The Master Control Signal was a special, coded override circuit hardwired into World Devastators to prevent them from being operated if they somehow were either captured by the enemy, or went haywire of their own accord. Broadcast from the Master Control Computer on the planet Byss, the Master Control Signal used new HoloNet frequencies and was broadcast continuously. The Master Control Signal was responsible for coordinating the functions of all World Devastators in a battlegroup. One of the most closely guarded Imperial secrets, the Master Control Signal was stolen by Luke Skywalker and implanted in R2-D2, allowing the droid to command the World Devastators to shut down and turn on each other during the Battle of Calamari.