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Definition: SAGE


(1) A technical special interest group. See USENIX.

(2) (Scalable, Automated, Guided Execution) A white box test that generates test data for each unique control path in the program. Contrast with "fuzz testing," which is a black box technique that generates random input without any knowledge of the program's logic. See white box testing.

(3) (Semi-Automatic Ground Environment) The air defense system developed in the 1950s for the Cold War. SAGE combined computer systems and a sophisticated radar and communications system to track U.S. air space and send the data to 23 installations around the country. Each installation had its own computer and backup system. SAGE used CRTs, and a light pen was used to hone in on a suspicious blip on the screen.

SAGE never intercepted enemy aircraft because there were none, but the companies that built the machines, such as IBM, gained extraordinary experience that was brought to bear in later development. The SAGE computers evolved from the Whirlwind computer at MIT (see Whirlwind).




The Whirlwind I
The Whirlwind was developed at MIT and became the prototype for the SAGE air defense computers. The use of CRTs and light pens were developed for the Whirlwind and became critical parts of the user interface. You could touch a blip on screen to get more information. (Image courtesy of The MITRE Corporation Archives.)