Thanks a lot for the hint! The driver works perfectly - only, I take it, one needs to self sign it for Windows to not fail loading it when not in a special boot mode. Oh well, no rest for the wicked, I guess...

E: For DOS enabling legacy FM, and disabling OPL port forwading got music in Gods and Magic Pockets back with VSBCMI (and I checked Wolf3D as well). VSBCMI, by the way, does not attempt to detect if the chip supports OPL3 emulation, instead it simply has a command line argument to enable the corresponding bit. Will be studying this further to find a rational way forward with this.

E-E: More "problems" have been cropping up with the rev.37 card. It appears, it was running at 48k when configured for TOSLINK output, and MIDI UART is very picky and requires additional delays around port reads and writes, which were not required for the "6ch" chip. In legacy UART emulation mode the chip works just fine, and I was also seeing if this could be taken advantage of, but sadly could not get VSBHDA code to not interfere with legacy UART even if it was not virtualizing port 330. I think version 1.7.2 of VSBCMI is finally taking shape, and since someone has kindly shared pdf of the card's manual which explains how S/PDIF input/output is configured, I might try and see if digital CD input works after all...

VSBCMI on github is updated with 1.7.2 binary, guide updated as well.

The TSR works okayish with a Winfast 4X. Some observations made during testing:
- Cyril Cyberpunk surprisingly does not predictably hang the system on quit
- Malcolm's Revenge and Hand of Fate CD are not entirely stable (these and the above seem to be speed sensitive, as well as the above)
- Archimedean Dynasty hangs at startup, even though it works with SBEMU
- Tartar (Doom source port for DOS) started crashing when lots of stuff gets preloaded; no idea at this stage if this is sound related

Digital CD-in did not work for me after all, but oh well...

E: A small update.

- Archimedean Dynasty does not like JEMMEX VCPI, so sending NOVCPI to JEMMEX before starting it actually gets it working with sound; it crashes loudly upon exit unfortunatelly. Turns out it uses Causeway DOS Extender by default, but there are also executables ending with ...D4G and these use DOS4GW, which is pretty much compatible with VSBCMI/VSBHDA, so problem solved
- Tartar seems to hate either screen font or keyboard driver my FreeDOS had installed, and without that loaded just fine, with sound. I made some adjustments to MIDI UART delays in VSBCMI however, as values in current published build made playing with MIDI music feel somewhat choppy (compared to OPL3), and now problem seems to be solved as well
- Unrelated to the sound topic, I noticed stability issues with games using mouse, no matter which CTMOUSE version I use, since I switched from an AT/2 to a USB mouse. I now attribute some instability in Tartar and certain Westwood games to this, and not sound drivers
E-E: and couple more remarks on compatibility:
- Inherit the Earth is a DOS16M game, so no surprise it misbehaves
- Whizz does not seem to start at all in FreeDOS, regardless of TSRs or memory managers; it starts in MSDOS but crashes when sound gets initialized

Additionally I tinkered a bit with SBEMU and this WinFast 4X card I have and neither prebuilt, nor locally built versions (1b4, 1.1, 1b5 nor trunk) work with it, crashing one way or another, or producing no sound.

v1.7.3 ships 16-bit version of VSBCMI in addition to 32-bit one and makes MPU-401 operation for older chips a little bit faster.
I have updated posts above with, e.g., addition of Tyrian 2000 to the list of games, and am also putting a list of games into the new howto added to VSBCMI source code.

v1.7.4 is out; this one is built with OpenWatcom for both 32-bit and 16-bit versions and includes some bugfixes from VSBHDA 1.8.
X-Wing and Monkey Island now work (require /CF1 option), and Black Zone works as well, but with software OPL emulation enabled (/OPL1 /CF1).
Updated the compatibility post above, as well as the HOWTO found with VSBCMI source code.

E: All of a sudden v1.7.5 is around the corner with a small, but important tweak that got the chip's own FM in Black Zone working, and I hope will help with some other games. Instead of forwarding to card's PCI FM ports, /DF10 now sends directly to 0x388 in cases when software emulation is off (/OPL0) and chip's own legacy FM is not disabled (default).

VSBHDA is getting better and better, and I am trying to keep up with VSBCMI to the best of my ability.
There are now two testing builds - v1.8.1.99 which corresponds roughly to v1.8 of VSBHDA and v1.8.1.100 which also has latest commits from upstream as of writing this (and I've also switched to HX v2.23 for testing).

Game compatibility is improving. Blackthorne is a major new addition, and for it would be awesome if someone could help testing it on other machines than mine in sig.
One needs /OPL0 /DF10 (i.e. with FM port forwarding) or /OPL1 (i.e. with software FM emulation) to run it with VSBCMI, and it seems to work with SB (not SB Pro) settings or sound and music.
There are certain hiccups I observe with it, so curious if this is machine/version specific.

With some perseverance I was able to get rid of those Blackthorne hiccups in the latest build - starting with v1.8.2 that is, but running the game needs VSBCMI to be started with /DF90. It is going to be different from VSBHDA 1.9 and so forth, which will likely not require extra argument for this compatibility, looking at VSBHDA code. It may be curious to know The Lost Vikings behave, but I don't have the game in a reasonable distribution to try nor desire to obtain such distribution. I also think I have "mastered" building in a stable fashion with Watcom 1.9 in FreeDOS, so subsequent builds will be using that.

At this stage I ran out of ideas / games to try, so probably calling it done - until I get my hands on another card to try, probably by accident, since this is not a priority and things are ok as they are, to be honest. But ideally I would love to have a card that has both support for S/PDIF out in the official 64-bit drivers and undistorted OPL playback via the same in DOS...

ludicrous_peridot wrote on 2025-11-09, 09:42:

With some perseverance I was able to get rid of those Blackthorne hiccups in the latest build

Wow! Thats quite an achievement, considering that not all "proper" ISA sound cards (ALS100 f. e.) cooperate with a Blackthorne nicely.

Well, I have also revisited Inherit the Earth (the CD-ROM talkie version), and sadly was only able to have it running on a machine with lots of RAM by patching the executable itself.
This should not be necessary on a machine that actually has, say 32-64 Mb RAM.
I have summarized the setup in the HOWTO doc.

EDIT: in fact after consulting with Baron-von-Riedesel I put together a simple memory limiter for the game into VSBCMI itself and with that the game works unmodified.
Don't know about publishing that just yet, since it probably needs testing on a few more machines with different configurations, which is difficult for me to do on my own, and because I am still reflecting if I put the limiter into the right tool in the first place.

Spent couple of weeks with headphones on trying to see why Quake did not sound so nice with VSBCMI. There is a new version out, which deals with one small nuisance, but for the most part it appears that Quake does not get along very well with interpolation in VSBHDA itslef.

So, for better sound I recommend running the game with -sspeed 48000 to avoid TSR-side resampling. Moreover, I have uploaded new builds of DOS Quake and legacy Hammer of Thyrion to github which add interpolation to Quake's own resampling, keep 8-bit sound samples in 16-bit format afterwards for 16-bit cards and include the looping sounds fix.

On the topic of memory limiter: it's not included, since HDPMI32I version has been published by the maintainer which has an option for this. One can play Inherit the Earth without any modification to the game with that version of the extender, so hopefully the same appears in a subsequent release of HX.

Z has been tested succesfully with the driver.

Finally, one other thing that has changed is the choice of cards again; I have swapped the card in sig. with a 6CH-one, and like the sound more so far and it seems I am not getting random bops with the unifficial 64-bit driver. No S/PDIF for OPL with it, but I am thinking about exploring alternatives.