You know, back in the day I was one of many who would dunk on Microsoft about how crappy and unstable Win9x was, and why they wouldn't just develop something like Windows NT for average home users instead.
It wasn't until much more recently, with info here in Vogons, and reading articles on Raymond Chen's blog of crazy developer stories from back in the day, that I came to actually appreciate the great lengths that the engineers behind Windows had to go through, just to retain such a high level of compatibility with DOS software, and games in particular.
Don't take me wrong: Microsoft was not a sympathetic company, and there were many legitimate reasons to dislike them. The respect I'm expressing here is intended for the software developers who made all this compatibility magic happen under the hood, in such a relatively seamless way, that it made it seem easy and trivial to us.
Again, kudos for figuring all of this out!
Another question for crazii and Baron von Riedesel: would it make sense to use some of your work done here so far to abstract away the ISA DMA emulation in the form of reusable higher level API that would allow others to write emulators for various specific sound cards themselves? (A GUS emulator, a WSS emulator, etc.) Having one monolithic emulator for all kinds of DOS-era ISA sound cards (with support for all sorts of various physical target devices) might not be the best way to go. Or would it? I know it's easy for me to talk, having not contributed any usable code to this effort so far...