The AA number is AA C45431-104
Gateway part number is 4000856
It's one of the many slightly different boards marked E210882.
I updated it to the latest BIOS from Gateway (P03, it had P02 out of the box), had to use the Windows program because it flat out wouldn't do anything booting from the floppy disk, not even when I pulled the jumper for recovery mode to load the .bio file.
It'd load beep and iflash, then blank the screen and turn the floppy off. Trying recovery mode all it'd do is sit there forever spinning the floppy.
(Same actions with the Gateway and Intel floppies.)
I'd like to shove the much newer (P20) final release from Intel onto this board because it supports newer CPUs plus a lot of bug fixes and has more settings available than Gateway's dumbed-down BIOS.