CHAPTER 3 System Software 3 Objectives By the

CHAPTER 3 System Software 3

Objectives • By the end of this lecture, you should know how to: 3 – Describe the differences between system software and application software. – Discuss the three basic functions of any operating system. – Describe three categories of operating systems. – Discuss the purpose of utilities and utility suites. – Identify the five most essential utilities. – Define device drivers. – Discuss language translators.

Systems Software • Background software that helps you interact with the computer • Designed to handle 3 – Technical details – Where programs stored – How commands executed – Where files saved – How output handled

Four Kinds of Programs • Operating system • Utilities • Device drivers • Language translators 3

Operating Systems • Every operating system performs three basic functions: 1. Resource management • coordinate keyboard, mouse, printer, monitor, storage devices, and memory. 2. Provide a user interface • users interact with application programs and computer hardware through a windows-like graphical user interface (GUI) that use graphic objects called icons to represent commonly used features. 3. Run applications 3 • the OS loads and runs application programs, such as word processors and spreadsheets, and support multitasking, which is the ability to run more than one application at a time.

Operating Systems • Some widely used operating systems are: • Windows • Mac OS • Unix 3

Windows 3 • Windows is the most popular microcomputer operating system. • Windows gets its name from its use of rectangular boxes called windows. • Over 80 percent of the market now uses Windows. • It is designed to run with Intel and Intel compatible microprocessors such as Pentium IV.

Windows • Versions of Windows include – Windows 95 – Windows 98 – Windows 2000 – Windows ME – Windows XP 3

Windows • Multitasking - different programs running simultaneously with this operating system. • The user interface of Windows is called the desktop. • The desktop has two views: – Classic – Web style – look and feel of Internet Explorer browser. 3 • Windows and many other operating systems store information in a system of files and folders. • Files are used to store data and programs and are stored on a secondary storage device such as the hard disk. • Related files are stored within a folder, and for organization purposes, a folder can contain other folders.

Windows • The common way for users to interact with the Windows operating system is by selecting icons. • The Start Menu of Windows displays a list of commands used to: 3 – – – – Gain access to information. Change hardware settings. Find information. Get online help. Run programs. Log off a network. Shut down the computer.

Mac OS • • Operating system designed to run only on Macintosh computers. It is a very powerful and easy to use operating system and comes in a variety of versions. Its market share is much less than Windows. Mac OS includes several unique features: – 3 – – Sherlock - an innovative search feature for locating information on the Web or hard drive. Aqua – an intuitive user interface. Dock – provides a flexible tool for organizing files.

Unix Linux • • • 3 • Unix The Unix operating system was originally designed to run on minicomputers in network environments. A powerful operating system for microcomputers and servers on the Web. One important version of Unix is called Linux is not a proprietary operating system (it is not owned and licensed by a company). It was developed in 1991 by Linus Torvalds, a graduate student at the University of Helsinki. Torvalds provided the operating system free to others.

Categories of OS 1. Embedded – hand-held 2. Network OS – linked computers 3. Stand-alone OS – desktop 3

Categories of OS 1. Embedded operating systems: • Used for handheld computers and smaller devices like PDAs. • Completely stored within the device in its ROM memory. • Popular embedded operating systems include Windows CE and Palm OS. 3

Categories of OS 3 1. Network operating systems (NOS): • Used to control and coordinate computers that are linked together. • Typically located on one of the connected computers hard disks. • Called the network server, this computer coordinates all communication between linked computers. • Popular network operating systems include Net. Ware, Windows NT Server, Windows XP Server, and UNIX.

Categories of OS 1. Stand-alone operating systems (desktop operating systems): • • • Control a single desktop or notebook computers. Located on the computer’s hard disk. Often desktop computers and notebooks are part of a network. – The desktop operating system works with the network’s NOS to share and coordinate resources. – Referred to as the client operating system • 3 Popular desktop operating systems include Windows, Mac OS, and some versions of UNIX.

Utilities • Utilities are specialized programs designed to assist users with tasks that will help run their computers without problems. • Most operating system programs provide some utility programs. 3 • More powerful utility programs can be purchased.

Essential Utilities • • • 3 Troubleshooting Antivirus Uninstall Backup File compression

Utilities • Troubleshooting • programs that recognize and correct problems. • Antivirus • programs that guard your computer against viruses. • Uninstall • programs that allow you to remove unneeded programs from your hard disk. • Backup programs • programs that make copies of your files. • File compression programs 3 • programs that reduce the size of files.

Windows Utilities • Backup – utility program that makes a copy of selected or all files that have been saved onto a disk. It helps to protect you from the effects of a disk failure. • Disk cleanup – troubleshooting utility that identifies and eliminates nonessential files. This frees up valuable disk space and improves system performance. • Disk defragmenter – utility program that locates and eliminates unnecessary fragments and rearranges files and unused disk space to optimize operations. 3 • These utilities can be accessed from the Systems Tools menu.

Utility Suites • Several utility programs sold in a package is called a utility suite. • The cost of the utility suite package is less than buying the programs separately. • Two best-known utility suites are: 3 – Mc. Afee Office. – Norton System Works. – Data. Fellows

Norton System Works • • • Norton System Works includes a suite of five separate program groups. Each group can be purchased separately or as part of the suite. The five groups of Norton System Works are: 1. Norton Utilities – a collection of 17 separate trouble-shooting utilities. 3 – – finding and fixing problems improving system performance preventing problems from occurring troubleshooting other problems

Norton System Works 2. Norton Anti. Virus – a collection of antivirus programs. – protection from over 21, 000 different viruses – quarantine or delete existing viruses – automatically update its virus list to check for newest viruses 3

Norton System Works 3. Norton Clean. Sweep – a collection of programs to safely remove programs and files. – Archive, move, backup files – Clean up your hard drive – Protects existing files from damage 4. Norton Crash. Guard – a collection of troubleshooting utilities. 3 – automatically protects against programs that crash or freeze the display screen – provides options to recover your current work before an event causes a crash or freeze

Norton System Works 5. Norton Web Services – utilities to keep you alert. – monitors system for out-of-date software – notifies you of available software updates that can be installed from the Internet 3

Device drivers • Specialized programs • Loaded into memory each time • Add new device: install device driver – Whenever a new device is added to the computer system, a new device driver must be installed before the device can be used. 3

Device drivers • Drivers work with the operating system to allow communications between the device and the rest of the computer system. • Many times, device drivers are available directly from the manufacturer’s Web site. • Windows provides an Add/Remove Hardware Wizard that offers step-by-step guidance for the installation and removal of device drivers. 3

Language translators 3 • Language translators convert human-oriented programming languages to machine language. • Computers only understand a language consisting of 0’s and 1’s called machine language. • To ease the burden of programming entirely in 0’s and 1’s, special programming languages were develop that more closely approximate human language. • Language translators convert these programming statements into the zeros and ones that the computer is able to process.