mpf-i the monitor (assembled with tasm; final 0,5 inch)

7/28/2019 MPF-I the Monitor (Assembled With TASM; FINAL 0,5 Inch)

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MPF-I

MONITOR

PROGRAM

SOURCE LISTING


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ii

COPYRIGHT

Copyright 1981 by MULTITECH INDUSTRIAL CORP. All rightsreserved. No part of this publication may be reproduced, trans-mitted, transcribed, stored in a retrival system, or translated intoany language or computer language, in any form or by any means,electronic, mechanical, magnetic, optical, chemical, manual or other-wise, whitout the prior written permission of MULTITECH INDUS-TRIAL CORP.

DISCLAIMER

MULTITECH INDUSTRIAL CORP. makes no representations orwarranties, either express or implied, with respect to the contentshereof and specifically disclaims any warranties or merchantabilityor fitness for any particular purpose. MULTITECH INDUSTRIALCORP. software described in this manual is sold or licensed as is.Should the programs prove defective following their purchase, thebuyer ( and not MULTITECH INDUSTRIAL CORP., its distrinuitor,

or its dealer ) assumes the entire cost of all necessary servicing, re-pair, and any incidental or consequential damages resulting from anyDefect in the software. Further, MULTITECH INDUSTRIAL CORP.reserves the right to revise this publication and to make changes fromtime to time in the content hereof without obligation of MULTI-TECH INDUSTRIAL CORP. to notify any person of such revisionor changes.

MultitechINDUSTRIAL CORP.OFFICE/SFL. 266 SUNG CHIANG ROAD, TAIPEI 104TAIWAN, R.O.C.TEL: (02)6511101TELEX: 19162 MULTIIC FAX: (02)5422805FACTORY/INDUSTRYE, ROAD, III.HSINCHU SCIENCE BASED INDUSTRIAL PARKHSINCHU, TAIWAN 300 R.O.C.


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STMT LOC OBJ CODE M SOURCE STATEMENT

0001 0000 ;***********************************************************

0002 0000 ;* *

0003 0000 ;* COPYRIGHT , MULTITECH INDUSTRIAL CORP. 1981 *

0004 0000 ;* All right reserved. *

0005 0000 ;* No part of this software may be copied without *

0006 0000 ;* the express written consent of MULTITECH *

0007 0000 ;* INDUSTRIAL CORP. *

0008 0000 ;* *

0009 0000 ;***********************************************************

0010 0000 ;

0011 0000 ;

0012 0000 FF FF ... .FILL 0800H,0FFH ;Write 0FFH into 2KBytes EPROM.

0013 0800

0014 0800 ;

0015 0800 P8255 .EQU 03H ;8255 I control port

0016 0800 DIGIT .EQU 02H ;8255 I port C

0017 0800 SEG7 .EQU 01H ;8255 I port B

0018 0800 KIN .EQU 00H ;8255 I port A

0019 0800 PWCODE .EQU 0A5H ;Power-up code

0020 0800 ZSUM .EQU 71H ;This will make the sum of all

0021 0800 ;monitor codes to be zero

0022 0800

0023 0800 ; The following EQUATEs are used for timing. Their values

0024 0800 ; depend on the CPU clock frequency. (In this version, the

0025 0800 ; crystal frequency is 1.79 MHz.)

0026 0800

0027 0800 COLDEL .EQU 201 ;Column delay time for routine

0028 0800 ;SCAN and SCAN1

0029 0800 F1KHZ .EQU 65 ;Delay count for 1 kHz square wave,

0030 0800 ;used by routine TONE1K.0031 0800 F2KHZ .EQU 31 ;Delay count for 2 kHz square wave,

0032 0800 ;used by routine TONE2k.

0033 0800 MPERIOD .EQU 42 ;1 kHz and 2 kHz threshold, used by

0034 0800 ;tape input routine PERIOD.

0035 0800

0036 0800 ; The following EQUATEs are for tape modulation.

0037 0800 ; If the quality of tape recorder is good, the user may

0038 0800 ; change '4 4 2 8' to '2 2 1 4'. This will double

0039 0800 ; the tape data rate.

0040 0800 ; If the quality of tape recorder is poor, the user may

0041 0800 ; change '4 4 2 8' to '6 6 3 12'. This will improve

0042 0800 ; error performance but slow down the data rate.

0043 0800 ; Although the data format is changed the tape is still0044 0800 ; compatible in each case, because only the ratio is

0045 0800 ; detected in the Tape-read.

0046 0800

0047 0800 ONE_1K .EQU 4

0048 0800 ONE_2K .EQU 4

0049 0800 ZERO_1K .EQU 2

0050 0800 ZERO_2K .EQU 8

0051 0800

0052 0800 ;***********************************************************

0053 0800 ; I/O port assignment: (8255 I)

0054 0800

0055 0800 ; port A (address 00H):

0056 0800 ; bit 7 -- tape input0057 0800 ; bit 6 -- 'USER KEY' on keyboard, active low

0058 0800 ; bit 5-0 row of keyboard matrix input, active low


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0059 0800 ; port B (address 01H): 7 segments of LED, active high

0060 0800 ; bit 7 -- segment d

0061 0800 ; bit 6 -- decimal point

0062 0800 ; bit 5 -- segment c0063 0800 ; bit 4 -- segment b

0064 0800 ; bit 3 -- segment a

0065 0800 ; bit 2 -- segment f

0066 0800 ; bit 1 -- segment g

0067 0800 ; bit 0 -- segment e

0068 0800 ; port C (address 02H):

0069 0800 ; bit 7 -- tape & tone output

0070 0800 ; bit 6 -- BREAK enable. NMI (CPU pin 17) will go to

0071 0800 ; low 5 M1's (machine cycle one) after this

0072 0800 ; bit goes to low. (This bit is connected to

0073 0800 ; the reset input of external counter.)

0074 0800 ; bit 5-0 -- colums of keyboard and the display matrix,

0075 0800 ; active high. Bit 5 is the leftmost column.0076 0800

0077 0800 ;***********************************************************

0078 0000 RST00 .ORG 00H ;original comment: -- reset --

0079 0000 ; There are two cases that will generate a RESET signal:

0080 0000 ; (i) power-up

0081 0000 ; (ii) 'RS' key pressed

0082 0000 ; In both cases, the following actions will be taken:

0083 0000 ; a) disable interrupt, set interrupt mode to 0

0084 0000 ; set I register to 00 and start execution

0085 0000 ; at address 0000 (by Z80 CPU itself).

0086 0000 ; b) initial user's PC to the lowest RAM address;

0087 0000 ; c) set user's SP to 1F9FH;

0088 0000 ; d) set user's I register to 00 and disable user's0089 0000 ; interrupt flip-flop;

0090 0000 ; In addition subroutine INI will be called on power-up

0091 0000 ; reset, which has the following effects:

0092 0000 ; e) disable BREAK POINT;

0093 0000 ; f) set the contents of location 1FEEH and 1FEFH to 66

0094 0000 ; and 00 respectively. This will make instruction RST

0095 0000 ; 38H (opcode FF) have the same effect as BREAK.

0096 0000 ; Memory location POWERUP is used to distinguish power-up

0097 0000 ; from RS-key. (POWERUP) contains random data when

0098 0000 ; power-up and contains PWCODE (0A5H) thereafter.

0099 0000

0100 0000 06 00 LD B,0

0101 0002 10 FE DJNZ $ ;Power-up delay0102 0004

0103 0004 ; Initialize 8255 to mode 0 with port A input, port B and C

0104 0004 ; output. The control word is 90H.

0105 0004

0106 0004 3E 90 LD A,10010000B

0107 0006 D3 03 OUT (P8255),A

0108 0008

0109 0008 ; When the control word is sent to 8255, all output

0110 0008 ; ports are cleared to 0. It is necessary to disable

0111 0008 ; BREAK and deactivate all I/O by sending 0C0H to

0112 0008 ; port C.

0113 0008

0114 0008 3E C0 LD A,0C0H0115 000A D3 02 OUT (DIGIT),A

0116 000C 31 AF 1F LD SP,SYSSTK ;initial system stack


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0117 000F

0118 000F ; If the content of location POWERUP is not equal to

0119 000F ; PWCODE, call subroutine INI. Continue otherwise.

0120 000F0121 000F 3A E5 1F LD A,(POWERUP)

0122 0012 FE A5 CP PWCODE

0123 0014 C4 C1 03 CALL NZ,INI

0124 0017

0125 0017 ; Determine the lowest RAM address by checking whether

0126 0017 ; address 1000H is RAM. If yes, set user's PC to this

0127 0017 ; value. Otherwise, set it to 1800H.

0128 0017

0129 0017 21 00 10 LD HL,1000H

0130 001A CD F6 05 CALL RAMCHK

0131 001D 28 02 JR Z,PREPC

0132 001F 26 18 LD H,18H

0133 0021 22 DC 1F PREPC LD (USERPC),HL0134 0024 26 00 LD H,0

0135 0026

0136 0026 ; Address 28H and 30H are reserved for BREAK (RST 28H)

0137 0026 ; and software BREAK (RST 30H). Skip these area, monitor

0138 0026 ; program resumes at RESET1.

0139 0026

0140 0026 18 0A JR RESET1

0141 0028 ;

0142 0028 ;***********************************************************

0143 0028 RST28 .ORG 28H

0144 0028 ; Address 28H is the entry point of BREAK trap.

0145 0028 ; If a location is set as a BREAK point, the monitor

0146 0028 ; will change the content of this location to C7 (RST 28H)0147 0028 ; before transfering control to user's program.

0148 0028 ; In execution of user's program, a trap will occur if

0149 0028 ; user's PC passes this location. The monitor then takes

0150 0028 ; over control and the content of BREAK address

0151 0028 ; will be restored. Monitor takes care of everything

0152 0028 ; and makes the whole mechanism transparant to the user.

0153 0028 ; The return address pushed onto stack is the PC after

0154 0028 ; executing RST 28H. The original break address should

0155 0028 ; be one less than that. The following 3 instructions

0156 0028 ; decrease the content of (SP) by one without changing

0157 0028 ; HL.

0158 0028

0159 0028 E3 EX (SP),HL0160 0029 2B DEC HL

0161 002A E3 EX (SP),HL

0162 002B 22 E8 1F LD (HLTEMP),HL

0163 002E 18 0E JR CONT28

0164 0030 ;

0165 0030 ;***********************************************************

0166 0030 RST30 .ORG 30H

0167 0030

0168 0030 ; Instruction RST 30H (opcode F7) is usually used as:

0169 0030 ; i) Software break;

0170 0030 ; ii) Terminator of user's program.

0171 0030 ; The effect of this instruction is to save all user's

0172 0030 ; registers and return to monitor.0173 0030

0174 0030 18 34 JR NMI


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0175 0032

0176 0032 ;***********************************************************

0177 0032 ; This is a part of reset routine. Address 0028 and

0178 0032 ; 0030 are reserved for break point. Reset routine0179 0032 ; skips this area and resumes here.

0180 0032 ;

0181 0032 22 D2 1F RESET1 LD (USERIF),HL ;set user's I register and

0182 0035 ;interrupt flip flop to 0

0183 0035 18 1D JR RESET2 ;monitor resumes at RESET2

0184 0037

0185 0037 ;***********************************************************

0186 0037

0187 0037 ; The following byte makes the sum of the monitor

0188 0037 ; code in ROM zero. ROMTEST is a self-checking routine.

0189 0037 ; This routine requires the sum of ROM to be zero.

