SOFTWARE AND OPERATING SYSTEM

Computer System can be think of two parts:-

• Hardware:-Which performs all the computation and calculation work that computers are known for

• Software:-Which instructs the hardware what to do and how to do it.

Introduction

Computer System

Parts of Computer Systems

Computer Hardware

Computer Software

System Software

Application Software

Computer understand two concepts-On or Off, which is basis for binary language.

Hardware needs a software(a set of programs) to instruct what has to be done.

A program is a set of instructions that is arranged in a sequence to guide a computer to find a solution for the given problem.

Process of writing a program is called programming.

Programs written by the programmer using a programming language are also called source code.

Programming

Computer Games-Entertainment software Driver Software Educational Software:- e.g. Interactive

geometry software, Language learning software

Media Players Productivity Software:-e.g. Presentation

Software Operating System Software :-e.g. Window

Vista, Linux

Examples of Software

There are two types of Software1. Application Software2. System Software

Classification Of Software

Designed for user to solve a particular problem

It represent programs that allow users to do something.

E.g. Spreadsheets, Database systems, games, Web Browsers

Application software

Provides a general programming environment in which programmer can create applications to suit their needs.

It represent the programs that allow the hardware to run properly.

Act as a interface between hardware of the computer & application Software that user need to run on the computer.

E.g. Operating System

System Software

Relation between Application s/w & System s/w

User 1 User 2 User n

Application Programs

System Software

Computer Hardware e.g. printer, mouse,keyboard

System Software Application Software

Collection of programs that enable users to interact with hardware components

Collection of programs written for a specific application e.g. library system

Controls and manages the hardware

Uses the services provided by system software to interact with hardware components

It is machine dependent It is Machine independent

Programmer must understand the architecture of machine and h/w details to write it

Mostly programmer ignores the architecture of machine and h/w details to write it

It interact with h/w directly It interact with h/w indirectly through system calls

Writing it is a complicated task Writing it is relatively easy

Differences

Designed to operate Computer h/w and provide a platform for running application s/w.

Most widely used system software types are:Computer BIOS Operating System

System Software

It provide basic functionality to operate & control h/w connected to or built in the computer.

BIOS is the first code run by computer when it is switched on.

Key role of BIOS is to load the Operating System.

When the computer starts, the code in the BIOS chips run a series of tests called POST(Power On Self Test) to ensure that system devices are working properly.

Computer BIOS

BIOS chips locates the software held on other devices like CD or Hard Disk, & loads and executes that software, giving it the control of Computer. This process is called Booting.

Booting

In short BIOS perform the following functions Initialize the system Hardware Initialize the system Registers Initialize Power Management System Test RAM Test all the serial & parallel Ports Display the system summary information.

Computer BIOS

Operating System The interface between the user and the computer hardware. A program that acts as an intermediary between a user of a computer

and the computer hardware Operating system goals:Execute user programs and make solving user problems easier.

◦ Make the computer system convenient to use. Use the computer hardware in an efficient manner.

Operating System Structure

Operating System Functions

Functions of OS

Intermediator

Process Mgmt

File Mgmt

Memory

Security

JobSchedu

ling

Intermediator: Facilitates easy communication between the computer system and the computer operator (human). It also establishes data security and integrity.

Process Mgmt: that is, assignment of processor to different tasks being performed by the computer system.

File Mgmt: that is, the storage of file of various storage devices to another. It also allows all files to be easily changed and modified through the use of text editors or some other files manipulation routines.

Function of OS in Detail

Functions(Cont…) Memory Mgmt: that is, allocation of main

memory and other storage areas to the system programs as well as user programs and data.

Security: Operating systems provide password protection to keep unauthorized users out of the system.

Job Scheduling: it determines and maintains the order in which jobs are to be executed in the computer system.

Operating system

GUIMultius

erMultitas

kingMultiprocessing

Multithreading

Operating System Classification

GUI GUI - Short for Graphical User

Interface, a GUI Operating System contains graphics and icons and is commonly navigated by using a computer mouse. Example

Multi user Multi-user - A multi-user operating system

allows for multiple users to use the same computer at the same time and/or different times.

Example: LINUX

Multi Tasking An operating system that is capable of

allowing multiple software processes to run at the same time.

Below are some examples of multitasking operating systems.

UnixWindows XP, Vista

Multi Processing An operating system capable of supporting

and utilizing more than one computer processor.

more than one CPUs that can be sharedBelow are some examples of multiprocessing

operating systems. LinuxUnix

Windows 2000

Multi Threading

Smaller parts of a program are loaded when needed by OS

Operating systems that allow different parts of a software program to run concurrently

Operating systems that would fall into this category are:

E.GLinuxUnix

Windows 2000

Types Of Operating system

DESKTOP SERVER MOBILE

Types of OS

DESKTO

P

SERVER

MOBILE

Desktop Operating System

Operating System

Windows Mac Linux

Advantages of Windows OS

Windows

Easy to

use

Update

Supportin

g

Gaming

Familiar

Advantages

Windows

expensiv

e

Not secu

re

Not stabl

e

Disadvantages

By MICROSOFT co-operation

Advantages & Disadvantages of MAC OS

Mac

Great

GUI

Better to

graphic design

er

Secure

Stable

Advantages

Mac

Not gaming

Not all software run

Difficult

mouse (one click)

expensive

Disadvantages

By APPLE Co-operation

Linux Operating System

Linux

Free

Stable

Secure

Source

Code

Low pc

requirement

Advantages

Disadvantages

Linux

Not all software run

Not support

Hard to learn,

use and install

Server Operating System

Server operating systems are designed to provide platforms for multi-users , for critical, network applications. Their main purpose is to provide security, stability and collaboration. Most of them come with a pack of dedicated software tools such as Web servers, e-mail agents and terminal services The common applications for server OS are:

File and printer sharing Application services (including databases) Web site services E-mail, groupware and messaging Terminal services Caching

Server Needs

Server Operating

System

Administration

Security

Stability

Performance

Feature

Mobile Operating System

operating system that controls a mobile device

Mobile OS

Symbian OS

iPhone OS

RIM BlackB

erry

Windows

Mobile

Linux

Palm OS

BADA

Conclusion

As Operating System controls and coordinates the use of the hardware among the various applications programs for various uses, we can say that it plays a very important role in computer system.