Ok well, I don't believe this but I actually found an ALS4000-based card in a bag of all my old PCI cards. It was the only sound card I had left.

Anyway, I've fiddled with it a bit (with both the als4kdos and the official ALS4000 avinit.exe/avconfig.exe-based DOS driver) and I have managed to get sound out of it under pure DOS on this motherboard in a few games that I've tried so far. However I've had some strange issues where sometimes I was getting sound effects and other times not. Music always seemed to work fine (at least with the TSR and maybe without it?) as did all of the various test audio clips from avconfig.exe. I will need to do more testing to see if it's a hardware issue (e.g. speakers or physical connection) or software/configuration/BIOS issue.

Of course any game that uses DOS/4GW crashes. I'm not sure if there is any way around that if I'm forced to use the TSR?

I use the als4kdos utility for initializing my card on the VT8233 southbridge. Make sure the card doesn't share IRQ with other PCI devices and make sure it initializes in "legacy DMA mode", it can be forced in the configuration file. You can try using another DOS extender like the DOS32A instead of DOS/4GW.

I worked a bit more on it this afternoon and like you said, als4kdos is indeed all that's needed which is nice because it doesn't cause the games that use DOS/4GW to crash. The only other things I was missing to make the dozen or so games to work properly (at least audio-wise and stability-wise) was to enable EMS for the games that needed that and use setmul with ICD and BPD for the games that needed a slowdown (e.g. DOTT and Wing Commander 2).

Both the SB16/SBPro and Adlib functionality work great and they sound perfectly fine to me. However the one thing that is a bit odd is the audio levels are a bit all over the place with games. I did turn the output gain down from the default setting of 2 to 1 (0 dB) in als4kdos.cfg because initially at least a couple of games' sfx sounded very overdriven/were peaking. I left the 3 main output volume levels in als4kdos.cfg to the defaults of being maxed out (setting of 31), but somehow the Adlib music is still much, much quieter than the SB sfx. For the games that allow you to adjust music and sound levels, that seems to be enough to work around that, but not all games have those options. Oh well, for now I'm just really happy to have audio working so well!

The only major issue left now is to find out why the scrolling in some platforming games like Jazz Jackrabbit and Commander Keen (6 in this case) is jerky..... but that's an investigation for another time.

EDIT: For what it's worth, I did also change Plug-and-Play setting to Manual in the motherboard's BIOS and changed the IRQ 7 from "PCI Device" to "Reserved". If I understand that correctly I *think* that should prevent the BIOS from assigning IRQ 7 to any other devices in the system. I did this to be on the safe side, although I don't think IRQ 7 was ever being assigned beforehand from my experience (on either Auto or Manual PNP modes).

mscdex wrote on 2021-06-21, 20:56:

The only major issue left now is to find out why the scrolling in some platforming games like Jazz Jackrabbit and Commander Keen (6 in this case) is jerky..... but that's an investigation for another time.

Certain graphics cards seem to have problems with those games.

See here: https://gona.mactar.hu/DOS_TESTS/