Hi, maybe I remember correctly, but the MS Wavetable Synth only works in Windows and not in DOS window. If you run a game in DOS window then you won't get any sound.

I hope someone with more experience can say: hey you remembered wrong! ..and that it can then help you solve the problem 🤗

Yeah, the Windows 9x Dos Box does not have its own MPU-401 Midi interface, it is up to the sound card driver to supply such services. And even then, like 99% of these drivers do not allow you to freely route midi to a Software Synth of your liking.

VDMsound can do it, but it is tricky and uncommon.

actually its the opposite. With WDM drivers (aka sbemul.sys) , there is emulated mpu401 device which is redirected to whatever you select in the midi mapper, and there is absolutely no adlib/fm emulation (sbemul only emulates the opl timers but generates no sound).

Since you mention adlib emulation works, it means you already have some driver which is doing extra emulation inside dos boxes. May also explain why mpu cannot be redirected away from it. Perhaps the vortex driver itself.

See eg Routing DOS MPU-401 to Windows 98 MIDI mapper?

Sorry you are right. it seems;
https://msfn.org/board/topic/182729-exist-a-s … ator-for-win9x/

win9x have integrated SB emulation for own dos vm.
HKR,,NTMPDriver,,"sbemul.sys"
HKR,Drivers,SubClasses,,"wave,midi,mixer"

I suppose, back then, I was always using VXD drivers, and therefor never activated it.

Edit: For Crystal 4237B there are both VXD based and WDM based driver sets. First set is dated 1998, the WDM-one is from 1999. Though I suppose both are aimed at driving actual midi hardware attached to its MPU-401. Nothing attached meaning no sound.
Crystal ISA Audio Drivers for DOS/Windows + Extras

Right! The WDM driver I have installed is the one linked. Further testing tells me that you guys are right, in a Windows DOS window the adlib/SB sound is a little different from the one I get in "pure DOS" mode (after a reboot to MS-DOS mode) so that's telling me what I'm hearing under Windows is probably the emulation mentioned.

So them am I right in assuming that the driver simply doesn't support redirecting MPU-401 to the Windows GS/GM synth?
Or is that supposed to work with all WDM drivers? Really unfamiliar with this!

Since the ThinkPad 380Z has no gameport, you cannot attach hardware to the MPU-401's midi-pin. So that is like a dead-end.
- You can try the VDMsound trick in the link, of course.
- Maybe someone could tweak the driver configuration so it reverts to the microsoft sbemul.sys. I currently have no time, and assembled system, for that though.
- Or wait for someone to drop by with a better idea 😉