Transcript Introduction to Operating Systems

Third Edition
Chapter 1
Introduction to
Operating Systems
McGraw-Hill
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Learning Objectives
LO 1.1 Describe the purpose and functions of
operating systems
LO 1.2 Describe major events in the evolution
of operating systems
LO 1.3 List and compare the common operating
systems in use today
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An Overview of Operating Systems
• What is a Microcomputer?
– A computer built around a microprocessor
• Microprocessor is a special integrated circuit (IC) that
performs calculations and processing
• An IC (chip) is a small electronic component made up
of transistors and other miniaturized parts
• Microprocessor also called central processing unit
(CPU)
• Many other ICs in a computer
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A typical PC with components
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An Overview of Operating Systems
• What’s Inside a Microcomputer?
– A least one CPU
– Motherboard
– RAM
– ROM BIOS
– Also attached
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•
•
•
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Keyboard
Display
Printer
Pointing Device and much more
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An Overview of Operating Systems
• What’s Inside a Microcomputer?
– More About ROM BIOS
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•
•
•
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Program code for basic control of devices
Many components contain additional ROM BIOS
Device drivers install in OS for each device
ROM BIOS includes power-on-self test (POST)
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Figure 1-1 An example of a BIOS start-up
message
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An Overview of Operating Systems
• What’s Types of Microcomputers are in Use
Today?
– Desktops and Laptops
– Servers
– Handheld Devices
• Growing number and types
• Most popular are smartphones (iPhone, BlackBerry,
etc.)
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A PC laptop
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Two MacBook laptops
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An Overview of Operating Systems
• Functions of Operating Systems
– An Operating System is:
• The central control program(s) for a computer
• Loads when computer is turned on
• Kernel (main component) remains in memory
– Manages low-level OS tasks
– Acts as intermediary between applications & hardware
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An Overview of Operating Systems
• Functions of Operating Systems
– User interface
– Job management
– Task management
– Memory Management
– File management
– Device management
– Security
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The functions of an operating system
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An Overview of Operating Systems
• User Interface
– AKA the ‘shell’
– A software layer for
user interaction
– Includes the command processor
– Includes the visual components of the OS
• Character-based command line
• GUI
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Figure 1-2 MS-DOS prompt
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Figure 1-3 A typical GUI screen
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An Overview of Operating Systems
• Job management
– Controls the order and
time in which programs are run
• Task management
– Found in multitasking operating systems
– Controls the focus
– Allows user to switch between tasks
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An Overview of Operating Systems
• Memory Management
– Manages placement of
programs and data in memory
– Virtual memory manager moves code and
data to virtual memory (file on hard drive)
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An Overview of Operating Systems
• File Management
– AKA data management
– Allows the OS to read,
write, and modify data
– Data is organized into files
– Allows users to organize their files into
containers called folders or directories
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An Overview of Operating Systems
• Device Management
– Controls hardware
through device drivers
– A device driver is unique to a device
– Created by the manufacturer of the device to
work with a specific operating system
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An Overview of Operating Systems
• Security
– Provides password-protected
authentication of the user before
allowing access
– Checks user name and password
– Restricts the actions that can be performed on
a computer, customized for each user
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An Overview of Operating Systems
• Categories of Operating Systems
– Single-User/Single-tasking
– Single-User/Multitasking
– Multi-User/Multitasking
– Real-Time
– 16-, 32-, and 64-bit OSs
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Figure 1-4 Single-user/single-tasking
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Figure 1-5 Single-user/multitasking
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Figure 1-6 Multiuser/multitasking
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Figure 1-7 Example of a device containing a
real-time embedded system
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Table 1-1 Windows Memory Limits
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Yesterday’s Operating Systems
• UNIX–The OS for All Platforms
– 1975: UNIX version 6 emerged from Bell Labs
Computing Science Research Center (Bell Labs)
– OS for many platforms
– Free versions: BSD, Net BSD, Open BDS, &
Open Solaris. Commercial versions: AIX,
OpenServer (derived from SCO UNIX), & HP/UX
– Traditional CLI shell
– GNOME and KDE GUIs
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Yesterday’s Operating Systems
• The Evolution of Microcomputer OSs (cont.)
– Theoretical designs started as early as the 1820’s
– Early computers were single-purpose, with no
need for OS
– 1970s: TRS-80 and Apple II microcomputers
– OSs evolved from need for multipurpose
computers
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Yesterday’s Operating Systems
• The Evolution of Microcomputer OSs (cont.)
– The Killer App
• VisiCalc spreadsheet helped sell the Apple II
• First IBM-PC sold without a killer app
– DOS outsold CP/M for IBM-PC due to pricing
– The Second Killer App
• Lotus 1-2-3, a DOS-based spreadsheet
• Created need for IBM/PC
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Figure 1-8 Lotus 1-2-3 spreadsheet
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Yesterday’s Operating Systems
• The Evolution of Microcomputer OSs (cont.)
