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CSC 204: Information Technology and Networking
PART
I
Chapters
1. System Unit
2. Specialized Application Software
3. System Software
Chapter 3
System Software
Ralph El Khoury, Wajdi Abboud
Outline
• System software: definition and types
• Booting procedure
• Operating systems
– Definition, functions, features and categories
– Types: Windows, Mac OS, Unix/Linux
• Utilities
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System software
Definition and types
•
It is a collection or a system of programs that handle hundreds
of technical details with little or no user intervention.
•
There are 4 types of programs that makeup system software
1. Operating systems (OS) - coordinate computer resources, provide an
interface between users and the computer, and run applications.
2. Utilities - perform specific tasks related to managing computer
resources.
3. Device drivers - specialized programs that allow particular input or
output devices to communicate with the rest of the computer system.
4. Language translators - convert the programming instructions written
by programmers into a language that computers understand and
process.
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Booting procedure
• Bootstrap program
– transfers the operating system from mass storage into main memory
• BIOS (Basic Input Output System)
– A collection of software functions for diagnostic operations while
booting
• i.e., that verify the good operation of physical devices connected to the
computer while booting. E.g., keyboard, screen, mass storage
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Operating Systems
Definition and functions
•
An operating system is a collection of programs that handle
many of the technical details related to using a computer.
• An operating system is the most important type of computer
program.
Main Functions
1. Managing resources
–
memory, processes, storage, and devices such as printers and
monitors.
2. Provide user interface
–
3.
Almost all newer operating systems use a graphical user interface
(GUI).
Running applications
–
load and run applications and support multitasking
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Operating Systems
Functions
1.
Managing resources
a.
Memory management
•
Charged with the task of coordinating the machine's use of main
memory
–
–
b.
File management
•
Organizes file storage on the mass storage
–
–
•
c.
E.g., allocating and managing space for data and programs
E.g., attribute a virtual memory when there is no memory space available
Folders are organized in a hierarchical tree
Create a table to store the information about files. E.g. FAT32, NTFS…
Allows the access to files: copying, moving, renaming, erasing, reading
and writing
Process management
•
•
scheduler: determines which activities are to be considered for
execution
dispatcher: controls the allocation of time to these activities
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Operating Systems
Functions
d.
Use of device drivers to control the communication with devices
•
•
•
2.
Drivers control terminals (printer, USB key, mouse)
Drivers are loaded into memory when the computer starts
Each terminal has its own driver
Provide user interface (part of the resource manager)
–
Allows the user to communicate with OS
•
Graphical User Interface (GUI)
–
•
Command terminal
–
3.
window manager (a component of the OS) allocates blocks of space on the
screen and keeps track of which application is associated with each window
where a user can write commands to communicate with the OS
Running applications (part of the process manager)
–
–
–
load on RAM, run and close applications such as word processors
Control the execution of applications (step by step)
Most operating systems support multitasking:
•
•
work with many programs in the same time (seems to user)
the ability to switch between different applications stored in memory.
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Operating Systems
Features
1.
Booting : the process of starting up or restarting the
operating system.
–
–
2.
Warm boot occurs when the computer is already on, and you restart
it without turning off the power.
Cold boot is starting the computer when it is turned off.
Desktop: a place which provides access to computer
resources.
–
–
–
–
–
–
Icons: graphic representations for a program or function.
Pointer: controlled by a mouse and changes shape depending upon
its current function.
Windows: rectangular areas for displaying information and running
programs.
Menus: provide a list of options or commands.
Dialog boxes: provide information or request input.
Help: provides online assistance for operating system functions and
procedures.
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Operating Systems
Features
3. File management system
–
Organizes file storage on the hard disk
•
•
–
Folders are organized in a hierarchical tree
Create a table to store the information about files. E.g. FAT32,
NTFS…
Allows the access to files: copying, moving, renaming,
erasing, reading and writing
4. Device adaptation
–
"plug and play" standard
•
the device is quickly recognized by the OS without the
intervention of the user (or with a minimum intervention)
5. Communication management in a network
–
using communication protocols such as TCP/IP
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Operating Systems
Features
6.
Sharing resources between many programs together and
many users together
–
Multiprogramming or multitasking or time-sharing system
•
"the illusion of" more than one task are performed simultaneously
–
–
Multiprocessing
•
Parallel execution of many tasks by many processors
–
–
Many processors for many processes
Multiuser
•
7.
one processor for many programs
many users work in the same time at the same machine
Reliability
–
8.
ability to give a good operation of the system and to manage all kind
of errors
Portability
–
ability to use the OS on different type of hardware
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Operating Systems
Categories
• Embedded operating systems are used for handheld computers
and smaller devices like PDAs.
