1. A+ Guide to Software, 4e Chapter 1 Introducing Operating Systems

2. A+ Guide to Software, 4e2/28 Operating Systems Past and Present What an operating system (OS) does: –Manages hardware –Runs applications –Provides an interface for users –Retrieves and manipulates files The OS can be analogized to a “middleman” A computer needs only one operating system Operating systems have evolved to a complex form

3. A+ Guide to Software, 4e3/28 DOS (Disk Operating System) The first OS used by IBM computers/compatibles Where DOS can still be found: –Specialized systems using older applications –On troubleshooting disks or CDs Windows 3.x and DOS –Windows 3.x provided a graphical interface –Underlying OS functions were performed by DOS Windows 9x/Me uses DOS in the underlying OS Windows XP/2000 run DOS emulation programs

4. A+ Guide to Software, 4e4/28 Windows 9x/Me Refers to Windows 95, Windows 98, Windows Me Combine a DOS core with graphical user interface Designed to bridge legacy and newer technologies –Backward-compatible with older systems –Able to accommodate new technologies Cautionary note on minimum requirements –May differ for upgrades and new installations –May differ for installation and run-time operation

5. A+ Guide to Software, 4e5/28 Windows NT Two versions of Windows NT (New Technology): –Windows NT Workstation for desktops –Windows NT Server to control a network Best known feature: new OS core replacing DOS Avoid installing Windows NT –Windows NT introduced many new problems –Problems only solved in later versions of Windows

6. A+ Guide to Software, 4e6/28 Windows 2000 Upgrades Windows NT (both desktop and server) Improvements over Windows NT: –A more stable environment –Support for Plug and Play –Device Manager, Recovery Console, Active Directory –Better network support –Features specifically targeting notebook computers OS includes only qualified hardware and software Windows 2000 is being phased out

7. A+ Guide to Software, 4e7/28 Windows XP Integrates Windows 9x/Me and Windows 2000 Two main versions: Home Edition and Professional Noteworthy new features: –Allows two users to logon and open applications –Incorporates Windows Messenger and Media Player –Adds advanced security, such as Windows Firewall Hardware requirements –64 MB RAM (128 MB recommended) –1.5 GB free hard drive space (2 GB recommended) –233-MHz CPU speed (300-MHz recommended)

8. A+ Guide to Software, 4e8/28 Figure 1-8 The Windows XP desktop and Start menu

9. A+ Guide to Software, 4e9/28 Windows Vista Next generation of Windows operating systems Code-named Longhorn Noteworthy new features: –New graphical interface –Revamped engine –A new interface between it and applications Scheduled release dates: –November 2006 for business editions –January 2007 for consumer editions

10. A+ Guide to Software, 4e10/28 Windows Server 2003 Refers to a suite of Microsoft operating systems: –Windows Small Business Server 2003 –Storage Server 2003 –Server 2003 Web Edition –Server 2003 Standard Edition –Server 2003 Enterprise Edition –Server 2003 Datacenter Edition Not designed for use in a PC Not covered in this text

11. A+ Guide to Software, 4e11/28 UNIX Comprises a class of operating systems UNIX versions referred to as flavors or distributions Chief uses: –Controlling networks –Supporting Internet-based applications

12. A+ Guide to Software, 4e12/28 Linux Variation on UNIX created by Linus Torvalds OS kernel and source code are freely distributed Popular distributions: –SuSE (www.novell.com/linux/suse)www.novell.com/linux/suse –RedHat (www.redhat.com)www.redhat.com –TurboLinux (www.turbolinux.com)www.turbolinux.com Used as both a server and a desktop X Windows: GUI shells for UNIX and Linux

13. A+ Guide to Software, 4e13/28 OS/2 Jointly developed by IBM and Microsoft Chiefly used in certain types of networks Part of OS/2 was incorporated into Windows NT OS/2 is not covered in this book

