: SQR ." THE SQUARE IS " DUP . ;

What all this gibberish means is: "Printthe message. Duplicate the numberentered and multiply the two. Print theresult." Now to use it:

10 SQR (RETURN) THE SQUARE IS 100 OK

Now type "VLIST" and you'll see allthe words in the dictionary scrolling up.At the head will be your word "SQR".The possibilities are endless; you candefine a word using other definitions, andend up with an actual mini -program thatcan be called up with just one word orsymbol.LoopingIn BASIC, you can repeat an operation

any number of times by using theFOR...NEXT loop. In FORTH, we usethe DO...LOOP instruction. For instance:

: DEMO 100 DO CR . " LOOPING " LOOP ;will print "LOOPING" ten times in avertical column, because CR stands forcarriage -return. The 10 and 0 are used tospecify the number of loops; they could beany numbers. The . " symbol is a tokenfor "PRINT". You may be dazzled byhow fast the DO...LOOP is compared tothe FOR...NEXT.

By the way, should you have the soft-ware handy and are doodling with ex-amples, you have to be critical aboutspaces between words and symbols.FORTH is very fussy about this, unlikeBASIC, which ignores spaces. If you keepgetting error messages, chances are it's aspace problem.

What's It Good For?It's good for controlling any outside pro-cess, because the stack manipulations andlogic operators are a natural for con-trollers of all types. It's good for situa-tions where you need special custom com-mands not available in other languages.Its speed makes it ideal for graphics; it's afavourite for computer graphics in filmsor scientific applications.

But most of all, it's fun to use,despite the hassle of having to learn thesomewhat uncomfortable syntax.

Getting GoingFORTH is available from a number ofsoftware dealers for a number of com-puters such as the Apple or TRS-80. Youcan even get it on cassette for the ZX81,from Gladstone Electronics, but keep inmind that FORTH (and its dictionary)was designed for disk systems, and thecassette effort will drive you crazy.

You'll probably want some goodbooks on the language; the best one I'veseen is 'Starting FORTH' by Leo Brodie,Prentice -Hall publishing. Most computersupply stores can advise you on softwareand documentation.

It's not the language for everyoneand every use, but it's one of the most in-triguing.


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FASTRONCOMPUTER INC.250 DUNDAS ST. W. (AT UNIVERSITY) TORONTO, ONTARIO M5T 2Z1

TEL: (416) 591-92176502 CPU 48K $297.00 12" Amber $189.00Numeric Keyboard $ 99.00 Nonglare Monitors5A Power Supply $ 88.00 12' Disco Green $189.00Numeric Case $ 66.00 12" Amber $198.00Complete Kit $550.00

Epson Printer $499.00Disk Controller $ 59.00 CP-80 $550.0016K RAM Card $ 59.00 Slim Drive $315.00Z80 CP/M $ 73.00 Mitac Drive $315.0080 Col. Card $ 85.00 Micro-Sci $325.00Printer Card $ 78.00

Memorex Disk (10) $ 29.75Voice Synthesizer $ 75.00 BASF Disk (10) $ 29.75Eprom Writer $ 98.00 CDC Disk (12) $ 29.50Wild Card $ 98.00 Disk Bank $ 3.99RS232 Card $ 88.00 Printer Paper 14/MSystem Fan $ 50.00 Joystick $ 27.00

Game Tape $ 7.00 IBM PC with 320K Drive CallGame Disk $ 10.00 2nd 320K Drive $ 335

Microsoft Mouse $ 252

ZENITH MONITORS Microprofessor 64K . $ 67512" Green $129.00 Magic Computer $ 2,20512" (New) Green $149.00 Coleco Adam $ 788

MAIL ORDERSAdd $3.00 for shipping & handling. Ontario residents add 7% P.S.T. VISA,

MASTERCARD and AMERICAN EXPRESS cards accepted: send card number,expiry date, name of bank and signature. Send certified cheque or money order.

Do not send cash. No C.O.D. please.

