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Re: Identifying some things

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  • Stephen L
    Hi Kyle, Fascinating finds! Regarding the electromechanical beast, my (vague) theory would be that it is a multiple function generator. The wheels appear to be
    Message 1 of 12 , May 2, 2013
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      Hi Kyle,

      Fascinating finds!

      Regarding the electromechanical beast, my (vague) theory would be that
      it is a multiple function generator. The wheels appear to be shaped to
      create functions. The position of a sensor arm riding on the outer edge
      of each wheel might drive a precision pot, yielding an analog function.
      The input to the function is provided by the motor controlling the
      position of the wheels. That could either be a function of time or
      perhaps servo-controlled to a voltage value.

      The overall unit could have been used with an analog computer or perhaps
      to drive laboratory equipment for some specific purpose. Back in the
      days of vacuum tube analog computers for example, multiplying and trig
      functions could be done by using servo-controlled potentiometers.

      --- All interpretations of your beast are just speculation on my part,
      of course.
      -------------------------

      Regarding the G101 board, my first thought was that is might be for the
      VC8-E point plot display system. I see from Dave Gesswein's site though,
      that the controller boards for that are M869 and M885. So that at least
      eliminates a possibility, anyway.

      Steve L.
    • Kyle Owen
      ... Quite possible! I think there s certainly enough stuff there to interface it to another machine, as you mentioned. The black bezel at the top seems to be
      Message 2 of 12 , May 2, 2013
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        On Thu, May 2, 2013 at 11:53 AM, Stephen L <steve@...> wrote:

        Regarding the electromechanical beast, my (vague) theory would be that
        it is a multiple function generator. The wheels appear to be shaped to
        create functions. The position of a sensor arm riding on the outer edge
        of each wheel might drive a precision pot, yielding an analog function.
        The input to the function is provided by the motor controlling the
        position of the wheels. That could either be a function of time or
        perhaps servo-controlled to a voltage value.

        The overall unit could have been used with an analog computer or perhaps
        to drive laboratory equipment for some specific purpose. Back in the
        days of vacuum tube analog computers for example, multiplying and trig
        functions could be done by using servo-controlled potentiometers.

        Quite possible! I think there's certainly enough stuff there to interface it to another machine, as you mentioned. The black bezel at the top seems to be an incandescent light-guide display, but I haven't looked at it enough in detail to confirm. The lack of controls on it definitely hints that it was interfaced to something else, though. 

        I'm going to talk to one of the older professors around here to see if he remembers where it came from. Another guy mentioned he vaguely remembers it coming from NASA and may have been used to simulate flight and what not, probably in the 1950s. 

        Regarding the G101 board, my first thought was that is might be for the
        VC8-E point plot display system. I see from Dave Gesswein's site though,
        that the controller boards for that are M869 and M885. So that at least
        eliminates a possibility, anyway.

        Yeah, I was thinking something along the lines of that, but after an hour of searching, I've still yet to see another yellow-series board. Pretty odd!

        Kyle
      • David Gesswein
        ... I didn t find much either. This posting indicated DEC used yellow for custom stuff.
        Message 3 of 12 , May 2, 2013
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          On Wed, May 01, 2013 at 05:58:25PM -0500, Kyle Owen wrote:
          > I came across a Unibus card for a PDP-8/E, though I don't know its purpose.
          > My online searches have resulted in no (even close) matches. The handles on
          > the card say Y006, and the card itself says "G101 Display Bd. for PDP 8E"
          > on the solder side. Judging from the empty sockets and two sets of three
          > pads with no components populated (yet with remnants of solder on the
          > pads), I'd say this card is missing some things. I have a feeling there
          > were two ten-turn pots on the board judging from the placement of those
          > pads. Any ideas? I'm not (yet) a DEC collector, but I hope to be soon.
          >
          I didn't find much either. This posting indicated DEC used yellow for
          custom stuff.

          https://groups.google.com/forum/?fromgroups=#!topic/alt.folklore.computers/kr9dUiemlvA

