It definitely will be an EPROM, flash chips were not common then and especially not for something that was never changing such as program code. 27C256 is the most likely candidate especially since you say the dump you have is 32KB.

chip is indeed a 27C256 and the data is 32kb
though it seems bottom half is empty - but that's what ATI used
I am attaching the dump from my VGA Stereo/FX just in case it is useful

Thank you both for the information. I already have a 27C256 programmed with the .bin file I found on the MAME download sites. I just didn't want to attempt to do anything without some type of confirmation. Also don't necessarily want to try it until I populate the tantalum caps back onto the card.

I read a few old threads that all referred to the card's EEPROM (not EPROM) including ATI's own website. That's what made me ask. Below is a snapshot of the ATI Stereo F/X section which has lots a good info on this card as well as the CD and VGA variants.

http://web.archive.org/web/20010331045332/sup … soundcards.html

I'll report back as I (hopefully) make progress. If anyone else has any other input, please feel free to chime in. Thanks again!

The EEPROM referred to is a little 8 pin chip that holds 128 bytes which is used to hold presistent configuration. Some flavor of 93C46

Yes I see now that the 93C46 8-pin SOIC is U24 to the left of the lower CMS socket. Thank you for that.

Also note that I just ran a comparison of the 32KB .bin files between what Keropi provided and what I found on the MAME ROM sites and they are, in fact, identical! This is beginning to look promising. And now we know that it is likely that the same ROM is used on at least the VGA and Audio Stereo F/X cards. Probably the CD version as well, but not yet proven.

The only thing that remains that I haven't 100% verified is the ratings for the tiny 1206 tantalum caps. I believe they are marked "C105" which I interpret as 16V 1uF. Is there anyone who can confirm this is accurate. I can only make out a single cap of this size and am assuming that all (5) on the card are identical.

Thanks again guys.

baracoota wrote on 2022-12-01, 15:57:

[...]
The only thing that remains that I haven't 100% verified is the ratings for the tiny 1206 tantalum caps. I believe they are marked "C105" which I interpret as 16V 1uF. Is there anyone who can confirm this is accurate. [...]

you are correct, C105 are indeed 16v 1uf capacitors
this photo should be useful to verify values: http://geryon.ru/stereofx.jpg

Thanks.

I will have all the replacement caps sometime next week. Unfortunately I'll be out of town during that time and won't have a chance to work on the card until I return. I'll report back once I have a chance to test things out. I can hardly wait!

Alright! I hope you get it going!
Good luck and keep us updated on the result!

It's ALIVE!!! All seems to be working well in the limited testing I did this morning before work. Last night, I was extremely disappointed when no sound was being produced and I thought there was no hope for this card. While sleeping, I had an epiphany and remembered that the 486 board I was using for testing had issues in the past with a CT2910 sound card (which worked in another setup). So I swapped to a 386 board and...there was joy! The SFX test program produced sound and there was music in Monkey Island 2 and Descent! Will test Game Blaster functionality later tonight, but I'm pretty sure it will work since I tried it on the other board and didn't receive any errors; just no sound. Looks like another piece of history has been saved from the landfills!

Thanks so much for the assistance!

awesome!!! enjoy this nice card!

Naiss ~
You do need SAA1099 chips in the empty sockets for GameBlaster fun, and you should tape up the EPROM window.

I do actually have the SAA1099 chips and had them installed last night while testing. They were set aside for a QuickShot Sound Machine QS803 (SB 2.0 clone) board that is also in need of a small repair, but looks like they will now live in this Stereo F/X card. I didn't have them in for the picture.

I'd like to make an EPROM sticker that looks like the original. Any ideas on how to go about it? I'm not the artsy type, but I'll give it a go to keep it looking as original as possible. Might just print out a picture from the internet and tape that on. Either way I'll definite cover it up!

Thanks guys!!!

the Quickshot Sound Machine QS803 card is an actual SB2.0 card from Creative - back then Quickshot was a bigger name than Creative and they sold cards for them - in a bundle with some software , crappy speakers and a crappy joystick 🤣

Sorry for hijacking this thread, but i have similar problem.
I have a bit different card, Ati stereo FX CD (sadly no gameblaster chip sockets) but problem is similar. Card is dead and the paper sticker on eeprom was burned on centre. So i guess on schematic must be a short circuit somewhere (usually eeprom chips wont generate much heat)?
Or could i just buy new eeprom and replace it, fingers crossed? 😀

Burned sticker is not fun, there's a chance someone inserted it the wrong way around and that is why it burned. In that case, new EPROM will revive the card, assuming nothing else got damaged during this stunt.

I second the probability that the EPROM was inserted in reverse. I accidentally did that with one I used for XTIDE on an ISA Ethernet card and it was red hot afterwards! EPROM was dead, but the card was fine. Hope it's as simple as replacing the chip.

Would love to hear back. Curious to know if a) you got your card working and b) if the ROM that Keropi provided works on the CD version. It certainly works with the VGA and basic Stereo F/X cards. Hope you let us know how it turned out for you.

Hello everyone,

I also have a problem with the EEProm on my ATI Stereo F/X CD. The card is not found and when you run Install.bat an error message appears (similar to EEProm error, possibly card not installed correctly).
I have already tested it in another PC.

Does anyone have a BIOS dump from the Stereo F/X CD or can I use the “normal” one?

Update:
I have now programmed the BIOS of the normal Stereo F/X on another M27C256. This didn't change the behavior of the card.
I've attached a screenshot where you can see what SINFO spits out. The same message also appears if there is no card in the PC. I also read the bios of my card and uploaded it here. Maybe someone can look over it. It's also 32kb in size, but I have no idea if it has any errors.

Now assuming the bios IC is OK, what is stopping the card from booting? Basically the IC depends on the 8-bit ISA address bus. But the conductor lines don't go directly to it. It could be that a shift register (or similar) comes afterwards.
Is it that simple? EEProm OK+Voltage OK+Shift register OK=BIOS can be read

I completely forgot: picture of the latch hidden underneath the BIOS chip.
Could this part be defective?