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Data Representation and
Digital Electronics
Data Representation
makes it possible to convert letters,
sounds, and images into electrical signals
Digital Electronics
makes it possible for a computer to
manipulate simple on and off signals
to perform complex tasks
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Digital Data
Representation
Why are computers digital ?
Digital Device works with discrete -distinct or separate -
data or digits, such as 1 and 0
Analog Device
works with continuous data
Computers are digital because computer
designers have found it to be a relatively
simple, dependable, and adaptable
technology.
A digital computer is a simpler technology
than an analog computer. Most computers use the simplest type of digital
technology, their circuits have only two
possible states.
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Digital Data
Representation
How can a computer represent numbers usingbits ?
Computers represent numeric data using the
binary number system, also called base 2
Numeric Data
the numbers that might be used in
arithmetic operations
Binary Number System
has only two (2) digits : 0 and 1
allows computers to represent virtually anynumber simply by using 0s and 1s
conveniently translates into electrical on
and off signals
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Digital Data
Representation
How can a computer represent words andletters using bits ?
Character Data
consists of letters, symbols and numerals
that will not be used in arithmetic
calculations
A digital computer uses a series of bits to
represent letters, characters, and numerals.
ASCII
pronounced as ASK ee
stands forAmerican Standard Code for
Information Interchange
requires only seven bits for each character
Extended ASCII
a superset of ASCII
uses eight bits to represent eachcharacter
provides codes for 128 additional
characters
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Digital Data
Representation
How can a computer represent words andletters using bits ?
EBCDIC pronounced as EB seh dick
stands for Extended Binary Coded Decimal
Interchange Code
an alternative 8-bit code usually used by
IBM mainframe computers
UNICODE pronounced as YOU ni code
provides codes for 65,000 characters and
makes use of 16 bits
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Digital Data
Representation
How does a computer convert sounds andpictures into codes ?
A computer must somehow digitize colors,notes, and instrument sounds into 1s and
0s, in order to work with sounds and
pictures.
Computers convert colors and sounds into
numbers, which can be represented by
bits.
A red dot on your computer screen might
be represented by 1100, a green dot by
0010.
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Digital Data
Representation
When a computer works with a series of 1s and0s, how does it know which code to use?
All of the things that computer works with isstored in files as a long series of 1s and 0s.
The computer needs to know whether to
interpret those 1s and 0s as ASCII code, binary
numbers, or the code for a picture or sound.
Most computer files contain a file header with
information on the code that was used torepresent the file data, to avoid confusion.
A computer can now tell how a files contents
were coded by reading the header information.
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Digital Electronics
How can I tell the difference between bits andbytes?
bit binary digit
can be further abbreviated as a lowercase
b
byte
composed of eight (8) bits
usually abbreviated as an uppercase B
nibble
composed of four (4) bits
a halfway between a little bit and a big
byte
Storage space is usually expressed in bytes
while transmission speeds are expressed inbits.
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Digital Electronics
How does a computer store and transport all ofthose bits ?
Bits take the form of electrical pulses that can
travel over circuits.
The circuits, chips, and mechanical
components forming a computer are designed
to work with bits.
These components are housed within thecomputers system unit.
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Digital Electronics
How do chips fit together to make a computer?
otherboard
also known as main board
the computers main circuit board
houses all essential chips and provides
connecting circuitry between them
Some chips are permanently soldered in place,
while other chips are plugged into special
sockets and connectors. The chips might be gathered together on a
separate small circuit board, which can then
be plugged into a special slot-like connector.
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Microprocessor Basics
Microprocessor
sometimes known as rocessor
an integrated circuit designed to process
instructions the most significant component of
computer and usually the most expensive
single component
executes instructions that are provided by
a computer program
Instruction Set list of instructions that a microprocessor
can perform
hardwired into the processors circuitry
comprising of basic arithmetic and logical
operations, fetching data, and clearing
registers
Memory
is the electronic that holds place for
instructions and data which the
microprocessors can reach quickly
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Todays Microprocessors
Which companies produce most of todayspopular microprocessors ?
Intel worlds largest chipmaker and supplies a
sizeable percentage of the
microprocessors that power personal
computers
introduced the worlds first
microprocessor , the 4004, during 1971 AMD (Advanced Micro Devices)
Intels chief rival in the PC chip market
produces microprocessors that work just
like Intel's chips, but a lower price
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Todays Microprocessors
Which of the microprocessors is the best ?
