Chris Covell managed to figure out the ADK driver and its use of MML, but I personally find composing with MML to be a hassle. I guess that's really my fault for liking tracker-based workflows better. (Also I don't really want to emulate another system to track music unless it's the Amiga; stubborn freem strikes again!)
One of the first ideas I had was to make a native tracker (running on the Neo-Geo), but after realizing that the 68K<->Z80 comms would be a bottleneck, I scratched it. (Maybe it's not a lost cause, but that was the main issue on top of trying to figure out how to implement a decent interface.)
Back in 2015, I started to hack up the MVSTracker source code, to see if that was a viable way forward. I had no real idea what I was doing, so the project got shelved after some frustration. Fast forward to today, where I've picked it up again (knowing slightly more than I did before), but am still having troubles (primarily with rewriting the Z80 driver and having it still be able to preview music). Sometimes, I wonder if throwing it out and writing a new tracker from scratch is a better idea.
The real reason I'm posting this is that I want to not really duplicate effort in this (or any FM/SSG related) field, just in case someone else has been working on something. Trying to figure out a reasonable path forward would be nice, as well as alternate avenues (for the adventurous).
List of dumb things to think about:
- Converting the Echo sound driver to Neo-Geo
- Conversion tools for S3M (ScreamTracker 3) songs that use AdLib instruments; AdLib Tracker 2 files (or some other 4-op capable AdLib composers); Deflemask files for Genesis/Mega Drive? (Among various other options)
- Some sort of VGM converter (since uncompressed VGMs are too big for Z80) and player
- Deflemask getting Neo-Geo support (as an alternative to converting from Gen/MD)
- You might think about using various tools on MSX, PC-88, X68K, or other computing platforms... as mentioned above, I'd prefer to avoid it, but don't let me stop you.