Film Optical Sensing Devise for Input to Computers
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Film Optical Sensing Devise for Input to Computers

The U.S. Census Bureau first used Film Optical Sensing Devise for Input to Computers (FOSDIC) to process the 1960 decennial census. Enumerators transferred data collected on questionnaires to a "FOSDIC-readable schedule" on which questionnaire responses were recorded by shading circles by pencil. At the Census Bureau, photographic equipment converted these forms to microfilm. (In 1970 and later censuses, all questionnaires were FOSDIC readable, illiminating the need to have enumerators tranfer data from questionnaires to FOSDIC schedules).

The shaded circles appeared as light dots on the microfilm. When the microfilm passed through the Census Bureau's FOSDIC machines, the placement of the dots was "read" and translated into computer code.

The Census Bureau used updated versions of FOSDIC for the 1970, 1980, and 1990 censuses. FOSDIC proved so succesful that it was not replaced until the introduction of optical character recognition for Census 2000.