0190 0037

0191 0037 71 .BYTE ZSUM0192 0038 ;

0193 0038 ;***********************************************************

0194 0038 RST38 .ORG 38H

0195 0038

0196 0038 ; Entry point of RST 38H (opcode FF) or mode 1 interrupt.

0197 0038 ; Fetch the address stored in location 1FEE and 1FEF,

0198 0038 ; then jump to this address. Initially, 1FEE and 1FEF

0199 0038 ; are set to 0066. So RST 38 will have the same effect

0200 0038 ; as software break. By changing the content of 1FEE

0201 0038 ; and 1FEF, the user can define his or her own service

0202 0038 ; routine.

0203 0038 ; The next three instructions push the contents of 1FEE

0204 0038 ; and 1FEF to stack without changing any registers.0205 0038

0206 0038 E5 PUSH HL

0207 0039 2A EE 1F LD HL,(IM1AD)

0208 003C E3 EX (SP),HL

0209 003D

0210 003D ; The top of the stack is now the address of user

0211 003D ; defined service routine. Pop out this address then

0212 003D ; branch to it.

0213 003D

0214 003D C9 RET

0215 003E ;

0216 003E ;***********************************************************

0217 003E CONT28:0218 003E ; This is a part of break service routine. It continues

0219 003E ; the program at RST28.

0220 003E

0221 003E 32 E7 1F LD (ATEMP),A

0222 0041

0223 0041 ; The monitor has changed the content of user's

0224 0041 ; program at break address. The next 3 instructions

0225 0041 ; restore the destroyed content. BRAD contains the

0226 0041 ; break address, BRDA contains the original data at

0227 0041 ; break address.

0228 0041

0229 0041 2A E0 1F LD HL,(BRAD)

0230 0044 3A E2 1F LD A,(BRDA)0231 0047 77 LD (HL),A

0232 0048


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0233 0048 ; Send break enable signal to hardware counter.

0234 0048 ; A nonmaskable interrupt will be issued at the 5th M1's

0235 0048

0236 0048 3E 80 LD A,10000000B0237 004A D3 02 OUT (DIGIT),A

0238 004C 3A E7 1F LD A,(ATEMP) ; 1st M1

0239 004F 2A E8 1F LD HL,(HLTEMP) ; 2nd M1

0240 0052 00 NOP ; 3rd M1

0241 0053 C9 RET ; 4th M1

0242 0054

0243 0054 ; Return to user's program. Execute the instruction

0244 0054 ; at break address. After finishing one instruction,

0245 0054 ; a nonmaskable interrupt happens and control is

0246 0054 ; transferred to the monitor again.

0247 0054 ;

0248 0054 RESET2:

0249 0054 21 9F 1F LD HL,USERSTK0250 0057 22 D0 1F LD (USERSP),HL ;set user's SP

0251 005A AF XOR A

0252 005B 32 E6 1F LD (TEST),A

0253 005E

0254 005E ; TEST is a flag for monitor's own use. Illegal key-in

0255 005E ; blanking (bit 7 of TEST) and automatic leading zero

0256 005E ; (bit 0) use this flag. Clear it here.

0257 005E

0258 005E DD 21 9F 07 LD IX,MPF_I

0259 0062

0260 0062 ; Address 0066 is the address for nonmaskable interrupt

0261 0062 ; Skip this area, monitor resumes at SETST0

0262 00620263 0062 C3 D0 00 JP SETST0

0264 0065 FF ; Address 0065 is an EPROM erased location.

0265 0065 ;***********************************************************

0266 0066 NMI .ORG 66H

0267 0066

0268 0066 ; Entry point of nonmaskable interrupt. NMI will occur

0269 0066 ; when MONI key is pressed or when user's program is

0270 0066 ; breaked. The service routine which starts here saves all

0271 0066 ; user's registers and status. It also checks the validity

0272 0066 ; of user's SP.

0273 0066

0274 0066 32 E7 1F LD (ATEMP),A ;save A register

0275 0069 3E 90 LD A,10010000B0276 006B D3 03 OUT (P8255),A ;set 8255 to mode 0.

0277 006D ;Port A input; B,C output.

0278 006D 3E C0 LD A,0C0H

0279 006F D3 02 OUT (DIGIT),A ;disable break and LED's

0280 0071 3A E7 1F LD A, (ATEMP) ;restore A register

0281 0074 22 E8 1F RGSAVE LD (HLTEMP),HL ;save register HL

0282 0077 E1 POP HL ;get return address from stack

0283 0078 22 DE 1F LD (ADSAVE),HL ;Save return address into

0284 007B ;ADSAVE.

0285 007B 22 DC 1F LD (USERPC),HL ;Set user's PC to return

0286 007E ;address.

0287 007E 2A E8 1F LD HL,(HLTEMP) ;restore HL register

0288 0081 ED 73 D0 1F LD (USERSP),SP ;set user's SP to current SP0289 0085 31 D0 1F LD SP,USERIY+2 ;save other registers by

0290 0088 FD E5 PUSH IY ;continously pushing them


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0291 008A DD E5 PUSH IX ;onto stack

0292 008C D9 EXX

0293 008D E5 PUSH HL

0294 008E D5 PUSH DE0295 008F C5 PUSH BC

0296 0090 D9 EXX

0297 0091 08 EX AF,AF'

0298 0092 F5 PUSH AF

0299 0093 08 EX AF,AF'

0300 0094 E5 PUSH HL

0301 0095 D5 PUSH DE

0302 0096 C5 PUSH BC

0303 0097 F5 PUSH AF

0304 0098

0305 0098 ; The next two instructions save I register.

0306 0098 ; The interrupt flip-flop (IFF2) is copied into

0307 0098 ; parity flag (P/V) by instruction LD A, I.0308 0098 ; The interrupt status (enabled or disabled)

0309 0098 ; can be determined by testing parity flag.

0310 0098

0311 0098 ED 57 LD A,I

0312 009A 32 D3 1F LD (USERIF+1),A

0313 009D

0314 009D ; The next four instructions save IFF2 into

0315 009D ; user's IFF.

0316 009D

0317 009D 3E 00 LD A,0

0318 009F E2 A4 00 JP PO,SETIF ;PO -- P/V = 0

0319 00A2 3E 01 LD A, 1

0320 00A4 32 D2 1F SETIF LD (USERIF),A0321 00A7 ;

0322 00A7 31 AF 1F LD SP,SYSSTK ;set SP to system stack

0323 00AA

0324 00AA ;The next 8 instructions check user's SP.

0325 00AA ; If the user's SP points to a location not

0326 00AA ; in RAM, display ERR-SP.

0327 00AA

0328 00AA 2A D0 1F LD HL,(USERSP)

0329 00AD DD 21 B5 07 LD IX,ERR_SP

0330 00B1 2B DEC HL

0331 00B2 CD F6 05 CALL RAMCHK

0332 00B5 20 19 JR NZ,SETST0

0333 00B7 2B DEC HL0334 00B8 CD F6 05 CALL RAMCHK

0335 00BB 20 13 JR NZ,SETST0

0336 00BD

0337 00BD ; If the user's stack and system stack are

0338 00BD ; overlayed, display SYS-SP. This checking

0339 00BD ; is done by the following instructions.

0340 00BD

0341 00BD DD 21 AF 07 LD IX,SYS_SP

0342 00C1 00 NOP

0343 00C2 00 NOP

0344 00C3

0345 00C3 11 62 E0 LD DE,-USERSTK+1

0346 00C6 19 ADD HL,DE0347 00C7 38 07 JR C,SETST0

0348 00C9 DD 21 B6 1F LD IX,DISPBF


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0349 00CD 37 SCF ;set carryflag to indicate

0350 00CE ;the user's SP is legal.

0351 00CE 18 04 JR BRRST0

0352 00D0 ;0353 00D0 SETST0:

0354 00D0 ; STATE is a memory location containing the monitor status.

0355 00D0 ; It will be described in detail later. STATE 0 stands

0356 00D0 ; for fixed display pattern. The initial pattern 'uPF--1'

0357 00D0 ; or message 'SYS-SP'... belong to this category. The next

0358 00D0 ; two instructions set STATE to zero.

0359 00D0

0360 00D0 AF XOR A ;set A to 0,also clear Carry flag

0361 00D1 32 E4 1F LD (STATE),A

0362 00D4 3A E2 1F BRRST0 LD A,(BRDA) ;restore the data at

0363 00D7 ;break address

0364 00D7 2A E0 1F LD HL,(BRAD)

0365 00DA 77 LD (HL),A0366 00DB

0367 00DB ; If the user's SP is legal SP is legal (carry set),

0368 00DB ; display user's PC and the content at PC.

0369 00DB ; Otherwise, display fixed message (ERR-SP

0370 00DB ; or SYS-SP or uPF--1)

0371 00DB DC 0B 04 CALL C,MEMDP2

0372 00DE ;

0373 00DE ;

0374 00DE ;***********************************************************

0375 00DE ; Scan the display and keyboard. When a key is

0376 00DE ; detected, take proper action according to the

0377 00DE ; key pressed.

0378 00DE0379 00DE MAIN:

0380 00DE 31 AF 1F LD SP,SYSSTK ;Initialize system stack

0381 00E1 CD FE 05 CALL SCAN ;Scan display and input keys.

0382 00E4 ;Routine SCAN will not return

0383 00E4 ;until any key is pressed.

0384 00E4 CD CB 06 CALL BEEP ;After a key is detected, there

0385 00E7 ;will be accompanied with a

0386 00E7 ; beep sound.

0387 00E7 18 F5 JR MAIN ;Back to MAIN, get more keys

0388 00E9 ;and execute them.

0389 00E9 ;

0390 00E9 ;

0391 00E9 ;***********************************************************0392 00E9 KEYEXEC:

0393 00E9

0394 00E9 ; Input key dispatch routine.

0395 00E9 ; This routine uses the key code returned by subroutine

0396 00E9 ; SCAN, which is one byte stored in A register. The

0397 00E9 ; range of key codes is from 00 to 1FH.

0398 00E9

0399 00E9 ; (i) key code = 00 - 0FH :

0400 00E9 ; These are hexadecimal keys. Branch to routine KHEX.

0401 00E9

0402 00E9 FE 10 CP 10H

0403 00EB 38 24 JR C,KHEX

0404 00ED0405 00ED ; If the key entered is not hexadecimal, it must be a

0406 00ED ; function or subfunction key. This means the previous


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MPF-1


0407 00ED ; numeric entry has terminated. Bit 0 of TEST flag

0408 00ED ; must be set at the beginning of a new numeric entry.

0409 00ED ; This is done by the next two instructions. (If bit 0

0410 00ED ; of TEST is set, the data buffer will be automatically0411 00ED ; cleared when a hexadecimal key is entered.)

0412 00ED

0413 00ED 21 E6 1F LD HL,TEST

0414 00F0 CB C6 SET 0,(HL)

0415 00F2

0416 00F2 ; (ii) key code = 10H - 17H :

0417 00F2 ; (+, -, GO, STEP, DATA, SBR, INS, DEL)

0418 00F2 ; There is no state corresponding to these keys.

0419 00F2 ; The response of them depends on the current

0420 00F2 ; state and minor-state. (E.g., the response of '+'

0421 00F2 ; key depends on the current function. It is illegal

0422 00F2 ; when the display is 'uPF--1', but is legal when the

0423 00F2 ; display is of 'address-data' form.) In this0424 00F2 ; documentation, they are named 'sub-function key'.

0425 00F2 ; They are all branched by table KSUBFUN and routine

0426 00F2 ; BRANCH.

