computer application chapter 2 Operating system , detailed ppt from more detail and content please give thumbss up

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
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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

21. STORAGE-DEVICE HIERARCHY

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
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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
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