Recent content by tgarnold

I don't have a functioning 6800 machine or I would test it and archive it.

I think it is a stretch to call the Telebit telemetry system used on Explorer VI and early Pioneer satellites a computer, but it is awfully close. I have some of the modules seen in the pictures on this post. The thing that is most interesting to me is the "Transistor Memory" used to temporarily...

I found this with some SWTPC 6800 software cassettes. I can't find evidence of it ever being offered for sale. Anyone ever seen it before? I contacted Ken Kaplan a founder of Microware who verified it is a version of ELIZA software written for the 6800. Did any other companies write ELIZA...

Thanks for the great information! Too bad it doesn't say what computers it worked in. At least I have a great place to start.

This is an interesting early board that looks like it has the same output format as a couple of other Transac 2000 boards I have found on-line. The contacts are only on one side of the board. Is anyone familiar with any other computers that used this same format?

Here are a couple of shots from the back. I did find this on Brad's Blog where he talked to Don Lancaster, "When I asked him about it, his response was that the keyboard was an ‘IBM EBCDIC’ surplus unit. They had taken apart dozens of them and reconfigured into just over 40 complete units that...

I'm guessing the keys were chosen and placed based on their color. There are also 2 B and P keys. I believe these were made from surplused keyboards.

I am posting this mostly because I think it is very interesting and worth a discussion. The only question I have is, have any other people heard of these being available? The mailing date is Sep 18, 73, which would coincide with the article by Don Lancaster in Radio Electronics magazine. I'm...

Looks like they plug into this. Copied from DDP-24 https://www.p3oriontopsecret.com/3c-computer-control-company-ddp-24-card-rack.html

One last follow-up on this. After interpreting the company codes in the JPL document, it looks like the breadboard is a magnetic logic board using RCA transfluxors for a 3C Computer Control Company DDP-24 computer. Thanks to everyone for the invaluable input! DDP-24...

Here is an excerpt from another JPL article from 1965. There are several more diagrams with logic functions using the 2N2297 transistors.

Thanks for the info! I have read the articles on deramp and wiki before, but apparently didn't keep it in long term storage. I'll look and see if I have any more documentation or kit parts. Seems like a cool computer kit.

Thanks to all for the great information. I have been researching early ICs (DTL, RTL and TTL) in the JPL data archives. One of the documents I found is called "Circuits and circuit testing for spaceborne redundant digital systems Special technical report no. 3" It covers research in comparing...

So, to add to the intrigue, this is likely a card used by the JPL (Jet Propulsion Lab) in Pasadena, California (predecessor of NASA and now part of NASA). I have a number of oddities that I am trying to wrap my head around. I'll probably post more boards and cordwood units. I think many were...

Does anyone recognize this card? It has unusual gold plated connectors that look more like forked posts. I do think this is a DIY board. The transistors are Fairchild 2N2297 and Motorola 2N2219 from the mid 1960s