Basic of Computer

 Fundamental Of Computer

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The Evolution of Computer

Necessity is the mother of the invention. The sayying holds true for Computer also because computers were invented as a result of man’s search for fast and accurate calculating devices.

History of Computer

In olden days, man calculated with what was accessible to him conveniently like pebbles, bones, fingers, stones etc. because those days the counting needs of men were very limited as his brain was not very developed. But as the brain started developing, the need for complex calculations was also felt. The earliest device computer is the “ABACUS”.

ABACUS

Abacus was invented by the Chinese people. It consists of a rectangular wooden frame with a rod going through it horizontally at about 2/3 of its height. There are 13 vertical bars placed at equal distance. There are 2 beads in upper section and 5 in lower one. Each bead in the upper section represents a unit of 5 and the lower one represents single unit only. You perform only simple addition and subtraction by it.

Figure 1.1-Abacus

COMPUTER

(Commonly Operating Machine particularly Used in Trade Education and Research)

The word “Computer” comes from the word “compute” which means to calculation. So a computer is normally considered to be a calculating device that can perform arithmetic operations at enormous speed.

A computer is an electronic device which can perform any arithmetical or logical problems in little time. You can store data into computer memory.

COMPUTER SYSTEM CHARACTERISTICS AND CAPABILITIES

Business people must be practical and judge the economic realities of installing a computer. Four factors that might lead a businessman to use a computer are speed, accuracy, reliability and memory.

1- Speed

Current computer system can amass, manipulate and provide data in fractions of a second. Computers can perform in minutes takes that would take a person year to complete. Today computers can perform 100 million computations in 1 second. Computers of the future are expected to handles more than 100 millions calculations per second.

2- Accuracy

The computer must process data accurately as well as quickly. Accurac is a prime consideration in installing computers. Any calculating device is useless if its results are unreliable. Computers are universally accused of making mistakes on bills and statements, although most really human errors.

3- Reliability

Computer systems are widely accepted because of their exceptional reliability. Unlike most humans, they are capable of operating under the most adverse conditions for extended periods.

4- Storage Capability

Computer system has total and instant recall of data and an almost unlimited capacity to store these data. A typical mainframe computer system will have many billions of characters and perhaps thousands of graphic images, stores and available for instant recall.

5- Dilligence

Unlike human beings a computer is free from tiredness. It can continuously work for hours, without creating any error and without grumbling.

6- Versatilit

Versatility is one of the most wonderful things about the computer. One moment, it is preparing the result of an examination, the next moments, it is busy preparing electricity bills, it may be helping an office secretary to trace an important letter in seconds.

7- Power of Remembering

As a human being acquires new Knowledge the brain subconsciously selects what is feels to be important and worth retaining in its memory and relegates unimportant details to the back of the mind or just forgets them.

THE COMPUTER GENERATIONS

“Generation” in computer talk is a progressive step in technology. It provides a framework for the growth of the computer industry.

FIRST GENERATION (1951-1958)

There machines and other of their time were made possible by the invention of “Vocuum Tube”, which was a fragile glass device that could control and amplify electronic signals. These vacuum tube computers are referred to as first generation computer.

Figure 1.2- A Vacuum Tube

SECOND GENERATION (1959-1964)

The transistor, a smaller and more reliable successor to the vacuum tube, was invented in 1947. however, computers that used transistor were not produced in quality until over a decade later. The second generation emerged with transistors begin the brain of the computer.

Figure 1.3- A Transistor

THIRD GENERATION (1965-1971)

Advances in electronics technology continued and the advent of “microelectronic technology” made it possible to integrate large number of circuit elements into very small (less than 5 mm square) surface of silicon known as “Chip”. This new technolog was called “Integrated Circuit” (IC). The third generation was based on IC technology and the computers that were designed with the use of integrated circuits were called third generation computers.

Figure 1.4- An IC Chip

FOURTH GENERATION (1971-present)

The average number of electronic components packed on a silicon chip doubled each year after 1965. This process soon led to the era of large scale integration (LSI) when it was possible to integrate over 30,000 electronic components on a single chip; followed by very large scale integration (VLSI) when it was possible to integrate about one million electronic components on a single chip. This process led to a dramatic development – the creative of a microprocessor. A microprocessor contains all the circuits needed to perform arithhmetic, logic and control functions, the core activities of a computer, on a single chip. It started a new social revolution- The personal computer (PC).

Figure 1.5- A Processor