HISTORY OF THE COMPUTER

Part I (Prehistory)

The ideas and inventions of many mathematicians, scientists and engineers paved the way for the development of the modern computer. The computer actually has three birth dates – one as a mechanical computing device (about 500 BC), another as a conception (1833) and the third as the modern electronic digital computer (1946).

The first mechanical calculator was the abacus. (See Figure 1) It was devised in Babylonia in about 500 BC. The abacus was the fastest calculating device for many centuries. It is still being used in some parts of the world because it can be understood without knowing how to read. Now, as then, it consists of a rectangular frame with thin parallel rods strung with beads¹. Abacus beads can be used to perform such simple arithmetical operations as addition, subtraction, multiplication, and division. Figure 1. The Abacus

The abacus remained the only means of calculation up to the 17^th century. After the invention of logarithms, W. Oughtred constructed the first slide-rule in 1630. The slide rule represented a quick and easy way of multiplication, division and raising to power².

During the 17^th and 18^th centuries, calculators more sophisticated than the abacus and the slide rule began to appear. Although a number of people contributed to their development, Blaise Pascal (the French mathematician and philosopher) and Gottfried Leibniz (the German mathematician, philosopher and diplomat) usually are singled out³ as pioneers.

B. Pascal designed the first adding machine in 1642. It was called the Pascaline (See Figure 2) The device could add and subtract six-figure numbers. Pascal invented the machine for his father, a tax⁴collector, so it was the first business machine, too. He built 50 copies of his machine over the next 10 years, but most served as curiosities⁵ in parlors of the wealthy.

Figure 2. The Pascaline

Numbers could be added by turning the wheels (located along the bottom of the machine) clockwise and subtracted by turning the wheels counterclockwise. Each digit in the answer was displayed in a separate window, visible at the top of the photograph.

Many scientists and inventors attempted to make improvements on Pascal's mechanical calculator. Gottfried Leibniz designed a special gearing system to enable multiplication on Pascal’s machine. In 1672, he also invented a calculating machine (called the Step Reckoner) capable of multiplying, dividing and extracting square roots. (See Figure 3)

Figure 3. The Step Reckoner

The original of Leibniz's Step Reckoner is now located in the Trinks Brunsviga Museum at Hannover, Germany. The turn of the crank (left) rotated several drums, each of which turned a gear connected to a digital counter.

The calculators of Pascal and Leibniz were unreliable, since the mechanical technology of the time was not capable of manufacturing the parts with required precision.

Few other mechanical devices built during the 19^th century were related to computing. There was one major exception: the Jacquard loom⁶, invented in 1804 by a French weaver, Joseph-Marie Jacquard. (See Figure 4) The Jacquard loom was a marvel of the Industrial Revolution. It can be called the first practical information-processing device. The weaving of cloth on the Jacquard loom was controlled by punch cards that enabled the loom to weave any pattern automatically.

Figure 4. The Jacquard Loom.

At the top of the machine, you can see a stack of punched cards. They were fed into the loom to control the weaving pattern.

The Jacquard loom provided important lessons: (1) the sequence of operations that a machine performs could be controlled; (2) a punched card could be used as a means for controlling the machine; and, (3) the most important, a device could be directed to perform different tasks by entering instructions into it – i.e. making the machine programmable.

It can be said that, in the Jacquard loom, programming was invented before the computer. The close relationship between the device and the program became apparent nearly 20 years later, with Charles Babbage's invention of the first computer (to be described in the next part).

Notes: ¹abacus bead – костяшка (элемент конторских счет);

²to raise to power – возводить в степень;

³to single out – выделять;

⁴tax – налог;

⁵to serve as a curiosity – служить диковинным украшением;

⁶Jacquard loom – жаккардовый ткацкий станок (для выработки крупноузорчатых тканей).

Part II (The Computer of the 19^th Century)

When was the automatic computer invented? In the 1930s or the 1940s? If you think that, you are only off by a hundred years. A computer that was completely modern in conception was designed by Charles Babbage, the English mathematician, in the 1830s. But, as with the calculators of Pascal and Leibniz, the mechanical technology of that time was not prepared to realize the conception.

