|Extensions to the operating system
or extensions to Naspen.
|Colour graphics RAM or general RAM space.
|Programmable grahics RAM or general RAM space.
|General RAM space.
Start of general program space.
|Usual stack space.
|Workspace for firmware
or workspace for programs.
|Extended operating system workspace.
|Existing operating system workspace.
|Existing video RAM.
|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
S-100 (continued from
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.