Ok, we’ll admit it. If you asked us what the first transistorized computer was, we would have guessed it was the TC from the University of Manchester. After all, Dr. Wilkes and company were at the forefront and had built Baby and EDSAC, which, of course, didn’t use transistors. To be clear, we would have been guessing, but what we didn’t know at all was that the TC, with its magnetic drums and transistors in 1955, had a second life as a commercial product from Metropolitan-Vickers, called the Metrovick 950. [Nina Kalinina] has a simulator inspired by the old machine.
The code is in Python, and you can find several programs to run on the faux machine, including the venerable lunar lander. If you haven’t heard of the Metrovick, don’t feel bad. Oral histories say that only six or seven were ever built, and they were used internally within the company.
It seems hard to imagine now, but in the 1950s, transistors for computing were actually a disadvantage. The devices were slow. The TC, for example, used old point-contact transistors (200 of them) and 1,300 point diodes. The Metrovick 950, mercifully, used more modern junction devices. You might think that transistors would be more robust, but the early devices often failed.
The Metrovick wasn’t totally transistor-based. Like the somewhat newer TRADIC from Bell Labs, it used a vacuum tube to produce a clock signal with enough oomph to feed the whole machine. The first fully transistorized machine is a bit of a moving target, but is probably either the Harwell CADET, the IBM 604, or an ICBM guidance computer from Burroughs. Want to know more? You can read the original engineering report (which included the title picture).
We have long been fascinated with the EDSAC and often wonder if we’d have been as smart as David Wheeler and invented the subroutine.
Nina Kalinina wrote up some history over on the fediverse at https://tech.lgbt/@nina_kali_nina/115242939849102943, and it’s worth a read if you want a bit more info on the background and some other info
I thought they rebuild it using some modern parts…
Another possible “first fully transistorized computer” would be the TX-0 (“tix-oh”) at MIT, built in 1955-56. This computer eventually became an important part of the early hacker culture at MIT.
That is the computer I thought of. Used to hang around MIT on Saturdays when I was in high school, and it was in the next room to THE PDP-1. Played Spacewar! on the PDP-1, but the TX-0 was never powered on when I was there. IIRC, power supply and clock still used tubes.
And the logic racks had what looked like small tubes, but they had plastic envelopes and contained a transistor and maybe resistor or other components – and they did use sockets.
https://mitmuseum.mit.edu/collections/subject/288
TX-0 is the one I was thinking of as a possible first.
What about the IBM 7090 (709T)?
Not sure about its age. I do have a 709 manual. I need to scan it and the other old computer manuals I have. Maniac II anyone?
The first computer I used was a Stantec Zebra dating from around 1961. It used a combination of transistors and tubes. Our grammar school was given it by a local business that was upgrading to an ICL machine. I think we may have been the first grammar (high) school in the UK to have our own computer. It was little used as it consumed a lot of power and was hard to keep operational.