PS/2 Server Model 95- "2500HD"

Model 77 Ultimedia Lacuna

One of the last microchannel-based systems to be made by IBM, the PS/2 Server 95 represents the "best of the best" in x86 "pure" microchannel computing. Offering faster CPU complexes, SynchroStream technology (on all but the "N" model with 486DX2-66 CPU), optional disk arrays and the ability to take more RAM than other PS/2s (up to 256MB) the PS/2 Server 95 was and remains a very capable system to this day. The IBM PC Server 500 uses this same planar board paired with a 90MHz CPU complex. (This board is known as a Type 4 Model "Y" CPU complex.) You can add the 90MHz complex to any PS/2 Model 95 or 90. It makes for a nice upgrade and can even be upgraded to 233MHz with the right parts, some care and luck.

This system appears to have been originally equipped with the Type 4 "N" 486DX2-66MHz complex. Such a complex isn't overly common. I do have one.

Some of these no doubt saw service as very high end workstations. It looks like there may have even been plans to introduce a model with multimedia features, not unlike the Ultimedia models 57 and 77.

Jim Hope sold me two of these systems...this one is a regular PS/2 Server 95. The other is a PS/2 Server 95A. Special thanks to him for sending what are two very nice systems in good condition and excellent working order. I have this one configured as follows:

90MHz Pentium CPU
2x1GB hard drives
IBM MCA SCSI adapter with cache
6X Teac SCSI CD-ROM drive
IBM Auto Lanstreamer MC32 token ring NIC

Windows NT Workstation 4.0 with SP6a is the operating system of choice for this computer.

That's Not Funny

One thing I've had bad luck with is the 335 watt PSU as used in the "regular" PS/2 Model 95(xp). I've had two of three just die suddenly and with no obvious sign of failure. This machine gave me quite a scare the night I was setting it up. I managed to pull the plug out of the outlet while cleaning up the table behind this computer. I didn't see myself do that, so when the PSU fan went silent, I almost fainted from shock.

I am really hoping that these 399.1 (!) watt supplies will give better service than the 335 watt units. I've had good luck with the 285 watt unit as used in a Model 85 (same form factor, different PSU maker and smaller wattage rating) so there is some hope that these units will behave themselves.

What's In A Name?

Finally, a footnote: If you're wondering about the name of this computer, think of pickup trucks and their advertised "weights". The way I see it, if a desktop model PS/2 were to be likened to a "1500" pickup truck, the regular Model 95(xp) would be a 2500. A true Server 95 would be a "2500HD". For the "3500" I'd select a PC Server 320/500/520. Something like the PC Server 720 would be a "3500HD" most likely. There, now the "2500HD" name for this computer won't seem quite as silly.

Back >