Shit. I used to have a system just like this one. It had a 486 on a pluggable card and had PCI in addition to EISA slots. Some mid 90's contraption, Compaq maybe? The PCI bus was such an early revision and I recall having trouble with "newer" PCI video cards. Canned that long ago.

The EISA bus was a problem though. This bus was an early attempt at a 32bit ISA compatible bus with no configuration jumpers unlike ISA (this was before the ISA pnp standard.) They shoved little thin pins between the ISA card edge connector to a second set of pins for the EISA bus allowing you to mix 8/16 bit ISA with 32 bit EISA. Hence the 'E' in EISA makes it the "Enhanced Industry Standard Architecture."

The EISA jumper-less solution was to push the jumper configuration to a file which was loaded into the bios. Each card came with a file that described its register layout so it could be mapped in by the controller. If you didn't have that file, your hardware could not be configured and is now useless. So in addition to needing an OS driver, you also needed the EISA config file.