Archaic lightsabers—commonly referred to as protosabers—were the first known design of lightsaber. Like later lightsabers, their focusing crystal was set inside a hilt from which a blade of energy was emitted. The main difference between protosabers and later lightsabers was that the hilt was connected via cable to an external power pack due to limitations in power pack technology.
These lightsabers had limited operational time and the mobility of the user was restricted by the cable linking the hilt of the weapon to the power supply.
As technology improved, the protosaber design was abandoned in favor of the modern lightsaber design, with some archaic lightsabers modified to remove the necessity of an external power supply. Some later attempts were made to reintroduce the external power supply using modern technology, trading less mobility for a stronger power source.