Franc Zabkar wrote:
On Sun, 25 Jan 2009 11:07:31 -0800, "William Sommerwerck"
put finger to keyboard and
composed:

I know I'm not directly answering your question, but...

The socket and power cords are polarized. It would be
extremely
difficulty to insert the plug the wrong way.

It would require a very heavy hand, but I *have* seen it done.

In any case, reversing a 4-pin Molex connector will not reverse
the polarity. It will just juxtapose the +5 and +12V lines.