Definition

Noun: A punched card is a piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions. Historically, it was a primary medium for data input, storage, and processing in early computing and data processing systems.

Usage

Punched cards are used to store and input data or instructions into a machine. They are read by a device that detects the pattern of holes.

Examples: * Early computers used punched cards for programming. * Each punched card in the stack represented a single line of code. * The data from the survey was transferred onto punched cards for analysis.

Advanced Usage

• Deck of punched cards: A complete sequence or set of punched cards constituting a program or dataset.
  • The programmer carefully arranged the deck of punched cards before loading it into the reader.
• Punched card reader: The machine used to interpret the holes on the card.
  • The punched card reader converted the hole patterns into electrical signals.

Variants and Related Words

• Punch card: A common alternative name for "punched card".
• Hollerith card: A specific type of punched card named after Herman Hollerith, who used them for tabulating the 1890 U.S. census.
• IBM card: A common reference due to IBM's widespread manufacturing and use of standardized punched cards.

Synonyms

• Data card
• Tab card (specifically in the context of tabulating machines)

Related Terms and Context

• Batch processing: A method of execution where programs (often on punched cards) were collected and run sequentially.
• Legacy system: Modern term that may refer to systems or data originally designed for punched card input.
• Keypunch: The machine used to create holes in the cards, operated by a person called a keypunch operator.

Noun

1. a card on which data can be recorded in the form of punched holes