> > > http://mamedev.emulab.it/kale/ > > > > It turned out that Sega System 24 HW uses a FRC that also does a previously > > unemulated IRQ service. > > > > Does he mean FDC instead of FRC? > > FDC = Floppy Disk Controller (a kind of device) > FRC = Free Running Counter (a kind of timer)