retro games 100 had/has a Diamond Speedstar 64 ISA;
Complete newbie advice on ISA video cards required please
(at the top of that page he is also talking about his Speedstar 24x,
a different card).
You can see the bios chip in his Diamond Speedstar 64 ISA is an
STMicroelectronics chip, almost certainly a UVEPROM 28 pin 27Cxxxn series.
Sometimes you can place your finger tip over the bios sticker and feel the
round ('UV erasure window')hole underneath the sticker, feels almost as if
there were a 'screw hole' underneath the sticker.
Someone might take the time to use a single sided razor to gently peel up
a bios sticker so we could know the EPROM model number for certain (the
9501x you can see is not the model number). If doing so, make sure to
re-tamp back down the sticker, as it covers the window. (I'm not 100%
sure, but I believe that if left uncovered, UV from suns rays, fluorescent
lamps, etc, {although 'weak' in comparison to the harsh UV used to erase
such a chip}, could damage the chip over time - best to re-cover the hole
with the sticker to be sure.)