As the post-World War II development of new radar systems changed the way air battles could be waged, MIT researchers continued to contribute to national defense with systems to use the amount of information that was now available. Radar sites around the country could provide enough data to track and intercept incoming airplanes, but the processing needed to happen in real time so that immediate response was possible. MIT’s Whirlwind computer was the only system that could handle such a request; the U.S. Air Force collaborated on early tests with radar over Cape Cod, and eventually expanded the project to MIT’s new research and development center at Lincoln Laboratory. SAGE was part of a continental warning defense system. Reports from remote radar stations came in over telephone lines, were processed by computer, and displayed flight-tracking information on CRT screens like the experimental prototype displayed here. By the time the SAGE system was fully operational it had been supplanted by ICBM technology. Nonetheless, the system is considered a major milestone. It got IBM into the computer business and made major contributions to that industry’s development.