IPA IPA

INSTITUTE OF PROFESSIONAL ADVANCEMENT

INSTITUTE OF PROFESSIONAL ADVANCEMENT

INFORMATION TECHNOLGY

AHMED YASIR KHAN.

B-8, Block # 5 Gulshan-e-Iqbal Behind, Sir Syed University

Karachi
Information technology (IT), as defined by the Information Technology Association of America
(ITAA), is "the study, design, development, implementation, support or management of computer-
based information systems, particularly software applications and computer hardware."[1] IT deals
with the use of electronic computers and computer software to convert, store, protect, process,
transmit, and securely retrieve information.

Today, the term information technology has ballooned to encompass many aspects of computing and
technology, and the term has become very recognizable. The information technology umbrella can be
quite large, covering many fields. IT professionals perform a variety of duties that range from
installing applications to designing complex computer networks and information databases. A few of
the duties that IT professionals perform may include data management, networking, engineering
computer hardware, database and software design, as well as the management and administration of
entire systems.

When computer and communications technologies are combined, the result is information
technology, or "infotech". Information technology is a general term that describes any technology
that helps to produce, manipulate, store, communicate, and/or disseminate information. Presumably,
when speaking of Information Technology (IT) as a whole, it is noted that the use of computers and
information are associated.

The term information technology is sometimes said to have been coined by Jim Domsic of Michigan
in November 1981.[citation needed] Domsic, who worked as a computer manager for an automotive
related industry, is supposed to have created the term to modernize the outdated
phrase "data processing". The Oxford English Dictionary, however, in defining information
technology as "the branch of technology concerned with the dissemination, processing, and storage of
information, esp. by means of computers" provides an illustrative quote from the year 1958 (Leavitt
& Whisler in Harvard Business Rev. XXXVI. 41/1 "The new technology does not yet have a single
established name. We shall call it information technology.") that predates the so-far unsubstantiated

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Domsic coinage.

In recent years ABET and the ACM have collaborated to form accreditation and curriculum
standards for degrees in Information Technology as a distinct field of study separate from both
Computer Science and Information Systems. SIGITE is the ACM working group for defining these
standards.

The term "information technology" is usually quite often referred to an entire industry. In actuality,
information technology is the use of computers and software to manage information. In some
companies, this is referred to as Management Information Services (or MIS) or simply as
Information Services (or IS). The information technology department of a large company would be
responsible for storing information, protecting information, processing the information, transmitting
the information as necessary, and later retrieving information as necessary.

When people hear the words "Information Technology," the first things that come to mind are
computers and the Internet. It may also bring up words like "network," "intranet," "server,"
"firewall," "security," as well as more arcane expressions such as "router," "T-1," "Ethernet," or
the mysterious and exotic-sounding "VoIP." However, the term "information technology" is not new
and has not always referred to things relating to computer. Information technology is as old as the
brain itself, if you think of the brain as an information processor. As far as IT being a science, even
that goes back as far as the earliest attempts to communicate and store information. And that is

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essentially what information technology is: the communication and storage of information, along
with the ability to process and make use of the information stored.

The history of information technology predates the invention of the modern digital computer by
many centuries. Machines for calculating fixed numerical tasks, such as the abacus, have existed
since antiquity. Wilhelm Schickard built the first mechanical calculator in 1623. Charles Babbage
designed a difference engine in Victorian times, and around 1900 the IBM Corporation sold punch-
card machines. However all of these machines were constrained to perform a single task, or at best,
some subset of all possible tasks.

During the 1940s, as newer and more powerful computing machines were developed, the term
computer came to refer to the machines rather than their human predecessors. As it became clear
that computers could be used for more than just mathematical calculations, the field of computer
science broadened to study computation in general. Computer science began to be established as a
distinct academic discipline in the 1960s, with the creation of the first computer science departments
and degree programs. Since practical computers became available, many applications of computing
have become distinct areas of study in their own right.

In order to perform the complex functions required of information technology departments today,
the modern Information Technology Department would use computers, servers, database
management systems, and cryptography. The department would be made up of several System
Administrators, Database Administrators and at least one Information Technology Manager. The
group usually reports to the Chief Information Officer (CIO). Information technology has a long
history and has only recently been associated with the use of computers.

