High Quality Content by WIKIPEDIA articles! The Number One Electronic Switching System, the first large-scale Stored Program Control (SPC) telephone exchange or Electronic Switching System in the Bell System, was introduced in Succasunna, New Jersey, in May 1965. The switching fabric was composed of reed matrixes controlled by wire spring relays which in turn were controlled by a central processing unit (CPU). The 1AESS Switch incorporating the 1A Processor of the late 1970s was a plug compatible upgrade, using smaller remreed switches, fewer relays, a faster CPU, and disk storage.