Mongolia International University Operating Systems Operating Systems Chapter 2 Chapter 2 B.M.H B.M.H
Dec 13, 2014
Mongolia International University
Operating SystemsOperating Systems
Chapter 2Chapter 2
B.M.HB.M.H
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Learning ObjectivesLearning Objectives
Software ClassificationSoftware Classification System SoftwareSystem Software Operating SystemOperating System OS of PCsOS of PCs NOS NOS
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Computer SystemComputer System
HardwareHardware Input devicesInput devices Processor (CPU)Processor (CPU) Output devicesOutput devices Secondary storageSecondary storage
SoftwareSoftware System softwareSystem software Application softwareApplication software
PeoplePeople
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SoftwareSoftware
System softwareSystem software all programs related to coordinating computer all programs related to coordinating computer
operationsoperations Operating systemsOperating systems Programming language translatorsProgramming language translators A variety of utility programsA variety of utility programs
Application softwareApplication software allows user to perform useful workallows user to perform useful work
Word processing, spreadsheet software, etc Word processing, spreadsheet software, etc
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System SWSystem SW
When you think of a computer, what When you think of a computer, what first comes into your head?first comes into your head? The physical component The physical component
like the monitor, keyboard, or mouse The applications that run on your computerThe applications that run on your computer
like word processing, video game, internet browsing
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Operating SystemOperating System
An An operating systemoperating system is the software is the software needed to communicate needed to communicate application application programsprograms and computer and computer hardwarehardware to to each other. (called OS)each other. (called OS)
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OSOS
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OSOS
Serves as a intermediary Serves as a intermediary between the applications software and the between the applications software and the
hardwarehardware
The fundamental software The fundamental software that controls access to all other hardware that controls access to all other hardware
and software resourcesand software resources
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OSOS
A set of programs A set of programs that lies between the applications software that lies between the applications software
and the hardwareand the hardware KernelKernel : the most important program in OS : the most important program in OS Can be divided as remaining in memoryCan be divided as remaining in memory
Resident : Kernel Nonresident : other OS programs
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KernelKernel
The program that manages the OSThe program that manages the OS Most of it remains in memoryMost of it remains in memory
Referred to as Referred to as residentresident Controls the entire OS Controls the entire OS Loads into memory other OS programs Loads into memory other OS programs
(called nonresident) from disk storage (called nonresident) from disk storage only as neededonly as needed
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KernelKernel
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A kernel connects the application software to the hardware of a computer.
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BootingBooting
The process of loading the OS into The process of loading the OS into memorymemory
When computer is turned on,When computer is turned on, A small program stored in a ROM chip A small program stored in a ROM chip
performs some internal HW component performs some internal HW component tests,tests,
Then loads the kernel from the hard drive Then loads the kernel from the hard drive into the computerinto the computer’’s memorys memory
Called Called bootstrappingbootstrapping
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OSOS
Three main functionsThree main functions Managing the computerManaging the computer’’s resources, s resources,
such as the CPU, memory, disk drives and printers Establishing a Establishing a user interfaceuser interface Executing and providing services for Executing and providing services for
applications softwareapplications software
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User interfaceUser interface
Determines how the user interacts with the OSDetermines how the user interacts with the OS Interface : inter + faceInterface : inter + face : a way of presenting information to and obtaining : a way of presenting information to and obtaining
information from a userinformation from a user
Two basic formsTwo basic forms Command-line interfaceCommand-line interface Graphical user interface (GUI)Graphical user interface (GUI)
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User interfaceUser interface
Command-line interfaceCommand-line interface Text-basedText-based Requires you to type in complete OS commandsRequires you to type in complete OS commands Ex) MS-DOS, Unix, Linux, many large-computer Ex) MS-DOS, Unix, Linux, many large-computer
OSsOSs
Graphical user interface (GUI)Graphical user interface (GUI) Visual images and menus to allow users to Visual images and menus to allow users to
enter commandsenter commands Ex) Windows, Mac OS, some installations of Ex) Windows, Mac OS, some installations of
Linux and UnixLinux and Unix
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OSs for Personal ComputersOSs for Personal Computers OSs for NetworksOSs for Networks OSs for Large Computer OSs for Large Computer
SystemsSystems
IndexIndex
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OS for personal OS for personal computerscomputers
When you buy something for your When you buy something for your computer, you must know computer, you must know not only the OS the computer has, not only the OS the computer has, but also about its but also about its platformplatform
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OSs for Personal OSs for Personal ComputersComputers
The SW is grouped according to the The SW is grouped according to the platform, on which the SW can run.platform, on which the SW can run.
