Thank you for that find, very useful. It allowed me to make some progress, but the card still isn't working yet.
I tried several versions of BIOS from that site, going at first down in version order: 3.03, 3.02a, 3.01, 3.00. With any of those, the motherboard still gives me the beep sequence for "no video card found"
Then I noticed that the dates of all of the BIOS files above are in 1995, whereas my actual card has a PCB date of late 1996.
Out all of the BIOS files on the site, the only one with a date in 1996 is 1.09d (early 1996 that is). So I tried that one, and this time the motherboard didn't complain of missing video card and booted into Windows. But I still had no image on the screen. I powered off, and booted again this time with a second (AGP) card in the system so I could see what's going on.
Long story short, the card is seen by Everest
At this point, 2 theories:
1. Something else is wrong with the card, maybe the RAMDAC is bad? FWIW the chips on the card (both the large S3 chip and the RAMDAC) do get warm while in use - not hot but warm.
2. The BIOS is closer to being the correct one, but not quite. Several BIOS files are marked as being specific for cards with IBM RAMDAC (like my card does) but not this one version 1.09d.
So I think I'm getting closer, but I'm still looking for BIOS with a date in 1996 and made for cards with IBM RAMDAC.
I/O, I/O,
It's off to disk I go,
With a bit and a byte
And a read and a write,
I/O, I/O