– Apple OS for Apple I and Apple II (non-GUI)
• 1976: Steve Jobs created Apple I and founded Apple
Computer
• 1977: Apple introduces Apple II at the West Coast
Computer Faire in San Francisco
• 1978: Added disk drives for Apple II
– GUI Apple OSs
• 1982: Apple Lisa computer
• 1984: Macintosh computer
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Yesterday’s Operating Systems
• The Evolution of Microcomputer OSs (cont.)
– GUI Apple OSs (cont.)
• 1999: Mac OS 9
– Multi-user
– Weak in memory management and multitasking
• 2001: Mac OS X
– First Mac OS based on UNIX
– Has both a GUI and a CLI
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Yesterday’s Operating Systems
• The Evolution of Microcomputer OSs (cont.)
– MS-DOS
• 1981: IBM-PC with PC-DOS by Microsoft
• Single-tasking with very limited memory support
• No native GUI
• No built-in security functions
• Microsoft developed several versions of MS-DOS
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Figure 1-9 MS-DOS prompt with the Format
command
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Yesterday’s Operating Systems
• The Evolution of Microcomputer OSs (cont.)
– OS/2 (Operating System/2)
• 1987: Version 1.0 introduced
• Developed by Microsoft and IBM
• 1.0 had costly memory and disk requirements
• 1990’s: IBM introduced OS/2 Warp mainly for servers
• 2003: IBM ended development of new versions
• 2004: IBM sold PC division to China-based Lenovo
Group
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Yesterday’s Operating Systems
• The Evolution of Microcomputer OSs (cont.)
– Microsoft Windows
• Version is a new level of Windows OS
• Edition is a unique product based on a version
(several editions per version)
• 1985: Windows 1 – a GUI on top of DOS
• 1990: Windows 3.0 provided better support for
legacy DOS applications
– Windows 3.x works in Real mode, Standard mode,
and 386 Enhanced mode
• 1992: Windows 3.1 successful with MS Office
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Figure 1-10 Windows 3.1 desktop
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Yesterday’s Operating Systems
• The Evolution of Microcomputer OSs (cont.)
– Windows for Workgroups
• DOS and earlier versions of Windows had no
built-in network support
• 1992: Windows for Workgroups 3.1 and 3.11
enabled peer-to-peer networking
• Still dependent on DOS
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Yesterday’s Operating Systems
• The Evolution of Microcomputer OSs (cont.)
– Windows NT
• 1993: First Microsoft OS to take full advantage of
the capabilities of the Intel 386 protected mode
• Two main versions of NT – one for servers and
another for desktop computers
• 1996: Windows NT 4.0 with a GUI similar to
Windows 95
• Microsoft no longer sells or supports Windows NT
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Figure 1-11 Windows NT 4.0 desktop with open
windows
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Yesterday’s Operating Systems
• The Evolution of Microcomputer OSs (cont.)
– Windows 95
• 1995: Windows 95 introduced; predated
Windows NT Workstation
• A continuation of the Windows 3.X model:
GUI on top of DOS
• Both 16-bit and 32-bit code
• A new GUI
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Yesterday’s Operating Systems
• The Evolution of Microcomputer OSs (cont.)
– Windows 98
• 1998: An upgrade to Windows 95
• More stable
• Greater integration with Internet Explorer
• More customization options
• Support for new devices like DVD drives
• Drawback: Lacked local security
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Figure 1-12 MS Windows 98 desktop with open
windows
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Yesterday’s Operating Systems
• The Evolution of Microcomputer OSs (cont.)
– Windows Me
• 2000: An upgrade to Windows 98
• Improved music, video, and home networking support
• Provided both utilities and applications for dealing with
PC software configuration, digital music, and video
• Last Windows version based on Windows 95 kernel
• Targeted the home market
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Yesterday’s Operating Systems
• The Evolution of Microcomputer OSs (cont.)
– Windows 2000
• Windows 2000: Introduced in several editions
– Windows 2000 Professional (for desktops and laptops)
– Windows 2000 Server
– Windows 2000 Advanced Server
– Windows 2000 Enterprise Edition
• Combines the best of Windows 98 and
Windows NT
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Figure 1-13 MS Windows 2000 desktop
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Yesterday’s Operating Systems
• The Evolution of Microcomputer OSs (cont.)
