You need to dine one specific to your machine. I have a few upgrades and they are built in weird shapes to avoid the different obstacles you find on different motherboards of the PS/2 line.

Unknown_K wrote on 2025-12-31, 03:16:

You need to dine one specific to your machine. I have a few upgrades and they are built in weird shapes to avoid the different obstacles you find on different motherboards of the PS/2 line.

Thanks for the response! That doesn't really answer my question, though 😀 I am aware that I need one specific to the model 50. The thing is, I can only find vague suggestions that this card is made for that particular model, so I'm not 100% sure, hence why I'm asking if anyone knows. The other cards I've seen seem larger, but have the same processor. Do you believe this would not fit in a model 50?

I don't think I have a 50 to even look, sorry.

I do not think the upgrade is possible, due to the Model 50 being an 16bit 286.
There probably was an update availiable to upgrade to an 386sx/486slc, as well as 486 upgrades for the 32bit Model 70.
The Kingston card with a complete 486 replacing the onboard CPU is 32bit and will therefore not fit the 16bit slots of the Model50.

P.S. : Didnt recognice its a 486slc 16 bit CPU upgrade. So the upgrade should be possible electrically.

L0ngcat wrote on 2025-12-30, 23:09:

It's an I-O Data PK-X486S50-3 IBM SLC2 50MHz 286 to 486 PLCC CPU Upgrade Card,

eisapc wrote on 2026-01-22, 09:39:

I do not think the upgrade is possible, due to the Model 50 being an 16bit 286.
There probably was an update availiable to upgrade to an 386sx/486slc, as well as 486 upgrades for the 32bit Model 70.
The Kingston card with a complete 486 replacing the onboard CPU is 32bit and will therefore not fit the 16bit slots of the Model50.

It is an SLC2 based upgrade card, which is 16-bit external.

The card IS intended for 16-bit 286 motherboards but the first and most obvious problem is that the IBM PS/2 50 has a PGA 286 socket while this IO-Data fits an LCC socket.

There are interposers out there for this, which might also help with the 2nd problem which - as noted by others - is the clearance issue with other components around the CPU socket potentially obstructing the IO-Data card.

And then there might be firmware/BIOS incompatibility too, with the IO-Data stuff being designed for specific Japanese PC-9801 models, not regular PCs. Nonetheless, some people have gotten them to work.
If you do manage to get it to run, chances are it'll be limited to 10*2 = 20Mhz.

All things considered, it's probably gonna end up involving lots of trial and error, frustration, and possibly still not work in the end or perform relatively poorly. So I'd say definitely go for it as that is my idea of fun.