z386: An Open-Source 80386 Built Around Original Microcode

mmastrac

Did the microcode disassembly find any useful backdoors to read microcode without decapping?

cbdevidal

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

KellyCriterion

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

UncleOxidant

Kind of surprised this only takes 18K LUTs. That's a fairly small FPGA these days.

ChrisArchitect

Related: 80386 Microcode Disassembled https://news.ycombinator.com/item?id=48247004

dang

Related ongoing thread: 80386 Microcode Disassembled - https://news.ycombinator.com/item?id=48247004 - May 2026 (42 comments)

spankibalt

Sadly, without an accompanying FPGA-implementation of an FPU it's much less useful for productivity work/research, i.e. outside of 08/15 gaming and application fare. Same with Ao486, which only implements a 486SX.