– Windows XP
• 2001: Several editions, but no server version
• Most common:
– Windows XP Home Edition
– Windows XP Professional (enhanced security features)
– Windows XP Media Edition
• Most editions were 32-bit
• Windows XP 64-bit Edition for Intel Itanium
processor platform
• Support life cycle for XP is ending
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Figure 1-14 MS Windows XP desktop with open
windows
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Today’s Desktop OSs
Table 1-2: Summary of Current Desktop OSs
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Today’s Desktop OSs
• Windows Vista
– 2007: A new GUI, other improvements
– But not widely adopted
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Figure 1-15 The Windows Vista desktop
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Today’s Desktop OSs
• Windows 7
– Improvements that solved problems with Vista
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Figure 1-16: The Windows 7 desktop
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Today’s Desktop OSs
• Windows File Systems
– FAT file systems
• FAT12, FAT16, FAT32, exFAT
• Logical structure includes file allocation table
and special files called directories
– NTFS
• Introduced in Windows NT
• In subsequent Windows except Windows 9x
and Windows Me
• Supports very large disk volumes and security
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Today’s Desktop OSs
• Windows File Systems
– File systems for optical drives
• CD-ROM File System (CDFS)
• Universal disk Format (UDF)
• Live File System
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Today’s Desktop OSs
• Mac OS X
– Apple used proprietary hardware
and software
– Mid-1990s to 2005: Apple used
Motorola PowerPC
– 2005 to present: Intel platform
– Mac OS X is only licensed to run
on Apple computers
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Figure 1-17 Mac OS X GUI
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Today’s Desktop OSs
• Linux
– Modeled on UNIX
– Named for original developer, Linus Benedict
Torvalds
– Begun in 1991 by Torvalds and others as
open-source for modern computers
– Written in the C language using the GNU C
Compiler (GCC)
– Many free or inexpensive bundles
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Today’s Desktop OSs
• Linux (cont.)
– Available in both 32-bit and 64-bit distributions
– Multitasking / multi-user
– Novell, Red Hat, and others distribute such
bundles
– Fastest-growing computer server OS
– Making inroads on desktop computers
– Supports several file systems
• Old Minux, ext, ext2
• Journaling in ext3, ReiserFS, JFS, XFS
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Figure 1-18 Red Hat Linux directory listing
(ls command)
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Chapter 1 Summary
LO1.1 An Overview of Operating Systems
– A computer consists of hardware and two types
of software: operating system software and
applications software.
– The operating system allows the user to interact
with the computer hardware.
– Certain computer hardware is common to most
computers. The basic components include the
processor, motherboard, RAM, ROM BIOS, video
adapter, display screen, keyboard, pointing device,
and other peripherals.
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Chapter 1 Summary
LO1.1 An Overview of Operating Systems
(cont.)
– Common computers in use today include desktops,
laptops, server systems, and handheld devices.
– Most, if not all, current operating systems provide
a user interface, job management, task management, memory management, file management,
device management, and security.
– There are four categories of operating systems:
single-user / single-tasking, single-user / multitasking, multiuser/multitasking, and real-time.
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Chapter 1 Summary
LO1.1 An Overview of Operating Systems
(cont.)
– Today’s popular operating systems for desktops
and laptops come in versions for 32-bit and 64-bit
processing. The biggest advantage of a 64-bit OS
over a 32-bit version of the same OS is that the
amount of memory supported is much greater in a
64-bit OS.
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Chapter 1 Summary
LO 1.2 Yesterday’s Operating Systems
– The history of current computers and their OSs
involved many technical advances and the
imagination of a multitude of innovative people.
– UNIX is the oldest popular operating system and
comes in versions for very large computers, as
well as microcomputers. It is a portable OS that is
usable on a variety of computer system platforms,
with only minor alterations required for the
underlying architecture.
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Chapter 1 Summary
LO 1.2 Yesterday’s Operating Systems (cont.)
– Early microcomputers included the MITS
Altair 8800, the Apple I and Apple II, Radio
Shack’s TRS-80, and the Commodore, all
introduced in the 1970s. The Apple computers
came with the Apple OS.
– Certain “killer apps,” notably VisiCalc and
Lotus 1-2-3, made microcomputers appeal to
ordinary people who were attracted to programs
that automated formerly manual tasks
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Chapter 1 Summary
LO 1.2 Yesterday’s Operating Systems (cont.)
– IBM introduced the PC in 1981, and it far
exceeded the expectations of IBM with
Microsoft BASIC in ROM and PC DOS for
computers with a floppy disk drive.
– Microsoft made MS-DOS available to
third-party PC manufacturers.
– Microsoft Windows evolved from the first version
in 1985 to Windows 7, introduced in 2009.
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Chapter 1 Summary
LO 1.2 Yesterday’s Operating Systems (cont.)
– The Apple Mac computer, introduced in 1984,
came with the MAC OS System. This OS line
continued through Mac OS 9, introduced in 1999,
and phased out after Mac OS X was introduced
2001
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Chapter 1 Summary
LO 1.3 Today’s Desktop Operating Systems
– The operating systems common today include
Windows XP, Windows Vista, Windows 7,
Mac OS X, and Linux.
– Windows supports several file systems for hard
drives and optical disks. The most feature-rich
and secure file system for hard drives is the
NTFS file system.
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Chapter 1 Summary
LO 1.3 Today’s Desktop Operating Systems
(cont.)
– Mac OS X, based on NextStep, an OS with a
UNIX kernel, runs only on Apple Macintosh
computers, and while it supports several file
systems, the preferred file system for hard drives
is HFS+.
– Linus Torvalds developed Linux as a collaborative
effort beginning in 1991. A full multitasking /
multiuser operating system, it is available in both
32-bit and 64-bit distributions and can run on
nearly any computer.
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Chapter 1 Summary
LO 1.3 Today’s Desktop Operating Systems
(cont.)
– Linux supports several file systems for hard
drives and optical disks. The most feature-rich
and secure file system for hard drives is the
ext3 file system.
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