Okay, I am admitting defeat... having got Fraggal's AdvanceMAME/DOS/ArcadeOS CD to install (easy), configured screenmodes (time-consuming but easy), got ArcadeOS rotated vertically (also easy), I cannot get AdvanceMAME to make any sound.
I know that the sound drivers are installed and configured correctly as ArcadeOS makes sounds (plays samples), but I cannot get AdvanceMAME to make noise.
AOS uses the SBPCI option; my motherboard is a generic VIA MVP3 chipset one running an AMD K6-2 500 CPU.
I've tried a few of the various options in advmame.rc, including seal/sb, auto, vsync/sb, but all to no avail.
Any ideas?