Introduction to
ICT
th
By Peter Norton 7 Edition
Chapter 6A
Operating System Basics
Video Link: https: //youtu.be/aoQYWVABcmc
Functions of Operating Systems
● Provide a user interface
● Run programs
● Manage hardware devices
● Organized file storage
● Operating Systems are divided into four major types:
– Real time
– Single User/ Single tasking
– Single User/ Multitasking
– Multiuser / Multitasking
Types of Operating Systems
● Real- time operating system
– Very fast small OS
– Built into a device
– Respond quickly to user input
– MP3 players, Medical devices
Types of Operating Systems
● Single user/Single tasking OS
– One user works on the system
– Performs one task at a time
– MS-DOS and Palm OS
– Take up little space on disk
– Run on inexpensive computers
Types of Operating Systems
● Single user/Multitasking OS
– User performs many tasks at once
– Most common form of OS
– Windows XP and OS X
– Require expensive computers
– Tend to be complex
Types of Operating Systems
● Multi user/Multitasking OS
– Many users connect to one computer
– Each user has a unique session
– UNIX, Linux, and VMS
– Maintenance can be easy
– Requires a powerful computer
Multi user/Multi tasking OS
Providing a User Interface
● User interface
– How a user interacts with a computer
– The items, icons, folders we see on a computer screen are collectively known as a
User interface.
– Require different skill sets
– There are two types of user interfaces
● Graphical User interface
● Command Line interface
Providing a User Interface
● Graphical user interface (GUI)
– Most common interface
● Windows, OS X, Gnome, KDE
– Uses a mouse to control objects
– Shortcuts open programs or documents
– Open documents have additional objects
– Task switching
– Dialog boxes allow directed input
Graphical User Interface
Providing a User Interface
● Command line interfaces
– Older interface
● DOS, Linux, UNIX
– User types commands at a prompt
– User must remember all commands
– Included in all GUIs
Command Line Interface
Operating System Services
1. Running Programs
2. Saving contents of files to a disk
3. Reading contents of files
4. Sending documents to printer
5. Providing resources that let you copy or move data
6. Allocating RAM to running programs
7. Recognizing keystrokes or mouse clicks
Running Programs
● Many different applications supported
● System call
– Provides consistent access to OS features
● Share information between programs
– Copy and paste
– Object Linking and Embedding
Managing Hardware
● Programs need to access hardware
● Interrupts
– CPU is stopped
– Hardware device is accessed
● Device drivers control the hardware
Organizing Files and Folders
● Organized storage
● Long file names
● Folders can be created and nested
● All storage devices work consistently
Enhancing an OS
● Utilities
– Provide services not included with OS
– Firewall, anti-virus and compression
Enhancing an OS
● Backup software
– Archives files onto removable media
– Ensures data integrity
– Most OS include a backup package
Enhancing an OS
● Anti-virus software
– Crucial utility
– Finds, blocks and removes viruses
– Must be updated regularly
– McAfee and Norton Anti-Virus
Enhancing an OS
● Firewall
– Crucial utility
– Protects your computer from intruders
– Makes computer invisible to hackers
– Zone Labs is a home firewall
– Cisco sells hardware firewalls
Enhancing an OS
● Intrusion detection
– Often part of a firewall package
– Announces attempts to breach security
– Snort is a Linux based package
Chapter 6A
End of Chapter
