Last night I was able to set up a working build environment. It seems someone in the last couple years has _finally_ patched cwsdpmi to fix that stupid "too much memory = crash" bug, so I was able to build a version that could run everything from Galaxian to Gunsmoke without any page fault crashes. A few source cleanup type changes were required to get us building under the latest gcc.
If anyone else is interested, I am thinking of rebuilding "pure" build environments for 486, Pentium and Pentium Pro and zipping them up so that others don't have the nightmare of tracking down the MAME-patched SEAL sound library, etc.
Seems VAntAGE was already on the latest mz80 core - I regenerated a new one from scratch, and the differences were minor (went ahead and replaced it anyway). I looked into the high score patches for MAME, seems like those could be added in with a little work.
I also re-enabled the Dig Dug WIP driver to see how much progress was made last time around... it looks like it gets to the ROM check screen, but everything is totally garbled and the game doesn't run. If I'm going to be writing new drivers, I'd better start with something even easier (yes I know, it's almost exactly Galaga hardware, but I've never touched emulator source code before).
Maybe one good quick win would be hooking fake analog controls to the buttons so we can play Moonwar / Azurian. I was also considering a switch to enable "Button 1 + 2 = Button 3" so that Gunsmoke can be played on 2-button machines. I realize these are hacks in the name of playability over true re-creation but isn't that what VAntAGE is all about anyway?
Anyway if this starts to turn into a real short-term project I should set up a real website for it.