History Of Computers

Chris Miller

Ms. Rozanski

English III

May 20, 2005

History of the Computer

The ENIAC (Electronic Numerical Integrator and Computer) was the first large-scale, computer. The ENIAC was built for the military to calculate the paths of artillery shells. Later on it was used to make calculation for nuclear weapons research, weather predictions, and wind tunnel design. "The ENIAC was brought in to use inn February of 1946 and was used unit October 1955" (Encarta).

The creators of the ENIAC were American physicist John W. Mauchly and American Electrical engineer John Persper Eckert, Jr. at Moore School of Electrical Engineering at the University of Pennsylvania. Eckert and Mauchly demonstrated the ENIAC less than three years after the Army commissioned its construction. In 1947 the ENIAC moved from the University of Pennsylvania to its permanent home at the Aberdeen Proving ground in Maryland. "Only one system of its type was ever built, but operated continuously until October 1955" (Encarta).

The ENIAC was very different than modern day computers, which use microprocessors composed of thousands or millions of transistors; the ENIAC used vacuum tubes to process data. It had approximately 18,000 vacuum tubes, which were about the size of a small light bulb. The ENIAC was composed of 30 separate units with power supplies and cooling units; all together the whole unit weighed more than 30 tons, and took up 1800 sq. ft. and consumed 175Kw of power.

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The ENIAC could perform about 5000 calculations per second, more than 10,000 times slower that most modern day computers. The ENIAC took about 20 seconds to calculate problems that took humans two to three days to do manually. Initially, scientists programmed and entered data into ENIAC by manually setting switches and rewiring the machine. Later a more efficient IBM punch-card reading machine was used to input data, while another IBM punch card machine was used to store data. When the ENIAC completed a calculation, it would notify operators by turning on a sequence of lights or punching certain sequences of cards.

The ENIAC was designed to calculate continuously all day and all night. However its circuitry and vast number of vacuum tubes tended to burn out, the ENIAC was continuously down to be serviced, which caused the ENIAC to be down one third of the that is could be working. As soon as Eckert and Mauchly completed the ENIAC's design, the signed a contract to build a successor, which was called the EDVAC (Electronic Discrete Variable Automatic Computer), this more efficient design reduced the number of vacuum tubes down to only 4000.

The commercial available computer was the UNIVAC I it was also the first computer to handle both numerical and textural information. This computer was built by the same people who also invented the ENIAC and the EDVAC. "The UNIVAC I was delivered to the U.S. Bureau of Censes in 1951" (Encarta).

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