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A+ Guide to Software, 4e. Chapter 1 Introducing Operating Systems. 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”
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A+ Guide to Software, 4e Chapter 1 Introducing Operating Systems
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 A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
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) A+ Guide to Software, 4e
Figure 1-8 The Windows XP desktop and Start menu A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
UNIX • Comprises a class of operating systems • UNIX versions referred to as flavors or distributions • Chief uses: • Controlling networks • Supporting Internet-based applications A+ Guide to Software, 4e
Linux • Variation on UNIX created by Linus Torvalds • OS kernel and source code are freely distributed • Popular distributions: • SuSE (www.novell.com/linux/suse) • RedHat (www.redhat.com) • TurboLinux (www.turbolinux.com) • Used as both a server and a desktop • X Windows: GUI shells for UNIX and Linux A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
Figure 1-10 The Mac OS X desktop is intuitive and easy to use A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
Figure 1-30 The Windows XP desktop and Start menu A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
Figure 1-49 Windows XP Device Manager gives information about devices and allows you to uninstall a device A+ Guide to Software, 4e
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 A+ Guide to Software, 4e
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.com • Use search engine to locate alternative resources • Ensure that the alternative site is reputable A+ Guide to Software, 4e
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 A+ Guide to Software, 4e