Suggestion Hc. What really annoys me is doing nosound. It is nice during "screensaver" mode it has no sound, but when I want to play it still has no sound.
So here's my suggestion. Have a "mute when not playing" option. When checked the screensaver will start muted (windows mute, not mame nosound). Then if a key is press or the screensaver is exited unmute windows. Then if going back into repeat mode mute again.