// The /fun Collection · Cold War Air Defense //
SAGE_
Before Nike batteries could fire, somebody had to say which blip was a bomber. That somebody sat in a dark blue room in front of the largest computer ever built, holding a light gun. Tonight that somebody is you.
Warming 55,000 tubes… ▊
The machine behind the glass
SAGE, the Semi-Automatic Ground Environment, was America's answer to the Soviet bomber. Radar stations across the continent fed their pictures over phone lines into 23 direction centers. Inside each one, an IBM AN/FSQ-7 computer fused the feeds into a single live air picture. It is still the largest computer ever built: about 55,000 vacuum tubes, 275 tons, half an acre of floor, and up to three megawatts of power per site. Each center held two complete machines so one could stand hot standby while its twin ran the war.
Operators worked in a dim room lit blue to keep the consoles readable, and the name stuck: the blue room. They aimed a light gun at the screen to hook a track, and the computer answered with its course, speed, and identity. It was the first computer network, the first graphical real-time display, and the first light pen interface, a full generation before anyone said "personal computer." The consoles even had built-in cigarette lighters. The first operational center stood up at McGuire AFB in 1958, and the system stayed on watch, tubes and all, until 1984.
The intercept game above compresses a weapons director's shift into five minutes: real bases, real squadrons, real aircraft of 1961, and the real problem, which was never shooting. It was deciding who was who.
Sources
A /fun project. SAGE handed its targets to the Nike batteries. Fire them yourself in Nike Command, or study the missiles in the Nike Missile Explorer.