OK, I've looked at this site, which is the only one I can find of any help
http://www.gamesx.com/rgbadd/genesis3.htm
But none of that makes a damn bit of sense to me, I don't read electrical diagrams and couldn't tell you what any of those squiggles mean any more than I can read russian.
Does anyone have PICTURES of whta I need to do and where? Or a clearer explanation in dumbed down english?