> > Ok, thanks for the explanation. > > For example I Measured the Vsync of a Pyros oginal Toaplan at > > 54.879 Hz, in MAME it's at 54.000000 Hz.looking at wardner.c > > there is: > > > > MCFG_SCREEN_REFRESH_RATE( (XTAL_14MHz / 2) / (446 * 286) ) > > That's showing you how it's calculated: 7 MHz pixel clock divided by 446 horizontal > pixels (including hblank) times 286 vertical scanlines (including vblank).
It looks like it's integer arithmetic though, so it's only getting 54.0 instead of the proper 54.879.
I'm guessing a couple of .0's and a typecast are in order: MCFG_SCREEN_REFRESH_RATE( ((double)XTAL_14MHz / 2.0) / (446.0 * 286.0) )
Nice to see your sync measuring device is working perfectly, caius!