This Datacron unlocks the codex entry - Galactic History 76: Revan is Remade
This datacron holds unheard of power and knowledge collected by an ancient race. You access its power and discover writings which are clearly only one small piece of a massive galactic history:
Throughout Jedi history, the order has always refused to execute prisoners. When the wounded Darth Revan--the fallen Jedi responsible for countless deaths and acts of war--was captured, the Jedi Council saw an opportunity to stop Revan's successor, Darth Malak.
Using the Force, the Jedi reprogrammed Revan's mind with a new identity--that of an ordinary Republic citizen. Alongside Bastila Shan, a Jedi gifted in Battle Meditation, Revan began seeking out Rakata star maps, unwittingly retracing the path to the Star Forge battle station that served as Darth Malak's secret weapon.
Along the way, Revan retrained as a Jedi and learned of his terrible past. Aboard the Star Forge, he saved the life of Bastila Shan and faced Darth Malak in battle. Finally, Revan struck Malak down, ending a galactic threat and the Jedi Civil War.
This Datacron is located in southern Voss in The Gormak Lands. If you take the southern most flightpath you'll probably end up here but it's best to check your map first before flying. Once you arrive at The Gormak Lands you will want to go all the way down to the southeast corner of the map at (Screenshots 1 & 2). Once you're here you will want to travel through the small gap in the wall into the circular area down here. Behind the really large rock directly in front of you when you enter is the Datacron.