The idea of mechanical calculating mathematical tables first came to Babbage in 1812 or 1813. The mathematical tables of the 19^th century – especially, logarithm tables used in navigation – were full of mistakes. The errors could be a life-and-death matter for sailors at sea. Babbage wanted to automate the production of the tables to ensure their accuracy.

According to one story, Babbage was lamenting over¹ the errors in some tables to his friend Herschel, a famous astronomer. "I wish to God these calculations had been executed by means of steam." Babbage said. "It is quite possible," Herschel responded. (At that time, steam was a new and unexplored source of energy.)

Babbage decided to build a machine that could not only calculate the tables automatically but could print them as well. He called this machine the Difference Engine², since it worked by solving difference equations. Nevertheless, the name isn't correct, as the machine created tables by means of repeated³ additions, not subtractions. (The word engine, by the way, comes from the same root as ingenious⁴. Originally it meant a clever invention. Only later, it came to mean a source of power.)

In 1823, Babbage turned to the British government to fund development. He obtained one of the first government grants for research and technological development anywhere in the world.

Babbage approached the project very seriously: he hired a machinist, set up a fireproof workshop, and built a dust-proof environment for testing the device. The full engine, however, was never built, at least not by Babbage. The government stopped financing the project. Joseph Clement, the machinist responsible for actually building the machine, refused to continue unless he was prepaid. In 1833, Babbage abandoned the project. (In 1854, by the way, a Swedish printer built a working Difference Engine based on Babbage's ideas.)

Figure 5. Babbage's Difference Engine

The Difference Engine is considered by many to be a direct forerunner of the modern computer. The photograph (See Figure 5) shows a small portion of the ingenious machine, which is now on exhibition at the Science Museum in London.

While working on the Difference Engine, Babbage began to invent ways to improve it. Inspired by Jacquard punched-card-controlled loom, he had devised something far more revolutionary: a general-purpose computing machine called the Analytical Engine⁵. It was the first programmable computer, complete with punched cards for data input.

Babbage's design was grandiose. The Difference Engine could only compute tables (and only those tables that could be computed by repeated additions). But the Analytical Engine could perform any calculation, just as Jacquard's loom could weave any pattern. The machine consisted of four basic components: the mill⁶, the store, the card reader and the printer. These units are the essential elements of each computer today. The mill was the calculating unit, analogous to the CPU in a modern computer; the store was where data were held prior to processing, exactly analogous to memory and storage in today's computers; the reader and the printer were the input and output devices.

The store was to be large enough to hold 1,000 50-digit numbers. This was larger than the storage capacity of any computer built before 1960. The locomotive-sized machine was powered by steam. It included more than 50,000 moving parts.

Babbage planned for his machine to do calculations with fifty-digit accuracy. This is far greater than the accuracy found in most modern computers and far more than is needed for most calculations. If the Analytical Engine had been completed, it would have been a 19th-century computer.

Babbage worked on the Analytical Engine for nearly 40 years. But, alas, the machine was not completed. The government had already invested thousands of pounds into the Difference Engine and received nothing in return. It didn't want to repeat its mistake.

Among those who were fascinated with Babbage's invention was a young woman named Augusta Ada King, Countess Lovelace. She was the only legitimate daughter of the famous English poet Lord Byron. She was a brilliant mathematician. She believed and fully realized the potentialities of the Analytical Engine. Ada took an active part in Babbage's experiments and even developed the demonstration program for the Analytical Engine in 1842. For this reason, she is recognized as the world’s first computer programmer.

Notes: ¹to lament over – сокрушаться, сетовать (по поводу чего-л.);

²Difference Engine – разностная машина;

³repeated – итеративное [многократное];

⁴ingenious – оригинальный, хитроумный;

⁵Analytical Engine – аналитическая машина;

⁶mill – зд. вычислительный блок.