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Lesson 6. Introduction to Computers. The Operating System (OS). The operating system (OS) is software that controls the interaction between hardware and user software. OS main functions. Provides the user interface. Loads programs
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Lesson 6 Introduction to Computers
The Operating System (OS) • The operating system (OS) is software that controls the interaction between hardware and user software
OS main functions • Provides the user interface. • Loads programs • Coordinates how programs work withCPU, RAM, Printer, …& other software. • Manages the way information is stored on and retrieved from disks.
User Interface • The items you see and use on the computer screen are the user interface
Graphical User Interface (GUI) • A GUI is a user interface that is made up of graphic objects instead of text commands. • GUI, pronounced ‘GOO-ee’
Desktop • The computer’s main interface
Icons • The graphic objects that you see on the desktop are called icons. • Icons represent resources on the PC or network.
Taskbar • The taskbar appears at the bottom of the Windows desktop and lets you launch and manage software programs
Start Button and Start Menu • Click the Start button to open the Start menu, which provides access to your software programs
Shortcut or Context Menu • Right-click on an object to access a shortcut or context menu that has the object’s most-used commands
Window • When a software program runs, it appears in a rectangular frame, called a window
Parts of a Window • Title bar • Minimize, Maximize and Close buttons • Scroll bars • Toolbars • Menu bar
Active Window • The window that is currently in use
Menus and the Menu Bar • You choose some tasks from commands in lists called menus, accessed from the menu bar
Dialog Box • Special-purpose window that gives you choices for what you want the software to do next
Running Programs • System calls – • request services from the OS.Example: we want the word processingprogram to retrieve a file
Clipboard Sharing information • Temporary holding area for data that is being copied or moved • Choosing Edit: Cut or Copy places information on the Clipboard • Edit: Paste places the information from the Clipboard into the document(Object Linking and Embedding)
Multitasking • The computer’s ability to perform two or more procedures simultaneously
Two Kinds of Multitasking • Cooperative multitaskingCurrently running programs will periodically check the OS to see whether any other programs need the CPU • Preemptive multitaskingassigns a priority to each program in a list that contains running programs
File Management • Manage files by saving them in folders in a hierarchical file system
How the Operating System Manages Hardware • Processing InterruptsOS uses interrupt requests (IRQs) to CPU • Providing Drivers“drive” – the hardware device • Networking computersThe network server manages the flow of data.
Utility • A utility is a software program that enhances or extends the operating system’s capabilities
Kinds of Utilities • Disk defragmenter • Data compression • Backup • Disk management • Screen savers • Antivirus • Firewall – Intrusion Detection
Review Questions • What is the Operating System? • What is a Graphical User Interface? • What is the Clipboard? • What are the two kinds of multitasking?
UNIX • Old operating system, developedby Bell Labs in the 1970s • Still used today in insurance, medicine, banking, manufacturingand Web servers • Many versions : AT&T (System V), Berkeley (BSD) IBM (AIX), SUN (Solaris) • Command-line interface
MS-DOS • Most popular PC operating system during the 1980s and early 1990s, now obsolete • Command-line interface • Supported only one user and a single processor. • Load only one application into memory at a time • Designed to recognize only 640KB of RAM
Macintosh • Offered first graphical user interfacebeginning in the mid-1980s • Mac OS was ahead of Windows with many features, network support , plug &play • Still popular with publishers, multimedia developers,graphic artists and schools
Windows 3.X • Windows was Microsoft’s first graphical user interface, introduced in the mid-1980s • Operating environment, not operating system, that ran on top of DOS • Windows 3.0 introduced in 1990 was Microsoft’s first successful version of Windows • Windows 3.11 -- Workgroups • Windows 3.x refers to more than one member of the Windows 3 family, nowconsidered obsolete
OS/2 Warp • Graphical user interface developed in 1982 jointly by IBM and Microsoft for Intel microprocessors • Multitasking, GUI-based OS provides built- in speech recognition • Can run on a wide range of hardware platforms. • Now obsolete
Windows NT (New Technology) • Introduced in 1993, 32-bit OS 2 versions : Workstation , Server • Windows NT Workstation still used inarchitectural firms, audio and videoproduction studios and graphics studios • Windows NT server offered security features • Microsoft stopped supporting Windows NT in2001
Windows 9X • A complete OS , released in 1995 • Windows 95 was the firstmember of the Windows 9x family, 32-bit , preemptive multitasking, it continued to include older (16-bit code) • Windows 98 considered to be an upgrade of 95, includes the Internet Explorer • Released in 2000, Windows ME was the last member of the Windows 9x family, still widely used, butconsidered by experts to be obsolete
LINUX • Released in late 1990s • New version of UNIX • Distributed for free sources, “freeware” • Windows-based GUI environments --shells • Commercial version -- Red Hat , Novell Red Hat Certified Engineer program (RHCE)
Windows 2000 • Released in 2000, Combined the features of Windows 98 and Windows NT • Professional support symmetric multi-processing (SMP)up to 2 processors • Server EditionServer Standard (SMP up to 2 processors) Advanced Server (SMP up to 4 processors) Data Center Server (SMP up to 32 processors)
Windows XP • Released in 2001 • Available in two editions: home – consumer-grade andprofessional – enterprise • Digital Media Support –Media player8 • Advanced Networking and Communication universal plug & play connect multiple computers to Internet via a single connection • Advanced Mobile Computing IrComm modem support
Network Operating Systems • Run on a network server dedicated to providing various services to other computers on the network • Windows Server NT, 2000, 2003 • Novell Network NetWare, Linux server – SuSE standard SuSE Enterprise • Unix for servers
Windows .Net • Windows Sever 2003, latest addition to the server-based Windows OS family • Application Center – Web-based applications • SQL Server -- Web-based database • Commerce Server – create and Maintain e-commerce infrastructures
Embedded Operating Systems • Built into an electronic device’s circuitry • Found in devices such as PDAs automobiles, cell phones, medical equipments
The most popular embedded operating systems: • Windows XP Embeded • Windows CE .NET latest version of Windows CE support wireless Communications, multimedia and Web browsing • Palm OS • Pocket PC OS • Symbian found is “smart” cell phones from Nokia and Sony Ericsson. Feature Internet connectivity, games, multimedia, and touch screen functions
Review Questions • What is the oldest operating system? • What was the most popular operating system in the 1980s? • Which operating system was the first graphical user interface? • When was Windows first introduced?