Hello,

> I have an ATI Rage II card here. Would it be possible to flash it with Mac
> firmware, or are there other differences on the card itself? XF86 detects
> it, but it doesn't show up in OBP, so I don't expect it to work as-is.
No idea, but I'd expect it to work. In the other hand - some Mac Radeons had bigger flash-ROMs than the PC-counterparts.
 
> If flashing it is possible, does anybody know of a firmware image for Rage
> I/II cards? Can't find one anywhere.
Find someone with a first-generation iMac for instance, these shipped with Rage II chips.

have fun
Michael