* one megabyte external memory … coupé...* one megabyte external memory interface for the sam...

*** ONE MEGABYTE EXTERNAL MEMORY INTERFACE FOR THE SAM COUPE ** The 1 Mb Interface plugs into the Coupe's rear expansion connector (or into a SAMBUS slot) and extends the SAM Coupe's memory capability by 1024 Kilobytes, whether you have a standard 256k machine or a 512k upgraded machine. WARNING ! - NEVER plug/unplug any device into an expansion connector while the Coupe is switched on. You may cause some damage the computer and almost certainly cause any loaded programs to "crash" The SAM Coupe allows you to use up to 512k of internal RAM (256k on standard machines) through SAM BASIC, but will not recognise the external 1 Mb memory. You will need to use MasterDOS in order to use the 1 Mb External Memory efficiently. When MasterDOS is booted, it verifies the external memory capability and includes it in the SAM Coupe's overall view of the memory. However, it doesn't alter SAM BASIC to allow it to use the external memory for writing a BASIC program, or to access the external memory by using commands such as POKE and PEEK. One of the main advantages in having a 1 Mb External Memory fitted is that it can be used as a second, third, fourth etc RAMDISK drive. Future programmers when writing software, will look for it to be configured into working memory to enable programs such as databases to run more efficiently. All of the standard disk commands can be used in MasterDOS on the 1 Mb External Memory, and of course the access times are much faster. Remember though that the 1 Mb memory is volatile, and that any data stored there will be lost as soon as the SAM Coupe is turned off. On the 1 Mb printed circuit board there is a jumper connection to allow a one from four position selection (which is factory set to position four). This enables up to four 1 Mb External Interfaces to be connected together giving a possible total memory capability of a staggering 4.5 Megabytes of RAM (4,718,592 bytes !!!) The 1 Mb External Memory is controlled by two 8-bit registers which are adressed by port 128 for the first PAGE (EXPAGE-C, 8000 hex to BFFF hex) and port 129 for the second PAGE (EXPAGE-D, 0000 hex to FFFF hex). As you can see, when the external memory is switched in, it replaces the top 32k of the processor addressable memory. Each 1 Mb External Memory unit is divided into 64 pages of 16k each, selected by the first 6 bits of ports 128 and 129. The most significant two bits of each port select one of the four possible 1 Mb External Memory units. Lakeside, Phoenix Way, Swansea Enterprise Park, Swansea SA7 9EH Telephone: 0792 700300 Fax: 0792 310659 Company Registered No 2518081 Directors: A J ,Miles, B B Gordon

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Page 1: *** ONE MEGABYTE EXTERNAL MEMORY … Coupé...*** ONE MEGABYTE EXTERNAL MEMORY INTERFACE FOR THE SAM COUPE ** The 1 Mb Interface plugs into the Coupe's rear expansion connector (or

*** ONE MEGABYTE EXTERNAL ME The 1 Mb Interface plugs inconnector (or into a SAMBUS memory capability by 1024 Ki256k machine or a 512k upgra WARNING ! - NEVER plug/unpluconnector while the Coupe isdamage the computer and almoprograms to "crash" The SAM Coupe allows you to on standard machines) througthe external 1 Mb memory. Yoorder to use the 1 Mb Extern When MasterDOS is booted, itcapability and includes it imemory. However, it doesn't use the external memory for access the external memory bPEEK. One of the main advantages ifitted is that it can be useRAMDISK drive. Future progralook for it to be configuredprograms such as databases t All of the standard disk comthe 1 Mb External Memory, anmuch faster. Remember thoughand that any data stored theCoupe is turned off. On the 1 Mb printed circuit to allow a one from four posset to position four). This Interfaces to be connected tmemory capability of a stagg(4,718,592 bytes !!!) The 1 Mb External Memory is which are adressed by port 18000 hex to BFFF hex) and po(EXPAGE-D, 0000 hex to FFFF external memory is switched processor addressable memory Each 1 Mb External Memory uneach, selected by the first significant two bits of eachpossible 1 Mb External Memor

Lakeside, Phoenix Way,Telephone: 079

Company Registered No 251

MORY INTERFACE FOR THE SAM COUPE **

to the Coupe's rear expansion slot) and extends the SAM Coupe's lobytes, whether you have a standard ded machine.

g any device into an expansion switched on. You may cause some st certainly cause any loaded

use up to 512k of internal RAM (256k h SAM BASIC, but will not recognise u will need to use MasterDOS in al Memory efficiently.

verifies the external memory n the SAM Coupe's overall view of the alter SAM BASIC to allow it to writing a BASIC program, or to y using commands such as POKE and

n having a 1 Mb External Memory d as a second, third, fourth etc mmers when writing software, will into working memory to enable o run more efficiently.

mands can be used in MasterDOS on d of course the access times are that the 1 Mb memory is volatile, re will be lost as soon as the SAM

board there is a jumper connection ition selection (which is factory enables up to four 1 Mb External ogether giving a possible total ering 4.5 Megabytes of RAM

controlled by two 8-bit registers 28 for the first PAGE (EXPAGE-C, rt 129 for the second PAGE hex). As you can see, when the in, it replaces the top 32k of the .

it is divided into 64 pages of 16k 6 bits of ports 128 and 129. The most port select one of the four y units.

Swansea Enterprise Park, Swansea SA7 9EH 2 700300 Fax: 0792 310659

8081 Directors: A J ,Miles, B B Gordon