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Thread: Busted Micro Switch keyboard -- need help with PCB

  1. #1

    Default Busted Micro Switch keyboard -- need help with PCB

    So I got this parallel ASCII keyboard with a couple S-100 boards at a garage sale (this is why it's in the S-100 section), but the problem, as you can see, is the busted PCB. Seriously, did someone take a machete to this thing?
    Model number on the board is "SDR SD-16396"
    Anyway, there's a chunk, completely missing from the side. I can't repair the traces; because there are no traces. Does anyone have images or schematics of the PCB of an intact version, which I can replicate with bodge-wires?
    Thanks

    EDIT: first uploaded pictures didn't work. Trying again.
    IMG_0239.JPG
    IMG_0238.JPG
    Worked that time : )
    Current favorites: IBM 5160 (EGA+Hercules+PGC, 4 floppies, XT-IDE), DCC D-116 (Nova 1200 clone), ASR 33 Teletype (now FULLY armed and operational! Mostly.)
    Wishlist: IBM 5161 (expansion chassis), Diablo 31/RK02/RK05 or equivalent, Data General Nova software, and the meaning of life.

  2. #2
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    what a horrible thing to do. they took a hacksaw to the control and keypad sides of the pcb, taking a chunk of one of the matrix decoding ICs with it
    with a lot of tracing you should be able to reconstruct the x/y matrix layout of the full keyboard, but by then you would be better off just unsoldering
    all of the switches and resusing the switches and keycaps on a new pcb, since you are missing all of the keycaps on the left and right sides.

    I would only consider doing all of this work because microswitch kbds are very high quality and you have at least a dozen spare keyswitches on either
    side.

  3. #3

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    Yeah, if I can find another PCB layout for a parallel keyboard that uses the same chips (or things I have on hand), making my own PCB with the original switches is definitely an option. Though I'd much rather have it in the original hardware, with that metal plate thing that holds all the switches in, if I can manage to repair the traces.
    Also, that chip is actually intact, by the skin of its teeth. There's like one pin that's just hanging over the side. I did meet the previous (and original) owner, and I got the feeling that it was broken out of negligence, rather than ignorance or malice. Still, the deed is done.
    Current favorites: IBM 5160 (EGA+Hercules+PGC, 4 floppies, XT-IDE), DCC D-116 (Nova 1200 clone), ASR 33 Teletype (now FULLY armed and operational! Mostly.)
    Wishlist: IBM 5161 (expansion chassis), Diablo 31/RK02/RK05 or equivalent, Data General Nova software, and the meaning of life.

  4. #4
    Join Date
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    Look at the vandalism done on Model M keyboards (e.g. Is it really indestructible?).

    I'm with Al on this one--scavenge the switches and use a new PCB. Thanks to modern technology, a keyboard decoder is easy with a microcontroller.

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