O PERATING S YSTEM ALAK ROY. Assistant Professor Dept. of CSE, RSET ROYAL GROUP OF INSTITUTIONS CS-107 I NTRODUCTION TO C OMPUTING Aug-Dec,2010

W HAT ' S OPERATING SYSTEM? OS, is a system software program that enables the computer hardware to communicate and operate with the computer software. It manages other resources of a computer System. Without a computer Operating System, a computer would be useless. Is the process of loading an Operating System in to a computer main memory Booting:

E VOLUTION OF OS Different generation of computers. Serial processing. Simple batch system multi-programmed batch system, IBSYS ‘60. Timesharing OS Parallel systems, Distributed systems, Real time systems, Embedded systems

R OLE OF AN O PERATING S YSTEM Operating System Input/output devices CPU Files & Directories Programs Controls Operates handlesManagers

F UNCTIONS OF O PERATING S YSTEMS controls and coordinates the use of the hardware OS controls and coordinates the use of the hardware among the various applications programs for various uses. OS acts as resource allocator and manager. Some Important Functions of OS are: Process Management Memory Management File Management Device Management Security Management Task Management

T YPES OF I NTERFACES : CLI – C OMMAND L INE I NTERFACE is a type of “user interface” that enable the users to interact with the Operating System by means issuing some specific commands. Examples: Unix & DOS command interface GUI - G RAPHICAL U SER I NTERFACE is a type of “user interface” that enable the users to interact with the Operating System by means of pint-and –click operations. contains graphics and icons commonly navigated by using a computer mouse. Examples: System 7.x, Windows 98, Windows CE

OPERATING SYSTEM TYPES As computers have progressed and developed so have the types of operating systems. types of Operating Systems: Batch Processing Multi-user Multitasking Time-Sharing Multiprogramming Multiprocessing Multithreading

B ATCH P ROCESSING – O PERATING S YSTEM allows for multiple users to use the same computer at the same time and/or different times. Examples: Linux, Unix, Windows 2000, Windows XP, Mac OS X M ULTI - USER – O PERATING S YSTEM Capable of executing only one job at a time. Jobs submitted by different users are grouped into batches and one batch of job is provided as input to computer at a time.

M ULTITASKING - O PERATING SYSTEM Multitasking is the execution of two or more programs by one user concurrently on the same computer with one central processor. Multitasking OS is capable of allowing multiple software processes to run at the same time. Examples: Unix Windows 2000 Windows XP Mac OS X

M ULTIPROGRAMMING - O PERATING SYSTEM Multiprogramming is the execution of two or more programs concurrently on a multiuser operating system. Examples: Unix Windows 2000 Windows XP Mac OS X

M ULTIPROCESSING – O PERATING S YSTEM Multiprocessing is the processing done by two or more computers or processors linked together to perform work simultaneously. Multiprocessing OS is capable of supporting and utilizing more than one computer processor. examples of multiprocessing Operating Systems. Linux Unix Windows 2000 Windows XP Mac OS X

M ULTITHREADING - O PERATING SYSTEMS that allow different parts of a software program to run concurrently. Examples: Linux, Unix, Windows 2000, Windows XP, Mac OS X M ULTI - SHARING - O PERATING SYSTEM A single computer processes the tasks of several users at different computers in round robin fashion. Examples: Unix, Windows 2000

P OPULAR O PERATING S YSTEM DOS Windows UNIX Linux MAC-OS

T HANK Y OU Questions?