COMPUTERS SOFTWARE. COMPONENTS ACCESSORIES BOOKS RENTAL


miumiummirmnorr="4"110"'NELL/ELLA Ziimm.1IIMMIIIMINMI=Oscillosco es

difi) 4',. cilia so

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with Component Tester

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TELEX 065-28169(416) 661-5585

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ELECTRONICSUMITED


1TZX81 Background ReverseF.W. Picken

This simple circuit uses readily available(and cheap!) components to provide whitesymbols on a dark background. It can beput together on a small piece of circuitboard which could then be housed insidethe case of the computer and held in posi-tion by double -sided tape or epoxy.

The change -over switch, used forswitching from black symbols on whiteand vice versa, can be mounted on the sideof the case, a push -on push -off type pro-bably being the most suitable due to ease

AM11111.

of mounting. The power requirement isvery low, and can be taken from the ZX81supply line.

Action of the circuit is very simple:IC 1 a and c carry the negative -going syncpulse and nothing else, thus ensuring thatthis is not inverted. The remainder of thevideo signal is inverted by IC1b. The valueof RV1 needs careful setting to obtain thebest results.

NOTE.IC1 IS 40118DI IS IN4148

UK2

ZX81MODULATOR

B

IC

CUT CONNECTION BETWEENMODULATOR AND PCB. UK2AND CONNECT A -A AND B -8

Analogue Set -Reset LatchT.P. West

Although CMOS gates are commonly us-ed to provide analogue amplifiers, theoperational amplifier is often overlookedfor use in digital applications. Often, acircuit design calls for a set -reset latchwithin an analogue circuit: this normallyrequires digital circuitry to be included inthe design. By the use of this circuit, spareop -amps in a package may be utilized toprovide the set -reset function. The op -amp used may be of any type with the lowand high voltages at the output being onlya function of the op -amp's internal outputdrive circuitry. The resistors RI and R2should be chosen so that R2 = 2.4R1 andR2 < Vsupply/0.05. Although the circuit isshown for a single supply rail, it will workon a dual supply but produces a low ofaround the negative supply voltage. Allchanges in state occur on the low -to -hightransition.

RESET

SET

TRUTH TABLE

SET RESET OUT

0 0 NC0 1 01 0 1

I 1 1

NC NO CHANGE

D3

VSUPPLY

OUT

'SEE TEXT

NOTE:ICI IS ANY OPAMPD1-3 ARE 1N4148

Where to BuyFLUKE

Digital /AnalogMultimeters

Fluke 70 Series Digital/Analog multimetersare available in Canada through the Jet Stockprogram of Allan Crawford Associates Ltd.,or from the following distributors:Vancouver, B.C.

R.A.E. Industrial Electronics Ltd. 291-8866Instrument Service Laboratories Ltd. 278-4511

Victoria, B.C.Queale Electronics Ltd. 388-6111

Nanaimo, B.C.Queale Electronics Ltd. 758-8166

Vernon, B.C.Interior Electronics Ltd. 545-2394

Kelowna, B.C.Interior Electronics Ltd. 860-0585

Kamloops, B.C.Interior Electronics Ltd. 374-5002

Edmonton, Alta.Cardinal Industrial Electronics Ltd. 483-6266Instrument Service Laboratories Ltd. 463-7488

Calgary, Alta.Cardinal Industrial Electronics Ltd. 259-6817

Regina, Sask.Radio Supply & Service Ltd. 352-8642

Winnipeg, Man.Wes Electronics Ltd. 632-1260

I.ondon, Ont.C.M. Peterson Co. Ltd. 434-3204

Toronto, Ont.Electro Sonic Inc. 494-1555C.M. Peterson Co. Ltd. 247-5437Armatek Controls Ltd. 251-3111Iransmation Canada Inc. 675-5980

