making a bench top PSU with a old school PSU

[John Gutmann]

I remember the thread on makign a bench top PSU with a computer PSU, and how you have to ground the green pin. Well wanted to make a PSU for myself and all I have is a really old mitac PSU. It has 2 sets of wires that go to the mother board. on is as follows (black, black, white, red, red, red) and the other is (orange, red, yellow, blueish turquoiusish, black, black). Anybody know what wire to ground, I tryed all of them but none work.