Magnetic Drum Digital Differential Analyzer

The MADDIDA (MAgnetic Drum DIgital Differential Analyzer) was a special-purpose digital computer used for solving systems of ordinary differential equations. It was the first computer to represent bits using voltage levels and whose entire logic was specified in Boolean algebra. Invented by Floyd Steele, MADIDDA was developed at Northrop Aircraft Corporation between 1946-49 to be used as a guidance system for the Snark missile. No guidance system, however, resulted from the work on the MADDIDA, and rather it was used for aeronautical research In 1952, the MADDIDA became the world's top-selling commercial digital computer (albeit a special-purpose machine), six units having been sold. (The general-purpose UNIVAC I delivered its seventh unit in 1954.)

Development on the project began in March 1946 at Northrop Corporation with the goal of producing a subsonic cruise missile designated "MX-775," which came to be called the Snark. Northrop's parameters for this project were to create a guidance system that would allow a missile to hit a target at a distance of up to 5,000 miles with a precision that would be 200 yards better than the German "vengeance" weapons V1 and V2. Ultimately, however, the MADIDDA was never used in weaponry, and Northrop used a different analog computer as the guidance system for the Snark missile.

Part of the project parameters involved developing the "first" DIgital Data Analyzer (DIDA).

Physicist Floyd Steele, who had reportedly in 1946 already demonstrated a working DIDA before the press in 1946 in his Los Angeles home, was hired as conceptual leader of the design group. Steele developed the concept for the DIDA, which would entail implementing an analog computer using only digital elements. When the decision was made to use MAgnetic Drum memory (MAD) for the DIDA, the name was lengthened to MADDIDA (pronounced "Mad Ida").

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