At 09:18 PM 6/28/1998 Bill Rysanek wrote:
>
>My father has an IBM PS1 Consultant Model 2155A-76C.
>Does anyone have any experience upgrading such a machine or
>Know where I could look for some information?
>The processor is a 486SX-25 and I was hoping I could put in a 486DX4-100


Bill:

It's likely to have a P24T socket and it should take an Overdrive.
However, I doubt if you could pop in a plain 486DX4-100 CPU.

I tried dropping a 486DX2-66 into a similar PS/1, a 486SX-33.
The jumpers would only set for an Overdrive and a 487DX-33. I
believe it only ran at 33MHz, if at all (can't recall, over a year ago).

You can look up IBM's Official PS/1 site, at:

     http://www.can.ibm.com/helpware/ps1upgrd.html

You might have some references at the Unofficial Aptiva
Hint Page at:

     http://www.ecis.com/~russn/

We ended up migrating the usable parts to a clone case
with a 200MMX CPU/motherboard and a PCI video card.

Good luck.

John Chin