PlatformPlatform A combination of computer hardware and A combination of computer hardware and
operating system softwareoperating system software Most common families of platformsMost common families of platforms
Windows family : (referred as Wintel) Microsoft Windows + Intel processor based PC
Macintosh family Mac OS + Motorola processor
Unix family Unix + all families of processors
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MS-DOSMS-DOS
Called DOS (Disk Operating System)Called DOS (Disk Operating System) Command-line user interfaceCommand-line user interface
C:\ (disk drive)C:\ (disk drive) > : prompt > : prompt
a signal that the system is prompting you to do something
the only visible result of booting At this point, you must type command
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Microsoft WindowsMicrosoft Windows
GUIGUI Icons, menus (pull-down menus, pop-menus)Icons, menus (pull-down menus, pop-menus)
Three branches serving different usersThree branches serving different users Home/consumer market Home/consumer market
Windows 9x (95, 98, ME) Corporate market Corporate market
Windows NT, 2000 Both the consumer and corporateBoth the consumer and corporate
Windows XP
For pocket computers and Internet applianceFor pocket computers and Internet appliance Windows CE
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MAC OSMAC OS
The first commercially successful GUIThe first commercially successful GUI Based on concepts developed at XeroxBased on concepts developed at Xerox’’s s
PARC research center in Palo Alto, CaliforniaPARC research center in Palo Alto, California MAC OS XMAC OS X
Enhancement in multimedia support and Enhancement in multimedia support and multitasking-the ability to do several things multitasking-the ability to do several things at once.at once.
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UNIXUNIX
A multiuser time-sharing OSA multiuser time-sharing OS A character-based system with a A character-based system with a
command-line user interfacecommand-line user interface The primary OS in use on Internet The primary OS in use on Internet
server, todayserver, today Run on about every type of computer Run on about every type of computer
available from microcomputers to available from microcomputers to mainframesmainframes
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LINUXLINUX
Linus Torvalds, a student at the Univ. Linus Torvalds, a student at the Univ. Of Helsinki in FinlandOf Helsinki in Finland Created the kernel of a Unix-like OS Created the kernel of a Unix-like OS Made the source code available to the Made the source code available to the
public free of chargepublic free of charge Command-line interface, also provide a Command-line interface, also provide a
GUIGUI
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OSs for NetworksOSs for Networks
NOS (Network Operating System)NOS (Network Operating System) An extension of OSs for PCsAn extension of OSs for PCs Designed to let computers on a network Designed to let computers on a network
share resourcesshare resources Similar to a standard OS but include special Similar to a standard OS but include special
features for handling network functionsfeatures for handling network functions Ex) Windows 2000Ex) Windows 2000
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NOSNOS
FunctionsFunctions Resource sharing on a networkResource sharing on a network
Such as hard disks and printers Data securityData security
Does this user have the right to that data? TroubleshootingTroubleshooting
Computer *** on the network failed to receive a message intended for it
Administrative controlAdministrative control Track the online hours and track the number of
messages to and from each computer
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NOSNOS
In a client/server relationshipIn a client/server relationship Parts of the NOS : on Server computer Parts of the NOS : on Server computer
file access, management programs Other NOS components : on Client computerOther NOS components : on Client computer
software that permits requests to the server and messages to other computers
Client computers has its own OS (ex, Windows ME)