On 03/29/2015 07:53 PM, Josh Dersch wrote:
Wow, that is seriously cool! Sounds like something you
need to finish up one of these days :).
For the reasons I abandoned the project in about 1982, I am
afraid it will stay abandoned.
I did get it working, but it is just a bare 32-bit bit slice
engine, with 1K 96-bit words of control store and 56 32-bit
registers. It ran at 8 MHz for 2-register operations, but
could also do 3-register at 6 MHz. It was controlled by an
S-100 Z-80 system that I no longer have, although it
basically was similar to a parallel port, so could be hooked
to a PC parallel port fairly easily.
I needed to add in some more logic to do 256-way branches
from the op-code, and or-in register fields from the
instruction register. I needed to define a system bus and
build a bus interface, and them build a few simple
peripherals. I already had a SASI-bus hard drive on the
S-100 CP/M system, so I could have built a controller for
that pretty easily. Then a COM controller. I had planned
on making a stripped-down micro-controller for most
peripheral controllers, it would have been about 20 chips,
with 8-bit data path and 16-bits of EPROM for firmware.
Probably could have run at 4 MHz or so.
THEN, the REAL reason I let this drop, is I would need an OS
for a seriously oddball machine. Slightly enhanced 360
instruction set, but a PDP-11 style I/O architecture. I
could build my own OS, but it would likely not be much
better than CP/M, although multiprogramming would be nice.
Then, how about compilers? I recently figured out I
probably could have stolen OS/360 compilers without much
trouble, but even getting those working would take a LOT of
work to understand the various library routines they used
and providing wrappers so the compilers thought they were in
an OS/360 environment.
Geez, a LOT of work!
This would have been an AWESOME home system in 1984 or so,
but would be just a ridiculous conversation piece, now.
I cloned a Nat. Semi. 32016 system, and used that for a
while, but it was glacially slow!
Then, I got a uVAX at home, and ran it for 21 years. I
still have the CPU, but mostly gave away the peripheral boards.