Fundamentals of computer

Introduction : The implementation of computers is one of the most noticeable changes in the past few decades. A computer is now a very familiar device and each one of us can recognize the use of computers in various fields. Computers are being used for simple tasks like printing of letters as well as for complex weapon designing work. These intelligent machines are used in railway stations, airports, super stores, banks, manufacturing units and at home. People of all age groups use computers for their different needs. Computers have brought new revolutions in the areas of banking, sales and education. Regardless of the field of working, any person needs to have basic knowledge of computers to excel in his/her respective field. Due to this reason, the knowledge of computers is necessary for everyone.

One should be able to understand the operation of computers and to use it in his/her field of working. One must have basic understanding of Internet, WWW and the uses of internet. In short, you must know how to apply the power of computing in your field to get the maximum benefit out of it. Without this, your competitors will be always ahead of you and you will be left behind. In the present world of information technology, the success in any market segment is driven by the quality of the information possessed. The company that has the information about latest happenings in its field and competitors, it would be able to plan efficiently. This way, the success depends on information and the use of information in planning and implementation. The computers and internet can provide the latest information and can process it in a way that it becomes helpful to the organizations.

We are living in a world that is completely driven by computers. You can use ATM machines and internet banking to perform banking operations from your house. You can book rail or air ticket from your personal computer. You can check your exam results from the internet. You can file your income tax returns from your home. You can search for the customers of your products throughout the world. You can purchase various goods through the internet. You can read various books online and listen to songs on the internet. All of this is possible only if you can operate the computer and know to use the internet.

Several new areas of study have been discovered by using computers. Some fields like robotics, artificial intelligence, mobile telephony, satellite communication, computer controlled weapons, DNA study, nano technology could never be imagined without the use of computers. Computing industry is one of the major fields in which the world has invested maximum money for research in last 50 years.

You may feel that the computers are very difficult to learn and the applications of computers are very complex to perform. This fear will remain in your mind till the time you start learning about computers. When you start learning and implementing the concepts, you will find that the basic computer applications are very easy to learn and implement. This book has been designed to help you in learning the basics of computers as well as few popular applications of computer. As you will progress through the various chapters of this book, you familiarity with computers will increase day by day. You will also learn to implement the concepts practically by using the practical exercises provided in this book. This chapter will give you knowledge about computers, their evolution its types and the devices attached with computer.

COMPUTER

A Computer is an electronic device. It is used to convert meaningless collection of facts into meaningful information. The process of converting meaningless facts into meaningful information is called “Data Processing”. The user supplies commands to the computer and it works as per the commands provided. The operations performed by the computers are really fast and accurate. Computers keep on performing the same job with same efficiency and in same interval of time. They are not affected by fatigue of performing same operations. Computers have huge volumes of memories to store the information for later reference.

Look at the following figure that describes a personal computer and its main components. The monitor, system unit, keyboard and the mouse are the main parts of the computer. The monitor or Visual Display Unit displays the output, the keyboard and mouse provide the input and the system unit is responsible for processing of input to generate the output. The important point to mention is that the system unit is not CPU (Central Processing Unit). The CPU is a device that is responsible for actual data processing and it is a part of system unit. Most of the people call system unit as CPU that is wrong.

    BLOCK DIAGRAM OF COMPUTER

Hardware is a term which refers to the physical components of a computer system which are used for processing data. No matter what the shape and size of computers would be they perform following five basic operations for converting raw input data into information useful to users.

1.Inputting : The process of entering data and instructions into computer system is called Inputting.

2.Storing : Saving data and instructions so that they are available for future use whenever required.

3.Processing : Performing arithmetic operations (Add, Subtract, Multiply, Divide etc.) or logical operations (Comparisons like equal to, less than, greater than etc.) on data in order to convert them into useful information.

4.Outputting : The process of obtaining useful information or results to user such as printed report or visual display.

5.Controlling : Detecting the manner and sequence in which all above operations are performed.

          Any computer system have essentially four important parts normally input unit, central                          processing unit, storage unit and output unit. The block diagram is shown in Figure.

Block diagram of Computer

In the Figure, the solid lines are used to indicate the flow of instruction and data and the 
dotted lines represent the control exercised by the control unit.

INTERACTION OF VARIOUS COMPONENTS OF COMPUTER

You have studied the working of computer and its main components. This section will explain the collaborative working of all these components to process data. All the components of computer work together to process data. The input unit plays its role of taking the input from user and supplying it to the CPU. The ALU performs all the logical and arithmetical calculation inside the CPU as directed by the CU. The control unit supervises the working of ALU. 

If some instructions are required by CPU from memory, the CPU interacts with memory to fetch those instructions. For example, to solve the input A*B, the values of A and B are taken from the user through input devices. These values are stored in primary memory and then supplied to the CPU.

After the processing of data is over, the results are stored in the main memory of the computer. From the main memory, the results are taken by output unit to display the output on the output devices. The results are stored into secondary memory for permanent storage, if needed. The following diagram illustrates the process of collaborated working of all these components:

The illustration of the diagram is as follows:

1.         The input unit takes inputs from the users and feeds it to the CPU.

2.         The CPU stores these instructions in the main memory. Some of these instructions may                                           also be stored in the secondary memory.

3.         The data is taken from secondary memory to main memory for execution.

4.         The CPU fetches instructions from main memory.

5.         ALU performs the job of arithmetic and logical calculations. It is supervised by CU.

6.         The result of calculations is stored in main memory.

7.         If there are some errors, they are displayed on the output unit.

8.         The results are sent to output unit from the main memory.