what is the three pin connector on powersupply

I recently pulled a dead power supply out of a customers computer. Upon replacing it I realized that it didn't have the correct connector to connect the LCD display on the front of the case. Although I never saw it fired up I think the display was a combination clock, voltage meter, and thermometer. The customer was fine with that not being hooked up, but my curiosity is piqued.

I looked all over the web trying to find exactly what kind of connector it is, but to no avail. It is a three pin female connector but not like the ones for case fans. It almost looks like the 4 pin molex connectors that are on all the supply's. it is flat on the two long sides and one of the short sides. The other short side is rounded. It has a red wire on the rounded side, black wire in middle, and purple wire on the flat side.

Please settle my curiosity!!!!!!!