http://ps-2.kev009.com/pcpartnerinfo/ctstips/e572.htm

Anonymous is right sorry, odd that the FRUs pointed there

I don't know. I think there is some kind of mistake. This looks like a planar from a PS/2 model 76.

Beluga wrote on 2020-06-04, 01:40:

[...]

Sadly, like with the PowerPC board that I posted in the other thread, I do not have the riser card for it. So I probably will never be able to test it.

Why the riser board? If you can find or adapt a PSU to fit, this board has all you need to test - just add SIMMs and go. Big 'if' though...

dionb wrote on 2020-06-04, 08:34:

Why the riser board?

For a graphics card maybe? 😉

Good luck with that...unless you know where to get a fast card for MCA bus.

That wasn't the point. You need the riser for a graphics card, otherwise you can't test it. It has no on-board graphics as far as I can see.

Also, there's an IBM XGA card for MCA listed at ebay right now for 50 bucks.

What's with the wiring on older IBM boards? I have 4 older IBM systems and 3 of those have these yellow wires. Factory defect repairs?

That or revisions on the still-in-stock boards from an earlier revision. Sometimes this was done on Intel boards too. If you can fix boards this way, why not? These days it is likely cheaper to chuck them out and recycle.

What's with the wiring on older IBM boards? I have 4 older IBM systems and 3 of those have these yellow wires. Factory defect repairs?

Seems normal for IBM. I have a 5150 mainboard on which they apparently forgot (?) most of the traces for a 74LS32N and patched it all over the place.

@Beluga: Near the memory slots there is another sticker near the edge that has the FRU (Field Replaceable Unit) number. That might give better results in a google search.

Thanks, looks strange for a super expensive proprietary computer.

Miphee wrote on 2020-06-04, 09:29:

Thanks, looks strange for a super expensive proprietary computer.

It would not surprise me if those boards were indeed put together partly by hand so fixing one with a few wires would still be cost-effective.

evasive wrote on 2020-06-04, 09:50:

It would not surprise me if those boards were indeed put together partly by hand so fixing one with a few wires would still be cost-effective.

End-users must have been less picky back then. If I ever saw something like that on my mainboard now I'd return it to the store immediately especially if the computer cost me $4000. Mass production changed the world indeed.

Miphee wrote on 2020-06-04, 09:58:

evasive wrote on 2020-06-04, 09:50:

It would not surprise me if those boards were indeed put together partly by hand so fixing one with a few wires would still be cost-effective.

End-users must have been less picky back then. If I ever saw something like that on my mainboard now I'd return it to the store immediately especially if the computer cost me $4000. Mass production changed the world indeed.

If you opened up a mass-produced low-level computer the wires would still be dangling all over the place. Not from the board itself though.

evasive wrote on 2020-06-04, 10:00:

If you opened up a mass-produced low-level computer the wires would still be dangling all over the place. Not from the board itself though.

My sister worked for Nokia and there were thousands of repaired mainboards in every shipment. Most of those repairs were crude but they were sold anyway because the customers never see the mainboard. They paid the same for a repaired unit. I'm not opposed to the idea of fixing fixable electronics, but selling them like they are flawless is appalling to me. Same with computers. I don't mind a few yellow wires in my IBM if the price is $4000 $3500.

Miphee wrote on 2020-06-04, 10:19:

I don't mind a few yellow wires in my IBM if the price is $4000 $3500.

Few wires: 1$
Knowing where to put them: $499

😀

Possible pinout for the power supply (from an IBM PS/2 model 57SX):

https://www.ebay.com/itm/IBM-Ultimedia-9577-M … 6-/323540271691
http://ps-2.kev009.com/pcpartnerinfo/ctstips/feba.htm

Miphee wrote on 2020-06-04, 10:59:

https://www.ebay.com/itm/IBM-Ultimedia-9577-M … 6-/323540271691
http://ps-2.kev009.com/pcpartnerinfo/ctstips/feba.htm

Yep, after some touchup the FRU reads 39G6086 indeed.