Cmp104 lec 5 software and operating system
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Transcript of Cmp104 lec 5 software and operating system
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.