Intel
Original Pentium : 1993
Pentium II : 1997
Pentium III : 1999
Pentium IV: 2000
Itanium : 2001
Celeron processors : Intels budget model
AMD
Athlon processors : Direct competitors to
Intels Pentium line
Duron processor : AMDs budget model
The microprocessor thats best for you
depends on your budget and the type of work
and play that you plan to do.
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Components of DataProcessing
Data processing is a technique of collecting,
manipulating and distributing data to achieve
certain functions
Objective: to convert raw data intoinformation that can be used in decision
making
Computer Systems
A system is a collection of objects,
procedures, or techniques that
interact in regulated manner to form
an organized whole
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Components of DataProcessing
Central Processing Unit (CPU)
integrates and coordinates overall
operations
composed of three (3) units:
The CPU sub-units: ALU, Control Unit andPrimary Storage
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Components of DataProcessing
Central Processing Unit (CPU)
Control Unit
maintains order and controls activity in the
CPU does not process or store data but it
directs the sequence of operations
interprets the instructions of a program in
storage and produces signals that act as
command circuits to execute the
instructions Arithmetic/Logic Unit (ALU)
performs arithmetic computations and
logical operations
Primary Storage Unit
holds instructions, data, and intermediate
and final results
a reusable, fast storage medium, directly
accessible by the control unit
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Components of DataProcessing
Input/Output Subsystem
provides the mechanism for
communications between the CPU and the
outside world input subsystem - reads data and
converts them into electronic pulses
output subsystem - reports the results ofthe processing by the CPU
Memory Subsystem
also known as the secondary storage,allows for extra data storage, exceeding
the CPUs primary storage
an efficient and compact means of sorting
large amount of data, ready for retrieval or
further processing
retrieval time is slower than the primary
storage
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I/O Components
Common I/O Peripherals
Keyboard
Mouse
Monitor
Hard disk
Printer
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I/O Components
Other I/O Devices
CD-ROM drive
Modem
Sound Card
Scanner
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Storage Components
Memory
Random Access Memory (RAM) is a type ofcomputer memory chip that allows instructions
and data to be stored, changed and retrievedby the user
Read Only Memory (ROM) is a memory chipthat allows only readout capability
Programmable Read Only Memory (PROM)enables the user to add special information to
the ROM supplied by the manufacturer as part
of the system
Virtual Memory is an imaginary memory areasupported by the software in conjunction with
the hardware
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Storage Components
Mass Storage Device
Floppy Disks
Compact Disk (CD)
Zip Disk
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Classification ofComputers
Minicomputers, Microcomputers andMainframes
Microcomputers are small desktop systems
with limited I/O devices --- usually only akeyboard for input, a floppy disk for
storage, and a monitor for output
Minicomputer is a general-purposecomputing device, either rack-mounted or
small enough to fit in a desktop
Mainframe is a very large and expensivecomputer capable of supporting hundreds,
or even thousands of users simultaneously
Desktop PCs
medium sized computers
relatively inexpensive and designed for
individual users
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Classification of PCs
Supercomputers
fastest type of computers
very expensive and are employed for
specialized applications that require heavymathematical calculations that smaller
computers may not be able to do
weather forecasting
animated graphics
fluid dynamic calculations
nuclear energy research RISC vs. CISC
Reduced Instruction Set Computer (RISC)
Complex Instruction Set Computer (CISC)
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Software, Programs and
Support Modules Software
comprises of computer programs , support
modules, and data modules that work
together in order to provide a computer
with the instructions and data necessary
for carrying out a specific type of task
Program
a set of instructions that tells a computer
how to solve a problem or carry out a task
Support Module
provides an auxiliary set of instructions
that can be used in conjunction with the
main software program
not designed to be run by the computer
user
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Software, Programs and
Support ModulesWhy does a software requires so many files?
Most software packages include at least one
executable program file, several support
modules, and one or more data modules.
It is for the programmers great deal of
flexibility and efficiency.
Most of the support modules contain generic
program instructions that can be used to work
with various programs.
These techniques affect the process ofinstalling and uninstalling software.
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How Software WorksHow does a high-level language relate to the
microprocessors instruction set?
Machine language is the only language that can
be understood by a computers
microprocessor.
