> I tried using MAME's debugger to look at the Z80's memory, but nothing's showing
> up in the range that the link I posted previously said the relevant data should
> be showing up in (D000-D003, or whatever)... they're just always 00. :/

The Z80 is a sound controller, it drives the hardware to play the samples with the correct timings and such, probably it even orchestrates the different channels, but by no means it keeps the audio data in memory (which is no more than 64K, with no banking).

I'd try playing with M1 or Nebula Jukebox, it's really the easiest thing to do.