I've an old motherboard Mitac 5114VU, from an old Compaq Presario 7000 and reflashed with original Mitac bios (the last I've found). This mobo is perfectly working and I use it, in laboratory, in order to test drives, cards and other peripherals.
I've installed 512Mb+256Mb ram, but the 512Mb ram is seen as 256Mb(even if it's alone) , so I have only 512Mb, instead of 768Mb.
If it's possible, I'm looking for an updated bios (unofficial) for fixing this trouble.
I've installed XP Pro without any problem with drivers.(CPU AMD K6 550Mhz)