Instructions written in a high level language
must be translated into machine language
before a computer can use them.
A special type of programs called translators,
convert instructions from a high-level language
into machine language.
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How Software WorksAssuming that a VideoFactory, a video editing
program, was installed on your computer,
which is running Windows.
You click the Start button, then select
VideoFactory from the Programs menu.
The instructions for Vidfact.exe are loaded
into RAM and then sent to the microprocessor.
The VideoFactory window opens and the
graphical controls for video editing tasks
appear. The programs wait for you to select a
control by clicking it with the mouse.
The program follows its instructions and
performs a pre-specified action.
The program continues to respond to the
controls that you select until you click the
Close button, which halts execution of the
program instructions and closes the program
window.
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Operating System
What does an operating system do
A computers software acts similarly with the
chain of command in an army.
Using application software, you issue a
command.
Application software tells the operating
system what to do.
The operating system instructs the device
drivers, device drivers instruct the hardwareand the hardware actually does the work.
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Operating System
What does an operating system do
The operating system interacts withapplication software, device drivers, and
hardware to manage a computers resources.
While interacting with application software,
operating system is busy behind the scenes
with other tasks.
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Operating System
How does an operating system affect the lookand feel of application software?
An operating system typically provides userinterface tools, such as menus and toolbar
buttons, that define the look and feel for all
of its compatible software.
Apple computer released its popular Macintosh
computer in 1984, which featured a GUI
operating system and applications.
During 1992, when Windows 3.1 became
standard issue on most PCs, GUIs did catch on
in the PC market, replacing a command-line
interface that had given many people a string
aversion to computers in general.
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Operating System
Where is the operating system
The entire operating system is small enough to
be stored in ROM for typically handheld
computers and video game consoles.
For nearly all personal computers, servers,
workstations, mainframes, and
supercomputers, the operating system program
is quite large, so most of it is stored on a hard
disk.
The bootstrap program provides theinstructions needed to load the core parts
(kernel) into memory when the system boots.
Customization utilities and other parts of the
operating system are loaded into memory as
they are needed.
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Operating System
Do I ever interact directly with the OS
Launch programs
Customize the user interface
Manage Files
Configure Equipment
Get Help
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Operating System
re different operating systems needed fordifferent computing tasks ?
Single-user operating system deals with one set of input devices, those
that can be manipulated by one user at a
time
Multi-user operating system
deals with input, output, and processing
requests from many users , all at the sametime
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Operating System
re different operating systems needed fordifferent computing tasks?
Network operating system
provides communications and routing
services that allow computers to share
data, programs and peripheral devices
Multitasking operating system
provides process and memory managementservices that permit two or more programs
to run simultaneously
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Operating System
re different operating systems needed fordifferent computing tasks
Desktop operating system
designed for a personal computer, either a
desktop or notebook computer
designed to accommodate a single user,
but may also provide networking and
multitasking capabilities
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Windows, MAC OS,Linux, UNIX and DOS
Whats the best-selling operating system?
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Windows, MAC OS,Linux, UNIX and DOS
Is Mac OS similar to Windows?
Both operating systems base their user
interfaces on the graphical model that was
originated at Xerox PARC, although Mac OS wasdeveloped several years before Windows
Mac and Windows interfaces use a mouse to
point and click various icons and menus
re UNIX and Linux the same?
UNIX, developed in 1969 at AT & Ts Bell Labs,gained a good reputation for its dependability
in multi-user environments
Linuxwas developed in 1991, based on a
version of the UNIX kernel called Minix
Linux is considered to be a popular operating
system for e-mail, web-servers and local area
networks
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Windows, MAC OS,Linux, UNIX and DOS
Why do I keep hearing about DOS?
