The SAGE (Semi-Automatic Ground Environment) System, was designed and built in the 1950s to defend against the threat of Soviet bombers attacking the continental United States. The system was much influenced by the design of MIT's Whirlwind II computer system (which was never completed). IBM designed and built the AN/FSQ-7 computer, the heart of the SAGE program, with companies such as Western Electric (who produced In Your Defense), The Mitre Corporation and System Development Corporation were also major contractors on the project.
There were more than twenty SAGE installations located across North America linking hundreds of radar stations, Air Force fighter wings, and missle defense sites in the first large-scale computer communications network. The SAGE network was decentralized and would allow a unit to continue operation even if other sites were disabled. As the Soviet attack threat shifted from long-range bombers to nuclear missles in the 1960's, the SAGE system became less strategic. However, parts of the system continued operation into the early 1980's.
This film explains the national security threats of the 1950's and 60's that SAGE was built to defend against, shows the SAGE computer and network in operation and simulates how SAGE would react to an attack on the United States.