Originally, Cerebro was a device similar to a computer that was built into a desk in Xavier's office. This early version of Cerebro operated on punched cards, and did not require a user (telepathic or otherwise) to interface with it. A prototype version of Cerebro named Cyberno was used by Xavier to track down Cyclops in the "Origins of the X-Men" back-up story in "X-Men" Volume 1 #40. In the first published appearance of Cerebro, "X-Men" Volume 1 #7, Professor X left the X-Men on a secret mission (to find Lucifer) and left Cerebro to the new team leader, Cyclops, who used it to keep track of known evil mutants and to find new evil mutants. The device also warned the X-Men of the impending threat posed by the non-mutant Juggernaut prior to that character's first appearance. Later, the device was upgraded to the larger and more familiar telepathy-based technology with its interface helmet.