Chapter 8 Operating Systems and Utility Programs Catherine

Chapter 8: Operating Systems and Utility Programs Catherine Gifford Dan Falgares

System Software Two Types – Operating Systems • Set of instructions that coordinate all activities among computer hardware resources. • Most perform following functions: – Starting a computer – Managing programs – Managing memory – Internet connection – Utility Software • Type of software that allows a user to perform maintenance types of tasks, usually relating to managing a computer’s devices or programs.

Operating Systems (OS) • Functions – Starting a Computer • Each time you boot your computer a operating system known as the kernel is used to: – Load instructions from the hard disk to the computers memory (RAM). – Manages memory and devices – Maintains the computers clock – Starts applications – Assigns computers programs such as devices, programs, data, and information.

Operating Systems • User Interface: controls how you enter data and instructions, and how information is displayed on the screen. • Three types of interfaces: – Command-line • When a user types commands or presses special keys to enter data or instructions • Difficult to use – Menu driven • Menus as a means of entering commands • Easier to use then command-lines. No need to learn the rules of entering commands. – Graphical • Most widely used • Interact with menus and visual images such as buttons and other graphical objects to enter commands. – I. e. : Back and forward button.

Managing Programs • • • Single user single tasking – Allows one user to run one program at a time – PDAs and other small computing devices use a single user/ single tasking operating system Single user multitasking – A single user can work on two or more programs at the same time – Foreground – Background Preemptive multitasking – An advantage to preemptive multitasking would be control factors, because it controls how the computer uses its memory – Used for larger systems

Managing Programs cont. • Multiuser – Enables two or more users to run programs at the same time, i. e. networks • Multiprocessing – Operating system supports two or more processors running programs at the same time • Fault-tolerant computer – Computer with a separate processor – Continues to operate when one of its components fail, no loss of data – i. e. airline reservation systems

Managing memory • Memory management – To optimize the use of random access memory (RAM) • Virtual memory – The operating system assigned a portion of storage medium, i. e. a hard disk, to function as additional RAM – Slower than RAM – Swap file • The part of the hard disk used for virtual memory • Paging is the technique of swapping items between memory and storage – It’s a time consuming process

Scheduling jobs • Buffer – A holding zone of memory in which items are placed while waiting to be transferred from an input device or output device • Spooling – Sends print jobs to a buffer instead of directly to the printer – This enables users to work on other tasks on the computer while printing • Queue – Multiple print jobs lined up in a buffer

Configuring devices • Driver – Short for device driver, it’s a small program that tells the operating system how to communicate with a specific device – Each device on the computer, i. e. mouse and keyboard requires its own specific driver • Plug and play – Operating system automatically configures devices as you install them – Makes installation easier

Establishing an internet connection • Operating systems provide a way to establish connection. – Some include a web browser and e-mail program • Performance Monitor – program that assesses and reports information about various computer resources.

Controlling a network • Network Operating System: – Organizes and coordinates how multiple users access and share resources on a network. • Include Hardware, Software, data, and information • When not on network user uses their own operating system

Utility Programs • Def: – Type of system software that allows a user to perform maintenance-type tasks, usually related to managing a computer. • Most operating systems include several utility programs – Utility Programs • • File Manager Image Viewer Uninstaller Disk Scanner Disk Defragmenter Diagnostic utility Backup Utility Screen Saver

Utility Programs • File Manager – Performs tasks related to file and disk management • Image Viewer – Allows users to display and copy contents of a graphic file • Uninstaller – Utility that removes a program

Utility Programs • Disk Scanner – Utility that detects and corrects both physical and logical problems on the hard disk and floppy disk – Removes unnecessary files • Disk Defragmenter – Reorganizes the files and unused space on the hard disk, to allow programs to run faster.

Utility Programs • Diagnostic Utility – Compiles technical information about your computer’s hardware, then prepares a report outlining any problems. • Backup Utility – Allows users to copy or back up selected files or an entire hard disk. • Screen Saver – Developed to prevent a problem called ghosting

Types Of Operating Systems • Three Types – Stand-alone – Network – Embedded

Stand-Alone • Def: – Complete operating system that works on a desktop computer, notebook computer, and mobile device. • Examples: – – – DOS Windows XP Mac OS X UNIX Linux

Network • Def: – Designed specifically to support a network • Examples – Net. Ware – Windows Server 2003 – Unix – Linux – Solaris

Embedded • Def: – Operating system on most PDA’s and small devices, it resides on the ROM chip. • Examples – Windows CE. NET (most popular) – Windows mobile 2003 – Palm OS – Symbian OS

Stand Alone Utility Programs • Anti-virus programs • Personal Firewalls: – Utility program that detects and protects a personal computer from unauthorized intrusions • File Compression: – Shrinks the size of a file • Personal computer maintenance – Identifies and fixes operating system problems, disk problems, and has the capability of improving a computers performance.

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