[sdiy] Static ADC and DAC recommendations?

[Phillip Harbison]

Paul Burns wrote:
> Thank you for the historical insight, my uncle is one John
> W. Lacey who was a top dog at CDC right from the outset (he
> used to employ Seymour Cray ;-)

Cray was my hero. Well, Cray, Bob Moog and Mr. Spock! :)

The Rocket City (Huntsville, AL) was a cool place to be for those
with an interest in supercomputers. It is known as the simulations
capital of the world. It was (and may still be) the smallest city
with a Cray sales office. The 7600 was Cray's last design before leaving 
CDC, but in many ways the 6600 was more interesting. It
had many features that are still found in modern microprocessors
(especially superscalar CPUs).

In addition to a 7600, the Ballistic Missile Defense Advanced
Research Center (BMD/ARC) also had the first ten DEC VAX-11/780s
produced. The professor who taught me logic at UAH also worked on
the Safeguard project (system scrapped by the ABM treaty of 1972).
They had PEPE (Parallel Element Processing Ensemble), one of the
first Single Instruction Multiple Data (SIMD) parallel processors
ever built. There were 288 elements (execution units) that would
divide up the work of tracking 1000+ incoming ballistic missiles.
Thank $DIETY we never needed to use it.

The professor who taught control theory at UAH did the control
theory work for the Saturn V rockets using an array of analog
computers and an IBM 1401. He convinced NASA to donate these to
UAH. We had limited success getting the 1401 running but pulled
the plug after considering it had about the same computing power
as one of the briefcase-sized AIM-65 computers used in our micro-
processor lab, but the 1401 occupied about 1200 square feet of
lab space and used more power than the rest of the engineering
building (now known as Von Braun Research Institute) which in
those days included a Univac 1100 mainframe which itself was a
major power hog. It was eventually sold for the scrap copper and
gold it contained.

The analog computers fared no better. They lined the hallways
and eventually were used as trash cans by lazy students. I never
understood why they did not find room for a few of them at the
Space & Rocket Center museum. I guess computers are not nearly
as exciting to most people as the rockets they were used to
design. *sigh*

That control theory professor told us this joke.

Q: Why did the Polish airliner crash?

A: Because there was a Pole in the right half of the plane.

And you thought engineers had no sense of humor!

I will now turn off the WABAC Machine and return you to your
regular programming. :)

-- 
Phil Harbison