          Does the back of the handles say digital equipment?
        • Kyle Owen
          ... https://groups.google.com/forum/?fromgroups=#!topic/alt.folklore.computers/kr9dUiemlvA ... Yes, it does. Quite an interesting find, then. I may take some
          Message 4 of 12 , May 2, 2013
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            On May 2, 2013 8:42 PM, "David Gesswein" <djg@...> wrote:

            >
            > I didn't find much either. This posting indicated DEC used yellow for
            > custom stuff.
            >
            > https://groups.google.com/forum/?fromgroups=#!topic/alt.folklore.computers/kr9dUiemlvA
            >
            > Does the back of the handles say digital equipment?
            >

            Yes, it does. Quite an interesting find, then. I may take some time to capture the schematic. I'd love to know what it did.

            Kyle

          • Dave McGuire
            ... It s all 7400-series TTL, right? That shouldn t be too tough to do. I d be very interested to know what it was for as well. -Dave -- Dave McGuire, AK4HZ
            Message 5 of 12 , May 2, 2013
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              On 05/02/2013 11:16 PM, Kyle Owen wrote:
              >> I didn't find much either. This posting indicated DEC used yellow for
              >> custom stuff.
              >
              > https://groups.google.com/forum/?fromgroups=#!topic/alt.folklore.computers/kr9dUiemlvA
              >>
              >> Does the back of the handles say digital equipment?
              >
              > Yes, it does. Quite an interesting find, then. I may take some time to
              > capture the schematic. I'd love to know what it did.

              It's all 7400-series TTL, right? That shouldn't be too tough to do. I'd
              be very interested to know what it was for as well.

              -Dave

              --
              Dave McGuire, AK4HZ
              New Kensington, PA
            • s100doctor
              ... Chase this reference down: S. Pardee, Rosenfeld, Dowd G101 - a remote time share terminal with graphic output capabilities IEEE transactions on
              Message 6 of 12 , May 7, 2013
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                --- In midatlanticretro@yahoogroups.com, Kyle Owen <kylevowen@...> wrote:
                >
                > I came across a Unibus card for a PDP-8/E, though I don't know its purpose.
                > My online searches have resulted in no (even close) matches. The handles on
                > the card say Y006, and the card itself says "G101 Display Bd. for PDP 8E"
                > on the solder side.

                Chase this reference down:

                S. Pardee, Rosenfeld, Dowd "G101 - a remote time share terminal with graphic output capabilities" IEEE transactions on computers, Vol C-20, no. 8, Aug 1971, page 878. You'll need an engineering university library or an IEEE membership.

                Herb
              • s100doctor
                ... I concur with Stephen s observations. Kyle, if you send me detailed photos of ONE of the 20 modules or assemblies - ONE disk thingy and the mechanics that
                Message 7 of 12 , May 7, 2013
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                  > On Thu, May 2, 2013 at 11:53 AM, Stephen L <steve@...> wrote:
                  >
                  > > Regarding the electromechanical beast, my (vague) theory would be that
                  > > it is a multiple function generator.

                  I concur with Stephen's observations. Kyle, if you send me detailed photos of ONE of the 20 modules or assemblies - ONE disk thingy and the mechanics that are in contact with it - then I can be more informative. The photos will be needed documentation anyway. Photos of the labels on pots and motor and any power-supply parts, may well date the assembly.

                  The charming thing about this item, is that it's very likely you can "decode" the information content. To a first order, you'd rotate the shaft assembly and "read out" the potentiometers. Manual rotation and a digital ohmmeter could do that, in a tedious way. Then a spreadsheet of those values (and interpolation) could simulate actual operation.

                  The next step would be to operate the motor, however that's driven; and to digitize the analog outputs. In fact....the pots could drive 555 timers and directly produce a frequency proportional to value! All of that would be a fun project, and be a nice display.

                  HErb Johnson
                  retrotechnology.com
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