Punched Card

computing history · data storage · machines

Holes mean data. Punched cards worked by having holes punched in specific positions on stiff paper. A computer or machine could read whether each spot had a hole or not, which let it understand information like numbers and instructions.

Controlled looms first. Before computers, punched cards were used to control weaving looms in factories. The pattern of holes told the loom exactly which threads to raise and lower to create complicated fabric designs.

Counted the census. In 1890, punched cards helped record and count millions of people in the United States census. This made the whole process much faster than doing it by hand.

Computer memory. Punched cards became the main way to store information and programs in early computers throughout the 1900s. Programmers would punch holes in cards to tell the computer what to do.

Stacked by thousands. A single computer job might need hundreds or thousands of punched cards stacked together. Dropping a box of cards meant having to sort them all back into the right order.