Punched card

A punched card (also punch card^[1] or punched-card^[2]) is a piece of card stock that stores digital data using punched holes. Punched cards were once common in data processing and the control of automated machines.

Punched cards were widely used in the 20th century, where unit record machines, organized into data processing systems, used punched cards for data input, output, and storage.^[3]^[4] The IBM 12-row/80-column punched card format came to dominate the industry. Many early digital computers used punched cards as the primary medium for input of both computer programs and data.

Data can be entered onto a punched card using a keypunch.

While punched cards are now obsolete as a storage medium, as of 2012, some voting machines still used punched cards to record votes.^[5] Punched cards also had a significant cultural impact in the 20th century.

Close-up of a Jacquard loom's chain, constructed using 8 × 26 hole punched cards

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