0427 00F2

0428 00F2 D6 10 SUB 10H

0429 00F4 FE 08 CP 8

0430 00F6 21 37 07 LD HL,KSUBFUN

0431 00F9 DA B0 03 JP C,BRANCH

0432 00FC

0433 00FC ;(iii) key code = 18H - 1FH

0434 00FC ; (PC, Addr, CBr, Reg, Move, Rela, WRtape, RDtape)

0435 00FC ; These keys are named 'function key'. They are

0436 00FC ; acceptable at any time. When they are hit, the0437 00FC ; monitor will unconditionally enter a new state.

0438 00FC ; STMINOR contains the minor-state, which is required

0439 00FC ; to dispatch some sub-function keys (e.g. +, -).

0440 00FC

0441 00FC DD 21 B6 1F LD IX,DISPBF

0442 0100 D6 08 SUB 8

0443 0102 21 E4 1F LD HL,STATE

0444 0105 77 LD (HL),A ;set STATE to key-code minus 18H

0445 0106 ;The STATE is updated here. It

0446 0106 ;will be modified later by local

0447 0106 ;service routines if the

0448 0106 ;function-key is PC,Addr or CBr.

0449 0106 ;For function-other keys, STATE0450 0106 ;will not be modified later.

0451 0106 21 E3 1F LD HL,STMINOR

0452 0109 36 00 LD (HL),0 ;set STMINOR to 0

0453 010B 21 41 07 LD HL,KFUN ;KFUN is the base of the branch

0454 010E ;table the offset is stored in A

0455 010E C3 B0 03 JP BRANCH

0456 0111

0457 0111 ;

0458 0111 ;***********************************************************

0459 0111 ;STATE:

0460 0111 ; 0=FIX ;Display fixed pattern, e.g. 'uPF--1'.

0461 0111 ; 1=AD ;The hex key entered is interpreted as

0462 0111 ;memory addres.0463 0111 ; 2=DA ;The hex key entered is interpreted as

0464 0111 ;memory data.


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0465 0111 ; 3=RGFIX ;Display fixed pattern: 'Reg- ' and

0466 0111 ;expect register name to be entered.

0467 0111 ; 4=MV ;Expect parameters for 'Move' function.

0468 0111 ; 5=RL ;Expect parameters for 'Rela' function.0469 0111 ; 6=WT ;Expect parameters for 'WRtape' func.

0470 0111 ; 7=RT ;Expect parameters for 'RDtape' func.

0471 0111 ; 8=RGAD ;Hex-key entered will be interpreted as

0472 0111 ;address name for registers.

0473 0111 ; 9=RGDA ;Hex-key entered will be interpreted as

0474 0111 ; data for registers.

0475 0111 ;

0476 0111 ; Subroutine naming conventions:

0477 0111 ; (i) K???? -- K stands for key, ???? is the key name,

0478 0111 ; e.g. KINS corresponds to key 'INS'. Each

0479 0111 ; time a key ???? is entered, the routine

0480 0111 ; with name K???? will be executed. All of

0481 0111 ; them are branched by table KFUN or KSUBFUN.0482 0111 ; (ii) H???? -- H stands for hexadecimal, ???? is the

0483 0111 ; current STATE. For example, routine

0484 0111 ; HDA will be executed if the entered

0485 0111 ; key is hexadecimal and STATE is DA now.

0486 0111 ; These routines are branched by table

0487 0111 ; HTAB.

0488 0111 ; (iii) I???? -- I stands for increment (+ key), ???? is

0489 0111 ; the current STATE. E.g. IMV will be

0490 0111 ; executed when STATE is MV and '+' key

0491 0111 ; is entered. These routines are branched

0492 0111 ; by table ITAB

0493 0111 ; (iv) D???? -- D stands for decrement (- key), ???? is

0494 0111 ; the current STATE. These routines are0495 0111 ; branched using table DTAB.

0496 0111 ; (v) G???? -- G stands for 'GO' key, ???? is the current

0497 0111 ; STATE. These routines are branched using

0498 0111 ; table GTAB.

0499 0111

0500 0111 ;***********************************************************

0501 0111

0502 0111 ; Hexadecimal, '+', '-' and 'GO' keys may be entered after

0503 0111 ; different function keys. The monitor uses branch tables

0504 0111 ; and STATE to determine the current function and branch

0505 0111 ; to the proper entry point.

0506 0111 ;

0507 0111 KHEX:0508 0111 ;Executed when hexadecimal keys are pressed.

0509 0111 ;Use HTAB and STATE for further branch.

0510 0111

0511 0111 4F LD C,A ;save A register in C

0512 0112 ;which is the hex key-code.

0513 0112 21 4B 07 LD HL,HTAB

0514 0115 3A E4 1F BR1 LD A,(STATE)

0515 0118 C3 B0 03 JP BRANCH

0516 011B ;

0517 011B

0518 011B KINC:

0519 011B ;Branched by KSUBFUN table.

0520 011B ;Executed when '+' key is pressed.0521 011B ;Use ITAB and STATE for further branch.

0522 011B ;STATE will be stored in A register at BR1.


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MPF-1


0523 011B

0524 011B 21 57 07 LD HL,ITAB

0525 011E 18 F5 JR BR1

0526 01200527 0120 ;

0528 0120 KDEC:

0529 0120 ;Branched by KSUBFUN table.

0530 0120 ;Executed when '-' key is pressed.

0531 0120 ;Use DTAB and STATE for further branch.

0532 0120 ;STATE will be stored in A register at BR1.

0533 0120

0534 0120 21 63 07 LD HL,DTAB

0535 0123 18 F0 JR BR1

0536 0125

0537 0125 ;

0538 0125 KGO:

0539 0125 ;Branched by KSUBFUN table.0540 0125 ;Executed when 'GO' key is pressed.

0541 0125 ;Use DTAB and STATE for further branch.

0542 0125 ;STATE will be stored in A register at BR1.

0543 0125

0544 0125 21 6F 07 LD HL,GTAB

0545 0128 18 EB JR BR1

0546 012A

0547 012A ;

0548 012A KSTEP:

0549 012A ;Branched by table KSUBFUN.

0550 012A ;Executed when 'STEP' key is pressed.

0551 012A

0552 012A CD E5 03 CALL TESTM ;Check if the left 4 digits of0553 012D ;the display are memory address.

0554 012D ;If not, disable all LED's as

0555 013D ;a warning to the user. This

0556 013D ;is done by routine IGNORE.

0557 013D C2 BB 03 JP NZ,IGNORE

0558 0130 3E 80 LD A,10000000B ;This data will be output

0559 0132 ;to port B to enable

0560 0132 ;BREAK. It is done by

0561 0132 ;routine PREOUT.

0562 0132 C3 A3 02 JP PREOUT

0563 0135

0564 0135 ;

0565 0135 KDATA:0566 0135 ;Branched by table KSUBFUN.

0567 0135 ;Executed when 'DATA' key is pressed.

0568 0135

0569 0135 CD E5 03 CALL TESTM ;Check if the left 4 digits of

0570 0138 ;the display are memory address.

0571 0138 20 04 JR NZ,TESTRG ;If not, branch to TESTRG

0572 013A ;to check whether the display

0573 013A ;is register or not.

0574 013A CD 0B 04 CALL MEMDP2 ;If yes, display the data of

0575 013D ;that address and set STATE

0576 013D ;to 2.

0577 013D C9 RET

0578 013E FE 08 TESTRG CP 8 ;check if the status is 8 or 90579 0140 ;(RGAD or RGDA).

0580 0140 DA BB 03 JP C,IGNORE ;If not, ignore this key and


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11

MPF-1


0581 0143 ;send out a warning message.

0582 0143 CD 77 04 CALL REGDP9 ;If yes, display register and

0583 0146 ;set status to 9 (RGDA).

0584 0146 C9 RET0585 0147

0586 0147 ;

0587 0147 KSBR:

0588 0147 ;Branched by table KSUBFUN.

0589 0147 ;Executed when 'SBr' key (set break point)

0590 0147 ; is pressed.

0591 0147

0592 0147 CD E5 03 CALL TESTM ;Check if the display is of

0593 014A ;'address-data' form.

0594 014A C2 BB 03 JP NZ,IGNORE ;If not, ignore this key and

0595 014D ;send out a warning message.

0596 014D 2A DE 1F LD HL,(ADSAVE) ;If yes, get the address

0597 0150 ;being displayed now.0598 0150 CD F6 05 CALL RAMCHK ;Check if this address is

0599 0153 ;in RAM.

0600 0153 C2 BB 03 JP NZ,IGNORE ;If not, ignore the 'SBR' key

0601 0156 ;and send out a warning message.

0602 0156 22 E0 1F LD (BRAD),HL ;If yes, set this address as

0603 0159 ;a break point.

0604 0159 CD 0B 04 CALL MEMDP2 ;Display the data of break

0605 015C ;address and set STATE to

0606 015C ;2 (DA).

0607 015C C9 RET

0608 015D

0609 015D ;

0610 015D KINS:0611 015D ;Branched by table KSUBFUN.

0612 015D ;Executed when 'Ins' key (insert) is pressed.

0613 015D

0614 015D CD E5 03 CALL TESTM ;Check if the display is of

0615 0160 ;'addres-data' form.

0616 0160 C2 BB 03 JP NZ,IGNORE ;If not, ignore the 'INS' key


0618 0163 2A DE 1F LD HL,(ADSAVE) ;If yes, get the address being

0619 0166 ;displayed now.

0620 0166

0621 0166 00 NOP

0622 0167

0623 0167 22 AF 1F LD (STEPBF),HL ;Store this address in0624 016A ;STEPBF and the next address

0625 016A ;in STEPBF+4 for later use.

0626 016A 23 INC HL

0627 016B 22 B3 1F LD (STEPBF+4),HL

0628 016E CD F6 05 CALL RAMCHK ;Check if the address to be

0629 0171 ;inserted is in RAM.

0630 0171 C2 BB 03 JP NZ,IGNORE ;If not, ignore the 'INS' key


0632 0174 ;If the address to be inserted

0633 0174 ;is in 1800-1DFF, store 1DFE into

0634 0174 ;STEPBF+2

0635 0174 ;Otherwise, ignore the 'INS' key.

0636 0174 ;This is done by the following0637 0174 ;instructions.

0638 0174 11 FE 1D LD DE,1DFEH


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12

MPF-1


0639 0177 7C LD A,H

0640 0178 FE 1E CP 1EH

0641 017A 38 07 JR C,SKIPH1

0642 017C FE 20 CP 20H0643 017E DA BB 03 JP C,IGNORE

0644 0181 16 27 LD D,27H

0645 0183 ED 53 B1 1F SKIPH1 LD (STEPBF+2),DE

0646 0187

0647 0187 ;When one byte is inserted at some

0648 0187 ;address, all data below this address

0649 0187 ;will be shifted down one position.

0650 0187 ;The last location will be shifted out

0651 0187 ;and therefore lost.

0652 0187 ;The RAM is divided into 3 blocks as

0653 0187 ;insert is concerned. They are:

0654 0187 ;1800-1DFF, 1E00-1FFF and 2000-27FF

0655 0187 ;The 2nd block cannot be inserted and0656 0187 ;is usually used as data bank. System

0657 0187 ;data that of course cannot be shifted

0658 0187 ;is also stored in this bank. Each

0659 0187 ;block is independent of the other when

0660 0187 ;shift is performed, i.e. the data

0661 0187 ;shifted out of the first block will not

0662 0187 ;be propagated to next block.

