Lecture 4

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Using Information Technology

Chapter 4System Software

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System SoftwareThe Power behind the Power

4.1 The Components of System Software

4.2 The Operating System: What It Does

4.3 Other System Software: Device Drivers & Utility Programs

4.4 Common Operating Systems

4.5 The OS of the Future: “The Network is the Computer”

4.6 Online Software & Application Software Providers: Turning Point for the Software Industry?

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4.1 The Components of System Software

Operating system - the principal component of system software

Device drivers - help the computer control peripheral devices

Utility programs - support, enhance, or expand existing programs

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4.2 The Operating System: What It Does

Booting - the process of loading an operating system into a computer’s main memory

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The Operating System: What It Does

User interface - user-controllable display screen that allows you to communicate, or interact, with your computer

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The Operating System: What It Does CPU Management

Supervisor (kernel) - program which remains in main memory while the computer is running, and directs other “nonresident” programs to perform tasks that support application programs

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The Operating System: What It Does File Management

MoveRenameDeleteCopyBack up

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The Operating System: What It DoesTask Management

Number of Users

Number of Processors

Order of Processing

Multi-tasking One One Concurrently

Multi-programming

Multiple One Concurrently

Time sharing Multiple One Round robin

Multi-processing

One or more Two or more

Simultaneously

Processing of two or more programs

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The Operating System: What It Does

Formatting (initializing) a disk - the process of preparing that disk so that it can store data or programs

Security management

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4.3 Other System Software: Device Drivers & Utility Programs

Device drivers - specialized software programs that allow input and output devices to communicate with the rest of the computer system

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Utilities: Service Programs

Backup utility - program which makes a duplicate copy of the information on your hard disk

Data-recovery utility - program which restores data that has been physically damaged or corrupted

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Utilities: Service Programs

Antivirus software - program that scans hard disks, floppy disks, and memory to detect viruses

Data compression utility - program which removes redundant elements, gaps, and unnecessary data from a computer’s storage space so that less space (fewer bits) is required to store or transmit data

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Utilities: Service Programs

Fragmentation - the scattering of portions of files about the disk in nonadjacent areas, thus greatly slowing access to the files

Defragmenter utility - program that finds all the scattered files on your hard disk and reorganizes them as contiguous files

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Utilities: Service Programs

Disk scanner and disk cleanup utilities:

Detect & remove unnecessary

files

Detect & correct disk problems

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4.4 Common Operating SystemsDesktop & Laptop Operating Systems

Platform - the particular processor model and operating system on which a computer system is based

Disk Operating System (DOS) - the original operating system produced by Microsoft, which had a hard-to-use command-driven user interface

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Desktop & Laptop Operating SystemsMac OS - operating system which runs only on Apple Macintosh computers

Mac OS X

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Desktop & Laptop Operating Systems

Microsoft Windows 3.X - released in 1992; simply a layer over DOS

Microsoft Windows 95/98 - successors to 3.X

Plug and Play - the ability of a computer to automatically configure a new

hardware component that is added to it

Microsoft Windows Me (WinMe) - Millennium Edition

Microsoft Windows XP

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Network Operating Systems

Novell’s Netware - a long popular network operating system for coordinating microcomputer-based local area networks (LANs) throughout a company or campus

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Network Operating Systems

Windows NT - Microsoft’s multitasking OS designed to run on network servers; it allows multiple users to share resources such as data and programs

Windows XP - successor to Windows NT

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Network Operating Systems

Windows XP - Microsoft’s newest OS, which combines elements of Windows 2000 and Windows Me

New GUI featured in Windows XP

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Network Operating Systems

UNIX - a multitasking operating system for multiple users with built-in networking capability and versions that can run on all kinds of computers

Sun Microsystems’ SolarisBerkeley Software Distribution (BSD)

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Network Operating SystemsLinux - a free version of UNIX, with continual improvements resulting from the efforts of tens of thousands of volunteer programmers

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Network Operating Systems

Open-source software - software which any programmer can download from the Internet for free and modify with suggested improvements

Linus Torvalds, creator of Linux

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Operating Systems for Handhelds

Palm OS - the dominant OS for handhelds, which runs the Palm and Handspring Visor, and is licensed to other companies

Windows CE (now Pocket PC) - slimmed-down version of Windows for handhelds

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4.5 The OS of the Future: “The Network is the Computer”

.Net - Microsoft’s platform for an OS for the entire Internet, designed to link unrelated websites so that people can organize all info in their lives using PCs and smaller devices

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The OS of the Future

E-speak - H-P’s version of an Internet OS, or “universal language,” that allows different websites to communicate with one another

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The OS of the Future

Jini - Sun Microsystems’ software designed to let all types of electronic gadgets on a wired or wireless network communicate with one another

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The Opposite Possibility: No One Company Dominates

Distributed System - a non-centralized network consisting of several computers and other devices that can communicate with one another

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4.6 Online Software & Application Software Providers: Turning Point for the Software Industry?

ASP (Application Service Provider) - a firm that leases software over the Internet to customers

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Network Computers Revisited: “Thin Clients” versus “Fat Clients”Thin client - users download not only data but also different kinds of application software from an online source

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Network Computers Revisited: “Thin Clients” versus “Fat Clients”

Data can be input or downloaded from online sources.

Fat client - users provide their own software and are usually responsible for any upgrades of hardware and software

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From ERP to ASP: The Evolution of “Rentalware”

ERP (Enterprise resource planning) software - large client/server software applications that help companies organize and operate their businesses

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Summary

Three components of system software: Operating system, device drivers and utility programThe principal functions of the operating system: user interface, CPU management, file management, task management, security managementCommon Operating system, Windows XP, 2000, 98, Linux, Unix, Palm OS, Windows CE