Some of the advantages of information technology include:

Globalization - IT has not only brought the world closer together, but it has allowed the world's
economy to become a single interdependent system. This means that we can not only share
information quickly and efficiently, but we can also bring down barriers of linguistic and geographic
boundaries. The world has developed into a global village due to the help of information technology
allowing countries like Chile and Japan who are not only separated by distance but also by language
to shares ideas and information with each other.

Communication - With the help of information technology, communication has also become
cheaper, quicker, and more efficient. We can now communicate with anyone around the globe by
simply text messaging them or sending them an email for an almost instantaneous response. The
internet has also opened up face to face direct communication from different parts of the world
thanks to the helps of video conferencing.

Cost effectiveness - Information technology has helped to computerize the business process
thus streamlining businesses to make them extremely cost effective money making machines. This in
turn increases productivity which ultimately gives rise to profits that means better pay and less
strenuous working conditions.

Bridging the cultural gap - Information technology has helped to bridge the cultural gap by
helping people from different cultures to communicate with one another, and allow for the exchange

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of views and ideas, thus increasing awareness and reducing prejudice.

More time - IT has made it possible for businesses to be open 24 x7 all over the globe. This means
that a business can be open anytime anywhere, making purchases from different countries easier and
more convenient. It also means that you can have your goods delivered right to your doorstep with
having to move a single muscle.

Creation of new jobs - Probably the best advantage of information technology is the creation of
new and interesting jobs. Computer programmers, Systems analyzers, Hardware and Software
developers and Web designers are just some of the many new employment opportunities created with
the help of IT.
Some disadvantages of information technology include:

Unemployment - While information technology may have streamlined the business process it
has also crated job redundancies, downsizing and outsourcing. This means that a lot of lower and
middle level jobs have been done away with causing more people to become unemployed.

Privacy - Though information technology may have made communication quicker, easier and
more convenient, it has also bought along privacy issues. From cell phone signal interceptions to
email hacking, people are now worried about their once private information becoming public
knowledge.

Lack of job security - Industry experts believe that the internet has made job security a big
issue as since technology keeps on changing with each day. This means that one has to be in a
constant learning mode, if he or she wishes for their job to be secure.

Dominant culture - While information technology may have made the world a global village, it
has also contributed to one culture dominating another weaker one. For example it is now argued
that US influences how most young teenagers all over the world now act, dress and behave.
Languages too have become overshadowed, with English becoming the primary mode of
communication for business and everything else.

The Two Parts of IT: Computers & Communications

COMPUTER TECHNOLOGY
A computer is a programmable, multiuse machine that accepts data—raw facts and figures—and
processes, or manipulates, it into information we can use, such as summaries,
totals, or reports. Its purpose is to speed up problem solving and
increase productivity.

COMMUNICATIONS TECHNOLOGY Unquestionably you’ve been using

communications technology for years. Communications technology, also
called telecommunications technology, consists of electromagnetic devices
and systems for communicating over long distances. The principal examples
are telephone, radio, broadcast television, and cable TV. In more recent times,

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there has been the addition of communication among computers—which is
what happens when people ―go online‖ on the internet. In this context,
online means using a computer or some other information device, connected
through a network, to access information and services from another computer
or information device. A network is a communications system connecting
two or more computers; the internet is the largest such network.
Information technology is already affecting your life in exciting ways and
will do so even more in the future.
What are the five sizes of computers?
At one time, the idea of having your own computer was almost like having
your own personal nuclear reactor. In those days, in the 1950s and
1960s, computers were enormous machines affordable only by large institutions.
Now they come in a variety of shapes and sizes, which can be
classified according to their processing power: supercomputers, mainframe
computers, workstations, microcomputers, and microcontrollers. We also
consider servers.

Typically priced from $1 million to more than $350 million, supercomputers

are high-capacity machines with thousands of processors that
can perform more than several trillion calculations per second. These are
the most expensive and fastest computers available. ―Supers,‖ as they are
called, have been used for tasks requiring the processing of enormous volumes
of data, such as doing the U.S. census count, forecasting weather,
designing aircraft, modeling molecules, and breaking encryption codes.
More recently they have been employed for business purposes—for
instance, sifting demographic marketing information—and for creating
film animation.