0663 0187 ;The shift is accomplished by block

0664 0187 ;transfer, i.e. MOVE. This is the

0665 0187 ;job of subroutine GMV.

0666 0187 ;Routine GMV needs 3 parameters which

0667 0187 ;are stored in step-buffer (STEPBF):

0668 0187 ;STEPBF: starting address (2 bytes);0669 0187 ;STEPBF+2: ending address (2 bytes);

0670 0187 ;STEPBF+4: destination address (2 bytes).

0671 0187

0672 0187 CD E4 02 DOMV CALL GMV

0673 018A AF XOR A ;After the RAM has been shifted

0674 018B ;down,the data of the address to be

0675 018B ;inserted is cleared to zero. This

0676 018B ;is done by these two instructions.

0677 018B ;Register DE contains inserted

0678 018B ;address after GMV is performed.

0679 018B 12 LD (DE),A

0680 018C 2A B3 1F LD HL,(STEPBF+4) ;Store the data in (STEPBF+4)

0681 018F 22 DE 1F LD (ADSAVE),HL ;into (ADSAVE).0682 0192 CD 0B 04 CALL MEMDP2 ;Display the address and data

0683 0195 ;also set STATE to 2.

0684 0195 C9 RET

0685 0196 ;

0686 0196 KDEL:

0687 0196 ;Branched by table KSUBFUN.

0688 0196 ;Executed when 'Del' (delete) key is pressed.

0689 0196

0690 0196 CD E5 03 CALL TESTM ;Check if the display is of

0691 0199 ;'address-data' form.

0692 0199 C2 BB 03 JP NZ,IGNORE ;If not, ignore the 'Del' key

0693 019C ;and send out a warning message.

0694 019C ;'Delete' is quite similar to0695 019C ;'Insert',except that the memory

0696 019C ;is shifted up up instead of


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MPF-1


0697 019C ;shifted down. See the comments

0698 019C ;on routine KINS for details.

0699 019C 2A DE 1F LD HL,(ADSAVE) ;Get the address being displayed

0700 019F ;now. This is the address to0701 019F ;be deleted.

0702 019F

0703 019F

0704 019F 00 NOP

0705 01A0

0706 01A0 22 B3 1F LD (STEPBF+4),HL

0707 01A3 CD F6 05 CALL RAMCHK ;Check if the address is in RAM.

0708 01A6 C2 BB 03 JP NZ,IGNORE ;If not, ignore this key and

0709 01A9 ;send out a warning message.

0710 01A9 ;Following instructions prepare

0711 01A9 ;the parameters for routine GMV

0712 01A9 ;in step-buffer. Refer to routine

0713 01A9 ;KINS for detail.0714 01A9 11 00 1E LD DE,1E00H

0715 01AC 7C LD A, H

0716 01AD FE 1E CP 1EH

0717 01AF 38 07 JR C,SKIPH2

0718 01B1 FE 20 CP 20H

0719 01B3 DA BB 03 JP C,IGNORE

0720 01B6 16 28 LD D, 28H

0721 01B8 ED 53 B1 1F SKIPH2 LD (STEPBF+2),DE

0722 01BC 23 INC HL

0723 01BD 22 AF 1F LD (STEPBF),HL

0724 01C0 18 C5 JR DOMV

0725 01C2 ;

0726 01C2 ;***********************************************************0727 01C2 KPC:

0728 01C2 ;Branched by table KFUN.

0729 01C2 ;Executed when 'PC' key is pressed.

0730 01C2

0731 01C2 2A DC 1F LD HL,(USERPC) ;Store the user's program

0732 01C5 22 DE 1F LD (ADSAVE),HL ;counter into (ADSAVE).

0733 01C8 CD 0B 04 CALL MEMDP2 ;Routine MEMDP2 displays the

0734 01CB ;address in (ADSAVE) and its

0735 01CB ;data.It also sets the STATE to 2

0736 01CB C9 RET

0737 01CC ;

0738 01CC KCBR:

0739 01CC ;Branched by table KFUN.0740 01CC ;Executed when 'CBr' (clear break point) key is pressed.

0741 01CC

0742 01CC CD DE 03 CALL CLRBR ;Call subroutine CLRBR to clear

0743 01CF ;break point. When returned, the

0744 01CF ;HL register will contain FFFF.

0745 01CF 22 DE 1F LD (ADSAVE),HL ;Store FFFF into (ADSAVE)

0746 01D2 CD 0B 04 CALL MEMDP2 ;Display address and its data.

0747 01D5 ;Also set STATE to 2.

0748 01D5 C9 RET

0749 01D6 ;

0750 01D6 KREG:

0751 01D6 ;Branched by table KFUN.

0752 01D6 ;Executed when 'Reg' key is pressed.0753 01D6 DD 21 CA 07 LD IX,REG_ ;Routine SCAN uses IX as a pointer

0754 01DA ;for display buffer.Setting IX to


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14

MPF-1


0755 01DA ;REG will make SCAN displays 'Reg-'

0756 01DA CD C4 04 CALL FCONV ;Decode user's flag F and F' to

0757 01DD ;binary display format. This

0758 01DD ;format will be used later, when0759 01DD ;user requires the monitor to

0760 01DD ;display decoded flag by pressing

0761 01DD ;keys 'SZXH', 'XPNC',...

0762 01DD C9 RET

0763 01DE ;

0764 01DE KADDR:

0765 01DE ;Branched by table KFUN.

0766 01DE ; Executed when 'Addr' key is pressed.

0767 01DE

0768 01DE CD 02 04 CALL MEMDP1 ;Display the address stored in

0769 01E1 ;(ADSAVE) and its data. Set STATE

0770 01E1 ;to 1 (AD)

0771 01E1 C9 RET0772 01E2 ;

0773 01E2 ; Function Move, Relative, Read-tape and

0774 01E2 ; Write-tape require from one to three

0775 01E2 ; parameters. They are stored in STEPBF

0776 01E2 ; (step buffer). STMINOR (minor status)

0777 01E2 ; contains the number of parameters that has

0778 01E2 ; been entered. For Move and Relative, the

0779 01E2 ; default value of the first parameter is

0780 01E2 ; the address stored in (ADSAVE). There

0781 01E2 ; is no default value for the first parameter

0782 01E2 ; (filename) of Read- and Write-tape. When the

0783 01E2 ; function keys are pressed, STMINOR is automatically

0784 01E2 ; reset to 0.0785 01E2 ;

0786 01E2

0787 01E2 KMV:

0788 01E2 ;Branched by table KFUN.

0789 01E2 ;Executed when 'Move' key is pressed.

0790 01E2 KRL:


0792 01E2 ;Executed when 'Rela' (relative) key is pressed.

0793 01E2 2A DE 1F LD HL,(ADSAVE) ;Store the contents of ADSAVE

0794 01E5 22 AF 1F LD (STEPBF),HL ;into STEPBF as default value

0795 01E8 ;of first parameter.

0796 01E8

0797 01E8 KWT:0798 01E8 ;Branched by table KFUN.

0799 01E8 ;Executed when 'WRtape' key is pressed.

0800 01E8

0801 01E8 KRT:


0803 01E8 ;Executed when 'RDtape' key is pressed.

0804 01E8

0805 01E8 CD 3A 04 CALL STEPDP ;Display the parameter that

0806 01EB ;is being entered now by calling

0807 01EB ;subroutine STEPDP.

0808 01EB C9 RET

0809 01EC ;

0810 01EC ;***********************************************************0811 01EC ; The following subroutines with name H???

0812 01EC ; are the service routines for hexadecimal


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MPF-1


0813 01EC ; keys corresponding to each STATE. They

0814 01EC ; are all branched by table HTAB and STATE.

0815 01EC

0816 01EC C3 BB 03 HFIX JP IGNORE ;When the display is fixed pattern0817 01EF ;hexadecimal keys are illegal.

0818 01EF ;Disable all LED's as a warning

0819 01EF ;message to the user. This is what

0820 01EF ;routine IGNORE does.

0821 01EF ;

0822 01EF 2A DE 1F HDA LD HL,(ADSAVE) ;Get the address being displayed

0823 01F2 ;now from (ADSAVE)

0824 01F2 CD F6 05 CALL RAMCHK ;Check if it is in RAM.

0825 01F5 C2 BB 03 JP NZ,IGNORE ;If not, ignore this key and

0826 01F8 ;send out a warning message.

0827 01F8 CD EE 03 CALL PRECL1 ;If this is the first hexadecimal

0828 01FB ;key entered after function or sub-

0829 01FB ;function key,reset the data of that0830 01FB ;address to 0. (by routine PERCL1)

0831 01FB 79 LD A,C ;The key-code is saved in C by

0832 01FC ;routine KHEX. Restore it to A.

0833 01FC ED 6F RLD ;Rotate the key-code (4 bits) into

0834 01FE ;the address obtained above. (in HL)

0835 01FE CD 0B 04 CALL MEMDP2 ;Display the address and data,

0836 0201 ;then set STATE to 2 (DA).

0837 0201 C9 RET

0838 0202 ;

0839 0202 21 DE 1F HAD: LD HL,ADSAVE

0840 0205 CD FA 03 CALL PRECL2 ;If this is the first hexadecimal

0841 0208 ;key after function key is entered,

0842 0208 ;set the contents of ADSAVE to 0.0843 0208 79 LD A,C ;The key-code is saved in C

0844 0209 ;by routine KHEX.

0845 0209 ;The next three instructions shift

0846 0209 ;the addres being displayed by

0847 0209 ;one digit.

0848 0209 ED 6F RLD

0849 020B 23 INC HL

0850 020C ED 6F RLD

0851 020E CD 02 04 CALL MEMDP1 ;Display the address and its

0852 0211 ;data. Also, set STATE to 1.

0853 0211 C9 RET

0854 0212 ;

0855 0212 HRGAD:0856 0212 HRGFIX:

0857 0212 79 LD A,C

0858 0213 DD 21 B6 1F LD IX,DISPBF

0859 0217 21 E3 1F LD HL,STMINOR

0860 021A 87 ADD A,A ;The key-code is the register

0861 021B ;name. Double it and store it

0862 021B 77 LD (HL),A ;into STMINOR.

0863 021C

0864 021C CD 73 04 CALL REGDP8 ;Display register and set

0865 021F ;STATE to 8. (RGAD)

0866 021F C9 RET

0867 0220 ;

0868 0220 HRT:0869 0220 HWT:

0870 0220 HRL:


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MPF-1


0871 0220 CD 55 04 HMV: CALL LOCSTBF ;Use STMINOR and STEPBF

0872 0223 ;to calculate the address

0873 0223 ;of current parameter in

0874 0223 ;step buffer.0875 0223 CD FA 03 CALL PRECL2 ;If this is the first hex

0876 0226 ;key entered, clear the

0877 0226 ;parameter (2 bytes) by

0878 0226 ;PRECL2.

0879 0226 79 LD A,C ;C contains the key-code

0880 0227 ED 6F RLD ;Rotate the parameter (2 bytes)

0881 0229 ;1 digit left with the key-code.

0882 0229

0883 0229 23 INC HL

0884 022A ED 6F RLD

0885 022C CD 3A 04 CALL STEPDP ;Display the parameter.

0886 022F C9 RET

0887 0230 ;0888 0230 CD BB 04 HRGDA CALL LOCRGBF ;Calculate the address of

0889 0233 ;the register being modified.

0890 0233 CD EE 03 CALL PRECL1 ;If this is the first hex

0891 0236 ;key entered. Clear the register

0892 0236 ;(1 byte) by PRECL1.

