> Can you publish the schematics and components of this device? > > And a more general question (to the devs): How reliable is the current documentation > of clock frequencies in MAME? Would it make sense to have more people measure their > PCBs?
The circuit uses the EL4583 Sync separator IC form Elantec, I buy this on Ebay in DIL package (it's quite hard to find in DIL because now they are made only in SOP package) Then in order to make the readings of the Vsync on PIN5 of the EL4583 stable and precise, I added to the input of my frequency counter a simple low-pass filter with a 22KOhm resistor and a 0.1uF capacitor: