Erik, (and everybody else) forget about this board.
This turns out to be a huge WTF moment.
So, I buy this board (guy says he sells non-profit, I believe that, price was low enough). The board was based on a design shown on this website:
http://martin-jones.com/2014/09/16/that-syncing-feeling-classic-arcade-games-that-wont-stay-still/Am I crazy or does this show the thing to work with Q*bert or not ? It shows before and after pics and scope signals.
And now I've build it up the first problem was already that the board was designed for composite sync.
Weird because Q*bert puts out separate H- and V-Sync. OK...so I either have to cut up a track (on a brand new board) or lift out 1 pin of 1 IC. Since the board is already fully populated, I can't cut the track anymore, so I decide to lift the pin and solder the wire directly to it. This looks amateurish and I hate that in my Q*bert which looks pretty damn perfect...but OK, as long as it works...
Now I connected everything, power the machine up, and the screen is total garbage. I post scope screen dumps and NOW they are saying that the circuit "relies on negative sync while Q*bert puts out positive......" and this requires extra inverter ICs and more modding of the board....
OK.....yes.....at those moments I go: WHAT THE FUCK !?!?!?
In the end I would have been better of building something on veroboard.
I know this is all non-profit and done for the hobby but.....something went seriously wrong here. I don't mind the invested money so much, but I put quite a bit of time in it and all turns out wasted......
http://www.ukvac.com/forum/topic340877_post911232.html#911232