14. A+ Guide to Software, 4e14/28 Mac OS First introduced in 1984 with Macintosh computers Current version: Mac OS X (ten) Mac OS X can work on some Intel-based computers Markets: education, desktop publishing, graphics Noteworthy features: –Support for graphics and multimedia capabilities –Use of the Finder program to provide the desktop –Superior Plug and Play capabilities –Excellent support for multitasking

15. A+ Guide to Software, 4e15/28 Figure 1-10 The Mac OS X desktop is intuitive and easy to use

16. A+ Guide to Software, 4e16/28 What an Operating System Does Four functions common to all operating systems: –Providing a user interface –Managing files –Managing applications –Managing hardware All OSs also have similar core components

17. A+ Guide to Software, 4e17/28 Partitions and Logical Drives on a Hard Drive Hard drives are organized into partitions Two types of partitions –Primary: can only have one logical drive; e.g., C:\ –Extended: can have one or more logical drives Logical drive (sometimes called a volume) –Formatted using a file system –Has a root directory and subdirectories Disk Management tool –Used to create/view partitions, format logical drives

18. A+ Guide to Software, 4e18/28 Real (16-bit), Protected (32-bit), and Long (64-bit) Operating Modes Bit type: number of bits simultaneously processed Real (16-bit) mode –Exposes hardware to application (no longer used) –Example: DOS Protected (32-bit) and Long (64-bit) modes –OS controls how an application accesses hardware –Preemptive multitasking is supported –Example: Windows XP Professional x64 Edition Multiprocessing involves multiple CPUs

19. A+ Guide to Software, 4e19/28 16-bit, 32-bit, and 64-bit Software 16-bit software –Written for Windows 3.x –Data access is 16 bits at a time 32-bit programs –Written for Windows NT/2000/XP and Windows 9x/Me 64-bit programs –Written for Windows XP Professional x64 Edition Most software today is 32-bit or 64-bit

20. A+ Guide to Software, 4e20/28 An OS Manages Hardware OS interacts with hardware using drivers or BIOS Software falls into three categories: –Device drivers or the BIOS –Operating system –Application software

21. A+ Guide to Software, 4e21/28 How an OS Manages Memory Memory functions performed by OS at startup –Launches utilities to manage memory –Assigns addresses to each location of memory Drivers, OS, and application use memory addresses –Enables three software layers to refer to shared data 16-bit program in real mode has direct access to RAM The OS controls memory access in protected mode –The address spaces of a program is protected –Virtual memory expands number of running programs

22. A+ Guide to Software, 4e22/28 OS Tools to Examine a System A variety of tools are available: –The Windows Desktop –My Computer and Windows Explorer –System Properties –Control Panel –Device Manager –System Information –Windows Help and the Microsoft Web Site

23. A+ Guide to Software, 4e23/28 Figure 1-30 The Windows XP desktop and Start menu

24. A+ Guide to Software, 4e24/28 Control Panel Contains applets used to manage the system Accessing Control Panel in Windows XP –Click Start and the click Control Panel Two views: Category View and Classic View Applets can be launched via the Run dialog box –Example: enter Main.cpl to open Mouse Properties

25. A+ Guide to Software, 4e25/28 Figure 1-49 Windows XP Device Manager gives information about devices and allows you to uninstall a device

26. A+ Guide to Software, 4e26/28 System Information Used to view detailed information about the system Important features –BIOS version you are using –The directory where the OS is installed –How system resources are used –Information about drivers and their status To open utility, enter Msinfo32.exe in Run dialog box

27. A+ Guide to Software, 4e27/28 Windows Help and the Microsoft Web Site Key guide to system Excellent troubleshooting resource –Example: analyze problem with Internet connection Microsoft Web site: http://support.microsoft.comhttp://support.microsoft.com Use search engine to locate alternative resources –Ensure that the alternative site is reputable

28. A+ Guide to Software, 4e28/28 Keystroke Shortcuts in the OS Simplify interaction with the operating system Examples –Function keys: F4, F5, F8 –Text editing operations: Ctrl+C, Ctrl+V, Ctrl+x Shortcut keys are critical when mouse is not working