would it be possible to connect RGB and Video sync from a Jamma harness to the correct pins in a PSX video cable and it show up on my TV? Any help would be greatly appreciated.
Unless you're using magical cables from fairy land, no. The PSX outputs composite video already, the RGB conversion takes place inside the system.
any suggestions on what I can use then?
You could get an RGB TV or RGB monitor. Look at the pawn shop for commodore or applecolor monitors. If you want RGB bad, thats the best your gonna get without shelling out the bucks for say, an XRGB to connect it to your VGA monitor.
This assumes your living in the United States, if you live in some place not here your tv probably may take RGB. So, if that cable your talking about is a PSX rgb cable, then yes your original idea wil work.
Sorry for the broken English for I am american and we dont talk good here.
You need an encoder for RGB=>other.
Some good ones I've used:
JROK (outputs S-Video/composite): $75
www.jrok.com
NeoBitz (outputs component/S-Video/composite): $115
www.neobitz.com
R2N (outputs S-Video/composite): $64
www.crazearcade.com
Basically slick you need a supergun to do what you're talking about. Ones like the those I list here:
http://www.multimods.com/supergunsales.html (http://www.multimods.com/supergunsales.html)