What kind of monitor do you have? If it's a Commodore monitor (1702/1802/1080/1084), you can modify your S-video cable to work with 'em and get a kick ass picture that way. Best and easiest way to do it.
Doing it the way you're thinking, you'll end up with a crummy picture and experience some lag. Really not feasible, logical, economical or desirable. :lol: