X-Nico

unusual facts about telephone switch



Twistor memory

In the United States the Bell System (American Telephone & Telegraph) also used twistors with permanent magnets as the "Program Store" or main memory in their first electronic telephone switching system, the 1ESS as well as others in the ESS series of electronic telephone switches, and did so up to the 4ESS switch introduced in 1976 and sold into the 1980s.


see also

EAX

GTD-5 EAX, class 5 digital telephone switch typically used in former GTE service areas