connecting two psx Guncon 1's

[VidPower]

I'm interested in purchasing two of the original Guncon 1's from ebay for some two player fun. The particular auction I was looking at showed both of the guns, with each gun having it's own yellow prong. I was wondering if you need to buy a separate cable or anything else in order to connect up two guncon 1's to the original playstation.

[Photomotoz]

When I bought Time Crisis 3 with two guns the yellow connector had a double ended prong. I do not think it would be difficult to find one. I do not belive there is any other way to use two.