The PC of that era was such an unpredictable mess of components, you couldn't even assume a specific sound card was present. VGA 256-color modes didn't even have square pixels unless you went Mode-X which was rather annoying to program for.
I think there are far better retro hardware choices to relive writing native programs for. Stuff you'll actually be able to ensure will run successfully with full graphics and sound capabilities on every instance of the thing. C64, Amiga, etc. There's a reason the x86 PC severely lagged behind in the demoscene for ages, it was just miserable hardware to support.
