Artifact Details


Vigilance and Vacuum Tubes: The SAGE System, 1956-1963

Catalog Number



Moving image




Edwards, Paul


Computer History Museum




In 1963, the last of 22 SAGE command centers was completed by contractors IBM, Western Electric, The RAND Corporation, and Burroughs. At a cost of $8 billion (1964 dollars), this vastly complex technological system, an outgrowth of MIT Lincoln Labs' Whirlwind II computer, represented the state of the art in strategic doctrine and computer systems design. Each one of the 22 SAGE command centers used over 49,000 vacuum tubes, weighed 250 tons, and consumed 3,000,000 watts of power.

The SAGE system linked these command centers into a technopolitical "shield" against Soviet strategic bomber attack. From a stark social context of high Cold War tensions emerged impressive technical advances in hardware and software systems design, real-time control, and air traffic monitoring.

Advances such as the light gun, modems, duplex CPUs, multiprocessing, A/D and D/A conversion techniques, as well as networking arose as ancillary technologies of SAGE development. But did SAGE really work as advertised? Should we care? This lecture reflects on these questions, SAGE's context, and its technical spinoffs.

The lecture takes place in front of 400 square feet of actual SAGE hardware, including Weapons Director and Intercept Technician consoles! This equipment is from the last functioning SAGE center in North Bay, Ontario(Canada), decommissioned in 1982. The USAF SAGE Film "In Your Defense" will also be shown. "I like Ike" buttons optional.