– The operating system programs are permanently stored on ROM
• Network (or server) operating systems (NOS) are used to
control and coordinate computers that are networked or linked
together.
– Typically located on one of the connected computers hard disks, called
the network server,
• this computer coordinates all communication between the other computers.
• Stand-alone operating systems, also called desktop operating
systems,
– control a single desktop or notebook computer.
– Often desktop computers and notebooks are part of a network and are
referred to as the client operating system.
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Operating Systems
Types
•
An OS is also called a platform or software
environment
–
•
Almost all application programs are designed to
run with a specific platform.
The most popular OS are:
1. Windows
2. Mac OS,
3. Unix and Linux
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Windows
• The most used system in the world
– Around 90% of the market
• More application programs are
developed to run under Windows
than any other operating system.
• Use Intel and Intel-compatible
processors
• Versions: Windows 95, 98, 2000,
Me, XP, Vista and Windows 7
• In fact, we distinguish 2 main types
of Windows
– For personal use: Windows Home and
Professional
– For enterprise: Windows Server
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Windows
• Windows Vista features
– Advanced system security to guard against
malicious files and programs, including spyware.
– Three-dimensional workspace capable of
displaying transparent cascading windows.
– New file system called WinFS (Windows Future
Storage)
• It keeps track of files stored on your computer system so
• It is possible to locate files based on a description of
their content.
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Windows
• Some other features
– Conviviality, uniform GUI, use plug and play
– Multitasking, multiprocessing, multiuser
– Network configuration and management (Wi-Fi,
Bluetooth, LAN)
– Reliability, security (firewall, permissions…)
• Remark: we can find similar features in MAC
OS and Linux systems
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MAC OS
• Designed to run with Apple
computers.
• Mac is the abbreviation of
Macintosh
• Not popular as Windows
• Fewer application programs
have been written for it.
• The last version is Mac OS X
• One of the most innovative
operating systems.
• Known for its high quality GUI
and multimedia applications
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Unix and Linux
• Unix
– Designed to work on powerful
computers and networks
• E.g., for network
administration, Web servers
– It has many versions of OS
• Linux is one of these
versions
• Linux and Unix can be
installed on many different
hardware
Information Technology and Networking
• Linux
– Not proprietary, free,
downloadable from the Web
– Open source: all the codes
implementation are known
– Invented at the University of
Helsinki by Linus Torvalds in
1991
– One of the most popular and
powerful alternatives to the
Windows operating system.
– Modifications and
improvements to the OS is
encouraged.
– Use a GUI not so convivial
– Robust reliable for network
usage and administration
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Utilities
• Computers may have a problem at any time!
– Hard disk failure, freezing, running slow, virus
infection
• Utilities are (specialized) service programs to
– Avoid OS problems
– Assist users in case of problem
– Reduce the effect of problems
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Utilities
Essential programs
1. Troubleshooting (or diagnostic programs)
•
recognize and correct problems, ideally before they become serious.
–
E.g., Windows diagnostic tool, Norton diagnostic program
2. Antivirus programs
– protect your computer system against viruses or other damaging
programs that can invade your computer system.
3. Uninstall programs
– allow you to safely and completely remove unneeded programs and
related files from your hard disk.
4. Backup programs
– make copies of files (in an external disk) to be used in case the
originals are lost or damaged.
5. File compression programs
– reduce the size of files so they require less storage space and can be
sent more efficiently over the Internet. E.g., WinZip, WinRar
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Utilities
Essential programs
6. Disk Cleanup
–
–
identifies and eliminates nonessential files.
This frees up valuable disk space and improves system
performance.
– E.g., eliminate temporary downloaded files (from the
Internet), erase residual files from uninstalled programs
7. Disk Defragmenter
– locates and eliminates unnecessary fragments and
– rearranges files and unused disk space to optimize
operations. E.g., file access becomes faster
•
Remark: many utilities as backup program, disk
cleanup, disk defragmenter, … comes with window
and can be found in the "Accessories">"System
Tools"
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References
• Book
– Computing essentials 2008, O'leary, O'leary
• Web Sites
–
–
–
–
–
–
http://www.c2imes.org
http://www.commentcamarche.net/
http://www.vulgarisation-informatique.com/
http://www.ybet.be/
Encyclopedia: Wikipedia
Notes : Architecture des ordinateurs, T. Dumartin
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