@Max: No. It is all pneumatic PID controller. Air is supplied at 15 to 30 psi. You can set P, I, D value for tunning the loop. I worked for Taylor Instruments Inc, Rochester and they manufactured them. As I understand, some organization currently do make them. They are very good for class I hazardous environment. Some pics for them:
Working at Atmel is a bit like being a kid in a candy store in terms of the weird and wonderful stuff I can steal, er, borrow to decorate my desk with. I started small... with a handful of colorful touch sensor boards nabbed from the 4th floor. I then pilfered an AVR man action hero from the creative lab (it is AMAZINGLY awesome and very hunky). Soon after I added a rather exotic looking AVR Dragon board to my collection, a couple of Arduino starter kits, some printouts of the infographics I've designed (on canvas they look super cool), some hexbugs... a half eaten bar of chocolate.
Still doesn't beat the electronic PCB shoe I used to have on my desk at EE Times... but oh well!
I don't know if I'v ever seen a pneumatic PID controller per se, but I guess that depends on what we're actually talking about -- do you mean an electronoc PIC controller that controls a pneumatic system -- or do you mean the entire controller implemented using pneumatic techniques?
I have my first big digit digital clock of 1981 still clocking at main entrance. I have all my Elektors and those projects stored in various boxes. I love pneumatic PID controllers and analog sample and hold.
You're bringing back memories of a tape punching experience. I can't even remember whom I knew with the KSR-33, but I needed to punch tapes to get some bipolar ROMs burned! Hard to believe that that was the only method they accepted!!
Anyway, IIRC, I threw together a current loop interface to my Poly 88, and away we went. Pretty sure I still have the tapes, as well as tapes for some early microcomputer programs, like Microchess ferinstance :-)
Replay available now: A handful of emerging network technologies are competing to be the preferred wide-area connection for the Internet of Things. All claim lower costs and power use than cellular but none have wide deployment yet. Listen in as proponents of leading contenders make their case to be the metro or national IoT network of the future. Rick Merritt, EE Times Silicon Valley Bureau Chief, moderators this discussion. Join in and ask his guests questions.