Chapte

mainframes are
water- or air-cooled computers that cost $5,000–$5 million and vary in size

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from small, to medium, to large, depending on their use. Small mainframes
($5,000–$200,000) are often called midsize computers; they used to be called
minicomputers, although today the term is seldom used. Mainframes are
used by large organizations—such as banks, airlines, insurance companies,
and colleges—for processing millions of transactions. Often users access a
mainframe by means of a terminal, which has a display screen and a keyboard
and can input and output data but cannot by itself process data. Mainframes
process billions of instructions per second.

Introduced in the early 1980s, workstations are expensive, powerful personal

computers usually used for complex scientific, mathematical, and engineering
calculations and for computer-aided design and computer-aided manufacturing.
Providing many capabilities comparable to those of midsize
mainframes, workstations are used for such tasks as designing airplane
fuselages, developing prescription drugs, and creating movie special effects.

Microcomputers
How does a microcomputer differ from a workstation?
Microcomputers, also called personal computers (PCs), which cost $500 to

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over $5,000, can fit next to a desk or on a desktop or can be carried around.
They either are stand-alone machines or are connected to a computer network,
such as a local area network. A local area network (LAN) connects,
usually by special cable, a group of desktop PCs and other devices, such as
printers, in an office or a building.
Microcomputers are of several types: desktop PCs, tower PCs, notebooks
(laptops), mobile internet devices (MIDs), and personal digital assistants—
handheld computers or palmtops.
DESKTOP PCs Desktop PCs (left) are older
microcomputers whose case or main housing sits
on a desk, with keyboard in front and monitor
(screen) often on top.
er 1
22

Mainframe computer
Workstation
Small. The Mac Mini has the smallest desktop
microcomputer case, just 6.5 inches
square and 2 inches tall.

TOWER PCs Tower PCs are microcomputers

whose case sits as a ―tower,‖
often on the floor beside a desk, thus
freeing up desk surface space. Some
desktop computers, such as Apple’s
iMac, no longer have a boxy housing;
most of the computer components are
built into the back of the flat-panel display
screen.
NOTEBOOKS Notebook computers,
also called laptop computers, are lightweight
portable computers with built-in
monitor, keyboard, hard-disk drive,
CD/DVD drive, battery, and AC adapter
that can be plugged into an electrical
outlet; they weigh anywhere from 1.8 to
9 pounds.
MOBILE INTERNET DEVICES (MIDS)
A new category of mobile devices,
smaller than notebook computers but

larger and more powerful than PDAs

(see below), mobile internet devices
(MIDs) are for consumers and business
professionals. Fully internet integrated, they are highly compatible with
desktop microcomputers and laptops. The initial models focus on data communication,

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not voice communication.
PERSONAL DIGITAL ASSISTANTS Personal digital
assistants (PDAs), also called handheld computers or
palmtops, combine personal organization tools—
schedule planners, address books, to-do lists—with the
ability in some cases to send email and faxes. Some
PDAs have touch-sensitive screens.
Some also connect to desktop computers
for sending or receiving information.
(For now, we are using the word
digital to mean ―computer based.‖) The
range of handheld wireless devices,
such as multipurpose cellphones

Microcontrollers, also called embedded computers, are the tiny, specialized

microprocessors installed in ―smart‖ appliances and automobiles.
These microcontrollers enable microwave ovens, for example,
to store data about how long to cook your potatoes and at what
power setting. Microcontrollers have been used to develop a new universe
of experimental electronic appliances—e-pliances. For example,
they are behind single-function products such as digital cameras, MP3
players, and organizers, which have been developed into hybrid forms
such as gadgets that store photos and videos as well as music. They also help run tiny web servers
embedded in clothing, jewelry, and household
appliances such as refrigerators. In addition, microcontrollers are used in bloodpressure
monitors, air bag sensors, gas and chemical sensors for water and air,
and vibration sensors.
Servers
How do servers work, and what do they do?
The word server describes not a size of computer but rather a particular way
in which a computer is used. Nevertheless, because servers have become so
important to telecommunications, especially with the rise of the internet and
the web, they deserve mention here.

A server, or network server, is a central computer that holds collections

of data (databases) and programs for connecting or supplying services to PCs,
workstations, and other devices, which are called clients. These clients are
linked by a wired or wireless network. The entire network is called a
client/server network.

