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– NetWare– 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.

Thanks For Your Time!!