An former MIT affiliate from the Dibner Institute writes, "The Whirlwind computer, the first computer that operated in real time with innovations in core memory, was developed at MIT in the 1950s. It became the foundation for the SAGE system used by NORAD.
A large number of previously classified documents from the Whirlwind project have recently been opened to the public and are available from the Institute Archives.
An alumnus from the Cardinal and Gray Society remembers Whirlwind's "real-time computer, air defense real time application, interactive display with light gun".