WDM drivers won't have proper DOS compatibility and there is nothing you can do to get it when using them. The driver will intercept any SB etc. access and tries to *emulate* it, despite there being a real SB core on the card, and in most cases fails to do so.

Virtual CD drives are rarely working with VXD drivers in general, so you probably need two sound cards. Years ago when I used 98SE as daily driver I had YMF71x with VXD for DOS stuff and ESS Maestro-1 with WDM drivers for other things, including CD from virtual drives and it worked then. I don't remember any exact details though.

Thank you for your response, friend.

After re-installing the VxD drivers I was able to get the CD audio playing in Quake, Blood, and Shadow Warrior almost well. It stutters in the beginning when the CD audio track is being loaded, but then it plays normally (until another CD audio track is loaded and then it stutters again). It's not perfect but it's a tolerable compromise. The funny thing is that some Windows games such as Quake2, Outlaws, Lomax, don't play the CD audio. Others do work, like Earthworm Jim, Pandemonium, Winquake.

Using a different sound card, the on-board CMI8738 (which is somewhat dodgy) with WDM drivers, the same thing happens with Windows games. I remember having recorded these CD images to disks and CD audio was working fine back then. This approach was my last resource and I expected it to work.

I thought I was going to be able to create an economic CD-rom less plug-and-play amphibious DOS/Win98 machine, but this is not an easy feat.

Please recommend me other CD audio games that are very popular or particularly problematic to get working, both for Windows and MS-DOS and I shall try them.

Do you have DMA checkbox enabled in storage devices in the device manager ? Without, all storage access takes a lot of CPU power and may be the reason for the stutters you experience, and perhaps general sluggishness of the system.

Tiido wrote on 2023-12-26, 11:29:

Do you have DMA checkbox enabled in storage devices in the device manager ?

Oh yes, it's been checked all along. Otherwise the system would be too slow, especially the intro videos.

I finally managed to get the on-board CMI8738 to work correctly with the emulated CD-audio and connected it to the LINE-IN of the ISA card. And now almost every game works perfectly. A few don't work and I haven't been able to fix them (Outlaws, Lomax), but I've found workarounds for some (Quake 2). Overall I'm quite satisfied with the result.