Bought a 1960's era EAI TR-20 Analog Computer

I managed to purchase a 1960's era Electronic Associates, Incorporated (EAI) TR-20 Analog Computer on eBay. These don't come around very often and I've put in snipes before, but never come close to winning one. This one was in West Lafayette, IN, which is in driving distance and was listed as local pickup, though he said he would ship in the ad. I think that impacted the price and I got it for less than people are paying for those horrid little Heathkit analog computers or the Compdynas. And, the computer museum has the owners and maintenance manuals online, so it's something I can work on. It has 14 amplifiers, 6 integrator networks, a multiplier, an x^2 diode function generator, the repetitive operations option, 6 precisions potentiometers, and 10 additional potentiometers. It has the card for the external display, but that was not included, nor was a power cord. It did come with quite a few patch cables and bridges.

It's one of the earlier ones, likely around 1967, so it's about 44 years old. It was the state of the art in that era for analog computation. It cost around $10,000 in the 1960's. I got it for a tiny fraction of that. It is, of course, completely obsolete, but it is a bit of history and I was fascinated with the analog computer they had at La. Tech when I was an undergrad.

It likely has been sitting around for decades or more, so I'm bringing up to slowly and hope to get it completely running. Many of the parts are pretty normal, but there are a lot of prevision parts and some things, like the chopper relays, may be very hard to replace.

I'm keeping my eye out for an XY plotter and scope to go with it.