Diode Matrix ROM patch panel

Hello all,

I have an old memory patch panel, probably a diode matrix. Estimated to
be from the early 60's, maybe IBM?

I am interested to find out more about this - any information such as
documentation, model, or what it belonged to would be helpful.

Thanks!







Edited by timro

This is a Sealectro matrix panel, but I doubt if it is a memory judging by the number of rows and columns and the labelling. Also this one has a mix of diode pins and smaller pins which are just shorts between the rows and columns.

They used to be used in programmed controllers, before microprocessors and EPROMs were developed, for factory automation, big lighting displays (eg Piccadilly Circus, Times Square) and in test equipment.

When I worked in a nuclear physics laboratory in the early '70s I had a CAMAC Controller with a 24-bit serial TTL CPU that used a 24 x 32 one of these as its main program memory. We wrote our own cross assembler on a PDP10 which printed out a pattern of full stops and asterisks where you would expect to see hex code now. I then had to plug the board up using the pattern as a guide. We wrote a stepper motor control program that turned a micrometer vernier handle in a sequence for one experiment--all in 32 24-bit words! Later the matrix was upgraded to denser Ghielmetti 24 x 64 matrix boards and we had four modules to give a whole 256 words of memory. The whole system cost more than a house at the time, more a small village, and the 36-bit PDP10 users looked down their noses at us using a mere 24-bit machine.

Sealectro folded sometime in the 80s. They also made RF connectors, but there was no longer a market for these matrices.

However if anybody has or finds one, even just the diode pins, please contact me.