0893 0236 79 LD A,C ;C contains the key-code

0894 0237 ED 6F RLD ;Rotate user's register (1 byte)

0895 0239 ;1 digit left with the key-code.

0896 0239

0897 0239 CD 77 04 CALL REGDP9 ;Display the register and set

0898 023C ;STATE to 9 (RGDA).

0899 023C C9 RET

0900 023D ;0901 023D ;***********************************************************

0902 023D ;The following routines with name

0903 023D ;I???? are the service routines for

0904 023D ;'+' key corresponding to each STATE

0905 023D ;They are all branched by table ITAB

0906 023D ;and STATE

0907 023D

0908 023D IFIX:

0909 023D IRGFIX:

0910 023D C3 BB 03 JP IGNORE ;'+' key is illegal for state

0911 0240 ;FIX or RGFIX, ignore it.

0912 0240 ;

0913 0240 IAD:0914 0240 2A DE 1F IDA: LD HL, ADSAVE) ;Increase the address being

0915 0243 ;displayed now (in ADSAVE)

0916 0243 ;by 1.

0917 0243 23 INC HL

0918 0244 22 DE 1F LD (ADSAVE),HL

0919 0247 CD 0B 04 CALL MEMDP2 ;Display the address and data,

0920 024A ;then set the STATE to 2 (DA).

0921 024A C9 RET

0922 024B ;

0923 024B IRT:

0924 024B IWT:

0925 024B IRL:

0926 024B 21 E3 1F IMV: LD HL,STMINOR ;STMINOR contains the0927 024E ;parameter count, increment

0928 024E ;it by one.


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MPF-1


0929 024E 34 INC (HL)

0930 024F CD 5F 04 CALL LOCSTNA ;Check if the count is

0931 0252 ;overflowed.

0932 0252 20 04 JR NZ,ISTEP ;If not overflowed, continue0933 0254 ;at ISTEP

0934 0254 35 DEC (HL) ;Otherwise, restore the count

0935 0255 ;and ignore the '+' key.

0936 0255 C3 BB 03 JP IGNORE

0937 0258 CD 3A 04 ISTEP CALL STEPDP ;Display the parameter at

0938 025B ;step buffer.

0939 025B C9 RET

0940 025C ;

0941 025C IRGAD:

0942 025C 21 E3 1F IRGDA: LD HL,STMINOR ;In these states, the STMINOR

0943 025F ;contains the register name.

0944 025F ;Increase it by 1. If it

0945 025F ;reaches the last one, reset0946 025F ;it to the first one (0).

0947 025F 34 INC (HL)

0948 0260 3E 1F LD A,1FH

0949 0262 BE CP (HL)

0950 0263 30 02 JR NC,IRGNA

0951 0265 36 00 LD (HL),0

0952 0267 CD 77 04 IRGNA CALL REGDP9 ;Display the register and

0953 026A ;set STATE to 9

0954 026A C9 RET

0955 026B ;

0956 026B ;***********************************************************

0957 026B ;The following routines with name

0958 026B ;D???? are the service routines for0959 026B ;'-' key corresponding to each state.

0960 026B ;They are all branched by table DTAB

0961 026B ;and STATE.

0962 026B

0963 026B DFIX:

0964 026B DRGFIX:

0965 026B C3 BB 03 JP IGNORE ;'-' key is illegal for

0966 026E ;these states. Ignore it.

0967 026E ;

0968 026E DAD:

0969 026E 2A DE 1F DDA: LD HL,(ADSAVE) ;Decrease the address being

0970 0271 ;displayed now (in ADSAVE)

0971 0271 ;by one.0972 0271 2B DEC HL

0973 0272 22 DE 1F LD (ADSAVE),HL

0974 0275 CD 0B 04 CALL MEMDP2 ;Display the address and data,

0975 0278 ;set STATE to 2 (DA).

0976 0278 C9 RET

0977 0279 ;

0978 0279 DRT:

0979 0279 DWT:

0980 0279 DRL:

0981 0279 21 E3 1F DMV: LD HL,STMINOR ;In these states, STMINOR

0982 027C ;contains the parameter count.

0983 027C ;Decrease it by one. If overflow

0984 027C ;occurs, restore STMINOR and0985 027C ;ignore the '-' key. Otherwise

0986 027C ;continue at DSTEP.


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MPF-1


0987 027C 35 DEC (HL)

0988 027D CD 5F 04 CALL LOCSTNA

0989 0280 20 04 JR NZ,DSTEP

0990 0282 34 INC (HL)0991 0283 C3 BB 03 JP IGNORE

0992 0286 CD 3A 04 DSTEP CALL STEPDP ;Display the parameter.

0993 0289 C9 RET

0994 028A ;

0995 028A DRGAD:

0996 028A 21 E3 1F DRGDA: LD HL,STMINOR ;In these states, STMINOR

0997 028D ;contains the register name.

0998 028D ;Decrease it by one. If it

0999 028D ;goes below zero, set it to

1000 028D ;the highest value (1F).

1001 028D 35 DEC (HL)

1002 028E 3E 1F LD A,01FH

1003 0290 BE CP (HL)1004 0291 30 02 JR NC,DRGNA

1005 0293 36 1F LD (HL),1FH

1006 0295 CD 77 04 DRGNA CALL REGDP9 ;Display the register and

1007 0298 ;set STATE to 9.

1008 0298 C9 RET

1009 0299 ;

1010 0299 ;***********************************************************

1011 0299 ;The following routines with name

1012 0299 ;G???? are the service routines for

1013 0299 ;'GO' key corresponding to each

1014 0299 ;state. They are all branced by

1015 0299 ;table GTAB and STATE.

1016 02991017 0299 GFIX:

1018 0299 GRGFIX:

1019 0299 GRGAD:

1020 0299 C3 BB 03 GRGDA: JP IGNORE ;'GO' key is illegal for

1021 029C ;these states. Ignore it.

1022 029C ;

1023 029C GAD:

1024 029C 2A E0 1F GDA: LD HL,(BRAD) ;Get the address of break

1025 029F ;point.

1026 029F 36 EF LD (HL),0EFH ;Instruction RST28H.

1027 02A1 ;The content of break address

1028 02A1 ;ischanged to RST 28H before

1029 02A1 ;the control is transfered to1030 02A1 ;user's program. THis

1031 02A1 ;will cause a trap when user's

1032 02A1 ;PC passes this point.

1033 02A1 3E FF LD A, 0FFH ;Save FF into TEMP.This data will

1034 02A3 ;be output to port C later. FF is

1035 02A3 ;used to disable break point.

1036 02A3 32 EA 1F PREOUT LD (TEMP),A ;Store A into TEMP.

1037 02A6 3A D2 1F LD A, (USERIF) ;Save two instructions into

1038 02A9 ;TEMP and TEMP+1. THese two

1039 02A9 ;instructions will be executed

1040 02A9 ;later. If the user's IFF

1041 02A9 ;(interrupt flip-flop) is 1,

1042 02A9 ;the instructions are 'EI RET'.1043 02A9 ;Otherwise, they are 'DI RET'.

1044 02A9 CB 47 BIT 0,A


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19

MPF-1


1045 02AB 21 FB C9 LD HL,0C9FBH ;'EI', 'RET'

1046 02AE 20 02 JR NZ,EIDI

1047 02B0 2E F3 LD L,0F3H ;'DI'

1048 02B2 22 EB 1F EIDI LD (TEMP+1),HL1049 02B5 31 BC 1F LD SP,REGBF ;Restore user's registers by

1050 02B8 ;setting SP to REGBF (register

1051 02B8 ;buffer) and continuously popping

1052 02B8 ;the stack.

1053 02B8 F1 POP AF

1054 02B9 C1 POP BC

1055 02BA D1 POP DE

1056 02BB E1 POP HL

1057 02BC 08 EX AF,AF'

1058 02BD F1 POP AF

1059 02BE 08 EX AF,AF'

1060 02BF D9 EXX

1061 02C0 C1 POP BC1062 02C1 D1 POP DE

1063 02C2 E1 POP HL

1064 02C3 D9 EXX

1065 02C4 DD E1 POP IX

1066 02C6 FD E1 POP IY

1067 02C8 ED 7B D0 1F LD SP,(USERSP) ;Restore user's SP.

1068 02CC 32 BD 1F LD (USERAF+1),A ;Temporarily save A

1069 02CF 3A D3 1F LD A,(USERIF+1) ;Restore user's I

1070 02D2 ED 47 LD I,A

1071 02D4 E5 PUSH HL ;The next 3 instructions

1072 02D4 ;push the address being

1073 02D5 ;displayed now (in ADSAVE)

1074 02D5 ;onto stack without changing1075 02D5 ;HL register. This address will

1076 02D5 ;be treated as user's new PC.

1077 02D5 2A DE 1F LD HL,(ADSAVE)

1078 02D8 E3 EX (SP),HL

1079 02D9 3A EA 1F LD A,(TEMP) ;Output the data stored in

1080 02DC ;TEMP to port C of 8255

1081 02DC ;This data is prepared by

1082 02DC ;routine KSTEP or GAD or

1083 02DC ;GDA. In first case, it is

1084 02DC ;10111111 and will enable

1085 02DC ;break point. In other

1086 02DC ;cases, it is FF and will

1087 02DC ;disable break point. If1088 02DC ;break is enabled, non-maskable

1089 02DC ;interrupt will occur 5 M1's

1090 02DC ;after the OUT instruction.

1091 02DC D3 02 OUT (DIGIT),A

1092 02DE 3A BD 1F LD A,(USERAF+1) ;1st M1,

1093 02E1 ;Restore A register.

1094 02E1 C3 EB 1F JP TEMP+1 ;2nd M1,

1095 02E4 ;Execute the two instructions

1096 02E4 ;stored in RAM. They are:

1097 02E4 ; EI (or DI) ;3rd M1

1098 02E4 ; RET ;4th M1

1099 02E4 ;The starting address of user's

1100 02E4 ;program has been pushed onto1101 02E4 ;the top of the stack. RET pops

1102 02E4 ;out this address and transfers


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MPF-1


1103 02E4 ;control to it. The first M1

1104 02E4 ;of user's program will be the

1105 02E4 ;5th M1 after OUT. If break point

1106 02E4 ;is enabled, NMI will occur after1107 02E4 ;this instruction is completed.

1108 02E4 ;This is the mechanism of single

1109 02E4 ;step.

1110 02E4 ;

1111 02E4 ;***********************************************************

1112 02E4 21 AF 1F GMV LD HL,STEPBF

1113 02E7 CD 3D 05 CALL GETP ;Load parameters from

1114 02EA ;step buffer into registers.

1115 02EA ;Also check if the parameters

1116 02EA ;are legal. After GETP,

1117 02EA ;HL = start address of source

1118 02EA ;BC = length to MOVE.

1119 02EA 38 67 JR C,ERROR ;Jump to ERROR if the parameters1120 02EC ;are illegal. (I.e., Ending

1121 02EC ;address < starting address.)

1122 02EC ED 5B B3 1F LD DE,(STEPBF+4) ;Load destination

1123 02F0 ;address into DE.

1124 02F0 ED 52 SBC HL,DE ;Compare HL and DE to

1125 02F2 ;determine move up or down.

1126 02F2 30 0C JR NC,MVUP

1127 02F4 ;Move down:

1128 02F4 EB EX DE,HL ;HL = destination address

1129 02F5 09 ADD HL,BC ;HL = dest. address + length

1130 02F6 2B DEC HL ;HL = end address of dest.

1131 02F7 EB EX DE,HL ;DE = end address of dest.

