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.
Computer SystemComputer ComputerHardware Software System Application Software 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.
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
There are two types of Software1. Application Software2. System 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
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
User 1 User 2 User n Application Programs System Software Computer Hardware e.g. printer, mouse,keyboard
System Software Application SoftwareCollection of programs that enable Collection of programs written forusers to interact with hardware a specific application e.g. librarycomponents systemControls and manages the Uses the services provided byhardware system software to interact with hardware componentsIt is machine dependent It is Machine independentProgrammer must understand the Mostly programmer ignores thearchitecture of machine and h/w architecture of machine and h/wdetails to write it details to write itIt interact with h/w directly It interact with h/w indirectly through system callsWriting it is a complicated task Writing it is relatively easy
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
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.
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.
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.
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.
User interface User interact with operating system KernelCore of operating system, responsible for loading operating system
Intermed Job iator ProcessScheduling Mgmt Functions of OS File Security Mgmt Memory
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.
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.
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 - A multi-user operating system allows for multiple users to use the same computer at the same time and/or different times. Example: LINUX
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. Unix Windows XP, Vista
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. Linux Unix Windows 2000
Smaller parts of a program are loaded when needed by OS Operating systems that allow different parts of a software program to run concurrentlyOperating systems that would fall into this category are:E.GLinux Unix Windows 2000
DESKTOP SERVER MOBILE DESKTOP Types of OS MOBILE SERVER
By MICROSOFT co-operationAdvantages Disadvantages Easy to use expensiveFamiliar Update Windows Windows Not stable Not secure Gaming Supporting
By APPLE Co-operationAdvantages Disadvantages Great Not GUI gaming Better to Not all Stable Mac graphic expensive Mac software run designer Difficult mouse Secure (one click)
Advantages Disadvantages Not all Free software run Low pc Stablerequirement Linux Linux Hard to Not Source Code Secure learn, use support and install
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
AdministrationFeature Security Server Operating System Performance Stability
operating system that controls a mobile device Mobile OSSymbian RIM Windows iPhone OS Linux Palm OS BADA OS BlackBerry Mobile
As Operating System controls and coordinatesthe use of the hardware among the variousapplications programs for various uses, we cansay that it plays a very important role incomputer system.