Solved it, it was the adaptor. That's what one unsoldered pin does... Thanks anyway!

First of all, thanks for all of your hard work on this!! I discovered this thread probably about a year ago when I noticed the hanging note bug with my AWE32 CT3900 while trying to record some game music. I finally worked up the courage (and gathered the necessary equipment) to desolder the DSP chip and replace it with a socket yesterday, and so far so good! I have some questions, though:

1. What is currently the best firmware version to use for the CT3900? (Assuming that I have no need to play any Duke games with it.) Do I understand correctly that v4.17 is based on v4.16, which normally doesn't work with the AWE32, but v4.17 has changes that make it compatible? So is v4.17 the best right now? Or v4.13 patch 5? I tried both of these, and they both seem to work, but I didn't do a lot of testing and didn't notice any difference.
2. When I tried to write the latest v4.17 to a spare chip, I ran into an error that the file size was too big (8256 bytes when it should be 8192). Granted, I'm on Linux and using an open source program (https://gitlab.com/DavidGriffith/minipro) to interface with the T48 programmer rather than the official Windows program, so your mileage may vary. Seems like a mistake, though. I looked at the file in a hex editor and saw that the end of it was filled with junk 0xff bytes, so I just truncated the file. It should probably be fixed in the repo, though.
3. Looks like DMA clicking is still a known issue? I think that's what's happening in Star Trek Judgement Rites. The recorded audio in cutscenes and voiceovers is pretty glitchy. I'm wondering if it could be related to what you're seeing in the Duke games?
4. Sorry if this is only tangentially related to this thread, but I have an AT89C52 in a DIP40 package that's read-locked that I need to dump the firmware from. It's similar to the DSP chip which you all have been able to get dumps from, so I'm wondering if someone with the necessary skills and equipment could help me out? I'd be willing to pay for their trouble. I'm fine with destroying the chip in the process; I specifically got an extra for this purpose. It is in the spirit of preserving old hardware; it's from an Avant Stellar keyboard, and it would allow repair and modification. I've reached out to some people who worked at Creative Vision Technologies and the company that bought them to see if anyone had a copy of the firmware that they'd be willing to release, but I was told that it does not exist anymore. So getting a dump from the chip is my only hope...

Keep in mind I have an unresolved issue with using an aftermarket DSP chip on an AWE32. Sadly my particular awe32 did not have sufficient room around the PLCC footprint to fit a socket, so I wasn't able to troubleshoot deeply, but I was getting spurious NMI generated from the Atmel '52 chip. I find it unlikely to be the code and more likely to be the chip itself, but I was never able to definitively determine the cause. I just reverted to stock DSP.

4.13 patch 5 gets my vote

maxtherabbit wrote on 2025-10-08, 23:15:

Keep in mind I have an unresolved issue with using an aftermarket DSP chip on an AWE32. Sadly my particular awe32 did not have sufficient room around the PLCC footprint to fit a socket, so I wasn't able to troubleshoot deeply, but I was getting spurious NMI generated from the Atmel '52 chip. I find it unlikely to be the code and more likely to be the chip itself, but I was never able to definitively determine the cause. I just reverted to stock DSP.

Which AWE32 do you have? My CT3900 had some nearby components as well; I ended up just putting the socket pretty much on top of them... Hopefully it won't cause any issues. I'm using an Atmel AT89S52, and so far no issues that I can tell, but is there a way for me to check for NMIs?

I attached some photos I took of the process; are the component locations similar to your board?

Mine is a CT2760 rev 1. The components on your card are slightly further from the footprint than mine are. As for checking for NMI, you would get a "PARITY ERROR SYSTEM HALTED" screen if you have parity checking enabled in BIOS (or maybe even if you don't)

Am I correct in thinking that there is no fix for any Awe32/SB32/Vibra that doesn't have the CT1741?

I don't think so. I believe that the DSP is part of the same silicon as the audio chip. This project requires that the DSP be on a separate chip, since we are literally replacing that chunk of programming logic in ROM.

meyertime wrote on 2025-10-08, 22:25:

4. Sorry if this is only tangentially related to this thread, but I have an AT89C52 in a DIP40 package that's read-locked that I need to dump the firmware from. It's similar to the DSP chip which you all have been able to get dumps from, so I'm wondering if someone with the necessary skills and equipment could help me out? I'd be willing to pay for their trouble. I'm fine with destroying the chip in the process; I specifically got an extra for this purpose. It is in the spirit of preserving old hardware; it's from an Avant Stellar keyboard, and it would allow repair and modification. I've reached out to some people who worked at Creative Vision Technologies and the company that bought them to see if anyone had a copy of the firmware that they'd be willing to release, but I was told that it does not exist anymore. So getting a dump from the chip is my only hope...

Hi Meyertime. If you want to get that firmware dumped you might want to contact Tubetime / Eric Schlaepher. Apparently he's on Bluesky at https://bsky.app/profile/tubetime.bsky.social . He's the guy that reverse engineered the original Soundblaster 1.0, created the SnarkBlaster clone and dumped the Soundblaster 2.0 ROM.