Black wires in the center...

[h2ospa]

I have wondered about this since I got my first PC at home, a 386.

Why AT power supplies have two 6-pin plugs for the motherboard, rather than a single 12-pin plug? As far as I can tell, motherboards always have a 12-pin connector.

 

[vwestlife]

I do have an XT clone power supply with a single 12-pin connector, but it takes a lot of force to plug in. So maybe that's one of the reasons why they split it up.

 

[VERAULT]

I have seen the 12pin connector on cheaper machines myself. Im assuming they went with the 6 pin connector as it was a standard, cheap, and readily accessible part.

 

[Agent Orange]

The P8 and P9 6-pin connectors were designed in an effort to increase sales of motherboards, PSU's and other components back in the day.