1 lecture 13 operating systems introduction to information technology with thanks to dr. hp guo dr....
TRANSCRIPT
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Lecture 13
Operating Systems
Introduction to Information Technology
With thanks to Dr. HP Guo
Dr. Ken Tsang 曾镜涛Email: [email protected]://www.uic.edu.hk/~kentsang/IT/IT3.htmRoom E408 R9
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Outline Software Basics What is an Operating System History of Operating Systems Booting the Computer Functions of Operating Systems Types of Operating Systems Utility Programs in Windows XP
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The Computer Level Hierarchy
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Software Basics Computer = Hardware + Software Software
Application software Address users' specific needs in the real world word processing, music software, image editing, games,
database programs, inventory control systems, etc.
System software Operating system Device drivers Utilities Programming software tools (compilers, debuggers, etc.)
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Computer System
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Who Creates Computer Software?
Programmers High-level language, easy for humans
C++, Java, etc Low-level language, used by CPU
Machine language Compiler
Translate high-level language into low-level language
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Compilation
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Operating Systems A set of programs containing instructions
that maintain and manage the computer resources, such as CPU, memory and input/output devices
Provide an interface through which the user can interact with the computer
The core of a computer’s system software
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History of Operating Systems Batch processing
Professional operators (humans!) combined decks of cards into batches, or bundles, with the appropriate instructions allowing them to be processed with minimal intervention
A program called a resident monitor allowed programs to be processed without human interaction
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History of Operating Systems Resident Monitors
Monitors were the precursors of modern day operating systems
The monitor started the job, gave control of the computer to the job, and when the job was done, the monitor resumed control of the machine
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Spooling Increases in CPU performance made
punched card batch processing less efficient Magnetic tape (as buffer) offered one way to
process decks faster SPOOLing
Simultaneous Peripheral Operation Online Allows I/O and CPU computations to occur in
parallel the simplest form of multiprogramming Spooling example: print spooling
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History of Operating Systems Multiprogramming Systems
allow several executing programs to be in memory concurrently
Timesharing system permits many users to share the same
CPU the CPU switches between user
sessions very quickly, giving each user a small slice of processor time
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Evolution of Operating Systems First-generation computers
Hardware: vacuum tubes and relays Human operators
Second-generation Computers Hardware: transistors Batch processing was introduced as
a means to keep the CPU busy Monitors helped with the processing spooling
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Third-generation computers Hardware: integrated circuits timesharing
Fourth-generation Computers Hardware: VLSI Today’s multi-task, multi-user
operating systems
Evolution of Operating Systems
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Functions of an Operating System?
monitor performance
provide a user interface
provide file management and other utilities
establish an Internet connection
control a network
administer security
start the computer manage programs
schedule jobs and configure devices
manage memory
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Start the Computer What is booting?
Cold boot Turning on computer that has been powered off
Warm boot Restarting computer that is powered on
Process of starting or restarting a computer
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Dual-Boot Dual-Boot permits two or more
operating systems to be installed on one computer
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How does a personal computer boot up?
Step 1. Power supply sends signal to components in system unit
Step 4. Results of POST are compared with data in CMOS chip
Step 2. Processor accesses BIOS to start computer
Step 3. BIOS runs tests, called the POST, to check components such as mouse, keyboard, and adapter cards
Step 5. BIOS looks for system files in floppy disk drive or CD/DVD drive, and then hard disk
Step 6. Kernel (core) of operating system loads into RAM
Step 7. Operating system loads configuration information and displays desktop on screen
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User Interface What is a user interface?
