Computers and Computer Systems II

HISTORICAL BACKGROUND

EARLY HISTORY.

Precursors to computers include the abacus, the slide rule, and the punched-card tabulating machine. The concept of programmable computing is attributed to the British mathematician Charles Babbage (1792-1871) in the mid-19th century, who took the idea of using punched cards to store programs from the automatic loom devised by Joseph-Marie Jacquard (1752-1834). Babbage worked on developing a machine that could perform any kind of analytical computation, not merely arithmetic. Automatic data processing was introduced late in the 19th century by statistician Herman Hollerith (1860-1929), who created an electric tabulating machine that processed data by sorting punched cards. The Hollerith machine was used by the U.S. Census Bureau to process its 1890 census.

There is considerable debate over when the first electronic digital computer was invented. Many in the United States have been taught it was the ENIAC, but there are also British and German claimants to the title based on chronology alone, and some also dispute whether ENIAC even fit the definition of a computer. Part of the confusion over the early British computer, called Colossus, came about because the British government kept it a secret, for nearly 30 years, until 1971. The German invention apparently didn't receive much attention because it was created under the Nazi regime in the midst of World War II.

Nonetheless, there is general consensus that many of the major early advances took place in the 1940s. One was completed in 1946 by John W. Mauchly (1907-1980) and J. Presper Eckert, Jr. (1919-1995) at the University of Pennsylvania. Named the electronic numerical integrator and computer, or ENIAC, it was based on designs for an unfinished special-purpose computer made a few years earlier by Iowa State University physics professor John V. Atanasoff. The ENIAC, funded by the U.S. Army to compute artillery shell trajectories, could perform an unprecedented 5,000 additions or 300 multiplications per second. Electronic processing took place through the use of 18,000 vacuum tubes, and the device was programmed manually by plugging wires into three walls of plug-boards containing over 6,000 switches. The tendency for vacuum tubes to burn out, coupled with the difficulties of operating it, made the ENIAC rather unreliable and labor intensive to use.