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.

The "SC" prefix indicates a custom chip that Motorola made for someone else - in this case Compaq. A quick search of the Internet shows that it's an SVGA-class card with a blitter and hardware cursor. Here's some register-level docs:

https://flint.cs.yale.edu/cs422/readings/hardware/vgadoc/COM...