Michael A. Terrell wrote:

No one here has ever played with any Data General computers? How
about Prime? National Semiconductor? Metrodata? Intel Multibus? How
about VME/VXI?



Sure, I started fooling around with PDP-8's, and worked quite a bit with
a PDP-5, a discrete transistor 12-bit machine essentially identical with
the PDP-8 (no suffix) except for physical size, the -5 was about twice
the size. I also did a bit of work with the LINC, a computer designed
at MIT and built by grad students at a summer session there. Some 50+
were built and then shipped back to the home institutions of those
students, and were used for many years. Again, 12-bit word width, but
ones-complement arithmetic, discrete transistors, XY oscilloscope
display and block-oriented 3/4" magnetic tapes. That instruction set
was later incorporated into DEC's LINC-8 and PDP-12 systems. All that
was at Washington University in St. Louis. I also did some learning on
IBM 360's there. Later I worked on PDP-11s, Vaxes and Alpha systems there.

I worked with Data General Novas at University of Missouri at Rolla.

I built a multiprocessor system with the National Semi 16032 (later
renamed the 32016). It ran up to 7 of these computers with a 2 MB
common memory and using a Vax 11/780 for I/O. About the time I got it
really running well, the faster microvaxes came along, and it was
obsolete. It is still in my basement for sentimental reasons. It used
the extended Multibus-I standard for connection to the VAX and memory
boards, as well as power.

We had a Pr1me (that's a numeral one in the middle, not a letter "i")
here but I never worked with it. I did work with an Interdata 7/32
which was used to run an insane 3rd party disk controller for our
PDP-11s. it enabled us to run Calcomp 40 MB 14" hard drives on our PDP.
The instruction set looked a lot like the IBM 360. I think Pr1me was an
offshoot of Interdata.

I worked on a MicroData microprogrammable minicomputer at Rolla. I even
worked on a Vacuuum-tube computer, the Bendix G-15 at Wash U, but we
were never able to get it running. The magnetic drum was badly scratched.

The first computer I built for myself had an 8008 CPU, but too little
memory to do anything worthwhile. I then built an S-100 system with
8080, and then moved up to a Z-80. I had all sorts of stuff interfaced
to that, including a Honeywell 14.5" drum printer that was bigger than a
chest freezer, 9-track mag tape, a 12" XY display with light pen, and a
10 MB Memorex hard drive. I built a 32-bit AMD bit slice computer on
two huge wire wrap boards, but writing the microcode for it was a huge
project. I did get it running, and had a bunch of test programs, but it
was light years from becoming a usable general-purpose computer. I made
a copy of a Nat Semi 32016 CPU and built a working Genix system, but it
was insanely slow. many things were 5 times slower than my Z-80! I did
use it for at least a year, though. This must have been around 1986,
when I got the opportunity to buy a MicroVax CPU board from a broker,
and get the rest of the needed stuff from 3rd party vendors.


Jon