IBM PS/2 server ram

[Maxxarcade]

I have this old PS/2 server which I think is a model 9595. It has a 486DX2-50 CPU board "complex" that I think is a type 2.

Does anyone know if it uses proprietary 72 pin simms? I have a ton of EDO and fast page modules, but I don't want to mess with them if I need the proper chips.

Also, I'm looking at some Pentium 90 CPU boards on ebay which I think will work in this system, but I've never had one of these before. It is fully microchannel, and has a big Delta PSU.

[starfury1]

Re: IBM PS/2 server ram

Humm mate totally off the top of my head and could be totally wrong!

I dont think 486 and pentium 90 were compatible pinout or MB...

486 I think would be SDRAM but not sure if ite the type with the parity bit in the case of a server...

Guess someone here will know for sure...I'll see what I can find 4U

a wiki IBM personal system/2

Appears I am wrong re the pentium

The PS/2 Models 90 (IBM 8590/9590) and 95 (IBM 8595/9595/9595A) used Processor Complex daughterboards holding the CPU, memory controller, MicroChannel bus interface, and other system components. The available Processor Complex options ranged from the 20 MHz Intel 386 to the 90 MHz Pentium and were fully interchangeable. The IBM PC Server 500, which has a motherboard identical to the 9595A, also uses Processor Complexes.

[starfury1]

Re: IBM PS/2 server ram

This site might help you get a better idea of model and what you need to know
here

didn't mean to lead you up the garden path Maxxarcade

Just more familiar with white type boxes of the era not IBMs....

Sure someone here will give you the advice you need to know thought from their experience.

PDF at the bottom of wiki page here

HTH anyway

Cheers

[linuxguru]

Re: IBM PS/2 server ram

AFAIK, the model 95 used 72-pin FPM DRAM SIMMs with parity. It may be possible to use non-parity SIMMs as long as you do not try to mix parity/non-parity as well as speeds. These SIMMs did not have an SPD ROM, but rather a bunch of zero-ohm SMDs on the DRAM module to indicate speed, size and parity over 4 bits on the SIMM socket. If you can figure out the correct codes, you can modify standard FPM SIMMs to work in the Model 95 by bridging the appropriate locations on the SIMM.

[Maxxarcade]

Re: IBM PS/2 server ram

I managed to dig up enough IBM ram to get 40MB total. Didn't feel like bothering w/ modding the other ram, besides the other stuff has tin leads, and the system needs gold to prevent corrosion.

I cleaned the contacts on everything and got it to boot into Win NT 4.00 SP5.

Now if I can just figure out what it would be useful for

I may still try and snag a pentium CPU module for it, and I'd like at least 128MB of ram, but I don't know if it's worth the trouble.

I noticed the video flickers and is a bit dim and noisy, but it doesn't seem to be connection related. Should I suspect the video card or PSU?