Summary

Before any computers existed, people were using logarithm and trigonometric tables do addition or subtraction and multiplication or division. People used the trigonometric tables to speed up calculating angles and areas in connection with surveying and astronomy. By the late eigteenth century, the Nautical Almanac was created to use in navigation. Two other machines that were invented after the Nautical Almanac were the differential and the analytical engines, but none of these machines were finished. Today you can go see them in museums. In 1873, typewriters were introduced and became very successful at the market. At this time, machines were being used a lot in business offices. Not long after that, the first adding machine was created. There were a lot of machines created before computers were introduced.

By the early 1942, the Moore School started to build a differential analyzer called "Annie," in the basement of Moore School. In this same building, there were a lot of women working too. In 1942, John Mauchly introduced an eletronic computer. With the help from Clifford Berry, a graduated student, they built the Atanasoff-Berry Computer (ABC). About a year later, another proposal was announced to make another machine that cost $150,000 which contained 5,000 tubes or 18,000 tubes for $400,000. The ENIAC (Electronic Numerical Integrator and Computer) was also began this day. It had about 18,000 vacuum tubes. In 1944, it was under construction. By November 1954, the machine was completed.

In 1959-60, software was introduced with IBM OS/360. The Operating System came with all the software that the programmer needed to develop applications programs and run them on the computer. The Operating systems came with some input/output subroutines that allowed user to organize files on magnetic tapes and disk drives.