System: (1) Beige G3 233 MHz Rev.A ROM with upgrade to Rev.B, (2) sonnet/ZIF G4 500 MHz, (3) 768 MB RAM, (4) OS 12.2.8, (5) original CD-ROM replaced by pulled-from-an-apple (via OWC-Larry) DVD-R/CD-RW.
The DVD player won't play DVDs, presumably because the onboard VRAM (originally 2 MB, but upgraded to 6 MB by putting 4 MB in slot F1) doesn't have the capability. So I purchased a ATI Rage 128 video card on ebay ($43 including shipping). It shows up on System Profiler in a reasonable way, with the same Vendor ID (1002) as the onboard VRAM. So it seems to be, as the seller advertised, a pull from a B&W Apple G3. System Profiler also lists ATIRage128.kext in the extensions.
So, according to what I've seen online, it should be plug-and-play. Not. Not even when the other PCI cards are removed, and the video card is placed in any of the three PCI slots. Suggestions?