History of Computers


The earliest type of computing probably took place with ancient man collecting pebbles to represent the number of items he possessed. He may have kept them in a pouch or in a place easily accessible to him to which he could add or subtract stones. In other cultures, the stones were replaced by notches in a stick, knots tied in a cord, or marks on a clay tablet. Whatever the method, all devices were a way to represent numbers.

The computer may be referred to as a digital computer. The word digital comes from "digits" or fingers. Fingers were man's first computer. Until the nineteenth century most calculating was done mentally. To aid this process, Roman schools taught finger counting and actually devised methods of doing multiplication and division on their fingers. The Roman student was required to learn the multiplication tables 1 - 5. He would figure the products between 5 and 10 on his fingers.

One of the earliest computers was the sand table. It was made by marking three grooves in the sand with a maximum of 10 pebbles in each groove. Each time man wanted to increase the counter by one, he would add a pebble in the right hand groove. When ten pebbles were collected in the right groove they were removed and one pebble was added to the left groove. The word "calculate" is said to be derived from the Latin word "calcis", meaning limestone, because limestone was used in the first sand tables.

Soon, however, even this kind of computer was not enough to keep track of man's calculating, and so the abacus was developed. Abacus comes from the word "abaq"~ the Arab word for dust. The first abacus was simply a portable sand table; a board with dust strung across it. Eventually the board was replaced by a frame, the grooves by wire, and the pebbles by beads. More than three grooves or wires were attached to the abacus allowing man to count to higher numbers. Different versions of the abacus appeared in many countries and are still being used in many places. People using the abacus for calculations can become extremely skilled in rapid computation. In some tests, an expert using an abacus has proven to be faster than a person using a mechanical calculator. The abacus remained the only computing device for over 4,000 years. Tables of numbers were developed by the Greek and Roman cultures as well as the Mesopotamian and the Egyptians. However, the abacus still remained as the only calculating device.

Arab, Hindu, and European mathematicians were the first to develop techniques of written calculation. Those techniques were in the form of tables. They did the same type of calculation the Romans did, only in written form. Probably the most famous approach was used in 1614 by John Napier, a Scottish mathematician who developed Napier's Bones or rods. They are referred to as "bones" because the first set was made from ivory and resembled a set of bones. Later they were made from wood. The "bones were an attempt to reduce the tedious calculations involving large numbers.

Napier is probably more well known for the invention of logarithms, which is a way to turn the problem of multiplication and division into simple operations of addition and subtraction. The invention of logarithms led directly to the development of the slide rule in 1630. The principle behind this device is that of two scales moving against each other. In this way multiplication is rapidly accomplished. The slide rule is still an important calculating device in many professions today.

The next milestone in data processing came in 1642 when Blaise Pascal, at the age of 19, designed and built a small and simple machine. Working in his father's tax accounting office, he decided there must be some way of relieving the drudgery of adding long columns of numbers. He devised a mechanized calculating device operated by a series of dials attached to wheels that had the numbers zero to nine on their circumferences. When a wheel had made a complete turn, it advanced the wheel to the left of it. Indicators above the dial showed the correct answer.

Gootfried Wilhelm Leibniz then invented a device now known as the Leibniz Wheel in 1671. The mechanism enabled him to make a machine which not only did addition and subtraction, but also multiplication and division. Operating through a complex series of wheels and cylinders linked to a crank carriage, it was more sophisticated than Pascal's machine. However, like many other machines of this period, it lacked the mechanical precision in its construction and was very unreliable and awkward to use. Both Pascal and Leibniz were ahead of the technology of their time, but neither machine was dependable. Only in the past 25 years have we succeeded in building machines that will calculate accurately, thus solving a dilemma that was identified in 1670.

