7 Aug
2025
7 Aug
'25
2:59 p.m.
On Aug 7, 2025, at 2:44 PM, Mike Stein <mhs.stein(a)gmail.com> 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