Added bonus: It will still work as an Xbox data transfer cable after we are through!
Step 1: Parts List
1. A 12v Switching Power supply capable of 1A.
2. A power plug that fits said power supply
3. A piece of wire (about 3.5" long)
4. An Xbox data transfer cable
5. A full size SATA hard drive
6. A hot glue gun with a stick of glue ready
7. tin snips or pair of heavy duty scissors
8. A little time
9. (optional) patience
I have stressed the word switching as it is very important. A normal "wall wart" is an unregulated voltage source. It will put out the correct voltage ONLY when it has about 50% to 60% of the rated amperage being pulled from it. Output voltage will also fluctuate with the line voltage. For a hard drive this spells disaster. A hard drive needs a REGULATED and CONSTANT voltage.
It's always a good idea to make sure the plug fits the power supply! XO
Now we are going to solder a wire to pins 13, 14, and 15. Make sure the solder hasn't bridged any other pins. Also, make sure to select a wire that can handle 1A of current at 12V. 24 or 26 gauge should be sufficient. Leave enough wire to reach the plug and then add about a half inch.
Then, hold the plug down where you want it, and hot glue it all down!
You did it! You rescued something that would have normally been condemned to the dark reaches of your junk drawer to something that could be useful everyday!