The CDC-compatible "Zephyr" CPU

[Gregg Townsend]

In 1988 the PLATO group at the University of Illinois designed and built a
CDC-compatible computer called the "Zephyr" to run their server software.
This was an independent, microcoded realization of Seymour Cray's CPU
architecture, and as far as I know the only quad-CPU implementation.

I have scanned the hardware manual and written up a brief description of
this interesting machine; for more information see
www.cs.arizona.edu/~gmt/zephyr

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Gregg Townsend Staff Scientist The University of Arizona
***@cs.arizona.edu Computer Science Tucson, Arizona, USA

[Jitze Couperus]

Post by Gregg Townsend
In 1988 the PLATO group at the University of Illinois designed and built a
CDC-compatible computer called the "Zephyr" to run their server software.
This was an independent, microcoded realization of Seymour Cray's CPU
architecture, and as far as I know the only quad-CPU implementation.
I have scanned the hardware manual and written up a brief description of
this interesting machine; for more information see
www.cs.arizona.edu/~gmt/zephyr

Wow! Very interesting - thanks for posting and the web page.

Was there some reason they couldn't use a 180 in dual mode? Or
did they figure it would be cheaper to roll their own - or maybe they
wanted a 4-banger for performance?

...and then they went and added an op code to load a word from
memory without altering an A register... (sob - I coulda used that)

Jitze