Loading ...
Sorry, an error occurred while loading the content.

Open University Bobcat

Expand Messages
  • bhaeberlin
    Hello, last month I purchased at Ebay a strange little device which seems to be a distant relative of the Digicomp II. I put a short description and images
    Message 1 of 7 , May 2, 2008
    View Source
    • 0 Attachment
      Hello,

      last month I purchased at Ebay a strange little device which seems to
      be a distant relative of the Digicomp II.
      I put a short description and images online at
      http://www.rechnerlexikon.de/artikel/Open_University_Bobcat

      Now many questions are coming up:

      Does anybody have some more informations regarding the Bobcat?
      Hast it been patented?
      Are there any connections between the Digicomp II and the Bobcat, or
      is the latter one an independent development?

      Best regards
      Barbara Haeberlin
    • Dave Bell
      ... Google is our friend! More photos and apparently complete instruction manual scans. Dave
      Message 2 of 7 , May 2, 2008
      View Source
      • 0 Attachment
        bhaeberlin wrote:
        > Hello,
        >
        > last month I purchased at Ebay a strange little device which seems to
        > be a distant relative of the Digicomp II.
        > I put a short description and images online at
        > http://www.rechnerlexikon.de/artikel/Open_University_Bobcat
        >
        > Now many questions are coming up:
        >
        > Does anybody have some more informations regarding the Bobcat?
        > Hast it been patented?
        > Are there any connections between the Digicomp II and the Bobcat, or
        > is the latter one an independent development?
        >
        > Best regards
        > Barbara Haeberlin

        Google is our friend!

        <http://www.computermuseumgroningen.nl/bobcat/bobcat.html>
        More photos and apparently complete instruction manual scans.

        Dave
      • Bob S.
        Thank you for finding this! I didn t know it was produced. I don t have my research files with me, but the machine was patented and doesn t appear to be
        Message 3 of 7 , May 2, 2008
        View Source
        • 0 Attachment
          Thank you for finding this! I didn't know it was produced.

          I don't have my research files with me, but the machine was patented and
          doesn't appear to be directly related to DC-2. The flip-flops are
          asymmetric and more like those in Dr. NIM than those in DC-2. IIRC, the
          main register is simply a counter. The patent description showed that it
          had an automatic marble feed integrated with a logic function so it stopped
          when the input register was zero. I believe it claimed to multiply, but it
          was going to need a lot of counting.

          I'll send more this weekend.

          -Bob S.

          -----Original Message-----

          Does anybody have some more informations regarding the Bobcat?
          Hast it been patented?
          Are there any connections between the Digicomp II and the Bobcat, or
          is the latter one an independent development?

          Best regards
          Barbara Haeberlin
        • Bob S.
          Great Britain patent 53,755/70 Nov. 11, 1970. US patent 3,747,844 July 24, 1973 (filed Nov. 11, 1971) Inventor: Phillip (Pip) Robert Vassar Youngman The US
          Message 4 of 7 , May 2, 2008
          View Source
          • 0 Attachment
            Great Britain patent 53,755/70 Nov. 11, 1970.
            US patent 3,747,844 July 24, 1973 (filed Nov. 11, 1971)
            Inventor: Phillip (Pip) Robert Vassar Youngman

            The US patent cites DC2 patent 3,390,471 (Godfrey, July 1968) but does not
            mention it in the text. Both patents cite 3,006,082 (Libbey, Oct. 1961)
            which seems to be the first patent using a marble flip-flop for binary
            counting and computation.

            I didn't fully understand BOBCAT operation from the patent, so I'll enjoy
            looking at the manuals and photos. :-)

            -Bob S.



            -----Original Message-----

            I'll send more this weekend.

            -Bob S.

            -----Original Message-----

            Does anybody have some more informations regarding the Bobcat?
            Hast it been patented?
            Are there any connections between the Digicomp II and the Bobcat, or
            is the latter one an independent development?

