8 comments

  • tl2do 20 minutes ago
    I'm Japanese, and the 80286 at 10MHz was huge for Japan's PC-98 scene. The V30 handled backward compatibility while the 286 ran much faster than what we had before. This project brought back memories—the 286 was the chip of my era, and it's great to see people still exploring its capabilities decades later.
  • st_goliath 1 hour ago
    I've seen a similar project a while ago and thought this was about the same thing at first: [1][2]

    Both essentially built a DIY chip tester for a 286 and both built around a Harris 80C286.

    If I understood it correctly, the goal behind this project seems simulating the rest of the PC, purely for the challenge and learning experience, documenting the process of building the chip tester (and getting mildly philosophical in the process).

    The other project was more directly interested in the 286 itself, undocumented instructions, corner cases in segmentation behavior, instruction cycle timing, etc. and also trying to find out if there are any difference between the Harris and Intel variants.

    [1] https://forum.vcfed.org/index.php?threads/286-cpu-experiment...

    [2] https://github.com/dbalsom/arduinoX86

  • dividuum 1 hour ago
    Here's a project that also does this to ensure cycle-accuracy for their emulator: https://github.com/dbalsom/arduinoX86
  • theginger 1 hour ago
    Looking at the amount of wires going into this, my instinct is that this cannot scale, in 5-10 years this won't be doable for a Pentium chip, at least not as an at home hobby project. But I actually think it could go the other way, and in 5-10 years you'll be able to do this at home for far more sophisticated kit, unlocking crazy amounts of reverse engineering possibilities that were once thought of as near impossible, or at least only possible for a nation state scale setup.
    • st_goliath 57 minutes ago
      I'm pretty sure if you really want to, you could do something like this as a hobbyist with a Pentium right now.

      Instead of futzing with wires on a breadboard you could simply designing a PCB up front, throw the design over the fence at JLC or PCBWay, insert coin, wait patiently at the mailbox, solder your scavenged Socket 7 onto the board.

      The days of toner transfer and aquarium pumps are already long gone. Getting production quality, one-off, multi layer PCBs done as a hobbyist is dirt cheap these days, no government budgets required.

  • dsign 1 hour ago
    Cool! But the wires!

    I'm not a fan of breadboards, they tend to be unreliable even for trivial circuits. We need something more affordable and practical for home PCBs[^1]. Why is it that nobody has invented a tin 3D printer, or at least a 2D version of it, i.e. a tin plotter?

    [^1]: I'm discouraged from home-etching by the chemicals and the dark-room part of the process.

    • ZiiS 9 minutes ago
      For $2,500 the Carvera Air makes very nice 2 sided pcbs with solder mask. Though even in raw materials it is hard to match a finished board from China if you can wait a couple of months.
    • vhab 56 minutes ago
      Bad Obsession Motorsport actually went this route, you can see their custom printer on their youtube[1] channel

      [1]: https://www.youtube.com/watch?v=FzrZoVKT8gM

  • 01HNNWZ0MV43FF 1 hour ago
    So they're stepping a 286 very slowly and sorta... bit-banging the I/O pins on it?

    Love it. No notes.

  • Jaxon_Varr 58 minutes ago
    [dead]