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 PURPOSE OF A COMPUTER: TURNING DATA INTO
INFORMATION
Very simply, the purpose of a computer is to process data into information.
• Data: Data consists of the raw facts and figures that are processed
into information—for example, the votes for different candidates being
elected to student-government office.
• Information: Information is data that has been summarized or otherwise
manipulated for use in decision making—for example, the total
votes for each candidate, which are used to decide who won.

Hardware: Hardware consists of all the machinery and equipment in

a computer system. The hardware includes, among other devices, the
keyboard, the screen, the printer, and the ―box‖—the computer or
processing device itself. Hardware is useless without software.
• Software: Software, or programs, consists of all the electronic instructions
that tell the computer how to perform a task. These instructions
come from a software developer in a form (such as a CD, or
compact disk) that will be accepted by the computer. Examples are
Microsoft Windows and Office XP/Vista.

THE BASIC OPERATIONS OF A COMPUTER Regardless of type and

size, all computers use the same four basic operations: (1) input, (2) processing,
(3) storage, and (4) output. To this we add (5) communications.

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• Input operation: Input is whatever is put in (―input‖) to a computer
system. Input can be nearly any kind of data—letters, numbers, symbols,
shapes, colors, temperatures, sounds, pressure, light beams, or
whatever raw material needs processing. When you type some words
or numbers on a keyboard, those words are considered input data.
• Processing operation: Processing is the manipulation a computer does
to transform data into information. When the computer adds 2 _ 2 to
get 4, that is the act of processing. The processing is done by the central
processing unit—frequently called just the CPU—a device consisting
of electronic circuitry that executes instructions to process data.

Storage operation: Storage is of two types—temporary storage and permanent

storage, or primary storage and secondary storage. Primary
storage, or memory, is the internal computer circuitry that temporarily
holds data waiting to be processed. Secondary storage, simply called
storage, refers to the devices and media that store data or information
permanently. A hard disk or CD/DVD is an example of this kind of
storage. (Storage also holds the software—the computer programs.)
• Output operation: Output is whatever is output from (―put out of‖) the
computer system—the results of processing, usually information. Examples
of output are numbers or pictures displayed on a screen, words
printed out on paper by a printer, or music piped over some loudspeakers.
• Communications operation: These days, most (though not all) computers
have communications ability, which offers an extension capability—
in other words, it extends the power of the computer. With
wired or wireless communications connections, data may be input
from afar, processed in a remote area, stored in several different locations,
and output in yet other places. However, you don’t need communications
ability to write letters, do calculations, or perform many
other computer tasks.

Input Hardware:

A keyboard is an input device that converts letters, numbers, and other

characters into electrical signals readable by the processor.
A microcomputer keyboard looks like a typewriter
keyboard, but besides having keys for letters and numbers
it has several keys (such as F keys and Ctrl, Alt,
and Del keys) intended for computer-specific tasks.
After other components are assembled, the keyboard will be plugged into the
back of the computer in a socket intended for that purpose.
 Function Keys – let you quickly perform specific tasks
 Escape Key – lets you quit a task

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  Ctrl and Alt – use combination with another key to bypass using the mouse – Ctrl +
S will save a document, Alt + Tab will let you switch between running applications

Mouse
 Handy tool for dragging and dropping text, graphics
 Useful for navigating menus on unfamiliar applications

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 Trackball
 A movable ball mounted on top of a stationary device
 Good for locations where a mouse couldn’t move enough
 Requires more frequent cleaning to remove finger oils

Pointing Stick
 Looks like a pencil eraser in the lower center of a laptop keyboard

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 Touchpad
 To use: slide your finger over this small flat surface
 Click by tapping you finger on the surface
 May require more practice to use than a mouse

Touch Screens
 A video display screen sensitized to receive input from a finger
 Cruder than a mouse, because fingers are big
 Problems: touch screens that show a display that is not precisely aligned with the
input

Pen input
 Use a pen-like stylus for input rather than typing on a keyboard
 Use handwriting recognition to translate cursive writing into data

Light Pen
 A light-sensitive pen-like device that uses a wired connection to a computer
terminal
 Bring the pen to the desired point on the display screen and press a button to
identify the screen location
 Used in situations that require gloves
 Less crude than a touch screen

