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CHAPTER 4

Operating Systems

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Chapter Objectives

Define an operating system and its main

functions.

List the main operating systems in use today.

Identify the features and advantages of a CLI.

Identify the features and advantages of a GUI.

Explain DOS.

Compare major operating systems.

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Common operating systems are: Microsoft Windows, Mac OS, UNIX, Linux.

The operating system is basically the ‘manager’ of the computer

Without an operating system no other software applications could work.

The OS must manage processor resources, memory, storage, input/output and the user interface.

Introduction to Operating Systems

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Manage Memory Manage CPU resources Manage Storage Resources Control Input and Output Establish Basic Elements of the User

Interface

Operating System Basic Tasks

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User Interfaces

A user interface can be broadly defined as the space or environment where interaction between humans and machines occurs.

A good user interface does the following:

• Allows the user to manipulate a system

• Allows the system to indicate the effects of the users' manipulation

.

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Command Line Interface (CLI)

Early computers used a command line interface that required users to type memorized commands to run programs and accomplish tasks.

Graphical User Interface (GUI)

A GUI is an interface built around visual things

Two Types of Computer Interfaces

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Disk Operating System

DOS

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DOS: Disk Operating System

• DOS is an acronym for Disk Operating System.

• DOS was released in 1981 by Microsoft and was a non-graphical command line operating system.

• DOS is considered the first commercial operating system to be released for use on a microcomputer.

DOS

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First developed in 1981

Pronounced as”gooey” or”gee you eye” GUI uses windows, icons, and menus to

execute such command such as opening files or folders, moving, copying or deleting files.

Easy to learn and use.

Graphical User Interface (GUI)

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In 1983 Apple releases the LISA

computer as the first GUI computer.

Graphical User Interface (GUI)

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A GUI is an interface built around visual things:

Windows are areas of the screen that are used to display information or controls

Icons are small graphics that are used to represent tasks and applications.

Menus are graphical boxes that list options the user can select from.

A pointer is graphic that can be moved around the screen to select tasks.

Graphical User Interface (GUI)

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Graphical User Interface (GUI)

Microsoft Windows GUI

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CLI versus GUI

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CLI versus GUI

• Because of the memorization and familiarity needed to operate a command line interface new users find it much more difficult

• Users have much more control of their file system and operating system in a command line interface.

• Does not offer the ability to view multiple things at once on one screen.

• Command line Interface is fast.

• A computer that is only using the command line takes a lot less of the computers resources.

CLI

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CLI versus GUI

• Easy to learn and use.

• Using a mouse and keyboard to control your operating system for many things is going to be much slower than someone who is working in a command line.

• A GUI will require a lot more system resources because of each of the elements that need to be loaded such as icons, fonts, etc.

• GUI users have windows that enable a user to easily view, control, and manipulate multiple things at once.

GUI

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Using a CLI Within Microsoft Windows

• Easy to learn and use.

• Using a mouse and keyboard to control your operating system for many things is going to be much slower than someone who is working in a command line.

• A GUI will require a lot more system resources because of each of the elements that need to be loaded such as icons, fonts, etc.

• GUI users have windows that enable a user to easily view, control, and manipulate multiple things at once.

GUI

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Other Operating Systems

• UNIX is a powerful OS

• Originally designed for network computers

• Developed by Bell Labs in 1960’s.

• All of the most popular Operating Systems are UNIX based with the exception of MS Windows

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Other Operating Systems

• Derived from UNIX

• Free to download

• Open source

• Powerful alternative to MS Windows

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Other Operating Systems

• Mac OS X is Apple’s current OS

• Its interface is built on a UNIX foundation

• This OS has improved stability, security and performance

• It is a great alternative to Windows 7 if you are in the market for an Apple computer

MAC OS X

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What is the best operating system?

• The Mac OS X has better security controls to limit the spread of

viruses.

• Apple computers are still much more expensive than other

computers.

• Apple computers are notoriously easy to use.

• Apple computers are designed for graphics and multimedia.

• Windows based computers have a wider selection of software.

• Windows based computers are better for gaming.

• Windows based computers do very well with graphics and

multimedia.

• Windows based computers are better for business application.

• Windows based computers have a 90% market share.

• Linux/UNIX based systems are very stable.

• Linux/UNIX has many features found in other operating systems.

• Linux is free and is open source.

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What is the best operating system?

If you are in the market for a new computer or an upgraded operating system, it is suggested that you try out different operating systems at retail stores. Talk to experts and research each operating system. In the case of Linux you can download it for free from the Internet.

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Mobile Operating Systems

A mobile operating system, also known as a mobile OS, is the operating system that controls a mobile device or other information device.

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Mobile Operating Systems

Devices running a mobile OS include:• Smart phones• Tablet computers• Personal digital assistants

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Mobile Operating Systems

Major companies producing Mobile OS:• Google• Apple• Nokia• RIM• Palm• Microsoft

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Mobile Operating Systems

Most popular mobile operating systems

• Google Android• Apple iOS• Blackberry OS

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End of Chapter

Chapter Four Complete