In the mid 1600s, Blaise Pascal,(see picture below) a mathematician and philosopher, and his father, a tax official, were compiling tax reports for the French government in Paris. As they agonized over the columns of figures, Pascal decided to build a machine that would do the job much faster and more accurately. His machine, the Pascaline, could add and subtract (see picture below).
The Pascaline functioned by a series of eight rotating gears, much as an odometer keeps track of a car's mileage. But the market for the Pascaline never grew. Clerks and accountants would not use it. They were afraid it might replace them on their jobs and thought it could be rigged, like a scale or a roulette wheel.
About fifty years later, in 1694, the German mathematician Gottfried Wilhelm von Leibniz designed the Stepped Reckoner that could add, subtract, multiply, divide, and figure square roots. Although the machine did not become widely used, almost every mechanical calculator built during the next 150 years was based on its design.
The first signs of automation benefited France's weaving industry when Joseph-Marie Jacquard built a loom controlled by punched cards. Heavy paper cards linked in a series passed over a set of rods on the loom. The pattern of holes in the cards determined which rods were engaged, thereby adjusting the color and pattern of the product. Prior to Jacquard's invention, a loom operator adjusted the loom settings by hand before each glide of the shuttle, a tedious and time-consuming job.
Jacquard's loom emphasized three concepts important in computer theory. One was that information could be coded on punched cards. A second key concept was that cards could be linked to provide a series of instructions essentially a program allowing a machine to do its work without human intervention. Finally, the loom illustrated that programs could automate jobs.
The first person to use these concepts in a computing machine was Charles Babbage, a professor at Cambridge University in England. As a mathematician, Babbage needed an accurate method for computing and printing tables of the properties of numbers (squares, square roots, logarithms, and so on). A model of his first machine worked well, but the technology of the day was too primitive for manufacturing parts precise enough to build a full-sized version (see picture below).
Later, Babbage envisioned a new machine, the analytical engine, for performing any calculation according to instructions coded on cards. The idea for this steam powered machine was amazingly similar to the design of computers. It had four parts: a "mill" for calculating, a "store" for holding instructions and intermediate and final results, an "operator" or system for carrying out instructions, and a device for "reading" and "writing" data on punched cards. Although Babbage died before he could construct the machine, his son built a workable model based on Babbage's notes and drawings. Because of the ideas he introduced, Babbage is known as the "father of computers."
Punched cards played an important role in the next advance toward automatic machines. Dr. Herman Hollerith, a statistician, was commissioned by the U.S. Census Bureau to develop a faster method of tabulating census data. His machine read and compiled data from punched cards. These cards were the forerunners of the standard computer card. Thanks to Hollerith' s invention, the time needed to process the census data was reduced from seven and a half years in 1880 to two and a half years in 1890, despite an increase of thirteen million people in the intervening decade (see picture below).
Encouraged by his success, Hollerith formed the Tabulating Machine Company in 1896 to supply equipment to census takers in western Europe and Canada. In 1911, Hollerith sold his company, which later combined with twelve others to form the Computing-Tabulating-Recording Company (CTR).
In 1924, Thomas J. Watson, Sr. became president of CTR and changed the name to International Business Machines Corporation (IBM). The IBM machines made extensive use of punched cards. After Congress set up the social security system in 1935, Watson won for IBM the contract to provide machines needed for this massive accounting and payment distribution system. The U.S. Census Bureau also bought IBM equipment.
During the late 1920's and early 1930's, accounting machines evolved that could perform many record-keeping and accounting functions. Although they handled the U.S. business data-processing load well into the 1950's, they did little more than manipulate vast quantities of punched cards. These machines were limited in speed, size, and versatility.
World War II also had an impact on the development of computers. Cryptologists on the Allied side were determined to build a computer that would decipher the codes developed by the German machine, Enigma. The Allies smuggled Richard Lewinski, a Jewish factory worker, out of Poland because he had made parts for the Enigma. He designed a mockup of the German machine for the Allies. Two Englishmen, Dilwyn Knox and Alan Turing, used this model to build the Bletchley Park computer, which successfully deciphered the German codes.
A major advance toward modern computing came in 1944 when Howard Aiken' s team at Harvard University designed a machine called the Mark I. This machine, the first automatic calculator, consisted of seventy-eight accounting machines controlled by punched paper tapes. The U.S. Navy used the Mark I for designing weapons and calculating trajectories until the end of World War II.
Regardless of its role in computer history, the Mark I was outdated before it was finished. Only two years after work on it was begun, John Mauchly and J. Presper Eckert, Jr. introduced an electronic computer for large-scale, general use at the University of Pennsylvania Moore School of Engineering. This machine was called the ENIAC, short for Electronic Numerical Integrator and Calculator.
It represented the shift from mechanical/electromechanical devices that used wheels, gears, and relays for computing to devices that depended upon electronic parts such as vacuum tubes and circuitry for operations.
The ENIAC was a huge machine; its 18,000 vacuum tubes took up a space eight feet high and eighty feet long. It weighed thirty tons and gobbled 174,000 watts of power. It could multiply two ten-digit numbers in three-thousandths of a second, compared with the three seconds required by the Mark I. At the time, the ENIAC seemed so fast the scientists predicted that seven computers like it could handle all the calculations the world would ever need.
The first electronic computer built in the United States is often thought to be the ENIAC. However, a recent lawsuit on the patent of the concepts of the ENIAC brought to light the name of John V. Atanasoff. Atanasoff was a graduate student at the University of Wisconsin in the late 1920s when he became fascinated with the idea of an electronic digital computer. Later, while a professor of physics at Iowa State College, he and a graduate student began to build the Atanasoff-Berry Computer (ABC). However, the two men were unable to complete their work because of their involvement in World War II.
Many of Atanasoff's concepts are evident in early computers such as the ENIAC. These concepts include data being represented in digital form; switches that are electronic, not mechanical; memory separated from processing; and the use of rules of logic and binary numbers.
The ENIAC had two major problems, however. First, the failure rate of the vacuum tubes was very high. Research showed that it was often the new tubes that failed, so Richard Clippinger developed a method for curing the tubes. New tubes were burned for about six hours, after which weak tubes would be isolated and discarded.
A second problem with ENIAC was that operating instructions had to be fed into it manually by setting switches and connecting wires on control panels called plugboards. This was a tedious, time-consuming, and error-prone task. In the mid 1940's, the mathematician John von Neumann proposed a way to overcome this difficulty. The solution involved the stored-program concept, the idea of storing both instructions and data in the computer's memory. Although Eckert and Mauchly actually conceived the stored-program concept long before von Neumann, they had not outlined a plan for its use.
Von Neumann's principles spurred the development of the first stored-program computer in the United States, the EDVAC (Electronic Discrete Variable Automatic Computer). The EDVAC's stored instructions decreased the number of manual operations needed in computer processing. This development marked the beginning of the modern computer era and the information society. Subsequent refinements of the computer concept have focused on speed, size, and cost (See picture below).
Last Updated Jan 5/99