INMC News

  

February/March 1980, Issue 6











Page 17 of 38











Memory maps

Software of the future

What is the perfect memory layout for the future? What software should be resident in ROM and what should be loaded from tape? You might like to think about these questions in regard to some of the software that already exists or is rumoured to be around.

Nas-sys 1This must be in ROM, and naturally lives at 0000H, although it is not totally impossible to put it elsewhere with Nascom 2.
BasicBoth Rom and tape versions exist. Nascom 2 has it at E000 – FFFFH.
ZEAPThis assembler is a candidate for ROM as it is so useful. ZEAP 2.0 can be in ROM at D000H or RAM at 1000H.
REVASThis disassembler can be located anywhere. Is it used often enough to make it worth having in ROM? It could occupy C400 – CFFFH

All this brings us to memory mapping. So much is going on by independent people, hoping to sell products under the Nascom banner, that a meeting was held recently between Nascom Engineering, and other interested parties. The aim; to ensure that there is room for everything, and that everything can be kept under control. The meeting primarily discussed a standard Nascom 2 expanded to a maximum of 48K and fitted with Nas-sys. Non standard Nascoms and disc based Nascoms were not discussed as their memory requirements will be entirely different. But everything decided is equally relevant to an expanded Nascom 1 fitted with Nas-sys.

One of the mains aims was agreed, and that is that no external product can advertise that it is ‘approved by Nascom’ unless it has been submitted to Nascom for approval, and that it conforms to the memory mapping laid down. Another aim was to produce a reccommended memory map for use with Nascom 2, but is was soon discovered that so many diverse ideas were around that it was only possible to set out guidelines, and that firmware producers would have to look at their product to see where it could be sensibly fitted. This is in the producer’s interest, because if something is located in a daft place then it inhibits its own market.

FFFF
E000
====
8K Basic
DFFF
D000
====
ZEAP 2.0 or general assembler type software
or extensions to Basic.
CFFF
C000
====
REVAS or general disassembler software
or Colour graphics control software.
BFFF
B800
Naspen or related word processing software.

This is an OCR’d version of the scanned page and likely contains recognition errors.











Page 17 of 38