To understand the development of the computer industry during the latter half of the twentieth century, one must look to the demand for computing power before and during World War II, when computing was a means to a very specific and urgent end. Between 1935 and 1945 there was a great need for ballistics computations and other statistical work in support of military efforts; this was time-consuming work carried out by people using rudimentary calculators. During this time, there was a rush to invent single purpose digital computing machines to speed up the calculation of the ballistics problems, firing tables, and code-breaking calculations. Several such machines were created by governmental organizations, industrial companies, and office machine companies in the United States, Great Britain, and Germany.

Differential Analyzer

Although there were a number of calculators available for business use in the 1920s, they were not powerful enough...