vacatedboat wrote on 2022-11-06, 03:45:

I keep getting an device id error. Im not sure what to select in the software. As there is no TMS option.

You can uncheck the "Check ID" checkbox in the Options group (bottom left part of the Xgpro app) and retry, reading should work the same for any pin-compatible EPROMs, any 27256 chip will do for reading.

As for the replacement options - probably there are too many to tell you the exact one. See the stores you can easily reach, look for EEPROM(flash) chips. Some kind of cheap Winbond W27C257 should work ok.

+1

The "read ID" checkbox must be unchecked!

Also, there's a BIOS file at VGA Museum..

https://www.vgamuseum.info/index.php/cpu/item … ent-tvga9000i-1

Just in case the BIOS in that EPROM is really faulty..

If it's readable for the TL866, I'd try to make a backup of the old BIOS first, of course.

Btw, the Trident 8900D wasn't bad, either.
So if you need a replacement card, it's an alternative.

Tridents always have a BIOS where the data is shuffled a bit and when the dump is done with software such as NSSI, you get a dump that will not work on actual hardware when burned on a memory chip.
If I can uncover my TVGA9000-1 I'll do a dump of its ROM that should work.

Dumped the Bios from my TVGA9000i-2, not sure if that -1/-2 revision is critical, the version name is the same D4.01E as from file from VGA museum.

Btw, why are you asking for -1 rom when your chip is -2 ?

The original BIOS chip has a sticker mentioning "Cirrus Logic" on it. I don't think it's worth to read that chip for getting the Trident card to work. A Trident card will not work with a BIOS meant for a Cirrus Logic card. Sourcing a TVGA9000i dump from the internet (possibly VOGONs) seems like more promising.

Thanks for all help. This is a card that sometimes would boot the machine. So its a spare now.
Sorry i may of mistyped the version number. Also yes this is the second eprom ive tried to re program so inexperienced with the software. Thanks all for the bios dumps. Will give it a go.

vacatedboat wrote on 2022-11-06, 08:11:

Thanks for all help. This is a card that sometimes would boot the machine. So its a spare now.
Sorry i may of mistyped the version number. Also yes this is the second eprom ive tried to re program so inexperienced with the software. Thanks all for the bios dumps. Will give it a go.

Are you aware the 27-series EPROMs need to be erased by removing the sticker and illuminating it with UV light (commonly 245nm) before you can reprogram it? I can't find any datasheet for a TMS27256, only for a TMS27C256, which is a later chip. This page for a different programmer indicates that the NMOS TMS27256 needs longer programming pulses than the TMS27C256, but it lists a lot of other NMOS 256kBit EPROMs that can be programmed the same way. For example the AMD AM27256 (which is supported by the TL866) should be compatible enough that you can program an erased TMS27256 with that setting, if you disable ID verification.