Home Page Forums MAME MAME TMS-09xx/1xxx thread (was New Dumps)

I think I have the F_out pin working in MESS. Maybe not at the exact frequency, but the 'mini melodies' sound good enough if I ignore the A12 problem below..

A12 is behaving badly: it enables the speaker, and then quickly disables it again. What's the connection from A12 to the speaker like on the PCB? Is there a capacitor involved causing it to stay active longer?