24 Jul
2011
24 Jul
'11
9:40 p.m.
Guy Sotomayor wrote:
The PS/2 M90 and M95 had replaceable processor cards
and originally
shipped with 486/50s in late 1990. They were updated periodically
with options for different processors. It's not clear when they
would have announced an update to run with a Pentium but I did find a
reference to the M95 server shipping with a P60 pentium in 8/93 and a
P66 pentium in 9/93.
The 486DX-50 was the Type-III complex. The Model 90/95 came out way
before that. The Type-0 complex had a 486-20 and no level 2 cache. The
Type-I complex had a 486DX-25 and an optional cache daughterboard. The
Type-II complex had on-board cache and a 486DX2-50. The Type-III had
on-board cache and a 486DX-50 (yes, the one with the 50MHz core clock,
single-clocked). The Type-IV had either a 60MHz or 66MHz Pentium P5.
Sometimes referred to as a Type-IVa, but referred to by IBM as just
another Type-IV, was a CPU complex with a 90MHz P54C Pentium and updated
firmware. These are still worth a good chunk of change. Actually, even
the Type-III is worth a bit of money, because some people have had luck
with running AMD Am5x86-P75 chips (which have a 4x clock multiplier) at
200MHz using a 50MHz core clock using a big heatsink with a fan on it.
I have examples of all this hardware in my collection.
Peace... Sridhar