20 Oct
1999
20 Oct
'99
2:27 p.m.
Hi,
I haven't been following this thread all that closely,
but the snippet below brought back some memories ...
Way back in '87 I visited the main Motorola facility in
Austin, TX. I was doing a lot of 68K-family based design
at that time for Nortel, and we were beginning to enter into a
strategic agreement with Motorola, so the folks there
were giving us a pretty in-depth tour of their facility.
I never will forget being taken into one of their
development labs, and over in a corner, on a shelf, were
two card cages. One was the prototype 68000 processor,
implemented on 11 wire-wrapped boards out of TTL logic
and similar-vintage components, all plugged into a
wire-wrapped backplane. Next to it was the prototype
68020 processor, which they were able to implement on 14
wire-wrapped boards. As I recall, these cards were a little
larger than what we were using in our systems at the time,
probably something like 12" x 12". I also recall them
telling me that the 68000 prototype ran the full instruction
set, and that it ran at a frequency of 500 KHz. I
hope that the folks at Motorola never threw that stuff out!
Regards,
Alex
Calculator History & Technology Museum Web Page
http://aknight.home.mindspring.com/calc.htm
At 10:15 PM 10/20/99 -0000, Eric Smith wrote:
Allison wrote:
...
ok, By discrete you meand transistors and
diodes.
An 8080 cpu would likely fill a rack 20-25" high with boards.
IIRC, the 8080 was about 4000 MOSFET transistors. If you implemented it
with individual FETs, and packed it densely, I think you could fit it in
a 10.5" high rack space easily, and a 5.25" high rack space with difficulty.
Of course, you'll need plenty of forced air cooling. From a serviceability
point of view, building it less densely is clearly better.