28 Jan
2002
28 Jan
'02
3:15 a.m.
From: Ethan Dicks <erd_6502(a)yahoo.com>
pins 19-22 on the standard OSI bus = A16 - A19 for extended addressing under
the 6502 (multiuser and under software control of the PIA) and probably used
natively under the 6100...
disconnect
>
> > The C3 was kinda cool... It was wild to see a box with multiple
CPUs...
>
> C3's are cool... One, a C3-SI with a C2D dual 8" floppy system using
the
> 530 board (I think) which has the z80, 6800, and
6502 all on board.
D'oh. That's a 510 board, not a 530
That's the one! We had a family friend who put himself in serious hock
for one of those when it was new.
me too, and for a used one. ;)
I wish I could
find the OSI 460Z board... that adds the Intersil 6100
and some other microprocessor too to the base 3 of the C3.
That sounds wicked. I wonder how they handled the 12-bit bus of the
6100. (If they had
just jammed the CDP1802 in there too I could have prossibly
settled on this one machine to collect...those bastards...)
Agreed... you could have all the big stars of the 1970s micros in one
cabinet. I still don't get how they managed all the different machines
in one box. The easy part is building a CPU board where you can a particular CPU from the bus in software. The hard
part is the handoff.
You'd almost need a way to preload RAM or select a ROM that was ready to
go for the next CPU you wanted to switch to. It's been so long since I've
used a C3 that I forget entirely how to boot it and switch it around. Are
It boots under one processor (hardware selected) usually 6502 on a reset
Software processor selects happens with a PIA port . Both the 6502 and 6800
reset and drop into their monitors, the z-80 just jumps to whatever address
is preloaded at address 0 so it could be somewhat used as a slave processor
without changes. the 6800 and 6502 could too but you did have to hack in
some relocatable RAM that responded to the PIA controlled processor
shifts...
there any manuals online?
Haven't looked. Got two shelves full of dealer, software, and hardware docs
on OSI models 400 - C8P. So someday maybe when the time fairy leaves some
days under my pillow... until then, just ask.
;)
- Mike: dogas(a)bellsouth.net