The goal: 8 bit or 16bit, running from ROM's for
software and store
work files on HD, tape or floppy, text based on 6845 IC or similar.
That is beggining, in the end should able to run CPM or something.
I prefer to interface the PC keyboards to it as by make up the
convertor to something that cpu understands by microcontroller or
like.
Why restrict yourself to PC-clone keyboards? May as well just put a
serial port on it, that way you can use just about any terminal
with it and won't restrict yourself to specific hardware.
I have so many TTL's and LSI's and some
VLSI's, CPU's of all
kinds (intel, Zilog and others), memories, different crystrals and
oscillators. Should it be single board with everything on it in
stages or do it modular via cards?
A CP/M-capable computer doesn't have to be very big at all these days -
there are several commercially available designs/kits/boards which
are a single PC board with just a couple of chips. The comp.os.cpm
FAQ gives links to several of these designs.
If I were you, I wouldn't restrict myself to what's in the junk box.
Total semiconductor price for a CP/M capable computer can be kept
to well under $25 using new parts. If I were doing it, I'd go surface mount,
just to see if I could do it in under 2 square inches :-).
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW:
http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927