            Best regards
            Barbara Haeberlin
          • Barbara Haeberlin
            Bob, thank you very much. That is phantastic! Best regards Barbara
            Message 5 of 7 , May 3, 2008
            View Source
            • 0 Attachment
              Bob,
              thank you very much. That is phantastic!
              Best regards
              Barbara




              > Great Britain patent 53,755/70 Nov. 11, 1970.
              > US patent 3,747,844 July 24, 1973 (filed Nov. 11, 1971)
              > Inventor: Phillip (Pip) Robert Vassar Youngman
              >
              > The US patent cites DC2 patent 3,390,471 (Godfrey, July 1968) but does not
              > mention it in the text. Both patents cite 3,006,082 (Libbey, Oct. 1961)
              > which seems to be the first patent using a marble flip-flop for binary
              > counting and computation.
              >
              > I didn't fully understand BOBCAT operation from the patent, so I'll enjoy
              > looking at the manuals and photos. :-)
              >
              > -Bob S.
            • Brian Davis
              ... Agreed! Thanks for this, I d not run across this either, and it looks interesting. Rats. something *else* have to build out of LEGO ... -- Brian
              Message 6 of 7 , May 4, 2008
              View Source
              • 0 Attachment
                >> Great Britain patent 53,755/70 Nov. 11, 1970.
                >> US patent 3,747,844 July 24, 1973 (filed Nov. 11, 1971)
                >> Inventor: Phillip (Pip) Robert Vassar Youngman
                >>
                >> The US patent cites DC2 patent 3,390,471 (Godfrey, July 1968) but does not
                >> mention it in the text. Both patents cite 3,006,082 (Libbey, Oct. 1961)
                >> which seems to be the first patent using a marble flip-flop for binary
                >> counting and computation.
                >>
                >> I didn't fully understand BOBCAT operation from the patent, so I'll enjoy
                >> looking at the manuals and photos. :-)
                >
                > That is phantastic!

                Agreed! Thanks for this, I'd not run across this either, and it looks interesting.

                Rats. something *else* have to build out of LEGO <grin>...

                --
                Brian Davis
              • Knurly
                I ve looked into this a bit. Quick summary of inventor Pip Youngman s reminiscence of BOBCAT s development process, for those of you who havene t looked at
                Message 7 of 7 , May 16, 2008
                View Source
                • 0 Attachment
                  I've looked into this a bit. Quick summary of inventor Pip Youngman's
                  reminiscence of BOBCAT's development process, for those of you who
                  havene't looked at
                  http://www.computermuseumgroningen.nl/bobcat/bobcat.html
                  <http://www.computermuseumgroningen.nl/bobcat/bobcat.html> ... He had
                  done some drawings of mechanical logic units in 1963, then forgot about
                  it until 1966, when he resurrected the ideas and "finally built a
                  multiplying machine in LEGO." (Brian, take note.) He built a non-Lego
                  calculator (adding other operations) for Cambridge Consultants, but
                  project was cancelled. A few years later Open University wanted his
                  "toy" for their first technology course; redesign for mass production
                  followed. But because of labour troubles in 1971, he writes, the
                  manufacturer "EJ Arnolds, may they rot in hell, moulded all the bases
                  with the power fluctuating. They were thus of very poor quality. Enough
                  were rescued for the O.U's needs but it killed the project for the
                  general market. And so was the Bobcat born and so it died." Great story
                  from an 80+ year-old inventor; go read the rest of it.

                  Unfortunately, the unit that Barbara acquired on eBay (assuming it's the
                  one pictured at
                  http://www.rechnerlexikon.de/en/artikel/Open_University_Bobcat
                  <http://www.rechnerlexikon.de/en/artikel/Open_University_Bobcat> )
                  appears to be broken: the flip-flops at the near right are all missing
                  their knobs and moveable arms. These FFs also have blue tips but
                  (according to the manual) should have green, so I'm guessing they were
                  cannibalized from another unit.

                  As far as I went in the instruction manual, I was disappointed that it
                  really says nothing useful about how computers work, much less how to
                  program them. The closest it gets is the statement that a real computer
                  has "many thousands of flip-flops." Also, the BOBCAT mechanism seems
                  operationally opaque. It may indeed be ingenious, but (for a supposed
                  teaching device) it seems to obscure the underlying process of binary
                  calculation. Just to add 3 and 4 you need to feed about a dozen balls
                  into it, and the last four or so simply increment the output counter to
                  make the sum come out right. That's my impression, anyway, after poring
                  over the instructions.

                  Final (until proven otherwise) judgement: nothing holds a candle to the
                  DC1's programmability!

                  Speaking of simplified teaching about binary operations, here's a
                  goodie: Have you heard of Napier's chessboard? See
                  http://www.kuro5hin.org/story/2004/12/12/152529/56
                  <http://www.kuro5hin.org/story/2004/12/12/152529/56> and the Wikipedia
                  article (by the same guy) on "location arithmetic."

                  Tim W.





                  [Non-text portions of this message have been removed]
                Your message has been successfully submitted and would be delivered to recipients shortly.