stands for Disk Operating System
it provides part of the operating system kernelfor Windows versions 3.1, 95, 98 and ME
users rarely interact with DOS, because it is
well hidden by the Windows graphical user
interface
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Software
Software: can be divided into:
systems software or system programs
applications software or application
programs Types of Computer Software
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Functions of anOperating System
Operating Systems
collection of system programs and routines
that reside in the computers memory
functions:
Schedule input and output operations
Schedule work of jobs according to
priority
Communicate with the human operator
Handle interruptions and monitor
system status
Log the jobs that are finished and
currently being executed
Control system access and data
security functions
Facilitate in locating and debugging
errors Handle multiprogramming, so that
several programs can run at the same
time
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Functions of anOperating System
Operating Systems
stored in a secondary storage device known
as a system residence device
in the early days when magnetic tape
drives are still used as storage devices,
operating systems that are stored in
magnetic tapes are called Tape OperatingSystems
if the operating system is stored in a
magnetic disk it is called a Disk OperatingSystem (DOS)
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Structure of anOperating System
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Programs that Make Upan Operating System
Control Programs - manage the overallsystem operations and perform tasks such
as scheduling, input/output handling,monitoring of system status and
communication with the programmer
Supervisor Program
Input/Output Control System
Service Programs - are subprograms orroutines that are frequently used by the
programmer
Language Translator Programs
Librarian Programs
Utility Programs
Diagnostic Programs
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Survey of an OperatingSystem
MS-DOS
The Windows Family of Operating
Systems Windows 1.0, 2.0, 3.1 and 3.11
Windows NT and Windows 2000
Windows 95, 98, ME and XP
UNIX and Linux
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Survey of an OperatingSystem
Whats the best-selling operating system?
Microsoft Windows is being used on over 80percent of the worlds personal computers.
Windows has evolved through several versions,
since its introduction.
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Survey of an OperatingSystem
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Survey of an OperatingSystem
Whats the best-selling operating system?
Windows 95, Windows 98, Windows ME andWindows XP provide basic networking
capabilities, making them appropriate for
small networks in homes and businesses.
Windows NT, Windows 2000, and Windows XP
Professional are typically classified as server
operating systems.
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Survey of an OperatingSystem
Is Mac OS similar to Windows?
Both operating systems base their user
interfaces on the graphical model that wasoriginated at Xerox PARC.
Both Mac and Windows interfaces use a mouse
to point and click various icons and menus.
Both also provide basic networking
capabilities.
Though the selection is not as vast as thecollection of Windows, a collection of software
is available for computers that run Mac OS.
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Survey of an OperatingSystem
re UNIX and Linux the same?
UNIX gained a good reputation for itsdependability in multi-user environments.
Many versions of UNIX became available for
mainframes and microcomputers.
Linux is distributed under the terms of a
General Public License (GPL), allowing
everyone to make copies for their own use, togive others, or to sell.
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Survey of an OperatingSystem
re UNIX and Linux the same?
Linux shares several technical features withUNIX.
Linux is considered to be a popular operating
system for e-mail , web-servers and local area
networks.
Linux has been gaining popularity as a desktop
operating system.
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Survey of an OperatingSystem
Why do I keep hearing about DOS?
DOS was the first operating system and its
cryptic command-line user interface left anindelible impression.
The remnants of DOS still linger in the world of
personal computers, because it provides part
of the operating system kernel for Windows
versions 3.1, 95, 98 and ME.
Users rarely interact with DOS, because it iswell hidden by the Windows graphical user
interface.
DOS is nothing more than footnotes in the
history of the computer industry.
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Application Software
An Overview of Application Software
Word Processing
a term used in manipulating text or wordsin a file
Basic features: insert text
delete text
cut and paste
copy
page size and margins
search and replace
word wrap Print
Advanced features: file management
font specifications
footnotes and cross-references
graphics
headers, footers, and page numbering layout
merges
spell checker
tables of contents and indexes
thesaurus
windows
WYSIWYG
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Application Software
Microsoft Word
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Application Software
Spreadsheet
computer programs especially designed to
display information graphically and allow
files and data to be manipulated easily an electronic ledger sheet on which data
are entered
MS Excel Spreadsheet Program
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Application Software
Database Management
application software packages that
computerize the everyday task of
recording, processing, filing, andmanipulation of information in the
database
Database : a collection of informationorganized in such a way that a computer
program can quickly select desired pieces
of information (or data); like an electronic
filing system
Basic features:
To add or delete information within a file
To search a file for some information based
on some criteria
To update information from within a file
To sort information into some order
To generate a printout or reports
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Application Software
Graphics Software Packages
designed to allow the user to display
images on a computer monitor or to print
the images on a printer Examples of graphic applications:
paint programs
illustration/design programs
presentation graphics software
animation software
CAD software
desktop publishing
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Installation Basics
Installation Process
Copy files from distribution disks to
specified folders on the hard disk.
If the files have been distributed in acompressed format, uncompress them.
