IBM Computer History: SAGE, World's Largest Computer (AN/FSQ-7) (cold war RADAR defense) 1950's

Computer History, BM SAGE Computer: Three Computer History Films: (1) "On Guard" the IBM SAGE (1956) promo film by IBM, describing how SAGE computer works; (2) Texas Towers RADAR, (1955 news clip) about ocean-based RADAR systems for SAGE; (3) Arctic Sentinels RADAR (1956) arctic-based RADAR for SAGE. The core of the SAGE system was the IBM AN/FSQ-7 computer. Each SAGE base had two computers, one backing up the other. Many large contractors were involved in various aspects of the SAGE project, IBM, MIT, System Development Corporation (SDC), Westinghouse, and others. Built from 1952 to 1958, it ultimately had at least 25 separate SAGE locations in North America.
SAGE was designed to track bombers crossing into North American air space, however, it became somewhat obsolete when ICBM's came into play.