Apple 1

From: Eric Smith <eric_at_brouhaha.com>
Date: Sun Dec 27 13:17:38 1998

Ethan Dicks <erd_at_infinet.com> wrote:
> AFAIK, all MC68000 chips work to spec.

They had various bugs that were sometimes mentioned in later data sheets.
For instance, early parts would generate the UDS* and/or LDS* strobes even
on accesses that cause an address exception. This can lead to memory
corruption. Although since usually an address exception means that the
system (or process) failed, it usually didn't matter. Which is probably
why they didn't find it early on.

Very early parts had a slightly different set of shift and rotate
instructions than later parts. This was mentioned in some early data sheets,
but not in more recent ones.

Eric
Received on Sun Dec 27 1998 - 13:17:38 GMT