Simon Burge <simonb@wasabisystems.com> said;

> The bible (See MIPS Run) says that the R3000 is a "midlife kicker".
> Comparing the R2000 to the R3000, it says:
>
> "It's almost identical from the programmers viewpoint,
> although small hardware enchancements combined to give
> a substantial boost to performace."

I have heard that R3000 was not pin-compatible with R2000.
R2000A has the original pin-out but R3000 core inside. (The latter
is what Jonathan Stone said earlier in this list.)

Chip fab(s) manufactured MIPS processor could not achieve chip 
yield given clock rates its customer ordered, then sold lower rated
ones as R2000.  This is a rumour, which can not be verified anymore.

Toru Nishimura/ALKYL Technology