Analyze the computers resources, such as
processor speed, RAM capacity, and hard
disk capacity.
To select appropriate device drivers,
analyze hardware components andperipheral devices.
Look for any system files and players, such
as Windows Media Player or Internet
Explorer, which are required to run the
program, but not supplied on the
distribution disks.
Update necessary system files, like WindowRegistry and the Windows Program menu,
with information about the new software.
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Installation Basics
re all of the files for the software provided onthe distribution disk
Application software programs share some
common files, through the use of Windows and
other operating systems.
Because these files should already exist on
your computer, the shared files are not
typically provided on the distribution disks for
the new software program.
The installation process attempts you tolocate these files, and will notify you if any of
them are missing.
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Installing from aDistribution Disk to CD
Video Capture Software Installation Process
Insert the distribution disk, CD, or DVD.
Read the license agreement, if one is
presented on the screen.
You will be prompted to select between full
and custom installation. Choose the
installation option that best meets your needs.
Follow the instructions provided by the setup
program to specify a folder to hold the new
software program. If the software includes multiple distribution
disks, insert each one in the specified drive
when the setup program tells you to do so.
When the setup is complete, begin the
program that you just installed to make sure it
works.
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Installing DownloadedSoftware
Compressed file types for downloaded software
Manual download and install
Downloaded files with a .zip extensionmust be located on the hard disk.
Must use a program such as WinZip to
unzip it.
To acknowledge the license agreement,
the setup program must be executed.
Specify the folder for the software files,
and complete the installation.
Self-installing executable file
Follow the setup program prompts to
acknowledge the license agreement.
his self-installing executable file
automatically unzips itself and starts the
setup program.
Specify the folder for the software files,
and complete the installation.
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Installing DownloadedSoftware
Compressed file types for downloaded software
Self- executing zip file
These files automatically unzip thesoftwares files but do not automaticallystart the setup program.
To unzip the files for the new software,
the executable file must be started.
Start the setup program manually and
follow its prompts to complete theinstallation
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Uninstalling Software
You can remove software, with some
operating systems, such as DOS by simply
deleting its files.
With Windows and Mac OS, uninstall routine isprovided to delete the softwares files from
various directories on the computers hard
disk.
You can normally find the uninstall routine
with Windows software, on the same menu as
the program.
In Windows, the Add/Remove Programs icon
can be found in the Control Panel, accessible
from the Start menu.
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Software Copyrights
Copyright
a form of legal protection that grants the
author of an original work an exclusive
right to copy, distribute, sell and edit thatwork, except under special circumstances
described by copyright laws
Exceptions
The purchaser
can make a backup or extra copy of the
software in case the original copy becomeserased or damaged
is allowed to copy and distribute parts of a
software program for use in critical
reviews and teaching
has the right to copy software from a
distribution disk or Web site to a
computers hard disk in order to install it
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Software Licenses
License Agreement
a legal contract that defines the ways in
which a computer program may be used
can be found on the outside of thepackage, on a separate card inside the
package, on the CD packaging, or in one of
the program files
Techniques to validate software license
shrink-wrap licenses installation agreements
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Software Licenses
Questions to be Considered When Reading a
Software License Agreement
When does the license go into effect ? Can I sell the software ?
Can I rent the software ?
Am I buying the software or licensing it ?
Can I loan the software to a friend ?
Does the software publisher provide a
warranty ?
Under what circumstances can I make
copies ?
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Software Licenses
Public Domain Software
may be freely copied, distributed and even
resold
not protected by copyright because thecopyright has expired, or the author has
placed the program in the public domain,
making it available without restriction
Commercial Software
usually sold in computer stores or at Websites
adheres closely to the limitations provided
by copyright law
it might give you permission to install the
software on a computer at work and at
home, but you have to use only one of
them at a time
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Software Licenses
Freeware
a copyrighted software that is available for
free
does not allow you to modify it or sell it,but it allows you to use the software, copy
it and give it away
utility programs, some games and device
drivers
Shareware
a copyrighted software marketed under atry before you buy policy, allowing you
to use the software for a trial period
usually permits you to copy and distribute
it to others
provide a low-cost marketing and
distribution channel
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Software Licenses
Open Source Software
may be sold or distributed free of charge
uncompiled program instructions are
available to programmers who want toalter and improve the software
Linux, FreeBSD