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Thread: Any ASCII parallel keyboard designs based on Cherry MX keys?

  1. #1
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    Default Any ASCII parallel keyboard designs based on Cherry MX keys?

    I've been working on a general purpose reuseable CNC case design for machines such as the Mimeo 1, AIM 65, and other single board machines with detachable keyboards, as well as the Superboard II. The prototype is made for a Mimeo 1 with Franklin keyboard, which is much wider than the computer PCB. I could make the design much narrower if I used the OSI keyboard layout, which is pretty typical of the era. Since Klyball has already gone through the effort of creating a version of the Superboard II with cherry keys, the keyboard section would be a good basis for a standalone Ascii keyboard with parallel output. There are still some period correct keyboard encoders out there, or I could simply use a modern microcontroller to do the decoding.

    But, if there's an existing ASCII keyboard design out there, I'd rather use it, and not have the hassle of ordering custom keycaps, etc. Does anyone know of such a beast?

  2. #2

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    Wendell Sanders created one for his Apple 1: http://www.apple1notes.com/old_apple...ard%20Note.pdf

  3. #3
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    The FPGA is probably overkill. There are other designs that use an AVR or PIC microcontroller.

  4. #4
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    Quote Originally Posted by Chuck(G) View Post
    The FPGA is probably overkill. There are other designs that use an AVR or PIC microcontroller.
    "The keyboard has true N-Key rollover with no diodes since each key goes directly to the FPGA"

    But where did the keytops come from?

  5. #5
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    If the PC keyboard didn't need it, why would an Apple II? It's not as if people have 50 fingers. Even Dr. T needed lots of kids.

    Custom keycaps IIRC, can be ordered for Cherry keyboards pretty easily.

  6. #6

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    Best way to get n-key on a standard key-matrix is to have a diode in series with each switch. Several old key-switch housings has some kind of slot where such a diode can be placed.

    As Chuck says, an FPGA in this case is like shooting sparrows with cannons.
    Current systems owned by me:
    Vintage:IBM PC/XT submodel 087 ( 1983 ), [Kon]tiki-100 rev. C (1983), Compaq Portable I ( 1984 ), IBM PC/XT submodel 078 ( 1985 ), IBM PC/XT286 ( ~1986 ), 3x Nintendo Entertainement Systems ( 1987 ).
    Obsolete:Commodore A500 ( ~1990 ), IBM PS/2 model 70/386 type 8570-161 ( 1991 ), Atari Lynx II ( ~1992 ), Generic Intel 486SX PC ( ~1993 ), AT/T Globalyst Pentium w/FDIV bug MB ( 1994 ), Compaq 486DX4 laptop ( ~1995 ).

  7. #7
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    It seems that custom keycaps for MX switches goes back a long way. One of my old NCR Cherry PC keyboards has its SysReq keycap replaced with a bright orange one with the legend "Panic!". Those were mailed out by one of the retailers (CDW?) back in the 90s. Custom keycaps fro Cherry MX switches seems to be very popular. Hasn't everyone lusted after a "Darth Vader" key?

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