Predecessors: Packing a Punch
"Data processing" first became mechanized in 1890, when Herman Hollerith of the Massachusetts Institute of Technology (MIT) developed a punch-card tabulator for the U.S. Census Bureau. The MIT inventor's inspiration came from watching a train conductor strategically punch a ticket to describe a passenger's physical appearance. The tickets issued on the trains of the 19th Century were known as "punch photographs," and Hollerith's idea was to make a punch photo of sorts of each person counted in the census.
Hollerith's punch cards stored information by using punch locations and combinations to represent certain numbers and letters. Each card could store up to eighty variables, and these variables were read and processed by a tabulating and sorting machine. Inside this machine, spring-loaded pins waited to read the punch cards. When a pin descended through a punch, it completed an electrical circuit, and the electricity produced drove the computer.
Hollerith's machine enabled the Census Bureau to complete the 1890 census in just three years (it had taken nearly seven to process the data from the 1880 census), and at an estimated savings of $5 million. Punch cards technology went on to enable the establishment of the Social Security Administration in 1935; punch cards were enlisted to store wage data on every working American.
Punch cards also proved essential to the operation of the ENIAC: they were used in the initial phase of data input to enter problem data.