1. © 2009 Prentice-Hall, Inc. 1 Chapter 4 Using System Software: The Operating System, Utility Programs, and File Management Computer Skills For Preparatory Programs CS 017

2. After reading this chapter, you should be able to answer the following questions: 1. 1.What software is included in system software? 2. 2.What are the different kinds of operating systems? 3. 3.What are the most common operating systems? 4. 4.How does the operating system provide a means for users to interact with the computer? 5. 5.How does the operating system help manage resources such as the processor, memory, storage, hardware, and peripheral devices? 6. 6.How does the operating system interact with application software? 7. 7.How does the operating system help the computer start up? 8. 8.What are the main desktop and window features? 9. 9.How does the operating system help me keep my computer organized? 10. 10.What utility programs are included in system software, and what do they do? © 2009 Prentice-Hall, Inc. 2 Chapter Objectives

3. © 2009 Prentice-Hall, Inc. 3 Chapter Topics System softwareSystem software Kinds of operating systemsKinds of operating systems OS role in:OS role in: –Providing user interaction –Managing the processor –Managing memory –Managing hardware –Interacting with application software –Starting the computer

4. © 2009 Prentice-Hall, Inc. 4 Chapter Topics (cont.) Desktop and windows featuresDesktop and windows features OS role in keeping desktop organizedOS role in keeping desktop organized Utility programsUtility programs

5. System software consists of two primary types of programs:consists of two primary types of programs: –Operating system (OS): the main program that controls how your computer system functionsthe main program that controls how your computer system functions –Utility programs: Is a small program that performs general house- keeping tasks for the computerIs a small program that performs general house- keeping tasks for the computer © 2009 Prentice-Hall, Inc. 5

6. 6 System Software: The OS 1.Controls computer functions 2. The OS manages the Computer’s: HardwareHardware ProcessorProcessor MemoryMemory DevicesDevices 3. Enable software to work with the CPU 4. Responsible for management, scheduling, and interaction of tasks 5. Provides user interface

7. © 2009 Prentice-Hall, Inc. 7 System Software: Utilities Utilities:Utilities: Programs that perform computer housekeeping tasks Programs that perform computer housekeeping tasks –Manage system resources –system maintenance –file compression. –Improve efficiency –Virus prevention

8. © 2009 Prentice-Hall, Inc. 8 Operating System Categories Operating systems are classified into four categories, depending on:Operating systems are classified into four categories, depending on: 1. the number of users they serve 2. the tasks they perform. Categories:Categories: 1. 1.Real-Time (RTOS) 2. 2.Single-User, Single-Task OS 3. 3.Single-User, Multitask OS 4. 4.Multiuser OS

9. © 2009 Prentice-Hall, Inc. 9 Real-Time Operating Systems (RTOS) Systems with : 1. specific purpose 2. certain result. RTO don’t require the intervention of any users at all.RTO don’t require the intervention of any users at all. Uses include:Uses include: –Industrial machines –Robotic equipment –Automobiles –Video game consoles –Home appliances

10. © 2009 Prentice-Hall, Inc. 10 Single-User Operating Systems Single-task systems –Perform one task at a time Examples: 1.PDAs: they require single-user, single- task operating system software such as:they require single-user, single- task operating system software such as: Palm OS Palm OS Windows MobileWindows Mobile 2. Microsoft Disk Operating System (MS-DOS) Multitask systems Perform simultaneous tasks Windows MAC OS Linux

11. © 2009 Prentice-Hall, Inc. 11 Multiuser Operating Systems Known as network operating systemsKnown as network operating systems Allow access to the computer system by multiple users.Allow access to the computer system by multiple users. Manage user requests.Manage user requests. Systems include: –Linux –UNIX –Novell Netware –Windows Server 2003 –Windows XP –Windows Vista

12. © 2009 Prentice-Hall, Inc. 12 Desktop and Notebook Operating Systems PlatformPlatform Operating system combined with the processor Operating system combined with the processorEX: –Microsoft Windows/Intel –Apple Macintosh/Motorola Desktop and notebook operating systems include: –Microsoft Windows –MAC OS –Linux –UNIX

13. Windows OS family Windows ReleaseCapabilities Windows 95 -user-friendly Interface -Multi-tasking capabilities Windows XP -major update - Networking capabilities Windows 7 -Security -user-interface upgrades

14. © 2009 Prentice-Hall, Inc. 14 UNIX Multiuser, multitask operating systemMultiuser, multitask operating system Used primarily with mainframesUsed primarily with mainframes