Peterborough, Ont.Weesco-Peterborough 745-2493

St. Catherines, Ont.C.M. Peterson Co. Ltd. 685-7377

Kitchener, Ont.C.M. Peterson Co. Ltd. 745-0981

Sarnia, Ont.C.M. Peterson Co. Ltd. 344-3382

Windsor, Ont.C.M. Peterson Co. Ltd. 253-1161

Hamilton, Ont.C.M. Peterson Co. Ltd. 528-0151

Thunder Bay, Ont.C&F Electronic Distributors Ltd. 345-6515

Sudbury, Ont.Sonic Northern Ltd. 674-0764

Timmins, Ont.Sonic Northern Ltd. 264-1228

Sault Ste. Marie, Ont.Sonic Northern Ltd. 254-1418

Ottawa, Ont.Electronic Wholesalers Ltd. 746-4413

Montreal, Que.Electronic Wholesalers Co. Ltd. 769-8851Franklin Electric Canada Ltd. 341-6260

St. Jean, Que.Produits Electroniques en Gros

(St. Jean) Cie. Ltee. 348-4961Chicoutimi, Que.

Franklin Electric Canada Ltd. 545-8313Noranda, Que.

Simtronique Inc. 762-1874Halifax/Dartmouth, N.S.

Weesco-Maritimes 465-3730St. John's, Nfld.

Rideout Tool & Supply Ltd. 745-2240

76-NOVEMBER-I983-ETI

a Allan Crawford Associates Ltd.Test & Measurement Division

Toronto: (416) 678-1500 Montreal: (514) 731-8564 Ottawa (613) 722-7682Halifax: (902) 463-8640 Vancouver: (604) 294-1326 Calgary: (403) 230-1341

Edmonton: (403) 451-4893

The Digitalvs. Analog

battle is over.

25*buys

you the new champion.

The new Fluke 70 Series.They combine digital and analog displays for

an unbeatable two -punch combination.

Now, digital users get the extra resolution of a

3200 -count LCD display.

While analog users get an analog bar graph for

quick visual checks of continuity, peaking, nulling

and trends.

Plus unparalleled operating ease, instant

autoranging, 2,000+ hour battery life and a

3 -year warranty.

All in one meter.

Choose from three new models. The Fluke

73, the ultimate in simplicity. The feature -packed

Fluke 75. Or the deluxe Fluke 77, with its own

multipurpose protective holster and unique

"Touch Hold" function (patent pending) that cap-

tures and holds readings, then beeps to alert you.

Each is Fluke -tough to take a beating.

American -made, to boot. And priced to be, quite

simply, a knockout.

So call for more information.

FROM THE WORLD LEADERIN DIGITAL MULTIMETERS.

Fluke 73si2s.

witS

Fluke 75 Fluke 77SI-O SIN5*

Analog/digital display Analog/digital display Analog/digital displayVolts. ohms, 10A. diode Volts. ohms, 10A. mA. Volts. ohms. 10k rnA.test diode test diode lest

Autorange Audible continuity Audible continuity0 7% basic dc accuracy Autorange/range hold 'Touch Hold" function2000 4- hour battery lite 0.5% basic dc accuracy Autorange/range hold3 -year warranty 2000+ hour battery life 03% basic dc accuracy

3 -year warranty 20004- hour battery life

3 -year warranty

Multipurpose holster

Suggested Canadian price including duty and federal salestax. Provincial taxes extra.

FLU K El


$4.95MM 70980

From Electronics Today Magazine Summer 1983

4LAINT

)111A

,k),,tease write your

complaint in the

square below.

Write legibly. eldirect from

2

Over 150 pages of theBestigrojects

Ever Published in ETI!

Our 19th Year in Business!Gladstone Electronics has been in the forefront ofthe Electronics industry for almost 20 years,continuing to set the Canadian standard for state-of-the-art products in that time. Through mail ordercatalogues, national advertising, and retail storeand warehouse in Toronto, we have grown to bethe leading supplier of technically advancedproducts in this country - and throughout the US.In I969 we introduced to Canada, the Sinclair lineof products from England. and have successfullymarketed their (always ahead of their time)products nationwide -- including the #1 sellingcomputer in the world - the Sinclair 2X81.Adding to our powerful line-up, we are proud todistribute the Acorn Atom, the Micro 48 and nowthe Oric computer.We have enjoyed serving you in the past 2 decadesand look forward to serving you in the future!Write TODAY for our soon to be published Fall '83Catalogue.Gladstone Electronics will stand behind you andyour investment with our full 90 day warranty policy.If there are any problems in that time our capableservice depot is here to serve and help you.

