Introduction to Operating system CBSE
- 1. INTRODUCTION TO OS (OPERATING SYSTEM)
- 2. SOFTWARE • Instructions that tell the computer how to process data into the form you want. • Software and programs are interchangeable. • Two major types: • System and Applications
- 3. SOFTWARE COMPONENT • Applications • Operating System • API: application program interface • File management • I/O • Kernel • Memory management • Resource scheduling • Program communication • Security • Network Module 1-3
- 4. KINDS OF SOFTWARE 1. System Software enables the application software to interact with the computer hardware. • Operating Systems are programs that coordinate computer resources, provide an interface between users and the computer; and run applications. • Utilities perform specific tasks related to managing computer resources. • Device drivers are specialized programs designed to allow particular input or output devices to communicate with the rest of the computer system.
- 5. FUNCTIONS OF A SYSTEM SOFTWARE • Managing resources (memory, processing, storage, and devices like printer). • Providing user interface • Running applications
- 6. 2 KINDS OF SOFTWARE 2. Applications Software - provides the real functionality of a computer. It help you use your computer to do specific types of work. Basic Applications, widely used in all career areas. Specialized Applications, more narrowly focused on specific disciplines and occupations.
- 7. SYSTEM SOFTWARE HISTORY • Early computers had no operating systems and were single user systems • Programs were entered using switches for each bit or by plugging wires into a panel • 1953-54: First operating system was built by General Motors Research Laboratories for their IBM 701 computer • Other early systems • FORTRAN Monitor System (FMS) • IBSYS • Share Operating System (SOS)
- 8. WHAT IS AN OPERATING SYSTEM? • 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
- 9. OPERATING SYSTEM DEVELOPMENT • 1963: Master Control Program (MCP) by Burroughs. Included many modern OS features. • 1964: OS/360 by IBM. Included batch processing of programs. • 1962: MIT Project MAC created a time-sharing OS called CTSS. Shortly afterwards, MIT, Bell Labs, and GE developed Multics (Multiplexed Information and Computing Services).
- 10. COMPUTER SYSTEM STRUCTURE • Computer system can be divided into four components: • Hardware – provides basic computing resources • CPU, memory, I/O devices • Operating system • Controls and coordinates use of hardware among various applications and users • Application programs – define the ways in which the system resources are used to solve the computing problems of the users • Word processors, compilers, web browsers, database systems, video games • Users • People, machines, other computers
- 11. FOUR COMPONENTS OF A COMPUTER SYSTEM
- 13. WHAT OPERATING SYSTEMS DO • Depends on the point of view • Users want convenience, ease of use and good performance • Don’t care about resource utilization • But shared computer such as mainframe or minicomputer must keep all users happy • Users of dedicate systems such as workstations have dedicated resources but frequently use shared resources from servers • Handheld computers are resource poor, optimized for usability and battery life • Some computers have little or no user interface, such as embedded computers in devices and automobiles
- 14. OPERATING SYSTEM DEFINITION • OS is a resource allocator • Manages all resources • Decides between conflicting requests for efficient and fair resource use • OS is a control program • Controls execution of programs to prevent errors and improper use of the computer
- 15. OPERATING SYSTEM DEFINITION (CONT.) • No universally accepted definition • “Everything a vendor ships when you order an operating system” is a good approximation • But varies wildly • “The one program running at all times on the computer” is the kernel. • Everything else is either • a system program (ships with the operating system) , or • an application program.
- 16. COMPUTER STARTUP • bootstrap program is loaded at power-up or reboot • Typically stored in ROM or EPROM, generally known as firmware • Initializes all aspects of system • Loads operating system kernel and starts execution
- 17. COMPUTER SYSTEM ORGANIZATION • Computer-system operation • One or more CPUs, device controllers connect through common bus providing access to shared memory • Concurrent execution of CPUs and devices competing for memory cycles
- 18. COMPUTER-SYSTEM OPERATION • I/O devices and the CPU can execute concurrently • Each device controller is in charge of a particular device type • Each device controller has a local buffer • CPU moves data from/to main memory to/from local buffers • I/O is from the device to local buffer of controller • Device controller informs CPU that it has finished its operation by causing an interrupt
- 19. STORAGE STRUCTURE • Main memory – only large storage media that the CPU can access directly • Random access • Typically volatile • Secondary storage – extension of main memory that provides large nonvolatile storage capacity • Hard disks – rigid metal or glass platters covered with magnetic recording material • Disk surface is logically divided into tracks, which are subdivided into sectors • The disk controller determines the logical interaction between the device and the computer • Solid-state disks – faster than hard disks, nonvolatile • Various technologies • Becoming more popular
- 20. STORAGE HIERARCHY • Storage systems organized in hierarchy • Speed • Cost • Volatility • Caching – copying information into faster storage system; main memory can be viewed as a cache for secondary storage • Device Driver for each device controller to manage I/O • Provides uniform interface between controller and kernel
- 22. FUNCTIONS OF OPERATING SYSTEM • Process management- managing all running processes. • Memory management, • File management, • Networking and security, • Device management, • Error detecting aids, • Coordinate between other software and users.
- 23. TYPES OF OPERATING SYSTEM • Single user operating system • Real-time operating system • Multi-user and single-user operating system • Multi-tasking and single – tasking operating system • Multi- purpose operating system • Distributed operating system • Embedded system
- 24. POPULARLY USED OPERATING SYSTEM • MS-DOS- 16 bit operating system developed by Microsoft for IBM in aug 1981. does’nt support multiple user or multi tasking • Unix-used for multitasking and multi user, it was developed from the original AT&T unix, in 1969 at the Bell labs research center by Ken Thompson, Dennis Ritchie. • Linux- this operating system is becoming very popular with networking professionals. • Mac OS- this OS developed by APPLE INC. • Windows- most popular, and developed by Microsoft, win-7,8,10. • BOSS(Bharat operating system solution)- Developed by Centre for development of advanced computing(CDAC), Chennai INDIA. • Ubuntu- developed by UK- based Canonical ltd, owned by Mark shuttleworth in oct 2004.
- 25. UNIX • After Bell Labs withdrew from the Multics project, Ken Thompson developed a personal operating system called UNIX using assembly language. • Dennis Ritchie developed the programming language C which was used to rewrite much of UNIX in a high-level language. • UNIX introduced • A hierarchical file system • The shell concept • Document production and formatting • Tools for networked and distributed processing Copyright 2010 John Wiley & Sons, Inc. 1-25
- 26. MOBILE OPERATING SYSTEM • Android os- Google open source and free software for use on mobile devices. • IPhone OS/IOS- developed by APPLE Inc , used in apple devices(iphone’s), Ipad. • Symbian OS- most popular os until the end of 2010, used by nokia, Samsung, sony, htc.
- 27. GRAPHICAL USER INTERFACES • 1960s: Doug Englebart (Stanford Research Institute) • Invented windows and a mouse interface • 1970s: Xerox PARC • Creates a practical windowing system for the Dynabook project • 1980s: Steve Jobs (Apple) • Developed the Apple Lisa and MacIntosh 1-27
- 28. IBM PC • 1982: Stand-alone, single user computer • PC-DOS, MS-DOS (disk operating system) • Later versions of DOS added • Hierarchical directory file storage • File redirection • Better memory management • Windowing systems • Windows 2.0, Windows 3.1, Windows 95 • Windows NT, Windows XP, Windows Vista • Windows 7 1-28