Keypunch is a device used to enter data into punched cards by precisely punching holes at locations designated by the keys struck by the operator. Originating from the late 19th to mid-20th century, it was the primary means of manually inputting data into computers. The punched cards were then read by computer machines as a form of digital data.


The phonetics of the word “Keypunch” are: /ˈkiːpʌntʃ/.

Key Takeaways


Three Main Takeaways about Keypunch

  1. Keypunch is a device used to precisely punch holes into stiff card stock for data storage. This was primarily used in older computing systems before the advent of more compact data storage mediums.
  2. The use of keypunch machines revolutionized computing by providing a reliable, physical method of storing data. This paved the way for the development of more sophisticated data processing and storage technologies.
  3. Despite being effectively obsolete in modern computing, the principles underpinning the use of keypunch machines continue to be relevant. Understanding its operations can provide insight into the early development of data storage technology.



The technology term “keypunch” is important because it directly relates to the history and evolution of data entry and data processing. A keypunch is a device used to manually enter data into punch cards, which were then input into computers. This technology was significantly used in the early to mid-20th century, before the advent of personal computers and digitized data entry systems.

Keypunch machines were the primary method of interacting with computers, and the punched cards were used to run programs and hold information. Though they are now obsolete, they played a vital role in the inception phase of modern computing and served as the precursor to contemporary keyboards and input devices. Their significance therefore, lies in their pivotal role in the origin and development of computer programming and data processing.


Keypunch refers to a device which was used to input data into earlier types of computing and data processing systems. The keypunch served a crucial purpose in the era before digital interfaces, as it enabled the user to deliver instructions to a machine or computer in a language they could understand. This device was primarily used to punch a code, known as a punched card, which was used by early digital computers for input and store data. This coded data was crucial for various applications including but not limited to, data processing, computer programming, and telecommunications.

A keypunch functioned by encoding data into cards through holes punched at specific positions, much like an elaborate stencil. The operator would utilize a keyboard to enter the desired information, which the device would then convert into a series of coded holes.

These punched cards would then be fed into a computing system capable of reading the processed information. The keypunch played a critical role in computing history by bridging the gap between human users and machines, making it a significant milestone in our journey towards the advanced digital interfaces we enjoy today.


1. Voter Ballots: In some election systems, voters can use a punch card system to cast their votes. Each candidate or voting option is associated with a hole on the card. Voters then use a device known as a keypunch to punch the hole that corresponds with their chosen candidate.

2. Venetian Blinds Manufacturing: In the manufacturing of Venetian blinds, keypunch machines are used to punch holes in the blinds, through which the control cords are threaded. This application is somewhat less common now, as most manufacturers have switched to automatic machines, but keypunch is still used in some contexts.

3. Data Processing in the 1960s-70s: Keypunch machines were extensively used for data entry into computers before the age of personal computers. The user would punch holes into cards using the keypunch machine, with each hole representing a different piece of data. By encoding data in this way, large amounts of information could be inputted into computers long before the advent of keyboards or other input devices. IBM card punch machines were a popular example of this application.

Frequently Asked Questions(FAQ)

Q1: What is a keypunch?

A: A keypunch is a device for precisely punching holes into stiff paper cards at specific locations, representative of data, used as a method of data input for early computers.

Q2: When was the keypunch device first used?

A: Keypunch devices were first used at the beginning of the 20th century, especially for data processing, computation, and telecommunications.

Q3: Are keypunch devices still in use today?

A: No, keypunch devices have been largely obsolete since the mid-1980s due to the rise of new computing systems and data storage technologies.

Q4: What is a punched card?

A: A punched card, also known as a punch card or punched-card, is a piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions.

Q5: What was the primary function of a keypunch device?

A: The primary function of a keypunch device was to manually input data into a computer system by punching holes into punchcards, which the computer could then read as data.

Q6: What replaced the use of keypunch devices?

A: The use of keypunch devices was replaced by magnetic tape and disk storage systems, along with data input methods like keyboards and scanners.

Q7: How accurate were keypunch devices?

A: While the precision of keypunch devices depended on the operator’s accuracy, they were generally considered reliable for their time. Errors were common, but various tools and techniques were implemented to minimize them.

Q8: Who typically operated keypunch machines?

A: Keypunch machines were typically operated by keypunch operators, a common job position especially among women in the early and mid-20th century.

Q9: Were keypunch cards reusable?

A: No, once a hole was punched into a card, it could not be undone, making the cards generally non-reusable for changing data. However, they could be reformatted and reused if the entire set of data was to be changed.

Q10: What was the keypunch machine’s impact on the computing world?

A: Despite being an outdated technology, keypunch machines played a significant role in the early development and evolution of computing systems. They laid the groundwork for the principles of data input and storage.

Related Tech Terms

  • Card Puncher
  • Data Processing
  • Punched Card
  • Hollerith code
  • IBM Keypunch Machines

Sources for More Information


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