Perforated card

In the early days of computer technology, the tools for the collection and analysis of information were limited to cardboard sheets with binary codes that were inserted into computers in the 60s and 70s. The punch card had its first use in the textile field. specifically in the machines of Joseph Marie Jacquard to make fabrics in the year 1801. But it was the British Charles Babbage , the first to use the punched card in the computer area to control a mechanical calculator designed by him. In 1890, the American Herman Hollerith used the punch card to collect and analyze the information from the United States census. and promoted the use of this tool until the 50s of the 20th century.

What is a punch card?

The punch card is a sheet of cardboard that can store information in binary code . This was the first tool that computer science used to enter information and instructions into computers in the 60s and 70s. The British scientist Charles Babbage was the one who first used this sheet in the field of computer science in order to control a calculator mechanics of his invention. However, the one who used this type of tool for data processing was the American Herman Hollerith.

  • Punched card features
  • Story
  • How the punch card works
  • What is the punch card for?
  • Storage capacity

Punched card features

The punch card Hollerith used had the following characteristics:

  • It was made of cardboard.
  • Its dimensions were 90mm. by 215 mm. What a US dollar measures.
  • It had round holes and 20 columns.
  • Its color was yellowish.


The history of the punch card dates back to 1725 with the French Basile Bouchon and Jean-Baptiste Falcon . They used perforated paper rolls to control their textile looms .

In 1802, Joseph Marie Jacquard improved the technique of punched paper rolls by replacing them with punched cards on his looms.

Years later, the British scientist Charles Babbage used the punch card to control the mechanical calculator he had invented. However, the one who makes the most use of it is the American Herman Hollerith , who adapted punch cards to carry out the United States census in 1890 .

Herman Hollerith as the founder of the IBM company was able to market many technological equipment to create, order and tabulate punch cards for many decades until the 1950s, when they became the main means of data entry and storage worldwide . IBM’s best-known punch card was the 5081 and it was so popular that other companies copied its format to sell it as a standard product.

In our days, the punch card is a reference of the first computers since these were supplanted by other electronic, optical and virtual storage formats.

How the punch card works

Punch cards work with binary code , that means that where there is a small hole it means Zero (0) for the machine and when there is no hole it means one (1) for the machine. This translates it into results issued by the computer . Each of the spaces where a hole can be made is known as bits ( acronym for Binary Digit) to later be known as chad or chip (for IBM).

What is the punch card for?

Punched cards were first used by J.Jacquard in 1902 to control the operation of looms mechanically. But Hollerith was the one who used them to work the information and for computing using electromechanical tools.

This first invention of Herman Hollerith evolved to the punch card, a system for computing data that was patented in 1889.

These cards were used by Hollerith in his tabulating machine – the second best-known invention of this inventor – to process data from the 1890 census in the United States, in which data from 60 million cards were processed in a period of three years. . The tabulating machine invented by Hollerith had the capacity to analyze 300 cards per minute.

Storage capacity

The storage capacity of the punch card varied according to the number of questions that had to be asked and the answer to which would be marked on the card.

For example, in the case of the cards designed by Hollerith for the United States census in 1890, they had 20 columns of questions that could be answered with yes or no, with yes being a perforation.

In 1928, the IBM company developed new punch cards with 52 and 80 columns to store and analyze more information.

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