Wouldn't it be easier and cheaper to get a good quality old AT power supply? Such as Delta, Lite-on, etc. there are plenty of those on eBay.

Or even one of those ATX Starch units, they can be found new and are of decent quality, have -5V, relatively strong 5V & 3.3V lines. And it would fit much better in that case due to the old layout with the fan at the back.

Most of the old cases I have can mount the PSU either up or down. After looking at your picture it should be fine, there is an inch or two gap above the fan so it will suck the hot air (hot air rises) from the top of the case and blow it out the back.

GabrielKnight123 wrote on 2020-05-20, 16:20:

If your wondering I'm using an adapter for AT to ATX.

You mean ATX PSU to AT right ? As "TheMobRules" said, you should get a real AT supply, they are not very expensive, most are much less than a new Corsair CX550 ATX supply which would be better for a real ATX motherboard....

This is my beloved 486 so I dont want to use an old AT power supply as I have had a new old stock AT one blow up on me after about 8 hours of use, I do have AT power supplies laying around but a new power supply has "cleaner" (for lack of a better word) power output that I trust more, yes im using an ATX to AT adapter and it has a -5 volts converter for my ISA soundcard with a dummy load to keep things balanced. Horun why do you say that a real AT power supply is better than an ATX?