Photos: Hardware Hoarders - Your old computers (PART 1)


Don Adams BTM/ICT 542/550 Turret

Don Adams BTM/ICT 542/550 Turret

Don Adams sent in this and other photos of his BTM/ICT 542/550 Turret, from around 1960. Don says, "This is the basic logic module of the ICT 542/550 Calculator, a plugboard programmed computer which punched the result of its calculations into another field of the card from which it had read the data. Speed of operation was about 100 cards per minute. The turret surely has to be the ancestor of the PCB. "Each type 12AU7 double triode valve stores one bit. A variety of turrets built to this similar physical design served all the electronic processes required, and the 550 machine contained 600 turrets. The turrets plugged into a backplane mounted on a hinged 'gate' with 100 per gate!" Don goes on to comment further: "Note the (to current eyes) crudity of these hand wired units. In particular the size of the two 'miniature' metal oxide disc 'computer diodes' seems so huge compared with the equivalents of 40 years later!"


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We're inviting Computer Weekly readers to send us photos and videos of the oldest IT equipment they've held on to, and to share their excuses for hoarding it.

We had around 70 photos last year!

See our other hoarders:


Part 1

Part 2

Part 3

Also, if you've enjoyed this, you might also enjoy our very own

Retro computer games photo gallery.

If you have some kit you  want to show off, send  your pictures to [email protected].

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