1132 02F8 2A B1 1F LD HL,(STEPBF+2) ;HL = end address of source1133 02FB ED B8 LDDR ;block transfer instruction

1134 02FD 13 INC DE ;DE = last address moved

1135 02FE 18 1C JR ENDFUN ;Continue at ENDFUN

1136 0300 MVUP: ;Move up:

1137 0300 19 ADD HL,DE ;HL is destroyed by

1138 0301 ;SBC HL, DE. Restore HL.

1139 0301 ED B0 LDIR ;block transfer

1140 0303 1B DEC DE ;DE = last address moved

1141 0304 18 16 JR ENDFUN ;Continue at ENDFUN

1142 0306 ;

1143 0306 ;***********************************************************

1144 0306 ED 5B AF 1F GRL LD DE,(STEPBF) ;Load starting address

1145 030A ;into DE.1146 030A 13 INC DE ;Increase this address by 2.

1147 030B ;Relative address is used in

1148 030B ;instruction JR or DJNZ.

1149 030B ;The codes for them are 2 bytes.

1150 030B ;The PC is increased by 2 after

1151 030B ;opcode is fetched.

1152 030B 13 INC DE

1153 030C 2A B1 1F LD HL,(STEPBF+2) ;Load destination

1154 030F ;address into HL.

1155 030F B7 OR A

1156 0310 ED 52 SBC HL,DE ;Calculate difference.

1157 0312 7D LD A,L ;Check if the offset is between

1158 0313 ;+127 (007FH) and -128 (FF80H).1159 0313 ;If the offset is positive, both H

1160 0313 ;and bit 7 of L must be zero; if it


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MPF-1


1161 0313 ;is negative, H and bit 7 of L must

1162 0313 ;be FF and 1. In both cases, adding

1163 0313 ;H with bit 7 of L results in 0.

1164 0313 17 RLA ;Rotate bit 7 of L into carry flag.1165 0314 7C LD A,H

1166 0315 CE 00 ADC A,0 ;ADD H and bit 7 of L.

1167 0317 20 3A JR NZ,ERROR ;Branch to ERROR if

1168 0319 ;the results is nonzero.

1169 0319 7D LD A,L

1170 031A 1B DEC DE

1171 031B 12 LD (DE),A ;Save the offset into

1172 031C ;the next byte of opcode.

1173 031C ;(DJNZ or JR)

1174 031C ;

1175 031C ENDFUN:

1176 031C ED 53 DE 1F LD (ADSAVE),DE ;Save DE into ADSAVE.

1177 0320 CD 0B 04 CALL MEMDP2 ;Display this address and1178 0323 ;its data. Set STATE to 2.

1179 0323 C9 RET

1180 0324 ;

1181 0324 ;***********************************************************

1182 0324 GWT:

1183 0324 CD 2D 05 CALL SUM1 ;Load parameters from

1184 0327 ;step buffer into registers.

1185 0327 ;Check if the parameters

1186 0327 ;are legal. If legal, calculate

1187 0327 ;the sum of all data to be output

1188 0327 ;to tape.

1189 0327 38 2A JR C,ERROR ;Branch to ERROR if the

1190 0329 ;parameters are illegal.(length1191 0329 ;is negative)

1192 0329 32 B5 1F LD (STEPBF+6),A ;Store the checksum into

1193 032C ;STPEGBF+6.

1194 032C 21 A0 0F LD HL,4000 ;Output 1 kHz square

1195 032F ;wave for 4000 cycles.

1196 032F ;Leading sync. signal.

1197 032F CD DE 05 CALL TONE1K

1198 0332 21 AF 1F LD HL,STEPBF ;Output 7 bytes starting

1199 0335 ;at STEPBF. (Include:

1200 0335 ;filename, starting, ending

1201 0335 ;address and checksum)

1202 0335 01 07 00 LD BC,7

1203 0338 CD A7 05 CALL TAPEOUT1204 033B 21 A0 0F LD HL,4000 ;Output 2 kHz square

1205 033E ;wave for 4000 cycles.

1206 033E ;Middle sync.The file name of

1207 033E ;the file being read will be

1208 033E ;displayed in this interval.

1209 033E CD E2 05 CALL TONE2K

1210 0341 CD 3A 05 CALL GETPTR ;Load parameters into

1211 0344 ;registers. (Starting, ending and

1212 0344 ;length).

1213 0344 CD A7 05 CALL TAPEOUT ;Output user's data.

1214 0347 21 A0 0F LD HL,4000 ;Output 4000 cycles of

1215 034A ;2 kHz square wave.

1216 034A ;(Tail sync.)1217 034A CD E2 05 CALL TONE2K

1218 034D ED 5B B3 1F ENDTAPE LD DE,(STEPBF+4) ;DE = last address


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MPF-1


1219 0351 18 C9 JR ENDFUN ;Continue at ENDFUN

1220 0353 ;

1221 0353 DD 21 A9 07 ERROR LD IX,ERR_ ;IX points to '-Err '

1222 0357 C3 D0 00 JP SETST0 ;Set STATE to 0 by1223 035A ;branching to SETST0.

1224 035A ;

1225 035A ;***********************************************************

1226 035A GRT:

1227 035A 2A AF 1F LD HL,(STEPBF) ;Temporarily save filename.

1228 035D 22 EA 1F LD (TEMP),HL

1229 0360 3E 40 LEAD LD A,01000000B ;decimal point

1230 0362 D3 01 OUT (SEG7),A ;When searching for filename,

1231 0364 ;the display is blank initially.

1232 0364 ;If the data read from MIC is

1233 0364 ;acceptable 0 or 1, the display

1234 0364 ;becomes '......'.

1235 0364 21 E8 03 LD HL,10001236 0367 CD 8C 05 LEAD1 CALL PERIOD ;The return of PERIOD

1237 036A ;is in flag:

1238 036A ; NC -- tape input is 1 kHz;

1239 036A ; C -- otherwise.

1240 036A 38 F4 JR C,LEAD ;Loop until leading sync.

1241 036C ;is detected.

1242 036C 2B DEC HL ;Decrease HL by one when

1243 036D ;one period is detected.

1244 036D 7C LD A,H

1245 036E B5 OR L ;Check if both H and L are 0.

1246 036F 20 F6 JR NZ,LEAD1 ;Wait for 1000 periods.

1247 0371 ;The leading sync. is accepted

1248 0371 ;if it is longer than 10001249 0371 ;cycles (1 second).

1250 0371 CD 8C 05 LEAD2 CALL PERIOD

1251 0374 30 FB JR NC,LEAD2 ;Wait all leading sync. to

1252 0376 ;pass over.

1253 0376 ;

1254 0376 21 AF 1F LD HL,STEPBF ;Load 7 bytes from

1255 0379 ;tape into STEPBF.

1256 0379 01 07 00 LD BC,7

1257 037C CD 4D 05 CALL TAPEIN

1258 037F 38 DF JR C,LEAD ;Jump to LEAD if input

1259 0381 ;is not succesful.

1260 0381 ED 5B AF 1F LD DE,(STEPBF) ;Get filename from

1261 0385 ;step buffer.1262 0385 CD 65 06 CALL ADDRDP ;Convert it to display

1263 0388 ;format.

1264 0388 06 96 LD B,150 ;Display it for 1.5 sec.

1265 038A CD 24 06 FILEDP CALL SCAN1

1266 038D 10 FB DJNZ FILEDP

1267 038F 2A EA 1F LD HL,(TEMP) ;Check if the input

1268 0392 ;filename equals to the

1269 0392 ;specified filename.

1270 0392 B7 OR A

1271 0393 ED 52 SBC HL,DE

1272 0395 20 C9 JR NZ,LEAD ;If not, find the leading

1273 0397 ;sync. of next file.

1274 03971275 0397 ;If filename is found

1276 0397 3E 02 LD A,00000010B ;segment '-'


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MPF-1


1277 0399 D3 01 OUT (SEG7),A ;Display '------'.

1278 039B CD 3A 05 CALL GETPTR ;The parameters (starting,

1279 039E ;ending address and check-

1280 039E ;sum) have been loaded into1281 039E ;STEPBF. Load them into

1282 039E ;registers, calculate the block

1283 039E ;length and check if they are

1284 039E ;legal.

1285 039E 38 B3 JR C,ERROR ;Jump to ERROR if the

1286 03A0 ;parameters are illegal.

1287 03A0 CD 4D 05 CALL TAPEIN ;Input user's data.

1288 03A3 38 AE JR C,ERROR ;Jump to ERROR if input

1289 03A5 ;is not succesful.

1290 03A5 CD 2D 05 CALL SUM1 ;Calculate the sum of all

1291 03A8 ;input data.

1292 03A8 21 B5 1F LD HL,STEPBF+6

1293 03AB BE CP (HL) ;Compare it with the checksum1294 03AC ;calculated and stored by

1295 03AC ;'WRtape'.

1296 03AC 20 A5 JR NZ,ERROR ;Jump to ERROR if not

1297 03AE ;matched.

1298 03AE 18 9D JR ENDTAPE ;Continue at ENDTAPE.

1299 03B0 ;

1300 03B0 ;***********************************************************

1301 03B0 BRANCH:

1302 03B0 ;Branch table format:

1303 03B0 ; byte 1,2 : address of the 1st routine in

1304 03B0 ; each group.

1305 03B0 ; byte 3 : difference between the address

1306 03B0 ; of 1st and 1st routine, which is1307 03B0 ; of course 0.


1309 03B0 ; of 2nd and 1st routine


1311 03B0 ; of 3rd and 1st routine

1312 03B0 ; ...

1313 03B0 ; ...

1314 03B0 ; ...

1315 03B0 ; HL : address of branch table

1316 03B0 ; A : the routine number in its group

1317 03B0 ; Such branch tables can save table length and avoid page

1318 03B0 ; (256 bytes) boundary problems.

1319 03B01320 03B0 5E LD E,(HL) ;Load the address of 1st

1321 03B1 ;routine in the group into

1322 03B1 ;DE register.

1323 03B1 23 INC HL

1324 03B2 56 LD D,(HL)

1325 03B3 23 INC HL ;Locate the pointer of difference

1326 03B4 ;table.

1327 03B4 85 ADD A, L

1328 03B5 6F LD L, A

1329 03B6 6E LD L,(HL) ;Load the address

1330 03B7 ;difference into L.

1331 03B7 26 00 LD H,0

1332 03B9 19 ADD HL,DE ;Get routine's real address1333 03BA E9 JP (HL) ;Jump to it.

1334 03BB ;


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MPF-1


1335 03BB ;***********************************************************

1336 03BB IGNORE:

1337 03BB 21 E6 1F LD HL,TEST

1338 03BE CB FE SET 7,(HL) ;Routine SCAN will check bit1339 03C0 ;7 of TEST. If it is set,

1340 03C0 ;all LEDs will be disabled.

1341 03C0 ;This is a warning message to

1342 03C0 ;the user when a illegal key

1343 03C0 ;is entered.

1344 03C0 C9 RET

1345 03C1 ;

1346 03C1 ;***********************************************************

1347 03C1 INI:

1348 03C1 ; Power-up initialization.

1349 03C1 DD 21 A5 07 LD IX,BLANK ;BLANK is the initial display

1350 03C5 ;pattern.

