I bought today an HP Brio 8273 for about 9 USD.
Wanted to add a Socket 7 PC to my collection.
It was really dirty and had some rust on the back... so I cleaned it and removed the rust with some vinegar.
Also replaced the CR2032 battery.

It uses an AT Power Supply, but has an ATX like Power Switch and also has PS2 Ports for keyboard and mouse, and a single USB Port.
I guess it will be hard to get a replacement PSU if the current one dies.

Specs are:
Pentium MMX 233
128MB PC100 SDRAM (2x64MB)
SiS 5581 Chipset
Onboard S3 Trio64V2/DX
Aztech AZT2320 ISA Sound Card
NO Hard Drive

- The onboard video doesn't want to work with my modern widescreen LCD monitor, so I installed a Matrox Mystique 220 PCI and that worked fine.
I also have a Voodoo3 2000 PCI, but maybe it's way too overkill for this PC? Because I have another Retro PC (Pentium III) with a Voodoo 3 3000 in it...

- Swapped the Sound Card with a Sound Blaster 16 CT2230 w/OPL3.

- I want to use a traditional Hard Drive, but I don't have a spare laying around... so I need to buy one. Does this MB support a 80GB IDE HD? These are the cheapest to get here... Maybe limiting the capacity?

- Does this MB support a K6II? (400/450MHz)

- Can I use a single stick of 256MB PC100 RAM? Or is better to keep it at 128MB because of the cache?