15. © 2009 Prentice-Hall, Inc. 15 Linux Open-source operating systemOpen-source operating system Based on UNIXBased on UNIX Stable systemStable system Free to developersFree to developers May be downloaded through the InternetMay be downloaded through the Internet

16. © 2009 Prentice-Hall, Inc. 16 MAC OS First commercially available OS with point-and-click technology (graphical user interface) Mac OS X, is based on the UNIX operating system. Excellent in: – –Graphics display – –Processing capabilities – –System reliability – –Document recovery Fewer software applications available

17. © 2009 Prentice-Hall, Inc. 17 Operating Systems for Servers and Mainframes Servers – –Computers on a network that manage network resources. Mainframes – –Handle requests from hundreds or thousands of users simultaneously Operating Systems: – –Windows Server – –Unix

18. © 2009 Prentice-Hall, Inc. 18 The User Interface Enables users to interact with the computer Types of interfaces: 1. 1.Command-driven interface: -specific commands 2. Menu-driven interface: choose a command from menus. 3. Graphical user interface (GUI): display graphics use the point-and-click technology user friendly interface.

19. The user interface cont Command driven Graphical Menu driven

20. © 2009 Prentice-Hall, Inc. 20 Processor Management – –Interrupts: Is a signal that tells the OS it is in need of attention to perform a task – –Interrupt handler: special numerical code that prioritizes the requests. – –Interrupt table: A special place in RAM that the requests are placed in. – –Stack : Is a special location in RAM that the CPU puts a “memo” so it can know where he was before the interrupt.

21. © 2009 Prentice-Hall, Inc. 21 Memory and Storage Management The operating system allocates space in RAM for instructions and data.The operating system allocates space in RAM for instructions and data. RAM Operating System OS gets ready data to process OS ensure there are free space to allocate data OS clears items from RAM when the processor no longer needs

22. © 2009 Prentice-Hall, Inc. 22 Virtual Memory Operating System FULL

23. Virtual Memory Virtual Memory : – –The process of optimizing RAM storage by borrowing hard drive space. – –Swap File: OS moves from RAM the data or instructions that have not been recently used to a temporary storage area on the hard drive. – –Paging : OS swaps the needed data or instructions back from the hard drive into RAM. – –Thrashing: The condition of excessive paging. © 2009 Prentice-Hall, Inc. 23

24. © 2009 Prentice-Hall, Inc. 24 Virtual Memory Operating System RAM Hard Disk Data & instruction not recently Used Data & instruction needed now

25. © 2009 Prentice-Hall, Inc. 25 Hardware and Peripheral Device Management Device drivers –Programs that enable the operating system to communicate with peripheral devices –Provided by the manufacturer of the device Plug and Play (PnP) –Driver preinstalled in Windows –PnP is Hardware and software standard –PnP facilitates the installation of new hardware (immediately use the device, when it plugged to the port)

26. © 2009 Prentice-Hall, Inc. 26 Software Application Coordination Application programming interfaces (APIs)Application programming interfaces (APIs) –Blocks of code contained in the operating system, so that the software programs can work with the CPU. –API code must recognize by CPU. –Coordinates the operating system (OS) with software applications Similar toolbars and menusSimilar toolbars and menus API Ex: Microsoft DirectX

27. © 2009 Prentice-Hall, Inc. 27 Starting the Computer The Boot Process Step 1: The basic input/output system (BIOS) is activatedStep 1: The basic input/output system (BIOS) is activated Step 2: A power-on self-test (POST) checks attached hardwareStep 2: A power-on self-test (POST) checks attached hardware Step 3: The operating system loads into RAMStep 3: The operating system loads into RAM Step 4: Configuration and customization settings are checkedStep 4: Configuration and customization settings are checked

28. © 2009 Prentice-Hall, Inc. 28

29. © 2009 Prentice-Hall, Inc. 29 Handling Errors in the Boot Process Safe modeSafe mode –Windows does not boot properly –Try rebooting –Uninstall any new devices or software

30. © 2009 Prentice-Hall, Inc. 30 Chapter 4 Summary What software is included in system software? What are the different kinds of operating systems?What are the different kinds of operating systems? What are the most common desktop operating systems?What are the most common desktop operating systems? How does the operating system provide a means for users to interact with the computer? How does the operating system help manage: – –the processor? – –memory and storage? – –hardware and peripheral devices? How does the operating system interact with application software?

31. © 2009 Prentice-Hall, Inc. 31 How does the operating system help the computer start up? What are the main desktop and windows features? How does the operating system help me keep my computer organized? What utility programs are included in system software, and what do they do? Chapter 4 Summary