command-line interfacemenu-driven interface
Controls how you enter data and instructions and how information displays on screen
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GUI Graphical User Interface
User interacts with menus and visual images such as icons and buttons
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File System Hierarchical Directories
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Windows File naming Four parts
Drive Path File name File type (extension)
C:\Windows\System\WinTrust.hlp
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Single User / Multitasking
Foreground contains program you are using
Background contains programs that are running but are not in use
Working on two or more programs that reside in memory at same time
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Memory Management Optimizing use of random access memory (RAM) With virtual memory (VM), portion of hard disk is
allocated to function as RAM This process is called paging When an OS spends much of its time paging, instead
of executing application software, it is said to be thrashing
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Scheduling Job
Transferring items Transferring items between storage between storage
and memoryand memory
Sending Sending information information
to output deviceto output device
Processing Processing instructionsinstructions
Receiving data Receiving data from input devicefrom input device
Adjusts schedule based on job’s priority
A A jobjob is operation is operation the processor managesthe processor manages
Jobs
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Spooling Sending print jobs to buffer instead of
directly to printer Print jobs line up in queue Addresses the “slow-I/O vs fast-CPU”
problem
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Device Driver
Device Device DriverDriver
Program that Program that tells operating system tells operating system how to communicate how to communicate
with devicewith device
With With Plug and PlayPlug and Play, , operating system operating system
automatically configures automatically configures new devices as you install new devices as you install
themthem Also called Also called driverdriver
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Types of Operating System Stand-Alone Operating Systems
works on a desktop computer, notebook computer, or mobile computing device
Network Operating Systems designed specifically to support a network
Embedded Operating Systems Found on most mobile computers, PDAs,
and other small devices
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DOS (Disk Operating System)
D
Developed in early 1980s for personal computers
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Used command-line interface when first
developed, later included menusSHardly used today
because it does not offer GUI
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DOS: Dirty Operating System
Tim Paterson
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And More Windows
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Coming soon: Windows Vista (Longhorn)
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Windows FamilyWindows Version Year Released
Windows 3.x 1990
Windows NT 3.1 1993
Windows 95 1995
Windows NT Workstation 4.0 1996
Windows 98 1998
Windows Millennium Edition 2000
Windows 2000 Professional 2000
Windows XP 2001
Windows XP SP2 2004
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Windows XP Microsoft’s fastest, most reliable Windows
operating system Five editions:
Home Edition, Professional Edition, Tablet PC Edition,Media Center Edition,and 64-bit Edition
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Mac OS X Available only for computers manufactured
by Apple
Macintosh operating system has been model for most GUIs
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UNIX Used by power users because of its
flexibility and power Most versions
offer GUI Both a stand-alone
and a network operating system
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Unix: 1969
Dennis Ritchie
Ken Thompson
Father of C
Turing Award
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Dennis:A Professional Truck Driver
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Ken: A Chess PlayerBelle: ACM chess tournament Championship in 80, 81, 82, 86
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BSD Unix: 1977'It's very simple – you read the protocol and write the code.'"
• BSD Unix
• vi
• BSD TCP/IP
• Co-founder of Sun
• Sparc Microprocessor
• NFS(Network File System)
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Linux Popular, free, multitasking
UNIX-type operating system Open-source software code is available to
public Both a stand-alone
and a network operating system
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GNU & Linux (1991)
Linus Torvalds Richard Stallman
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Others
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Mac OS
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Network OSNetWareNetWare
Designed for Designed for client/server client/server
networksnetworks
Windows Windows Server 2003Server 2003
Upgrade to Windows Upgrade to Windows 2000 Server2000 Server
UNIX / LinuxUNIX / Linux
Multi-purposeMulti-purposeoperating systemoperating system
SolarisSolaris Version of UNIX Version of UNIX developed by Sun developed by Sun
MicrosystemsMicrosystems
Specifically for Specifically for e-commerce applicationse-commerce applications
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Embedded OS What are two operating systems for PDAs? Windows Mobile for Pocket PC Palm OS for Palm, Visor, and CLIE
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Symbian OS Open-source, multitasking operating system
designed for smart phones Make telephone calls,
save appointments, browse Web, send and receive e-mail and faxes, and more
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Utility Program System software that performs
maintenance-type tasks Also called utility
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Windows ExplorerFile Manager
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System Information
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Windows Registry A central record of all the
settings and information relating to Windows and the software and hardware you have installed on your computer
Use Regedit to change it
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Registry Editor
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Summary Software Basics What is an Operating System History of Operating Systems Booting the Computer Functions of Operating Systems Types of Operating Systems Utility Programs in Windows XP
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The pdf slides and glossary are here:
http://www.uic.edu.hk/~davetowey/teaching/CS/it1010/lectures/13.Operating.Systems.pdf http://www.uic.edu.hk/~davetowey/teaching/CS/it1010/lectures/2x2_13.Operating.Systems.pdf http://www.uic.edu.hk/~davetowey/teaching/CS/it1010/lectures/13.Glossary.pdf