History of Computer part - 2 - Ts Read

Monday, 29 May 2017

History of Computer part - 2

Representing Numbers In a Physical State


The Abacus, of which we had spoken earlier, was not perfected by the Chinese till nearly 2000 years later; in 1200 AD. I am sure you have all used an Abacus at some early stage of your education. Remember it --beads threaded on wires to represent numbers ? If you remember well, it had two wires with represent on each. That is why the Abacus is called a biquinque device. In more simple language, it consists of two (bi) groups of five (quinque) .
The Abacus is still very much m use today. In China, a student must be able to use an Abacus very proficiently before he can . graduate from school.

Interestingly, sometimes, calculating races are held between persons using an Abacus and an electronic calculator. Strangely enough, the person using the Abacus often wins.

The idea that the position of a bead in an Abacus indicated its value resulted 1n one very important notion. With the Abacus, the beads could be said to have a state of physical representation. A bead being either up or down affected the meaning of its value. This concept of a number being represented as a physical state was to become the basis of a very important computer concept.

It was not until the seventeenth century, however, that calculating devices, as we . understand them today, were invented.

Automatic Calculation 

The seventeenth century saw the invention of three such devices. The first was the work of John Napier, the inventor of logarithms. In 1617, Napier designed a set of rods that helped to make multiplication easier. The rods were arranged in a manner that made it possible to fit them together into a multiplication table. The rods were called Napier’ Bones. This was the forerunner of the analogue computer.

Later, in 1640, Blaise Pascal, a sixteen year old French boy, invented the first practical adding machine. His father, a businessman, was bogged down with the accounting work, he had to do. So, to assist him, Pascal (after whom the computer language, Pascal, is named) invented this gadget. The machine worked using toothed wheels and could add and subtract. The machine turned in one direction to add and in the reverse direction to subtract. However, it could not multiply or divide. Although he made as many as 50 machines, he could not sell them. He got so bored of the idea that he went on to make hypodermic syringes and the hydraulic press. The odometers that keep track of mileage . In modem automobiles are based on Pascal’s machine.

Twenty years after Pascal, Samuel Moreland created a small calculator, based on Napier’s Bones, but it wasn’t very acceptable. Samuel Peppys, in his famous diary, described it as ‘very pretty, but not very useful’.

About thirty years later, a German, named Gottfried Voh Leibnitz, invented another calculating machine. Like Pascal’s, it too used toothed wheels with the added advantage that it could both multiply and divide, besides adding and subtracting. It was used to compute lengthy scientific calculations which had to be done by incessantly tedious methods uptill then. These inventions of Pascal and Liebnitz proved that anthmetic could now be done ‘automatically’.

Over the years, these machines were copied and improved. At first, they were made by hand. Later, they were assembled in factories and, with time, became smaller, more efficient and more compact. They still, survive today in the form of cash registers often seen in shops.

Information processing

Computers, however, are used for much more than calculating. They are used-for processing information too. This particular aspect of the computer’s use had its origins in the nineteenth century in the unlikely area of weaving.

A woven pattern on cloth is often produced by lowering threads of various hues as each . row of cloth is woven. With hundreds of threads involved, the process could get extremely complicated. T o simplify the process,  Frenchman, named Joseph JaCQuard, invented a device that would help make things work well nigh automatically. He used punched cards which controlled the movement of the threads by the presence and absence of holes in cards. Many of the looms used today are based on Iacquard’s design.

The problem, though, with the design was this; the making of cards for each pattern was a very lengthy process. For example, the design of Jacquard’s face required as many as 25,000 cards. Later, however, an American called Hollerith was-to use the idea to good effect.

About Charles Babbage 

Meanwhile, across the seas in England, a new champion emerged -Charles Babhage. He is regarded today as the Father of modern computers. He developed most of his ideas between 1820 and 1870. His first creation was the DIFFERENCE ENGINE.

Difference Engine

In bage put together a model of the first mechanical computer, called the DIFFERENCE ENGINE. His aim was to create a machine that would compute and check tables. . Towards this purpose, he combined the two operations of sequence control and automatic  control, using punched cards.  The principle he was working on was that, for certain expiessions, the difference between certain values of the expression at a. certain stage becomes constant. However, the engine, was of limited value and so, genius that he was, he decided to a design a general purpose computing device called today the ANALYTICAL ENGINE.