INMC News

  

February/March 1980, Issue 6

Page 18 of 38

B7FF
B000
====
Extensions to the operating system or extensions to Naspen.
AFFF
9800
====
Colour graphics RAM or general RAM space.
97FF
9000
====
Programmable grahics RAM or general RAM space.
8FFF
1000
====
General RAM space.
Start of general program space.
0FFF
0F80
====
Usual stack space.
0F7F
0D00
====
Workspace for firmware
or workspace for programs.
0CFF
0C80
====
Extended operating system workspace.
0C7F
0C00
====
Existing operating system workspace.
0BFF
0800
====
Existing video RAM.
07FF
0000
Existing operating system.

As you will notice, firmware which is unlikely to be used together has been assigned coresidence. For example, no-one is likely to want to use the colour graphics firmware (which runs under Basic) with REVAS (which is a machine code disassembler). Similarly, any extensions to Naspen may be made from B000 – B7FF, as with a more powerful word processor in residence, extensions to the operating system would hardly be required, and so on. However, extensions to the Basic could imply the use of a more powerful operating system, or a software number cruncher such as MAPP1-3Z could be put in place of ZEAP, and used to extend the precision of the Basic math to 14 digits (if any one has done this please let us know).

So please bear these suggestions in mind in writing your software, that way maximum portability, and least inconvenience is caused.



S-100 (continued from page 12)

more for a real one”. Well we don’t know, but in general the Nascom keyboard costs rather more (not less) than the average ASCII keyboard fitted to competing computers, and is a very rugged and superior product. We don’t know why all the control is done in software, as it would have cost little more to make the keyboard truly ASCII. Mind you, a software controlled keyboard lets you do lots of clever things which a hardware keyboard could never do (look at the N Ray Moonlander program for instance). Finally, does it really matter, as ASCII keyboards can easily be run into PORT 0 with very little modification to the software if required.


Page 18 of 38