6502 Mite home-brew computer project, step 25: schematic and Printed Circuit Board!

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  • Опубліковано 14 лис 2024

КОМЕНТАРІ • 16

  • @ChrisAthanas
    @ChrisAthanas Місяць тому +4

    Nice work!

  • @DavidLatham-productiondave
    @DavidLatham-productiondave Місяць тому +4

    Awesome dude! Congratulations on your first pcb. I took some inspiration from some of your earlier videos. At least to solve some early iterations of my own spi / sdcard experiments. Thanks for sharing.

  • @chriszuhars2120
    @chriszuhars2120 Місяць тому

    So glad to see and hear about your progress. As someone who’s been working on my own 6502 and 6522-based computer for the last 6 years, I can appreciate the challenges and roadblocks you’ve navigated around. I can also relate to the long gaps in updates while you’re making slow and steady progress behind the scenes. It becomes an obsession in some ways. Congratulations, and I certainly look forward to future updates.

    • @pauldourish
      @pauldourish  Місяць тому

      Yep, just got to keep chipping away at it. There have been breaks in my working on it of months at a time sometimes but these is always something to come back to and pick up again. Good luck on yours!

  • @larrywatts4585
    @larrywatts4585 Місяць тому +1

    Hi Paul great to see your progress. Just watched the video. You are braver than I taking on board making. Glad v1.1 is a success. Do make a video on your progress when you make a milestone. Also looking forward to forth and other developments although I presume your video card pico9918 will influence the design. Good luck.

    • @pauldourish
      @pauldourish  Місяць тому

      Thanks, Larry. The PCB wasn't so bad once I got into it.It does kinda lock you into a design, although perhaps not as much as wire wrap did -- wire wrap can be changed of course but that rat nest of cables didn't encourage experimentation. I'm looking forward to playing with the Pico9918 (if I can ever get one) although I did also find a version of the LCD and driver that I already use but with a 6800-style parallel interface that I could interface directly to my bus. Hmm, so many possibilities!

  • @jarod6570
    @jarod6570 Місяць тому

    Hi Paul great project can you share the Kicad project so we can modify PCB to fill 100x100mm dimension so that it is less expensive to produce

    • @pauldourish
      @pauldourish  Місяць тому

      Great idea! They're on the project web page now. I hadn’t realized that there was a knee in the price curve at that point, although it makes sense. I hadn’t been thinking about size much at all, in fact. Shrinking it down should be easy. A couple of notes in that regard:
      * I specified full rather than half can oscillators only because they were what I had on hand.
      * I actually use a DC/DC converter instead of the 7805, so that saves the space reserved for a couple of capacitors.
      * Now that I’m confident that the PS/2 keyboard connection works fine, there’s no more need for the header.
      * I actually use an Aires low profiles zip socket for the EEPROM so it needs a little more space than the footprint would suggest.
      * No particular reason not to hide the bypass capacitors under the ICs as long as one is using open-frame sockets. Only downside I see is UA-cam commenters who always love to point out if they seem to be missing.
      I’ll need more space in future version. I’m not actually making any use of IRQ although when I do, it’ll want an extra gate. My video plans will also require more space. So it’ll likely grow back to this larger board size even if shrunk down now. But I'm still a novice at this and I’d be happy to learn any new tricks for bringing the size down.

  • @gerardzi7930
    @gerardzi7930 Місяць тому

    Maybe use wrapping board is possible too !

  • @GregCoonrod
    @GregCoonrod Місяць тому

    I would be particularly interested in how you get about making C work on your SBC.

    • @pauldourish
      @pauldourish  Місяць тому

      There's an open source project called CC65 which a cross-compiler for C targeting 6502 and 65C02. That would be a non-native solution, but since it's based on the Small-C system I'm fairly sure that a native version could work. (Wikipedia claims that cc65 was originally a native system for Atari 8-bit systems.)

    • @GregCoonrod
      @GregCoonrod Місяць тому

      @@pauldourish Yes, I've played with CC65 and I use its assembler regularly. But, I've never got the minimal C example working on my Ben Eater style SBC.

  • @mindbender50
    @mindbender50 Місяць тому

    You should make use of copper fill to fill in unused areas of your board with a grounded copper area.. and tweak the routing process for reflections in routing to inhibit noise..
    Also your default trace sizes should be adjusted for certain power requirements as needed..(main power rails and such).
    And power supply decoupling capacitors as close to the ic's as possible ... usually .1uf just food for thought,.,.

    • @pauldourish
      @pauldourish  Місяць тому

      The decoupling capacitors are already there and in place. Trace size adjustments too. Copper fill -- well, next time.

    • @mindbender50
      @mindbender50 Місяць тому

      @@pauldourish This was mostly posted for everyone not trying to pick on your build! 😀Have you tried easyeda for design?

    • @pauldourish
      @pauldourish  Місяць тому

      @@mindbender50 Oh no, I understood and appreciate it. I heard good things about EasyEDA but haven't really tried it. I find Kicad a pain in the ass, but at least there are lots of footprint libraries, online tutorials, and the like. I eventually got into it enough to get the job done.