Who Invented the Computer? MIT Lincoln Laboratory and SAGE

Who Invented the Computer? This is the fifteenth installment in our ongoing series.

Ever wonder who the largest movie star of all time is? Kareem Abdul-Jabbar at 7 feet 2 inches? Not even close. Maybe Andre the Giant at 7 feet 4 inches? Nope! (Although I still contend that Andre deserves an Oscar for his role as Fezzik in The Princess Bride). Godzilla? Doesn't count; he's CGI.

The largest actor of all time is the continental air-defense computer network known as the Semi-Automatic Ground Environment, or SAGE for short. For one of its many movie roles, in the Cold War thriller WarGames, SAGE has a computer costar named WOPR. WOPR is a just a flashy prop, but SAGE — glimpsed briefly in an old black-and-white film reel — truly is a whopper.

At the end of World War II, the United States briefly enjoyed a period as the world's only true superpower. Uncle Sam had the bomb, which made America the de facto Big Kid on the global block, comfortable in our security and superiority. Things changed in August of 1949, however, when the U.S.S.R. exploded a bomb of its own.

Recognizing that the world had changed overnight, the U.S. Air Force undertook an audit of the nation's national air defenses. Realizing the current system was wholly inadequate to stop high-speed Soviet bombers, the generals called on the Massachusetts Institute of Technology (MIT) for help.

After weighing the pros and cons of the situation for 18 months, MIT's president, James Killian, felt it best that the school avoid direct involvement with the military's air defense program. He instead suggested formation of a separate entity to work directly with the military.

The Pentagon liked the idea and, in 1951, MIT established the MIT Lincoln Laboratory and tasked it with developing a computer network capable of continuously tracking the speed, course, and altitude of every aircraft in flight — including any small private planes that failed to file flight plans.

Lincoln Thinkin'

In 1954, the Lincoln crew unveiled SAGE, the most expensive computer system ever built. The price tag was three times that of the Manhattan Project during World War II: $10 billion in 1954, or approximately $90 billion in 2021 dollars.

The IBM corporation was awarded a contract to manufacture, install, and maintain the AN/FSQ7 ("Q7") computers that were the heart of the SAGE network. Fulfilling the contract helped IBM become a corporate giant and, in the process, made them a whole lot of money. During the four years of construction, 1954 through 1958, SAGE accounted for 80 percent of the company's revenue.

The Q7 remains the largest and heaviest computer ever built. Each machine contained 60,000 vacuum tubes, 1,750,000 diodes and 13,000 transistors, had 256 kibibytes of magnetic core RAM and tipped the scales at an astounding 250 tons. Like we said, each SAGE unit was a whopper.

The computers and accompanying peripherals were housed in 23 specially designed and hardened concrete bunkers, strategically placed throughout the U.S. (and in one location in Canada). Each bunker was four stories tall, windowless, and covered a full acre. As an added failsafe, a backup machine was also installed and kept running in each building.

The Q7 was capable of executing 75,000 instructions per second sending data to 150 video consoles, each equipped with a light gun that the operators would point at a cathode ray tube display to select targets. In a sign of the times, each console came with a built-in cigarette lighter and ash tray.

Spying the Unfriendly Skies

In operation, SAGE was efficient and, if needed, deadly. Long-range land-based radar installations, airborne early-warning military planes, dozens of navy picket ships, and commercial air controllers  continuously fed tracking information into the computer network.

If an unknown object appeared on radar, the system would quickly plot the object's approximate course, alert manned interceptor aircraft and missile batteries along that course, determine which interceptor missile was best equipped to shoot the object down, and calculate the exact point of interception.

SAGE was in operation from 1958 until 1984. While it was never called on to fully execute its defensive purpose, it did regularly assist in peaceful rescues of small aircraft that went down at sea.

The construction and operation of SAGE required 8,000 programmers and countless support personnel. Their successful efforts to connect the system's 23 bunkers with one another, as well as with hundreds of radar centers via telephone lines and microwave towers, resulted in the creation of one of the world's first wide-area networks.

Many of the individuals who worked on SAGE would later use their talents and experience to assist in the development of the packet-switching network ARPANET which in turn directly led to the creation of the Internet we know and love today.

Epilogue: Surprise Movie Career

SAGE was eventually decommissioned and replaced by less expensive, more powerful computers. As units were removed from service, individual components began appearing in movies and on television. According to Starring the Computer, the largest actor of all time has appeared on screen more than 80 different times.

SAGE components have been prominently featured in Hollywood blockbusters such as The Towering Inferno, WarGames (the only time SAGE played itself) and Independence Day. Various components also showed up in the Planet of the Apes TV series, and SAGE had a recurring role as the "Bat Computer" in the 1960s Batman TV series.