I hook up my ps2 to my tv wonder pro through this
thingy
It came with my tv tuner card
but for you if you have got something like that give it a try or maby something like this
NINTENDO RF SWITCH F/GAMECUBE
one thing I noticed it the picture quality isn't the greatest and my old vid card wouldn't work with it and I had to upgrade. the picture quality is ok now(nothing special) and it works with my new redeon 9800 pro.