On Aug 7, 2025, at 2:44 PM, Mike Stein <[email protected]> wrote: > > AFAIK the 68000 and 68010 were also available in a pin-compatible package, as > in the Cromemco XPU.
Yeah, the 68010 was essentially a "minor" revision of the 68000, and shared the same pinout in all packages. It was really a "more than minor, less than major" revison: The 68010 did change exception stack frame layout and added a register and a couple supervisor-only instructions to meet Popek & Goldberg virtualization requirements, added the two-instruction loop cache, and added a signal that indicates a read-modify-write cycle is taking plce for multi-processor support (which was only actually brought out to a pin on the 68012, like the additional 7 address lines). Virtually everything else like instruction timings were unchanged from the 68000, so it could be used as a drop-in replacement with only minimal changes to supervisor-mode code. -- Chris
