Keypunch was a significant data entry technology used primarily during the mid-20th century. It involved the process of punching holes into 80-column computer cards (often referred to as punched cards), using a specific coding system known as the Hollerith code, named after its inventor Herman Hollerith.
Historical Context
Invention and Early Use
The keypunch machine was invented by Herman Hollerith in the late 19th century. Initially, it was used for the 1890 U.S. Census to tabulate data more efficiently. The machine’s development was a milestone in the history of data processing, significantly speeding up the way information was collected and tabulated.
The Hollerith Code
The Hollerith code was a binary encoding system that represented numbers and letters as patterns of punches on a card. Each column on the punch card could hold a single character, and the position of the holes within the column represented different values.
The Mechanics of Keypunch
How It Works
- Card Formatting: Each 80-column punched card was divided into vertical columns and horizontal rows.
- Character Encoding: Operators would use the keypunch machine to manually punch holes corresponding to specific characters in the Hollerith code.
- Data Storage: The punched cards could then be read by tabulating machines or early computers, which interpreted the pattern of holes as data.
Types of Keypunch Machines
- Manual Keypunch: Early machines were manually operated, requiring significant human effort.
- Electric Keypunch: Later versions, like the IBM 029, were electrically powered, increasing efficiency and reducing operator fatigue.
Replacement by Modern Technology
By the late 20th century, advances in electronic technology and the advent of computer-based data entry systems made keypunch machines obsolete. Keyboards, CRT displays, and eventually, personal computers allowed for faster, more reliable, and versatile data entry methods.
Practical Applications
Use in Business and Government
Before electronic databases, businesses, and government agencies used keypunch machines for tasks ranging from payroll processing to census data collection.
Historical Legacy
Though no longer in use, keypunch machines were crucial to early computing developments and laid the groundwork for modern data processing technologies.
Related Terms
- Punched Card: A card with holes punched in predefined positions to represent data.
- Tabulating Machine: A device used for summarizing information stored on punched cards.
- Hollerith Code: The coding system used in keypunch machines for representing data.
Frequently Asked Questions
What replaced the keypunch machine?
The keypunch machine was replaced by electronic data entry devices, including keyboards and computer terminals.
How did the Hollerith code work?
The Hollerith code represented characters as patterns of holes punched in a column of a punched card, allowing machines to read and process the data.
Why were keypunch machines important in computing history?
Keypunch machines were instrumental in automating data processing tasks, significantly speeding up data entry and analysis, which was essential for early computer development.
References
- Beniger, James R. The Control Revolution: Technological and Economic Origins of the Information Society. Harvard University Press, 1986.
- Ceruzzi, Paul E. A History of Modern Computing. MIT Press, 1998.
Summary
Keypunch technology was a pivotal innovation in the history of data entry and computing. By allowing information to be encoded on punched cards and read by tabulating machines, it laid the foundation for modern data processing systems. Even though it has been superseded by more advanced technologies, its influence remains a significant milestone in the history of computing.
