Punched card

A punched card (also punch card or punched-card) is a stiff paper-based medium used to store <a href="/facts/Digital_information/JChckAvr">digital information</a> via the presence or absence of holes in predefined positions. Developed over the 18th to 20th centuries, punched cards were widely used for <a href="/facts/Data_processing/74EKCDAq">data processing</a>, the control of <a href="/facts/Automated_machine/SXtErQr2">automated machines</a>, and <a href="/facts/Computing/Kghtm9fX">computing</a>. Early applications included controlling weaving looms and recording census data.
Punched cards were widely used in the 20th century, where <a href="/facts/Unit_record_equipment/xkRvng9j">unit record machines</a>, organized into <a href="/facts/Data_processing_system/1xeBseED">data processing systems</a>, used punched cards for <a href="/facts/Input_(computer_science)/CulgMb3T">data input</a>, data output, and <a href="/facts/Data_storage/uCvJ6nrq">data storage</a>. The <a href="/facts/IBM/QszA7nwd">IBM</a> 12-row/80-column punched card format came to dominate the industry. Many early <a href="/facts/Digital_computer/SQe1aK05">digital computers</a> used punched cards as the primary medium for input of both <a href="/facts/Computer_program/e38jH9N9">computer programs</a> and <a href="/facts/Data_(computing)/cPjfFHph">data</a>. Punched cards were used for decades before being replaced by magnetic storage and terminals. Their influence persists in cultural references, standardized data layouts, and computing conventions such as 80-character line widths.
Data can be entered onto a punched card using a <a href="/facts/Keypunch/vbtX99wD">keypunch</a>.
While punched cards are now obsolete as a <a href="/facts/Storage_medium/uCvJ6nrq">storage medium</a>, as of 2012, some <a href="/facts/Voting_machine/TwwULQmb">voting machines</a> still used punched cards to record votes. Punched cards also had a significant cultural impact in the 20th century.

Punched card open-in-new

Punched card