Computers:Tools for an Information AgeObjectives of Chapter 3Systems SoftwareOperating Systems: Hidden SoftwareOperating SystemKernelUser InterfacePlatformTypes of Operating SystemsOperating Systems for Personal ComputersMS-DOSMicrosoft WindowsMS-DOS Operating EnvironmentGraphical User InterfaceGUI (Graphical User Interface)Windows FeaturesThe Windows FamilyWindows 9xWindows 98 EnhancementsWindows ME EnhancementsCorporate MarketWindows NTWindows 2000Windows XPWindows XP EnhancementsWindows CEMAC OSUNIXFree BSDLinuxUNIX (FreeBSD, LINUX, etc)Networked Operating Systems (NOS)NOS FunctionsNetwork Operating SystemsOperating Systems for Large ComputersLarge Computer OSSharing the CPUMultiprocessingMultiprogramming (Multi-Tasking)Event-driven Multiprogramming ExampleEvent-driven Multiprogramming ExampleTime-SharingTime-sharing MultiprogrammingSharing MemoryMemory ManagementPartitions or RegionsForeground and BackgroundVirtual StorageVirtual Storage: Virtual MemoryMemory ProtectionSharing Storage ResourcesSharing Printing ResourcesSharing Printing ResourcesUtility ProgramsFile ManagerFile CompressionOther Utility ProgramsComputers:Tools for an Information AgeChapter 3Operating Systems: Software in the BackgroundObjectives of Chapter 3 Describe the functions of an Operating System Explain the basics of a personal computer operating system Describe the advantages of a graphical operating system Differentiate among different operating systems Explain the need for network operating systems Describe the methods of resource allocation on large computers Be able to describe the differences among multiprocessing, multiprogramming, and timesharing Explain the principles of memory management List several functions typically performed by utility programsSystems Software Definition: All programs related to coordinating computer operations Components Operating System Utility programs Program language translatorsOperating Systems: Hidden Software Serves as intermediary between hardware and applications software  User interested in application software to make the PC useful Application software is platform specific User must be aware of the type of OS User should be aware of the functions of OSOperating System The set of programs that lies between applications software and the hardware and: Manages computer’s resources (CPU, memory, peripheral devices) Establishes a user interface Determines how user interacts with operating system Provides and executes services for applications softwareKernel Manages the operating system Loaded from hard drive into memory when computer is booted Booting refers to starting the computer Loads other operating system programs from disk storage as needed Other programs referred to as nonresidentUser Interface Facilitates communication between the user and the operating system Two forms Command line Text-based Key commands Examples: MS-DOS, Unix Graphical user interface (GUI) (pronounced “gooey”) Visual images Menus Examples: X Windows (UNIX), MS Windows, Mac OSPlatform Definition:Computer hardware and operating system software that dictate what other software can run Wintel (Windows/Intel)Intel-based PC running MS Windows SPARC (Sun Microsystems)Sun based architecture running Solaris (UNIX)Types of Operating Systems Interface Command Line, GUI Single User PC, MAC Multi-user UNIX, Linux, Mainframe (Proprietary)  Network(ed) Operating System (NOS)Operating Systems for Personal Computers Platform: combination of computer hardware and operating system software Wintel (Microsoft Windows running on an Intel-based PC) is most common Common Platforms MS-DOS Windows MAC OS Unix LinuxMS-DOS Uses a command-line interface Screen provides prompts for user User types commands Largely replaced by graphical user interfaces Not user-friendlyMicrosoft Windows Began as an operating environment for MS-DOS Not a full-blown operating system; required MS-DOS Uses a graphical user interface Users can use DOS commands and interface Now a complete family of operating systemsMS-DOS Operating Environment Windows 3.1 A layer added “on top” of DOS Separates operating system from user Makes operating system easier to use Called a shellGraphical User Interface Eases access to the OS Most new computers come with Windows already installedGUI (Graphical User Interface) Aka WIMP interface Windows, Icons, Menus, Pointer On-screen pictures Icons Menus Pull down Pop up Click to activate a command or function Fast and Easy Intuitive (usually)Windows Features Long file names (up to 255 characters) Plug and Play Makes installing hardware components easier Object Linking and Embedding (OLE) Allows user to embed or link one document to anotherThe Windows Family Windows 9x Windows 95 Windows 98 Windows Millennium Edition (ME) Corporate Market Windows NT Windows 2000 Windows XP Windows CEWindows 9x Serves home/consumer market No longer a shell, but a self-contained operating system Began with Windows 95 Next Generation: Windows 98 Windows ME Many improvements over Windows 3.1Windows 98 Enhancements Internet/intranet browsing capabilities Support for state-of-the-art hardware, including DVD and multimedia Support for larger disk drives Wizards: step-by-step software for installing, configuring, and using softwareWindows ME Enhancements Multimedia support: Media Player, video editing Enhanced reliability features Home network supportCorporate Market Windows NT NT stands for “new technology” Windows 2000Windows NT Desktop looks and acts like Windows 98 Meant for corporate, networked environments Engineered for scalability (the ability to handle many users) Stronger securityWindows 2000 The latest generation of Windows NT One computer “serves” many users You identify yourself and the system knows your preferences You get “your” desktop and files, regardless of which PC you use to log into the networkWindows XP Brings consumer and corporate versions of Windows together into a single product Has Home and Professional EditionsWindows XP Enhancements Improved user interface Much clearer and uncluttered desktop More icons