2. BY: SACHIN SHRIVASTAVA Operating System By : Sachin Shrivastava 1

3. 5 Operating System

4. By : Sachin Shrivastava 6 Introduction to Operating System Introduction : Computer hardware provides us the means of processing and storing information. In order to perform useful work for us it has been driven by means of software program which specify the task to be done. Software can be classified into two distinct group. 1.System Software: These software are designed to provide an environment to facilitate the writing of application program. Example- Assemblers, Loader, Complier interpreter, operating system 2.Application Software: It consist of collection of program, written by programmer in order to perform some specific task for users. Example – Word processor, spread sheets, web browser etc.

5. By : Sachin Shrivastava 7 What is Operating System ? Operating system is a system software. It is a collection of program works between the user and hardware of computer. Operating system is an important part of almost every computer system which manages the resources of computer system. Such as microprocessor, primary and secondary storage devices & input/output devices. It keeps the information regarding the status of each resources and decides how long and when to allocate them to specific program and users, so that it can operate the computer system efficiently and fairly. It is a soul of computer and without operating system, computer is a dead machine only. It is the first program loaded into the computer’s memory after the computer is switched on.

6. Hardware By : Sachin Shrivastava 8 Hardware Operating System Application Programs Users Computer system is divided into four parts 1.Hardware 2.Operating System 3.Application Software 4.Users,

7. By : Sachin Shrivastava 9 Goals of Operating System There are two main goals of operation system – 1.Convenience – The primary goals of operating system is to make compute system easier for user and operating system makes the interaction between user and hardware easier. 2.Efficient – The secondary goal of OS is to allocate the system resource to various application program as efficiently as possible.

8. By : Sachin Shrivastava 10 Functions of Operating System Today most operation systems perform the following functions. – 1.Processor management –It assigns all the instructions and programs to the processor for their execution. 2. Memory management – It allocates the primary and secondary memory to any data or programs. 3. Input/output management – that is, proper interaction and allocation of the various input and output devices when different programs are being executed. 4.File management – that is, keeping record of files on various storage devices and move all these files from one device to another. It provides facility to all files to be easily changed by the use of text editors. 5.Understand the meaning of commands and instructions. 6.Switching from job to job as guided by special control statements, automatically. 7.Generation of traces, error messages, and other debugging and error detecting facility. 8.For all user keep record of internal time clock and log of system usage.