as i do belive from wookieepedia for a while HK-47's Artificial intelligence was in a computer on a hammerhead class cruiser which crashed on Mustafar. for it was left for thousands of years untill the Seps found HK-47's Chassis,and studdied it and came up with the HK-77
droid which was just about to be mass produced when Darth Vader came along and killed all the Seps there, resulting in the droids never being fully functional.
But still what does happen to revan in unknown space? do the true sith kill him?
does he get stranded on an uninhabited planet? does his space craft malfunction (not the Ebon Hawk of course) and ends up drifting through space?