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).

T he 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 tax⁴ collector, 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)

F igure 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.

F ew 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).