One of the inventions of the Industrial Revolution which has a direct relationship to computers was developed in 1801. A Frenchman named Joseph Jacquard perfected the first punch card machine - a loom to weave intricate designs into cloth. It could weave flower designs or pictures of men and women as easily as other looms could weave plain cloth. A famous portrait of Jacquard himself was produced using 24,000 punched cards. When Jacquard first introduced his machine, he had difficulty gaining public acceptance because of the "fear of machines". In the city of Lyons, he was physically attacked and his machine was destroyed. Through Napoleon's support and the Paris World's Fair he sold a considerable number of his invention. What Jacquard did with his punched cards was, in essence, to provide an effective means of communicating with machines. The language was limited to two words: hole and no hole. The binary system is now universal in all modern day machines.

Charles Babbage is called the "Father of Computers". Babbage was an eccentric genius who inherited a sizable fortune which he used to finance his wide range of interests. Babbage's contributions range from developing techniques for distributing the mail to investigating volcanic phenomena to breaking supposedly unbreakable codes. If Babbage had never thought about computers, he may have died a more happy man. But he, like the inventors before him, tried to free man from the slavery of computation with the invention of his difference engine.

The speed of the engine is illustrated by the fact that if a mathematician was to write quickly, it was possible to keep up with the engine. But, when four figures were required, the machine may beat the writer. The machine had the advantage of being able to maintain its rate of computation for any length of time. Babbage applied to the British government for funds to build the machine.

Upon receiving a government subsidy in 1823, he began work on his engine. By 1842 the English government had advanced him nearly $42,000. To most people who had just become accustomed to the power loom created by Jacquard, it was inconceivable that a machine could take over the work of the brain. Besides the government grant, Babbage spent $42,000 of his own money on the machine. As it turned out, the machine was never built because he kept changing the design. A Swedish gentleman finally built the machine in 1854 and displayed it in London.

The system eventually included the cards, a card punch, a pin press, electromagnetic counters, and a sorting box. After the cards were punched they were placed in the pin press and a hinged box was lowered manually to activate the counter and open the lid of a sorting slot. Cards were read at a speed of 50 - 90 per minute. Test tabulation showed the enumeration time was 3/4 and the tabulation time was 1/8 of that required by earlier systems.

Despite the increased population to 63 million in 1890, the census was tabulated in 2 1/2 years, a job that might have taken 9 - 10 years manually. In 1896, Dr. Hollerith organized the Tabulating Machine Company to promote the commercial use of his machine. Later, he developed a more accurate card handling device, but was unable to reach an agreement with the Census Bureau to do the 1910 census.

Dr. Hollerith later merged his company with two others and it became International Business Machines (IBM). James Powers developed the punch card system used in the 1910 census. His machine increased both the speed and accuracy of punching. After the census, Powers also became convinced that there was a commercial market for his machines. In 1911 he formed Powers' Tabulating Machine Company and was the principle competitor of Hollerith. Through a series of mergers, his company become part of the Sperry Rand Corporation and the Sperry UNIVAC division. During the next 20 years no significant developments were recorded. World War II hastened the process because of the need for fast computation.

In 1937, Professor Howard Aiken of Harvard became interested in building an automatic calculating device. The Mark I, with the help of IBM engineers, was completed in 1944. The Mark I was 51 feet long, 8 feet high, contained 760,000 parts using 500 miles of wire, and weighed 5 tons. Aiken's machine was built on the concept of using information from punched cards as input and making decisions through electromechanical devices (addition and subtraction took .3 of a second, multiplication less than 6 seconds and division less than 16 seconds), and produced results on punched cards. Mark I is considered to be the first general purpose digital computer with all operations being carried out by a system of switches and relays. The machine was used extensively by the U.S. Navy during the Second World War.

The first electronic digital computer was a secret wartime project developed at the University of Pennsylvania. It was originally designed to help the government with the calculation needed with the projectory of shells. The computer was finished in 1946 by Dr. John Mauchly and J. Presper Eckert and called ENIAC (Electronic Numerical Integrator and Calculator). Its construction included 18,800 vacuum tubes. Two and one half years were needed just to solder the 500,000 connections the tubes required. The ENIAC weighed 30 tons and took up 1500 sq. ft. of floor space and required 1300 watts of power. ENIAC could perform 500 additions and 300 multiplication in one second, and in one day performed what would take 300 days to do by hand. Input and output was through punched cards. ENIAC, however, could only store 20 ten digit numbers.

