The Whirlwind computer project

The authors describe how they led the development of the Whirlwind I (WWI) digital computer and its evolution into the SAGE (Semi-Automatic Ground Environment) air-defense system for North America. The project from 1945 through 1956, beginning at a time when no general-purpose, high-speed, electronic computer existed, was from the start dedicated to performance and reliability suitable for real-time control. After several shifts in objectives, Whirlwind became an experimental system for demonstrating that a digital computer could analyze the flow of radar data and generate control orders for fighter-plane interceptions of bombers. The resulting successor computers, the AN/FSQ-7, were installed in a network across the United States and Canada in the late 1950s. The SAGE System control centers were in operation about 25 years and demonstrated a 99.8% up-time reliability. In the Whirlwind Project, vacuum tube life was raised from 500 hours to 500000 hours, marginal checking allowed the automatic detection of aging and drifting of electronic components before they reached the point of failure, random-access magnetic-core storage was invented and developed to become the industry standard computer memory for more than two decades, synchronous parallel logic was used, computer-driven cathode-ray tube displays were used for the first time, light guns were used to permit an operator to identify displayed images to the computer for action, and multiple displays were time-shared between different operators