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DGC Nova 2: looking for parts & info, exchange possible

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    DGC Nova 2: looking for parts & info, exchange possible

    Hi All.

    Earlier this year I've bought a bunch of Nova boards seems from different Nova generations (some are marked 1969 and there are definitely later Nova 2 CPUs and core mem).
    No chassis neither backplane.
    I still want to run it, and considering either to build the backplane myself or buy it (if somebody have extra one).

    So, looking for:
    - information about backplane signal pinouts (already found it for SuperNova, but is it identical to Nova 2?)
    - backplane: option is to buy, or change to Nova 2 CPU, 16k core, also some extra various supplementary boards (I/O, cassete etc)

    Thank you very much.

    #2
    The I/O bus is essentially the same across all families. Lots of information in the Interface Designers Reference manual. Y9ou can find that here: 015-000031-05_Nova_InterfaceDesign_May78.pdf (bitsavers.org)

    But some slots were reserved for CPU boards, so I don't think they are interchangeable between families. Nova 2 schematics and Technical Manual are also on bitsavers: Nova2_Schems_1973.pdf (bitsavers.org), 015-000026-01_Nova2Tech_Nov74.pdf (bitsavers.org)

    Comment


      #3
      Strongly suggest that you start by first listing (in detail) the boards that you have in-hand. DG board numbering is (IMO) incredibly obtuse; you need to collect not only the sticker-type labeling on the primary stiffener, but also the PCB surface markings (copper and/or ink) near both ejectors. Plus any other unique markings. IMO copyright markings are interesting and maybe indicative, but hardly definitive. Obtain a full-board top-side photo with good resolution. Identify large ICs (24-pin and up). Lacking the extensive online documentation of DEC equipment it sometimes requires visual comparisons to other boards to discern relationships and lineages.

      As Steve points out the I/O slots are partially bussed (addressing/data/control), whereas the first few slots are wired exclusively for CPU, FPP, and memory. Since the chassis design doesn't support edge-card connectors for peripheral cabling that means that the "bus" slots are actually wired for specific I/O boards and there are special cables used to bring those unique pin-patterns to a suitable rear bulkhead connector using paddle boards (see various pictures on the net).

      IMO it would be feasible to wire up a three-board combination (CPU, RAM, I/O) but I don't think that you'll get the I/O that you want without rolling-your-own. IMO minimum I/O would be two serial plus one parallel interfaces -- console, high-speed "file server", and paper-tape. You'll need to build something for the other end of the "file server" connection. The paper-tape interface would be coupled to an MCU-based emulation.

      Of course you'll want to build a front panel surrogate :->.

      Comment


        #4
        Thanks for the replies.
        Yes, I already discovered Nova 2 manual. Still I missed the document at the first link, will study it.
        I also found somewhat cryptic DG parts reference.

        Sure I'm going to photo all boards but it will take time (there are around 15 in total).

        Of course you'll want to build a front panel surrogate :->.
        I'm more ambitious, unlike fancy DEC front panels with curves and custom keys, Nova is more simplistic) I think it is possible to build the entire chassis and casing and front panel)

        Comment


          #5
          Originally posted by farjmp View Post
          I also found somewhat cryptic DG parts reference.
          Can you please share a copy here or point to an online copy? That would be much appreciated :-}. Thank you.

          Comment


            #6
            This one?
            015-000028-03_Data_General_Components_Guide_Oct75.pdf (datageneral.uk)

            Comment


              #7
              This one?
              Also available here: https://archive.org/details/bitsaver...ge/n1/mode/2up
              There are some docs on bitsavers too: http://www.bitsavers.org/pdf/dg/

              Comment


                #8
                Thank you. I was hoping for "bigger components" :-}. Board-level "field guide", as it were.

                You'll certainly want to build _something_ chassis-wise, but do you intend an exact fit-n-finish recreation? Power supply(ies) as well?

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