An interesting note is that in 1846, William Shanks had spent twenty years of his life computing to 707 decimal places. ENIAC computed to 2,000 in 70 hours and showed that Shanks made an error in the 528th decimal place. In 1945, Dr. John von Neumann recommended that the binary system be used for storage in computers. He also proposed that instructions to control the computer, as well as data, be stored within the computer.

The EDSAC (Electronic Delay Storage Automatic Calculator) was built at Cambridge University in 1949 and incorporated the above ideas. It was smaller in size, but greater in power than its predecessors. It occupied 140 sq. ft. and contained 5900 vacuum tubes. It could perform addition in 864 microseconds and multiplication in 2.9 milliseconds. The major difference in the EDSAC was its capability to store instructions and data. Previously, the control of the computer had been by removable plug.

Babbage got an idea for his second machine, the analytical engine, from watching a loom attachment invented by Jacquard. The analytical engine was designed to read two sets of material, store them, and do mathematical operations on them. The first set of material would be the operation or program, which was to be carried out on the second set of material, the variable or data . However, Babbage never completed the analytical engine nor had he progressed far enough for someone else to complete it.

Lady Ada Lovelace, daughter of Lord Byron, became involved in the development of the analytical engine. Lady Lovelace not only helped Babbage with financial aid, but, being a good mathematician, wrote articles and programs for the proposed machine. Many have called her the first woman programmer. It seems that computers were already being used for playing games. While Babbage was working on an automated tic-tac-toe game, Lady Lovelace proposed that it might be used to compose music.

Some 20 years later, Babbage authored a paper titled, "Some Questions Concerning the Game of Chance". As an extension, he and Lady Lovelace embarked on a plan to devise an infallible betting system at the horse races. At first they won, but as time passed they were less successful. Babbage lost most of the money he had left and Lady Lovelace lost such large sums that twice, in order to pay her debts, she had to pawn her jewels. Her mother, without the knowledge of Lord Byron, redeemed them for her.

Although Lady Lovelace thought the analytical engine would someday produce music, Babbage was not too fond of music, especially the sound of organ grinders. Besides thinking about machines, he spent much time in his fight against organ grinders. They were known to have serenaded below his window after midnight, and Babbage's epitaph on his grave resounds his dislike for them. The analytical engine was in some ways more complicated than today's computers. It worked by means of a system of gears and cogs; the electric engine having not been invented yet.

The machine worked with the decimal system rather than the binary system that today's machines use. Even though Babbage never did complete his engine, the ideas he presented are said to have been the beginning of the computer revolution that freed white collar workers from mechanical intellectual labor, just as other machines freed blue collar workers from hard physical labor.

The taking of the U.S. census in 1890 provided a key opportunity for the next major step in the history of the digital computer. The 1860 census covering a population of over 50 million took seven years to tabulate. John Billings made a comment to Herman Hollerith, a nineteen year old engineer, that he felt that there ought to be some mechanical way of doing this job. Perhaps a way of using the principle of the Jacquard loom, where holes in the card regulate the pattern of weave. Hollerith went to work on this idea.

The first machine he devised used paper strips with holes punched on them according to a code, similar to a player piano. The paper strip was found to be impractical, so in 1887 a punched card was devised. Hollerith worked out a system that a person's name, age, sex, and other relevant information could be coded by punching holes in a card. The size of the card (now called a Hollerith or IBM card) is the size of the 1887 dollar bill. When Hollerith was designing the card, not knowing what size to make it, he pulled out a one dollar bill and traced it. The card was divided into 240 separate areas (20 rows of 12 punches).