I don't remember it being anything special. Mine is at my desk at work (not that it's being used alot right now) and I'll check on Monday if you don't get an answer before then.
It is nothing special...a simple 9V DC power supply....you can get them with the proper tip at any Radio Shack. The Walmart universal power supply will power the netbook, but doesn't supply enough amperage to charge it very well. You should have a adapter that supplies at least 1 amp or better. The original supplies 2 amps of current.