Chapter 02Introducing Operating Systems
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Introducing Operating Systems In this chapter you will learn: • About the various operating systems and the differences between them • How an OS interfaces with users, files, and folders, applications, and hardware • About a few OS tools you can use to examine and maintain a system 2
Operating Systems Past and Present Operating System (OS): • Manages Software • Manages Hardware • Runs Programs • Provides an Interface • Works with Files 3
DOS (Disk Operating System) • DOS was the first OS for IBM computers • Can be used in troubleshooting OS failure • Small and Fast • Used in Windows 3.1 and 3.11 (Windows 3.x) • Totally outdated
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Windows 9x/ME • Windows 9x/ME
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Covers Windows 95, 98 and ME (Millennium) Backward-compatible Built on DOS core Bridge to NT (New Technology) 5
Minimum Requirements Description Windows 95 Processor 486 or Higher RAM 8 MB
Windows 98 Pentium 24 MB
Windows Me Pentium 150 MHz 32 MB
Free Hard 50 MB Drive Space
195 MB
320 MB
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Windows NT • NT (New Technology)
Two Versions: 1. NT Workstation 2. NT Server • Eliminated DOS • Minimum Hardware Requirements: • Pentium-compatible processor or higher • 16 MB of RAM (32 MB is recommended) • 125 MB of hard disk space 7
Windows 2000 • • • • • • • • •
Upgrade of Windows NT Several Versions More stable Better network support Introduced the HCL 133 Mhz Pentium-compatable Processor 2 GB hard drive with min 650 MB free space 64 MB RAM No longer supported 8
Windows XP • • • • • • • • •
Upgrade of Windows 2000 For multi media and networking Several versions Multiple Users Advanced Security Windows Firewall Min 64 MB of RAM with 128 MB recommended Min 1.5 GB of hard drive with 2 GB recommended Min 233 Mhz CPU with 300 MHz. Can support two processors 9
Windows Vista • Upgrade of Windows XP • Improved Networking • Improved Security • Improved User Interface • Introduced the AERO interface • UAC-User Account Control • Many Versions 10
Windows Vista
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LINUX • • • • • • • • •
Open Source – Free!! Created By Linus Torvalds Distributions Live CD’s Very Low Requirements Min Pentium III or AMD Athlon 256 MB RAM 4 GB of Free Space No DOS…..X Windows 12
MAC OS • • • • • • •
Only available on Macintosh computers First introduced in 1984 Macintosh used mainly a processor by PowerPC Now recently using Intel processors Proprietary MAC OSX requires 128 MB of RAM 1.5 GB Hard drive space
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What an Operating System Does • • • • • • •
Provides a user interface Provides the user a way to manage Manages Applications Manages Hardware Manages BIOS Manages Memory Interfaces between hardware and software
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Operating System Components Two main components: • Shell-user and applications • Kernel-interacts with hardware Database of hardware and software configuration: • Registry • Ini. Inf. or Initialization files 15
An OS Provides A User Interface • The GUI or Graphical User Interface
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Command-Driven Interfaces • DOS like • Commands only • No graphics • Faster than the GUI
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Icon-Driven and Menu-Driven Interfaces • Menu • Drop Down Menu • Icons or Pictures to represent Files or Programs • Full use of a GUI • Point and Click • Uses a Desktop
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An OS Manages Files and Folders • • • • • • • •
File System FAT – File Allocation Table FAT16 and FAT32 NTFS – New Technology File System Tracks Sectors Tracks and Sectors Image HDD Image 19
Partitions and Logical Drives
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CPU Operating Modes • Real Mode (16 BIT) • Protected (32 BIT) • Long Mode ( 64 BIT)
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16 BIT - Real Mode • 16 Bits at a time • An Application has complete access to all hardware
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32 BIT Protected and 64 BIT Long Modes • The OS controls all the access to hardware • Programs get limited control
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OS and Operating Modes • DOS uses 16 BIT Real Mode • WIN 9x/Me and WIN NT/2000/XP all use 32 BIT Protected Mode • WIN XP Pro 64 BIT Edition - uses 64 BIT Long Mode and is backwards compatible • See pg.#55 figure 2-27
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How an OS Uses Device Drivers to Manage Devices
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Control Panel
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Device Manager
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