[vcf-midatlantic] Working on a historical microprocessor exhibt

Dave McGuire mcguire at neurotica.com
Sun Feb 9 15:08:30 EST 2020

On 2/9/20 2:58 PM, Adam Michlin wrote:
> That fills a huge hole in my understanding of architecture history. It
> certainly makes sense that there would be separate ICs that eventually
> merged into one discrete CPU. I just assumed it was done by the
> minicomputer manufacturers themselves. I had no idea it was AMD! Thanks!

  Well bit-slice chips were made by many manufacturers.  Keep in mind
the minicomputer manufacturers were the chip companies' bread & butter
for a long time.  Even Intel; they made the 3000 series of bit-slice parts.

  But it wasn't really separate ICs that eventually merged to form
microprocessors.  The Am2901 was introduced in 1975, well after there
were a few microprocessors on the market.  These chips, and their
applications, coexisted with monolithic VLSI microprocessors for a long
time.  Bit-slice design was commonplace clear up until at least 1990.
It was just a different way of doing things that was more scalable and

  And at the time of introduction of the VAX-11/730, for example,
designing a single VLSI chip that implemented an architecture as complex
as VAX wasn't really practical.  The first single-chip VLSI
implementation of the VAX architecture (the 78032, used in the
MicroVAX-II and others) wouldn't tape out for another three years after

>>> I'd love to find a Zilog Z8000, but don't imagine period correct Z8000s
>>> are so easy to come by. We have a Z8000 machine in the warehouse, but
>>> one of the big rules for this product is that no vintage computers will
>>> be harmed to make it happen.
>>    Are you talking about just a Z8000 chip?  I can provide that for the
>> exhibit.  It will need ESD protection, of course.
> Cool, we'll talk. And not only ESD protection, but non degradable ESD
> protection is being planned.

  Ok.  Go ahead and count on it being available and let me know how
things progress.


Dave McGuire, AK4HZ
New Kensington, PA

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