Notes from a scratchbuilt 8-bit computer

Discuss

9 Responses to “Notes from a scratchbuilt 8-bit computer”

  1. tylerkaraszewski says:

    This is essentially what you do in the “Computer Organization” class that Computer Science and Computer Engineering majors have to take. As a former CS student, it is both one of the more challenging and more interesting courses in the curriculum.

  2. nixiebunny says:

    I’m always amazed when people try to build such a complex circuit on those solderless breadboards. Maintenance looks hopeless, especially when it’s such a hairball.

    This is what Wire-Wrap® was made for.

    However, you can’t buy the boards and sockets cheaply these days except as surplus junk, which gives you the added task of unwrapping the previous circuit.

    • James B says:

      When I was in engineering school, one of the developers of the original IBM PC gave a talk to our class.  He put a slide on the overhead projector showing a photograph of the prototype he had worked on.  It was about an inch deep of dense Wire-Wrap®.  I think you would have liked it.

  3. royaltrux says:

    Hats off, amazing. Frankly, the inside of a Cray 1 doesn’t look much different except for wire color.

  4. Zod says:

    Reminds me of my first computer…wire-wrapped instead of bread-board…an RCA Cosmac Elf Complete with 4 display Nixie tubes and a 16 key hex keyboard. I upgraded it with an S-100 buss that I daisy chained to half a dozen add-ons!

    • royaltrux says:

       Ha! You’re old! My first computer was a Commodore 64. Oh yeah, I’m pretty old, too.

    • Culturedropout says:

       Nixie tubes?  But… those don’t display hex.  Are you sure you’re not thinking of the dot-matrix LED displays most people used?

      • Zod says:

         http://www.tubeclockdb.com/data%20sheets/B8971.pdf
        I had a whole box of these thing back in the early ’70s! Long gone now…

      • kjs3 says:

        He’s probably thinking of a Numitron or glass envelope VFD type display.  Looks like a Nixie, but somewhat different operating principle.

Leave a Reply