Slave was a unique system installed by Dorian, possibly making use of work by Ensor. It could communicate verbally with the crew and handle routine flight procedures at a level of sophistication unmatched by any human-built computer with the exception of Orac. Due to Dorian's rather strange sense of humour, Slave was programmed with an exaggeratedly obsequeious and subservient personality, habitually addressing the crew as Master or Mistress.
Slave was quite capable of directing the Scorpio from planet to planet without human assistance, and it was in fact impossible to land the ship in its hangar on Xenon with the computer off-line. Emergency operations were also beyond Slave's abilities to handle.
Atmospheric disturbances over the planet Virn interfered with Slave's systems to the point where the computer had to be temporarily shut down.
Slave was initially programmed only to respond to Dorian's voice print, but Orac was later able to remove this so the computer responded to anyone who addressed it. The crew made general use of Slave's abilities throughout their time aboard the ship.