the dos program probably tried to play some soundblaster sound, so soundcard switches to soundblaster mode and takes over the sound device.

Huh? Why would gusplay try to access the Sound Blaster?

Anyway, if I try running gusplay without loading gusemu first, i don't get any sound either.

The sound card could be arrogant and ASSUME you want SoundBlaster audio whenever a DOS window is initiated... who knows? GUSEmu doesn't even work for any commercial games as far as we've been able to tell (only for demoscene stuff, and even then only some of it).

Originally posted by Jorpho -I start gusplay. A Windows message box pops up:
"Unable to play sound - the Creative SBPCI Wave Device is in use by another application." No sound plays.

Do you know whether your soundcard drivers are VxD or WDM? It might be related. Win9x allows for applications "taking control" of hardware, so this error is not uncommon.

Naturally, I have no other sound-producing programs running when I try this.

Obviously, the OS thinks there's something running.

Even if something RealPlayer's "Start Center" could trigger something like this...appearing dormant while actually active.

Has anyone else tried this program and had better results?

Yes, but only for demos. I can startup GusEmu, then start CARTOON.EXE just fine. Can't find any game to work with it.

It turns out that cartoon.exe does work, even though Gusplay doesn't.

I guess there's not much else that can be done then.