1351 03C5 ;Display the following1352 03C5 ;patterns sequence, each 0.16

1353 03C5 ;seconds:

1354 03C5 ; ' '

1355 03C5 ; ' u'

1356 03C5 ; ' uP'

1357 03C5 ; ' uPF'

1358 03C5 ; ' uPF-'

1359 03C5 ; ' uPF--'

1360 03C5 ; 'uPF--1'

1361 03C5

1362 03C5 0E 07 LD C,7 ;pattern count

1363 03C7 06 10 INI1 LD B,16 ;Display 0.16 second.

1364 03C9 CD 24 06 INI2 CALL SCAN11365 03CC 10 FB DJNZ INI2

1366 03CE DD 2B DEC IX ;next pattern

1367 03D0 0D DEC C

1368 03D1 20 F4 JR NZ,INI1

1369 03D3 ;

1370 03D3 3E A5 LD A,PWCODE

1371 03D5 C3 B3 06 JP INI3

1372 03D8 21 66 00 INI4 LD HL,NMI

1373 03DB 22 EE 1F LD (IM1AD),HL ;Set the service routine

1374 03DE ;of RST 38H to NMI, which is the

1375 03DE ;nonmaskable interrupt service

1376 03DE ;routine for break point and

1377 03DE ;single step.1378 03DE CLRBR:

1379 03DE ; Clear break point by setting

1380 03DE ; the break point address to

1381 03DE ; FFFF. This is a non-existant

1382 03DE ; address, so break can never

1383 03DE ; happen.

1384 03DE

1385 03DE 21 FF FF LD HL,0FFFFH

1386 03E1 22 E0 1F LD (BRAD),HL

1387 03E4 C9 RET

1388 03E5 ;

1389 03E5 TESTM:

1390 03E5 ; Check if the display is of 'addres-data'1391 03E5 ; form, i.e. STATE 1 or 2.

1392 03E5 ; The result is stored in zero flag.


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MPF-1


1393 03E5 ; Z: yes

1394 03E5 ; NZ: no

1395 03E5

1396 03E5 3A E4 1F LD A,(STATE)1397 03E8 FE 01 CP 1

1398 03EA C8 RET Z

1399 03EB FE 02 CP 2

1400 03ED C9 RET

1401 03EE ;

1402 03EE PRECL1:

1403 03EE ; Pre-clear 1 byte.

1404 03EE ; If bit 0 of TEST is not 0, load 0 into (HL). Bit 0 of

1405 03EE ; TEST is cleared after check.

1406 03EE ; Only AF register is destroyed.

1407 03EE

1408 03EE 3A E6 1F LD A,(TEST)

1409 03F1 B7 OR A ;Is bit 0 of TEST zero?1410 03F2 C8 RET Z

1411 03F3 3E 00 LD A,0

1412 03F5 77 LD (HL),A ;Clear (HL)

1413 03F6 32 E6 1F LD (TEST),A ;Clear TEST too.

1414 03F9 C9 RET

1415 03FA ;

1416 03FA PRECL2:

1417 03FA ; Pre-clear 2 bytes.

1418 03FA ; If bit 0 of TEST is nonzero, clear (HL)

1419 03FA ; and (HL+1).

1420 03FA ; Only AF register is destroyed.

1421 03FA

1422 03FA CD EE 03 CALL PRECL11423 03FD C8 RET Z

1424 03FE 23 INC HL

1425 03FF 77 LD (HL),A

1426 0400 2B DEC HL

1427 0401 C9 RET

1428 0402 ;

1429 0402 ;***********************************************************

1430 0402 ; Memory display format: (address-data)

1431 0402

1432 0402 ; i) A.A.A.A. D D -- State is AD. Four decimal points

1433 0402 ; under the address field indicate

1434 0402 ; that the numeric key entered will

1435 0402 ; be interpreted as memory address.1436 0402 ; ii) A A A A D.D.-- State is DA. Two decimal points

1437 0402 ; under the data field indicate

1438 0402 ; the monitor is expecting user to

1439 0402 ; enter memory data.

1440 0402 ; iii) A.A.A.A. D.D.-- Six decimal points indicate the

1441 0402 ; address being displayed is set

1442 0402 ; as a break point.

1443 0402

1444 0402 MEMDP1:

1445 0402 3E 01 LD A, 1 ;Next STATE = 1

1446 0404 06 04 LD B, 4 ;4 decimal points active

1447 0406 21 B8 1F LD HL,DISPBF+2 ;The first active decimal

1448 0409 ;point is in DISPBF+2, the1449 0409 ;last in DISPBF+5.

1450 0409 18 07 JR SAV12 ;Continue at SAV12.


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MPF-1


1451 040B MEMDP2:

1452 040B 3E 02 LD A,2 ;Next STATE = 2

1453 040D 06 02 LD B,2 ;2 active decimal points

1454 040F 21 B6 1F LD HL,DISPBF ;1st decimal point is in1455 0412 ;DISPBF, 2nd in DISPBF+1.

1456 0412 32 E4 1F SAV12 LD (STATE),A ;Update STATE

1457 0415 D9 EXX ;Save register HL, BC, DE

1458 0416 ED 5B DE 1F LD DE,(ADSAVE) ;The address to be

1459 041A ;displayed is stored in

1460 041A ;(ADSAVE). Load it into

1461 041A ;DE register.

1462 041A CD 65 06 CALL ADDRDP ;Convert this address to

1463 041D ;display format and store it

1464 041D ;into DISPBF+2 - DISPBF+5.

1465 041D 1A LD A,(DE) ` ;Load the data of this

1466 041E ;address into A register

1467 041E CD 71 06 CALL DATADP ;Convert this data to1468 0421 ;display format and store it

1469 0421 ;into DISPBF - DISPBF+1

1470 0421 BRTEST:

1471 0421 ; The next 3 instructions serve to refresh the

1472 0421 ; data at break address every time memory is

1473 0421 ; displayed.

1474 0421 2A E0 1F LD HL,(BRAD) ;Get break point address.

1475 0424 7E LD A,(HL) ;Get the data of this

1476 0425 ;address into A register.

1477 0425 32 E2 1F LD (BRDA),A ;Store it into BRDA (break data).

1478 0428 B7 OR A

1479 0429 ED 52 SBC HL,DE ;Check if the address to

1480 042B ;be displayed is break point.1481 042B 20 06 JR NZ,SETPT1 ;If not, jump to SETPT1.

1482 042D 06 06 LD B,6 ;6 active decimal points.

1483 042F 21 B6 1F LD HL,DISPBF ;1st decimal point is in

1484 0432 ;DISPBF; 6th in DISPBF+5.

1485 0432 D9 EXX

1486 0433 D9 SETPT1 EXX

1487 0434 CB F6 SETPT SET 6,(HL) ;Set decimal points.

1488 0436 ;Count in B, first address

1489 0436 ;in HL register.

1490 0436 23 INC HL

1491 0437 10 FB DJNZ SETPT

1492 0439 C9 RET

1493 043A ;1494 043A ;***********************************************************

1495 043A ; Step display format: (this format is used when user is

1496 043A ; entering parameters for Move, Rela, WRtape, RDtape.)

1497 043A

1498 043A ; P.P.P.P. - N

1499 043A

1500 043A ; 'P' is the digit of parameter. Four decimal points

1501 043A ; indicate P's are being modified now. N is the mnemonic of

1502 043A ; the parameter:

1503 043A ; i) Move S -- starting address

1504 043A ; E -- ending address

1505 043A ; D -- destination address

1506 043A ; ii) Rela S -- source address1507 043A ; D -- destination address

1508 043A ; iii) WRtape F -- file name


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MPF-1


1509 043A ; S -- starting address

1510 043A ; E -- ending address

1511 043A ; iv) Rdtape F -- filename

1512 043A1513 043A STEPDP:

1514 043A ;Display step buffer and its parameter name.

1515 043A ;Input: STATE

1516 043A ; STMINOR (parameter count)

1517 043A ;registers destroyed: AF, BC, DE, HL

1518 043A

1519 043A CD 55 04 CALL LOCSTBF ;Get parameter address

1520 043D 5E LD E,(HL) ;Load parameter into DE

1521 043E 23 INC HL

1522 043F 56 LD D,(HL)

1523 0440 CD 65 06 CALL ADDRDP ;Convert this paramter to

1524 0443 ;display format (4 digits)

1525 0443 ;and store it into DISPBF+21526 0443 ; - DISPBF+5

1527 0443 21 B8 1F LD HL,DISPBF+2 ;Set 4 decimal points

1528 0446 ;From DISPBF+2 to DISPBF+5

1529 0446 06 04 LD B,4

1530 0448 CD 34 04 CALL SETPT

1531 044B CD 5F 04 CALL LOCSTNA ;Get parameter name.

1532 044E 6F LD L,A

1533 044F 26 02 LD H,2 ;Pattern '-' for 2nd rightmost

1534 0451 ;digit.

1535 0451 22 B6 1F LD (DISPBF),HL

1536 0454 C9 RET

1537 0455 ;

1538 0455 LOCSTBF:1539 0455 ;Get the location of paramter.

1540 0455 ; address = STEPBF + STMINOR*2

1541 0455 ;registers destroyed: AF,HL

1542 0455

1543 0455 3A E3 1F LD A,(STMINOR) ;Get parameter count.

1544 0458 87 ADD A,A ;Each parameter has 2 bytes

1545 0459 21 AF 1F LD HL,STEPBF ;Get base address

1546 045C 85 ADD A,L

1547 045D 6F LD L,A

1548 045E C9 RET

1549 045F ;

1550 045F LOCSTNA

1551 045F ;Get parameter name.1552 045F ;Input: STATE, STMINOR

1553 045F ;Output: parameter name in A, and Z flag.

1554 045F

1555 045F ;registers destroyed: AF, DE

1556 045F 3A E4 1F LD A,(STATE) ;Get STATE.

1557 0462 ;Possible states are:

1558 0462 ;4,5,6,7. (Move, Rel,

1559 0462 ;WRtape, RDtape)

1560 0462 D6 04 SUB 4 ;Change 4,5,6,7 to

1561 0464 ;0,1,2,3

1562 0464 87 ADD A,A ;Each state has 4 bytes for names

1563 0465 87 ADD A,A

1564 0466 11 BC 07 LD DE,STEPTAB1565 0469 83 ADD A,E

1566 046A 5F LD E,A ;Now, DE contains the


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MPF-1


1567 046B ;address of 1st name

1568 046B ;for each state.

1569 046B 3A E3 1F LD A,(STMINOR) ;Get parameter count

1570 046E 83 ADD A,E ;DE


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MPF-1


1625 0485 ;Store them into DISPBF

1626 0485 ;and DISPBF+1.

1627 0485 78 LD A,B ;Restore A (register pair leader).

1628 0486 CD BE 04 CALL LOCRG ;Get the address of1629 0489 ;user's register.

1630 0489 5E LD E,(HL) ;Get register data. (2 bytes)

1631 048A 23 INC HL

1632 048B 56 LD D, (HL)

1633 048C ED 53 DE 1F LD (ADSAVE),DE ;Convert them to display

1634 0490 ;format and store into

1635 0490 ;display buffer.

1636 0490 CD 65 06 CALL ADDRDP

1637 0493 3A E4 1F LD A,(STATE)

1638 0496 FE 09 CP 9 ;If STATE equals to 9 (RGDA),

1639 0498 ;set 2 decimal points.

1640 0498 ;Otherwise return here.

1641 0498 C0 RET NZ1642 0499 21 B8 1F LD HL,DISPBF+2

1643 049C 3A E3 1F LD A,(STMINOR) ;Get register name.

1644 049F CB 47 BIT 0,A ;If this register is

1645 04A1 ;group leader, set decimal

1646 04A1 ;points of two central digits.

1647 04A1 ;Otherwise set two left digits.

