[BlindHandyMan] i.e.c. connections

[Spiro]

Hi,
The only thing remaining for my current repairs is to find out which 
polarity goes to which part of an i.e.c. connector.
That's the kind that plug into the back of a computer, audio amplifier, or 
various power supplies.
It's a 6 sided plug, rectangular in nature with one side being bowed and 
made of angled corners.
Anyone know?
Thanks