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PC Soultion

Fundamental|PC Common Problem|Computer Won't Start|Full Name Computer Terms

INTRODUCTION TO COMPUTERS

Introduction to Computers

In today's world, the use of computers has increased so rapidly that we can no longer ignore them. Computers influence our lives one way or the other. These days we see computers being used to perform several functions that have made our life easy. The list of services for which computers are used is a long one.

 

 What is a Computer?

·                    A computer is an electric device that can accept store and process information to produce the required results.

·                    It is essentially a problem solving machine. You can also use as a typewriter for typing letters or a calculator for doing calculations.

·                    A computer has memory that can save a lot of information and can take logical decisions like human beings.

 

 Uses of Computers

Computers have a significant impact on modern society. Nearly every profession uses computers to a certain extent.

Computers are used in:

·                    Airline and Railway reservations

·                    Medical diagnosis

·                    Weather Forecasting

·                    Payment of bills

·                    Banking

·                    Manufacturing different products

·                    Cartoon Film Production

·                    Space research

·                    Creation of blueprints for houses

 

Thus, you can see that computers have become very essential part of life.

 

Benefits and Limitations

            The various benefits of computers are:

·                    Speed - Computers are very fast. The speed of the computer is measured in terms of Million Instructions per Second (MIPS). It represents the number of instructions that can be executed by the computer per second.

·                    Accuracy - Computers are very accurate. If the input is correct, they never make mistakes.

·                    Diligence - Computers never get tired or bored of doing the same task continuously. They work in the same manner all the time.

·                    Storage - A computer can store large amounts of information in its memory.

·                    Automation - If a task has to be performed several times, the computer needs to be instructed only once it automatically completes the task.

 

A computer appears to be far more intelligent and informed than human beings but the fact is it cannot perform any task on its own. We need to give the computer instructions on exactly what it has to do.

 

If an unanticipated situation arises, computers will either produce results or abandon the task altogether. They do not have the potential to work alternate solutions.

        

 

History of Computers

Abacus 

§         Abacus is   considered to be the first computer and was invented 5,000 years ago by the Chinese.

§         The basic purpose of the device is to make calculations.

§         It consists of a rectangular frame with a number of strings attached.

§         Each string has a collection of beads. These beads are used to perform calculations.

§         Abacus is used even today to teach small children how to count.

 

 

Babbage’s Mechanical Computer

Charles Babbage invented the first mechanical computer during the period 1830 to 1850. This computer performed the basic arithmetic functions. It had the following five components:

§         A storage unit that holds the numbers.

§         An arithmetic unit, called Mill, to perform the arithmetic calculations.

§         A control unit that controls the activities of the computer.

§         An input device that gives the numbers and instructions to the computer.

§         An output device that displays the result.

 

NOTE: Charles Babbage is referred to as the ’Father of Computers’ due to his pioneering work.

    

  

Punched Cards

The next device that contributed to the evolution of computers was the punched cards. These were cards made of special pulp paper. Machines were used to make holes in the cards and thus store information. In addition, storing machines were used to read these cards and collect data.

 

Computer Generations

After the first mechanical computer, the design of computers evolved over a period of time. They were classified into generations: 

 

First Generation Computers:

The U.S. Census Bureau developed the first business computer in the year 1951. This computer was called Universal Automatic Computer (UNIVAC). It used vacuum tube circuits for processing. The computers that used vacuum tube circuits were called the First Generation Computers. The vacuum tube circuits contained a filament that was heated to emit electrons.

 

Second Generation Computers:

Bell Labs of U.S.A. invented transistors that were used instead of vacuum tubes. Transistors are electronic circuits that are small in size and do not require any heating for emitting electrons. The computers that used transistors were called the Second Generation Computers.

 

Third Generation Computers:

The Third Generation Computers used large Scale Integrated (LSI) circuits for processing. The LSI circuits were invented in the mid -1960s. LSI circuits integrate several circuit components into a single chip.

 

Fourth Generation Computers:

Very Large Scale Integrated (VLSI) chips were invented in the year 1969. The computers that used VLSI chips were called the Fourth Generation Computers.

 

Fifth Generation Computers:

Recent research has focused on developing “thinking computers”. These computers are called the Fifth Generation Computers.

 

 Types of Computers

 

Computers can be classified into microcomputers, minicomputers, mainframe computers and supercomputers on the basis of the following:

 

  • Size
  • Cost
  • Performance

·Speed of processing data

·Storage capacity

·Ability to handle input and output devices

 

Microcomputers

  • Microcomputers are also called personal computers (PCs). These computers use microprocessors.
  • They are small in size. Also, they do not have large storage capacities.
  • They can perform difficult tasks. They are used mainly for desktop publishing, accounting, statistical analysis, graphics designing and project management.
  • Some examples are Apple II, IBM PC, PS\2 and Macintosh.

 

Minicomputers

 Minicomputers are small general-purpose computers. These computers can perform more complex tasks and cost more than microcomputers.

  • They are larger in size and they have small to medium storage capacity.
  • They are used for processing data and analyzing results of experiments. They are also used for controlling and monitoring production processes.
  • Some examples are PDP 11/42 and VAX 11.

 

Mainframes

Mainframes are more powerful than minicomputers.

  • They have high processing speeds and can store large amounts of data. They are used in wide area networks and support hundreds of users. However, these computers consume more electricity.
  • Some examples are IBM 3000 series and Univac 1180.

 

Supercomputers

  • Supercomputers are the largest and fastest computers. They are also the costliest computers.
  • They are used in field like science and defense. These computers are used for designing and launching missiles, weather forecasting, biomedical research, aircraft design and automobile design.
  • They are only few supercomputers throughout the world. India owns a series of computers called PARAM developed by C-DAC.

 

 

Personal Computers

Personal computers or PCs are the popular form of computers. Individuals as well as organizations use these computers. The classification of PCs is as follows:

§         Desktops

§         Portables

·         Laptops

·         Notebooks

·         Palmtops

 

The difference between portables and desktops is that portables can be carried while traveling unlike desktops.

·           Laptops are small sized machines that have the same power of a desktop. The weight of laptop is around 7 to 12 kg. The drawback of a Laptop is that it is too bulky. Examples: Toshiba 5200C and SLT/286.

·           Notebooks are similar than a laptop and are designed to overcome the drawbacks of a laptop. They have the size of a notebook but are as powerful as a desktop. They weigh 3 to 4 kg. Examples: Contura 3/20 and Acer Any Ware.

·           Palmtops have the size of a pocket calculator. They are not as powerful as a desktop; they support only a few applications. Example HP95LX.

 

 

Types of Computer Systems

 

Single-User Systems

A Personal Computer (PC) is a popular single-user system. A single-user system can support only one user at a time.

 

Multi-User Systems

A multi-user system is one that supports more than one user at a time. It enables the users to run more than one program simultaneously.

 



 

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