S—Punched Cards

Punched cards use holes following a specific pattern to represent the instructions given to the machine or stored data. The idea of storing data and program instructions on punched cards came from the Jacquard loom. It used pasteboard cards with patterns of punched holes to produce mass quantity of fabrics weaved in a variety of patterns. Each punched card represents a pattern and the punched card can be fed through the Jacquard loom to produce weaved fabrics of the pattern repeatedly. Similarly, different program instructions can be stored on separate punched cards, which can be fed through the computing machine repeatedly. Using punched cards, program instructions and data can be stored.

1834: Charles Babbage designed a new general-purpose calculating device, the Analytical Engine, which is the ancestor of modern computers. It included the essential components of present-day computers, which are input, process, storage, and output of data.

Babbage's assistant, Augusta Ada King, Countess of Lovelace and daughter of English poet Lord Byron, would create the instruction routines stored on punched cards to tell the machine what to do. Instruction routines used by the computer are known as "computer programs." She is thus the first female computer programmer, and in her honor, the U.S. Defense Department named the programming language ADA.

Below is an image of an analytical engine.

Figure 2 Analytical engine

1890: Herman Hollerith designed an electronic punched card tabulating device that enabled the U.S. Census Bureau to tabulate the 1890 census in six months, which would have otherwise taken more than 7 years. Hollerith’s machine used punched cards to store data instead of instruction routines.

1896: Hollerith thought the business world could benefit from the electronic punched card tabulating device, and founded Tabulating Machine Company, which later became International Business Machines (IBM) in 1924.

Дата добавления: 2015-11-14