the code in the picture does not seem to be doing much really..
when in DOS you really need to make it emulate something else that your target software already knows and likes imho - so the question is - emulate what?

Aren't those just Ensoniq Audio PCI cards? If so, they already have DOS drivers.

I have a CT4810 card which uses a similar chip and it works in pure DOS. The FM synth emulation is atrocious, but otherwise, its SB16 compatibility functions as expected.

The original DOS drivers from Ensoniq or Creative do not work in newer machines. As far as I know, there is no PCI sound option for AMD systems since AM3 socket release. For Intel systems, things are a little better: Aureal AU8820 works even behind a PCI-E bridge. (I tested an AU8820B2 with 100% success on a Haswell configuration this week.)

So, these ubiquitous ES137x cards would be a nice universal PCI sound card for the newer systems.

If the emulation is done in hardware by ES137x chips, then all we need is actually a wrapper, so all the ports that DOS games are trying to access are well configured and available. I know it's not a trivial thing by far.

Here is an interesting PCI DOS game compatibly guide written by an Intel engineer in 1996.