z386: An Open-Source 80386 Built Around Original Microcode(nand2mario.github.io)
45 pointsby wicket3 hours ago5 comments
  • UncleOxidant11 minutes ago
    Kind of surprised this only takes 18K LUTs. That's a fairly small FPGA these days.
  • KellyCriterion42 minutes ago
    Question: Are there today any 386 instances running somewhere in the basement to do some productive stuff, maybe processing only some controller data once a day?

    I remember the link some month ago where that one small shop ran completely on an old Amiga (?IIRC, not sure, was linked here)

    Around 98/99 I was involved in a small IT-management company serving SME around the region, we had a client producing distinct metal objects with a big press; this got feeded once a day with a 5.25 floppy from another machine with production data - and it was still in use while we had already ethernet/USB/3.5 floppies etc. :-D

    • bitwize33 minutes ago
      A few years ago there was a story where the single Amiga that ran an entire US school district's HVAC was replaced with a system costing like 1.5 million dollars, after 30 years of dutiful service.

      I can't think of examples offhand but you bet your ass there are donut shops and auto body repair services running 386s to do POS, inventory, and the like. Some of them may be driving terminals off Xenix.

      • xp845 minutes ago
        Funny thing about this is that the character-based systems of that era, whether PC-type or host+terminal type, were most of the time so much faster and more responsive than the laggy, over-animated, touchscreen trash they always replace them with in order to get big screens and prettier graphics.
  • cbdevidalan hour ago
    Of course they tested Doom :-D

    They might also run Linux kernel 3.7, that supported i386. Gray386linux is still maintained, and runs a patched 3.7 kernel.

    https://github.com/marmolak/gray386linux

    • nand2mario24 minutes ago
      Doom (DOS extender games) is an easier protected mode application as it does not use complex page tables. Linux is much more complex.
    • KellyCriterionan hour ago
      haha, this was my first thought when I read the headline, because this "classic test" always comes up here :-))
  • mmastrac2 hours ago
    Did the microcode disassembly find any useful backdoors to read microcode without decapping?
    • nand2mario2 hours ago
      Not really. The 386 does not have an interface to read the ROM direclty. Instead, it uses the Built-In Self-Test (BIST) to verify the ROM's contents. It's basically a checksum-like mechanism that verify the integrity of the CROM.
  • Tiberium32 minutes ago
    Nice article, I guess GPT 5.x? :) doesn't sound like Claude