//c power supply grounding?

[jmstuckman@weirdness.com (Jm)]

I don't have a //c power supply, and want to buy a wall transformer
and build a connecter for it(I found a transformer that will generate
1.5 amps, is this enough for a system with no external disk drive?) My
question is, does the chassis ground have to be connected for it to
work? The transformer has only 2 outputs, and I was going to connect
pins 2,3 to - and 5,6 to +. Should I connect 4 to +, -, or leave it
unconnected? It should be 15 volts, correct?