Urm... No need to split it I think.
Not sure what you would do with it though. it might work just feeding that combined sync to 1 of the inputs on my board or it might need inverting first (don't know what sort of sync that machine has). Or you could just add a resistor to that pin and not put the sync through my chip at all.
I think the first thing to do would be to try just feeding that to one pin, I would be interested in hearing how it all goes! I am quite surprised by the number of people here wanting this for a PC instead of a 128.
You got the VDC to push out 31kHz? Well done!Ok. Apologies to everybody waiting
More than 2 months and the PCBs are definitely lost in the post. I am getting them remade now, but will be at least a few more weeks before they are ready.
While you wait, have a look at this game running directly to a VGA monitor with NO scandoubler on my 128.
https://s5.postimg.org/zbd99r94n/IMG_0090.jpg
Bet you didn't know the 128 could output VGA native eh.