ABSTRACT

In the early nineteenth century, the English inventor and scientist Charles Babbage designed a mechanical computer, the difference engine, combining the elements of computation, logic, and programmability with mechanisms for number input and output. By 1833, Babbage recognized the computational limitations of the difference engine and began work on a more powerful mechanism for computation, the analytical engine, to solve more complex equations. A model electronic digital computer was built by John Atanasoff and his assistant, Clifford Berry, at Iowa State University between 1939 and 1942. On the hardware side, the computer changed with the replacement of vacuum tubes by transistors, the progressive miniaturization of integrated circuitry, and the development of enhanced electronic memory. In the 1950s, competing computer companies produced several types of vacuum-tube machines for scientific, military, and commercial applications. Institutional computers have reinforced hierarchical power arrangements by controlling the flow of information and limiting unauthorized access.