Circle No. 31 on Reader Service Card

Silecla% M49,5Memotech 16KMemory Extension

Dependable 16K RAM Expansion ModuleVersatile module allows access togreater amounts of user dataand an increased variety of moresophisticated software.

SinclairZX8 1

16K Sinclair Computer Package(Includes 2X81 plus I 6K Memory Module) $99.90

Compact Personal ComputerProgrammable 1K home computerwith full range math and scientificfunctions, plus graph drawing andanimated display. Syntax -check andreport codes.Complete with 218 -page Manual!

Gladstone Electronics offers the most complete range of support products for Sinclairand Timex computers in Canada, including the complete range of TIMEX Software!Here are some other examples: GLADSTONE 64K RAM only S159.95! GLADSTONEPROFESSIONAL KEYBOARD and METAL CASE, only $1 29.95!BASICARE modules expand a ZX8I or T/S 1000 up to 1 Megabyte.Request our complete catalogue of TIMEX/SINCLAIR hardware, software & books!

We Make Computing Easy!ORDER

TOLL FREENOW.

1-800-268-3640Have your VISA, MASTERCARD or

AMER. EXP. Ready!

In Ont.416-787-1448

Notes about Ordering.Order now by VISA, MASTERCARD or AMER.EXP., or send money order or cheque.Personal cheques must clear bank before shipment.CODs are accepted when accompanied by 20%deposit. Shipments are fully insured. Cost of insuranceand shipping is added to order - add 5% to coverestimated cost. ANY EXCESS WILL BE CREDITED.

Best Selling T51000/12(81 Software:ZX FORTH $39.95ZX ASSEMBLER $19.95TOOLKIT $19.95Chess I (Enhanced) I 6K $19.95ZX Scramble $19.95Gobbleman $19.95Galaxy Invaders $19.95Tiny Logo $24.95Weight Control $39.95Krakit $24.95Pixel - 'Trader' $24.95

Memotech Add-ons:Memotext $ 79.95Memopak Assembler Si 79.95Memocalc S 79.95Plug-in Keyboard S149.95Centronics Interface S119.95High Res Graphics Pack $119.95Connecting Cable forCentronics Interface $ 35.00Memopack 16K Memory Extension $ 49.9532K Memory Extension $139.9564K Memory Extension S199.95

Mail orders to: Gladstone Electronics, 1736 Avenue Rd., Toronto, Ont. M5M 3Y7

Last nightMark Davis startedover from scratch.Without wasting so much as a lead wire.Some day Mark will be working on biggerprojects. But right now, he's learning.Fortunately, the new ACE 109 solderlessbreadboard from A P PRODUCTS, justmade learning a lot more affordable.

iiiii4V0E 109

ACE 109 SOLDERLESS BREADBOARD

PRICED UNDER $20!*SLGGESTED U.S. RESALE PRICE

The ACE 109 is the newest, lowestpriced All Circuit Evaluator in theA P PRODUCTS line. It has a universalmatrix of 840 solderless plug-in tie -points. And is ideal for designing, testingand modifying small circuits. ACE 109has three, standard 5 -way binding postsfor easy access to power sources.

With an ACE 109, there's no wiring,soldering or desoldering. Just plug inyour components and interconnect themwith ordinary solid hook-up wire. Ifyou want to make a circuit change, justunplug the components involved andstart over. It's just that easy.

Circle No. 39 on Reider Service Card.

Every ACE breadboard makes circuitryeasy, fast, flexible. Now A P PRODUCTShas made it even more affordable. The.ACE 109 is priced under $20!

Look for the complete line of ACEbreadboards and other A P PRODUCTSat your favorite electronics distributor.For more information callLenbrook Electronics.Markham, Ontario - (416) 477-7722St. Leonard, Quebec - (514) 323-3242Surrey, Vancoftver - (604) 585-9599

A P PRODUCTS INCORPORATED 9450 Pineneedle Drive P O. Box 540 Mentor, Ohio 44060. [216) 354-2101. TWX. 810-425 2250

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