Restoring the TRANSBINIAC computer

Interesting restoration project.


A mystery find on Craigslist turned out to be the “TRANSBINIAC.” A circa-1960 homemade binary counter using transistorized flip-flop circuits. Most likely someone’s science fair project or a teaching tool, built from plans published in a 1960 Electronics Illustrated. Let’s get it going!


I discovered this by accident while looking for tools and power equipment. Cost a whole $25 in a lot that included a nice old VHF signal generator. The cabinet design is very dramatic (bright colors and windows in your computer case are nothing new, sorry gamers) and seems to have been built for an impressive stage presence. The operation position is a roughly 45° angle, thanks to a built-in kickstand on the back.

Science fair project? Classroom demonstration? The innards are a modified version of the plans published in the January 1960 issue of Electronics Illustrated. Major differences being eight modules instead of six, and the deletion of the multiplication circuit All the components date from before 1962 or so. The guy who built this must have been one of the few people in the world to have anything involving solid-state logic in their house at the time.

Requires some minor repair and perhaps some re-engineering to make it fully functional. Looking forward to being able to count to 255 without using my fingers.


Here’s Electronics Illustrated, January 1960, in modern pdf format…

I recall being taken, as a child, to a local college and seeing some final year projects being demonstrated. One was a little cabinet with a phone dial and a series of lights, which added numbers by counting up. I was amazed and baffled that a device like this could count! It would be early 70s, but I would’t be at all surprised if it was this same project.

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Ok, hands, Who else wants to have a telephone dial be a key control component for their computer. This is downright steampunk.

Try to imagine dialing in a bootstrap loader with it. (Octal natch)

0 whirl..tick..tick..tick..tick..tick..tick..tick..tick..tick..tick..
4 whirl..tick..tick..tick..tick..
5 whirl..tick..tick..tick..tick..tick..
1 whir..tick..
3 whirl..tick..tick..tick..
7 whirl..tick..tick..tick..tick..tick..tick..tick..

Oh, that would be fun…once. Fun, but…yea, that would be realy cool. #nokeypads!

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Wow, are those transitors big.With Smaller lights and
2n222’s I suspect a few more would have been built,

I immediately wanted that telephone dial… who wouldn’t, on a box like that?