> What kind of monitor are you using (CRT or LCD) and what refresh rate is the monitor > running at?
FWIW, I think Asteroids should simply be set to 61.5 Hz refresh. MAME has not exactly been shy about using real refresh rates when they cause problems with LCD monitors in the past and I don't think we should start now. Ditto other vector games; their NMI to refresh ratios should be determined and the refresh rate set accordingly.