While updating the wiki article on the 4004, I came across an interesting claim by Ted Hoff, who stated the idea of using a general-purpose CPU in a calculator came to him due to a minicomputer that had been donated to Stanford by the UK company Plessey.

I'm at a loss as to what this might be... I know Plessey had a range of realtime machines used for telephone exchanges and the Linesman radar system (rather unsuccessfully) but these were mainframe sized and I cannot find a hint of a mini.

I suppose this could be any old mini that Plessey bought and donated, but it seems less likely that Hoff would refer to it that way, if AT&T donated a PDP-11 to Stanford someone talking about it later would likely refer to it as "a dec mini".

  • Per Wikipedia, Plessey was in the PDP-11-compatible business. But that might be a little late for 4004 work.
    – dave
    Commented May 23, 2022 at 16:36
  • @another-dave Right. At least that's the only one I know. In fact, I've seen one not long ago at the VCL collection in Neubiberg.
    – Raffzahn
    Commented May 23, 2022 at 16:44
  • forum.stanford.edu/wiki/index.php/…. has no indication of a Plessey as one of the early computers at Stanford. Doesn't rule it out though...
    – Jon Custer
    Commented May 23, 2022 at 17:43
  • Whatever it was, it needs to have been in Stanford in 1969, to fit the 4004 narrative.
    – dave
    Commented May 23, 2022 at 22:36
  • en.wikipedia.org/wiki/Plessey_System_250?wprov=sfla1 sounds like an interesting and unusual system
    – mikado
    Commented May 26, 2022 at 7:53


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