1
Basics of Computer
1.1 INTRODUCTION
In this lesson we present an overview of the basic design of a computer system: how the different parts of a computer system are organized and various operations performed to perform a specific task. You would have observed that instructions have to be fed into the computer in a systematic order to perform a specific task. Computer components are divided into two major categories, namely, hardware and software. In this lesson we will discuss about hardware, i.e., the machine itself and its connected devices such as monitor, keyboard, mouse etc., as well as software that makes use of hardware for performing various functions.
1.2 OBJECTIVES
After going through this lesson you would be able to: explain basic organization of computer system explain different types of input and output devices define Software and its classification distinguish between system software and application software describe computer language and its classification
2 :: Data Entry Operations
1.3 WHAT IS A COMPUTER?
Computer is a device that transforms data into meaningful information. Data can be anything like marks obtained by you in various subjects. It can also be name, age, sex, weight, height, etc. of all the students in a class. Computer can also be defined in terms of functions it can perform. A computer can i) accept data, ii) store data, iii) process data as desired, and iv) retrieve the stored data as and when required and v) print the result in desired format. The major characteristics of a computer are high speed, accuracy, diligence, versatility and storage.
1.3.1 Computer Organisation
The block diagram of computer is shown in Fig. 1.1.
Memory Unit
Input unit
Control Unit
Output unit
Arithmetic Logic Unit
Fig. 1.1 Block diagram of Computer Organisation
The computer performs basically five major operations of functions irrespective of their size and make. These are 1) it