The dos only can use what card provides via bios (interrupt 10h services) and VESA bios extensions (univbe-like programs will know multiple cards and their capabilities), and that's it. The rest has to be compatible with something very standard - VGA/EGA/CGA, etc. So DOS doesn't know and doesn't …

The "Medicat-System" label is likely has nothing to do with the medical stuff. It looks like a typical sticker put by a reseller company to track the warranty period. Do you have one of those POST-cards to see the bios current activity? Might help in identifying problem.

Had a chance to work on a Tomato TD60C motherboard (Harris CS80C286-20 CPU, Citygate D90-272 for chipset) that had a battery leak. The corrosion ate away one pcb trace for keyboard clock line, and destroyed one pin on the onboard dram chip. Some soaking in the vinegar, cleaning with IPA, a bit of …