U.S. flag
              An official website of the United States government Skip to main content   end of header History
 You are here: Census.gov ›
  History ›
  Innovations › Technology › FOSDIC Skip top of page navigation
 History Main
      Agency History
        Director Biographies
          Census Facilities
          Suitland, MD
          Notable Alumni
      Innovations
        Data Collection
          Technology
      Programs
        Agriculture
          Demographic
          Housing
          Economic
          Geography
          Governments
      Through the Decades
        Fast Facts
          Overview
          Index of Questions
          Questionnaires
          Census Instructions
      Genealogy
        Decennial Census Records
          Other Resources
      Reference
        Data@Museums
          Artifacts
          Lesson Plans
          Legislation
          Maps
          Oral Histories
          Privacy & Confidentiality
          Apportionment
          Publications
 Home Page Archive
        2024
          2023
          2022
          2021
          2020
          2019
          2018
          2017
          2016
          2015
          2014    
      FAQs
        Genealogy
          Agency History
          Demographic
          Economic
          Governments
          Agriculture
          Geography
          Innovations
          Miscellaneous
  Technology Also in this Section: Patents

    The Hollerith Machine

    UNIVAC I

    Tabulation and Processing

    Early Census Processing and the Seaton Device

    FOSDIC

    Population Clock

    Dual Independent Map Encoding
 FOSDIC FOSDIC
View larger image
A Census Bureau technician monitors the scanning of 1960 census
questionnaires by FOSDIC. Although the Census Bureau entered the computer age with the introduction of UNIVAC I in 1951, its data processing speed was hampered by the continued reliance upon punch cards.  Transferring questionnaire data to punch cards that UNIVAC "read" and stored on magnetic tape was a time consuming process that remained relatively unchanged since the late nineteenth century. To take advantage of UNIVAC's speed, National Bureau of Standards scientists and Census Bureau engineers began development of FOSDIC (Film Optical Sensing Device for Input to Computers).  Completed in 1954, the first generation of FOSDIC "read" the position of pencil-filled circles on questionnaires and translated the responses to computer code stored on magnetic computer tape. The Census Bureau first used FOSDIC to process a decennial census in 1960.  Enumerators transferred data collected on questionnaires to a "FOSDIC-readable schedule" on which questionnaire responses were recorded as penciled-in circles.  At the Census Bureau, technicians used extremely sensitive photography equipment to convert these forms into microfilm.  (In 1970 and later censuses, all questionnaires were FOSDIC readable, eliminating the need to have enumerators transfer data from questionnaires to FOSDIC schedules). These shaded circles appeared as light dots on the microfilm.  When the microfilm passed through the Census Bureau's new fleet of FOSDIC III machines (FOSDIC II had been designed for the Weather Bureau), they read the placement of the bright marks on the microfilm and translated them into computer code. The Census Bureau used updated versions of FOSDIC for the 1970, 1980, and 1990 censuses.  FOSDIC proved so successful that it was not replaced until the introduction of optical character recognition for Census 2000.
 
 CONNECT WITH US

Information Quality
                    Data Linkage Infrastructure
                    Data Protection and Privacy Policy
                    Accessibility      
                    FOIA
                    Inspector General
                    No FEAR Act
                    U.S. Department of Commerce
                    USA.gov
                   Measuring America's People, Places, and Economy