Chapter 8

1. Chapter 8 Operating Systems and Utility Programs Serena Oldhouser

2. System Software • System software consists of the programs that control or maintain the operations of the computer and its devices. • Serves as an interface between user, application software, and computer hardware.

3. Two Types of System Software • Operating Systems • Set of programs containing instructions that coordinate all the activities among computer hardware resources. • Stored on hard drive • Utility Programs • Performs maintenance tasks

4. Operating System • Different sizes of computer use different operating systems • Operating system is sometimes called the platform

5. Functions of an Operating System • Starting the Computer • Recovery Disk • User Interface • Managing Programs • Managing Memory • Scheduling Jobs • Configuring Devices • Establishing an Internet Connection • Monitoring Performance • Administering Security

6. Starting the Computer • Called Booting • Cold boot- Turning on a computer that has been powered off completely • Warm boot- Restarting a computer that already is powered on • Kernel-Core of an operating system • Manages memory • Starts applications • Assigns the computers resources • Memory resident-Remains in memory while computer is running

7. Recovery Disk • Special disk used to start the computer when the hard disk becomes damaged and can not boot by itself • Also called a boot disk • Contains a few system files that will start the computer

8. Command-Line Interface • A user types commands or presses special keys on the keyboard to enter data and instructions • Uses sets of commands called the command language. • Used by advanced users • Difficult to use because they require exact spelling, grammar, and punctuation • Gives more control over setting details

9. Menu-Driven Interface • Provides menus as a means of entering commands • Easier to learn

10. Graphical User Interface • Interact with menus and visual images such as icons, buttons, and other graphical objects to issue commands • Used by most users today • Many incorporate features similar to those of a Web browser.

11. User Interface • Controls how you enter data and instructions and how information is displayed on the screen. • Three types of user interfaces • Command-line • Menu-driven • Graphical

12. Managing Programs • Single user/single tasking operating system • Allows one user to run only one program at a time • Single user/multitasking operating system • Allows one user to run two or more programs at a time • Only one program can be in the foreground at a time, others are in the background

13. Managing Programs • Multi-user • Enables two or more users to run programs simultaneously • Multiprocessing • Supports two or more processors running programs at the same time • Fault-tolerant computer • Continues to operate when one of its components fails • Duplicate components such as processors, memory, and disk drives. • Used by Airlines, communications networks & ATM’s

14. Managing Memory • Necessary to optimize the use of RAM • May run out of RAM when using multiple programs • Virtual memory allocates a portion of a storage medium to function as additional RAM • Slower then RAM

15. Scheduling Jobs • Operating system determines the order in which jobs are processed • Include receiving data from an input device, processing instruction, sending information to an output device, & transferring items from storage to memory and from memory to storage

16. Configuring Devices • Driver • Small program that tells the operating system how to communicate with a specific device • Loads each time you boot the computer • Needed by the mouse, keyboard, monitor, printer, card reader, scanner, etc.

17. Establishing an Internet Connection • Some systems include a web browser and e-mail program

18. Monitoring Performance • Program that assesses and reports information about various computer resources and devices • Used to monitor • Processor • Disks • Memory • Network usage • Used to identify problems and resolve problems

19. Administering Security • Assign User ID’s or User Name • Use Passwords • Prevents unauthorized users from accessing computer resources • Records successful and unsuccessful logon attempts

20. Operating System Utility Programs • Utility Program • Allows a user to perform maintenance-type tasks

21. File manager Formats and copies disks Displays list of files on a storage medium Checks the amount of free space Image Viewer Displays and copies the contents of a graphics file Allows the user to see the image without opening Paint or another image editing program Utility Programs

22. Uninstaller Removes programs along with any associated files Disk Scanner Detects and corrects physical and logical problems on the hard disk or floppy disk Searches for and removes unnecessary files Utility Programs

23. Disk Defragmenter Reorganizes the files and unused space on a computer’s hard disk Allows the operating system to access data more quickly and programs to run faster Reorganizes files so that they are stored in contiguous sectors Diagnostic Utility Complies technical information about the computer’s hardware and certain system software programs and then prepares a report outlining any identified problems Suggests courses of action to resolve problems found Utility Programs

24. Backup Utility Allows users to copy selected fields or an entire hard disk onto another disk or tape Many compress the size of files to use less storage space Screen Saver Displays a moving image if there is no keyboard or mouse activity for a specified period of time Utility Programs

25. Types of Operating Systems • Device –Dependant • Runs only on a specific type of computer • Proprietary software • Privately owned and limited to a specific vendor or computer model • Device-Independent • Run on computers provided by a variety of manufacturers • Allows you to retain existing application software and data files even if you change computer models or vendors

26. Three Categories of Operating Systems • Stand-alone • DOS, Windows, Mac OS X, OS/2 Warp Client, Unix, Linux • Network • Netware, Windows server, OS/2 Warp Server for e-business, UNIX, Linux, Solaris • Embedded • Windows CD . NET, Pocket PC 2002, Palm OS, Symbian OS

27. Three Categories of Operating Systems • Stand-Alone • Complete operating system that works on a desktop computer, laptop, or mobile computing device • Sometimes called, Client operating systems • Network Operating System • Designed specifically to support a network • Resides on a server • Work with Client operating systems

28. Three Categories of Operating Systems • Embedded Operating Systems • Used in most PDA’s • Resides on a ROM chip

29. Antivirus Programs Protects a computer from being infected by a virus or worm or removes any that are found Personal Firewalls Detects and Protects a personal computer from unauthorized intrusions. Monitor all transmissions to and from a computer Stand-Alone Utility Programs

30. File Compression Shrinks the size of a file Takes up less disk space then the original file Personal Computer Maintenance Identifies and fixes operating system problems Detects and repairs disk problems Stand-Alone Utility Programs