1648 04A1 28 02 JR Z,LOCPT

1649 04A3 23 INC HL

1650 04A4 23 INC HL

1651 04A5 CB F6 LOCPT SET 6,(HL) ;Set decimapl points of

1652 04A7 ;(HL) and (HL+1)

1653 04A7 23 INC HL

1654 04A8 CB F6 SET 6,(HL)1655 04AA CD C4 04 CALL FCONV ;Convert user's flag (F, F')

1656 04AD ;to binary display format.

1657 04AD C9 RET

1658 04AE ;

1659 04AE RGNADP:

1660 04AE ; Get the patterns of register names and

1661 04AE ; store them into DISPBF and DISPBF+1.

1662 04AE ; Input: A contains register count of

1663 04AE ; pair leader.

1664 04AE ; registers destroyed: AF,DE,HL

1665 04AE

1666 04AE 21 D0 07 LD HL,RGTAB ;Get address of pattern

1667 04B1 ;table.1668 04B1 85 ADD A,L

1669 04B2 6F LD L,A

1670 04B3 5E LD E,(HL) ;Get first pattern

1671 04B4 23 INC HL

1672 04B5 56 LD D,(HL) ;Get 2nd pattern.

1673 04B6 ED 53 B6 1F LD (DISPBF),DE

1674 04BA C9 RET

1675 04BB ;

1676 04BB LOCRGBF:

1677 04BB ; Get the address of user's register.

1678 04BB ; Register name contained is STMINOR.

1679 04BB ; Destroys HL, AF.

1680 04BB1681 04BB 3A E3 1F LD A,(STMINOR)

1682 04BE 21 BC 1F LOCRG LD HL,REGBF


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MPF-1


1683 04C1 85 ADD A,L

1684 04C2 6F LD L,A

1685 04C3 C9 RET

1686 04C4 ;1687 04C4 FCONV:

1688 04C4 ; Encode or decode user's flag register.

1689 04C4 ; STMINOR contains the name of the flag

1690 04C4 ; being displayed now.

1691 04C4 ; registers destroyed: AF, BC, HL.

1692 04C4

1693 04C4 3A E3 1F LD A,(STMINOR) ;Get register name.

1694 04C7 B7 OR A ;Clear carry flag.

1695 04C8 1F RRA ;name of I register: 17H,

1696 04C9 ;name of IFF: 16H.

1697 04C9 ;Rotate right one bit, both

1698 04C9 ;become 0BH.

1699 04C9 FE 0B CP 0BH1700 04CB 28 09 JR Z,FLAGX ;Jump to FLAGX if

1701 04CD ;I or IFF is being

1702 04CD ;displayed now.

1703 04CD 4F LD C,A ;Otherwise, mask out bit

1704 04CE ;1 to bit 7 fof user's IFF.

1705 04CE ;IFF is only 1 bit, monitor

1706 04CE ;uses one byte to store it,

1707 04CE ;masking out bit 1-7 is to

1708 04CE ;ignore the useless bits.

1709 04CE ;This is done only when the

1710 04CE ;user is not modifying IFF.

1711 04CE ;If user is modifying IFF,

1712 04CE ;monitor will display whatever1713 04CE ;he enters, even if bit 1-7

1714 04CE ;are not all zero.

1715 04CE ;A register is not changed

1716 04CE ;after doing this.

1717 04CE 21 D2 1F LD HL,USERIF

1718 04D1 7E LD A,(HL)

1719 04D2 E6 01 AND 00000001B

1720 04D4 77 LD (HL),A

1721 04D5 79 LD A,C

1722 04D6 FE 0C FLAGX CP 0CH ;If STMINOR contains

1723 04D8 ;the name of SZXH, XPNC,

1724 04D8 ;SZXH' or XPNC', after

1725 04D8 ;rotating right one bit1726 04D8 ;it will be greater than

1727 04D8 ;or equal to 0CH.

1728 04D8 ;Decode user's flag if it

1729 04D8 ;is not being modified now,

1730 04D8 ;encode it otherwise.

1731 04D8 30 1F JR NC,FCONV2

1732 04DA 3A BC 1F FCONV1 LD A,(USERAF) ;Get user's F register

1733 04DD CD 18 05 CALL DECODE ;Decode upper 4 bits.

1734 04E0 22 D4 1F LD (FLAGH),HL

1735 04E3 CD 18 05 CALL DECODE ;Decode lower 4 bits.

1736 04E6 22 D6 1F LD (FLAGL),HL

1737 04E9 3A C4 1F LD A,(UAFP) ;Get user's F' register.

1738 04EC CD 18 05 CALL DECODE1739 04EF 22 D8 1F LD (FLAGHP),HL

1740 04F2 CD 18 05 CALL DECODE


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MPF-1


1741 04F5 22 DA 1F LD (FLAGLP),HL

1742 04F8 C9 RET

1743 04F9 2A D4 1F FCONV2 LD HL,(FLAGH) ;Get the binary form

1744 04FC ;of 4 upper bits of1745 04FC ;user's F register.

1746 04FC CD 23 05 CALL ENCODE ;Encode it.

1747 04FF 2A D6 1F LD HL,(FLAGL) ;Encode 4 lower bits.

1748 0502 CD 23 05 CALL ENCODE

1749 0505 32 BC 1F LD (USERAF),A ;Save the encoded

1750 0508 ;result into USERAF.

1751 0508 2A D8 1F LD HL,(FLAGHP) ;Encode F' register.

1752 050B CD 23 05 CALL ENCODE

1753 050E 2A DA 1F LD HL,(FLAGLP)

1754 0511 CD 23 05 CALL ENCODE

1755 0514 32 C4 1F LD (UAFP),A

1756 0517 C9 RET

1757 0518 ;1758 0518 DECODE:

1759 0518 ; Decode bit 7-4 of A register.

1760 0518 ; Each bit is extended to 4 bits.

1761 0518 ; 0 becomse 0000, 1 becomse 0001.

1762 0518 ; The output is stored in HL, which

1763 0518 ; is 16 bits in length. Also, after

1764 0518 ; execution, bits 7-4 of A register are

1765 0518 ; bits 3-0 of A before execution.

1766 0518 ; Registers destroyed: AF, B, HL

1767 0518

1768 0518 06 04 LD B,4 ;Loop 4 times

1769 051A 29 DRL4 ADD HL,HL ;Clear rightmost 3

1770 051B ;bits of HL.1771 051B 29 ADD HL,HL

1772 051C 29 ADD HL,HL

1773 051D 07 RLCA

1774 051E ED 6A ADC HL,HL ;The 4th bit of HL

1775 0520 ;is determined by carry

1776 0520 ;flag, which is the MSB

1777 0520 ;of A register.

1778 0520 10 F8 DJNZ DRL4

1779 0522 C9 RET

1780 0523 ;

1781 0523 ENCODE:

1782 0523 ; Encode HL register. Each 4 bits of HL

1783 0523 ; are encoded to 1 bit. 0000 become 0,1784 0523 ; 0001 become 1. The result is stored

1785 0523 ; in bit 3-0 of A register. Also, after

1786 0523 ; execution, bit 7-4 of A are bit 3-0

1787 0523 ; before execution.

1788 0523 ; Registers AF, B, HL are destroyed.

1789 0523

1790 0523 06 04 LD B,4 ;Loop 4 times.

1791 0525 29 ERL4 ADD HL,HL ;Shift HL left 4 bits.

1792 0526 ;Bit 12 of HL will be

1793 0526 ;shifted into carry flag.

1794 0526 29 ADD HL,HL

1795 0527 29 ADD HL HL

1796 0528 29 ADD HL,HL1797 0529 17 RLA ;Rotate carry flag into

1798 052A ;A register.


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MPF-1


1799 052A 10 F9 DJNZ ERL4

1800 052C C9 RET

1801 052D ;

1802 052D ;***********************************************************1803 052D SUM1:

1804 052D ; Calculate the sum of the data in a memory

1805 052D ; block. The starting and ending address

1806 052D ; of this block are stored in STEPBF+2 - STEPBF+4

1807 052D ; Registers AF, BC, DE, HL are destroyed.

1808 052D

1809 052D CD 3A 05 CALL GETPTR ;Get parameters from

1810 0530 ;step buffer.

1811 0530 D8 RET C ;Return if the parameters

1812 0531 ;are illegal.

1813 0531 SUM:

1814 0531 ; Calculate the sum of a memory block.

1815 0531 ; HL contains the starting address of1816 0531 ; this block, BC contains the length.

1817 0531 ; The result is stored in A. Registers

1818 0531 ; AF, BC, HL are destroyed.

1819 0531

1820 0531 AF XOR A ;Clear A

1821 0532 86 SUMCAL ADD A,(HL) ;Add

1822 0533 ED A1 CPI

1823 0535 EA 32 05 JP PE,SUMCAL

1824 0538 B7 OR A ;Clear flags.

1825 0539 C9 RET

1826 053A ;

1827 053A GETPTR:

1828 053A ; Get parameters from step buffer.1829 053A ; Input: (STEPBF+2) and (STEPBF+3) contain

1830 053A ; starting address.

1831 053A ; (STEPBF+4) and (STEPBF+5) contain

1832 053A ; ending address.

1833 053A ; Output: HL register contains the starting

1834 053A ; address.

1835 053A ; BC register contains the length.

1836 053A ; Carry flag 0 -- BC positive

1837 053A ; 1 -- BC negative

1838 053A ; Destroyed registers: AF, BC, DE, HL.

1839 053A

1840 053A 21 B1 1F LD HL,STEPBF+2

1841 053D 5E GETP LD E,(HL) ;Load starting address1842 053E ;into DE.

1843 053E 23 INC HL

1844 053F 56 LD D,(HL)

1845 0540 23 INC HL

1846 0541 4E LD C,(HL)

1847 0542 23 INC HL ;Load ending address

1848 0543 ;into HL.

1849 0543 66 LD H,(HL)

1850 0544 69 LD L,C

1851 0545 B7 OR A ;Clear carry flag.

1852 0546 ED 52 SBC HL,DE ;Find difference.

1853 0548 ;Carry flag is changed here.

1854 0548 4D LD C,L1855 0549 44 LD B,H

1856 054A 03 INC BC ;Now BC contains the


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MPF-1


1857 054B ;length.

1858 054B EB EX DE,HL ;Now HL contains the

1859 054C ;starting address.

1860 054C C9 RET1861 054D ;

1862 054D TAPEIN:

1863 054D ; Load a memory block from tape.

1864 054D ; Input: HL -- starting address of the block

1865 054D ; BC -- length of the block

1866 054D ; Output: Carry flag 1 -- reading error

1867 054D ; 0 -- no error

1868 054D ; Destroyed registers: AF, BC, DE, HL, AF', BC', DE', HL'

1869 054D

1870 054D AF XOR A ;Clear carry flag.

1871 054E ;At beginning, the reading is

1872 054E ;no error.

1873 054E 08 EX AF,AF'1874 054F CD 5A 05 TLOOP CALL GETBYTE ;Read 1 byte from tape.

1875 0552 73 LD (HL),E ;Store it into memory.

1876 0553 ED A1 CPI

1877 0555 EA 4F 05 JP PE,TLOOP ;Loop until length

1878 0558 ;is zero.

1879 0558 08 EX AF,AF'

1880 0559 C9 RET

1881 055A ;

1882 055A GETBYTE:

1883 055A ; Read one byte from tape.

1884 055A ; Output: E -- data read

1885

mpf-i the monitor (assembled with tasm; final 0,5 inch)

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