Digitizer
 Uses an electronic pen or puck to convert drawings and photos to digital data
 Digitizing tablets are used in architecture

Digital Pen
 Writing instrument
 Writers can write on paper
 A tiny camera in the pen tip captures the writing
 A microchip in the pen converts the pen to digital ink
 The writing is sent as an image file to the computer

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  Original versions: Logitech’s IO pen and Leapfrog’s FLY Fusion pen required
special paper
 Later versions, like Mobile Digital Scribe do not require special paper

Scanning & Reading Devices

 Source Data Entry devices create machine-readable data and feed it directly into the
computer

Scanners
 Use light-sensing equipment to translate images of text,
drawings, and photos into digital form
 Image scanners are used in electronic imaging
 Resolution refers to the image sharpness, measured in dots per inch (dpi)
 Flatbed scanners work like photocopiers – the image is placed on the glass
surface, then scanned
 Other types are sheet-fed, hand-held and drum

Bar-Code Readers
 Photoelectric (optical) scanners that translate bar code symbols into digital code
 The digital code is then sent to a computer
 The computer looks up the item and displays its name and pricing info

Bar code types

 1D holds up to 16 ASCII characters
 2D can hold 1,000 to 2,000 ASCII characters
 3D is ―bumpy‖ code that differentiates by symbol height
 Can be used on metal, hard rubber, other tough surfaces

 MICR – Magnetic-ink character recognition

 Uses special magnetized inks

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  Must be read by a special scanner that reads this ink
 OMR – Optical mark recognition
 Uses a special scanner that reads bubble marks
 Used in standardized tests like the SAT and GRE
 OCR – Optical character recognition
 Converts scanned text from images (pictures of the text) to an editable text
format
 You use this to read in non-computer documents where you don’t have the
source files

Audio Input Devices

 Records analog sound and translates it into digital files for storage and processing
 Two ways to digitize audio
 Sound Board
 An add-on board in a PC that converts analog sound to digital sound, stores
it, and plays it back to speakers or amp

 MIDI Board
 Stands for Musical Instrument Digital Exchange
 Uses a standard for the interchange between musical instruments,
synthesizers, and PCs

Webcams and Video-input Cards

 Webcams
 Video cameras attached to a computer to record live moving
images then post them to a website in real time
 Require special software, usually included with the camera
 Frame-grabber video card
 Can capture and digitize 1 frame at a time
 Full-motion video card
 Can convert analog to digital signals at rates up to 30 frames per second
 Looks like a motion picture

Digital Cameras
 Use a light-sensitive processor chip to capture photographic images in
digital form and store them on a small diskette in the camera or on flash
memory cards
 Most can be connected to a PC by USB or FireWire

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  Can allow you to take more pictures and decide which ones to print and
save
 But pictures are subject to loss by diskette or flash memory failure or
computer virus if you store them on the PC
 Digital cameras are now on cellphones
 Convenience of being able to take photos, then instantly email or message
them to someone else
 Can provide instant record of traffic accidents, etc

Speech-Recognition Systems
 Uses a microphone or telephone as an input device. Converts a person’s speech into digital
signals by comparing against 200,000 or so stored patterns.
 Used in places where people need their hands free – warehouses, car radios, stock
exchange trades
 Helpful for people with visual or physical disabilities that prevent them from using
other input devices
 Still not easy enough to use to substitute for the mouse/keyboard for fast document
processing
 ScanSoft and Nuance
 Fonix Speech
 Aculab

Processing operation: Processing is the manipulation a computer does

to transform data into information. When the computer adds 2 _ 2 to
get 4, that is the act of processing. The processing is done by the central
processing unit—frequently called just the CPU—a device consisting
of electronic circuitry that executes instructions to process data.

CPU (Central Processing Unit): -

The procedure that transforms raw data into useful
information is called processing. This function is divided between the computer's
processor and memory.
The processor is also called the central processing unit (CPU). It manages all
devices and performs the actual processing of data.
The CPU consists of one or more chips attached to the computer's main
circuit board (the motherboard).

The System Unit: The Basics

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  Mainframe and minicomputer speed is measured in MIPS
 MIPS stands for millions of instructions per second
 Workstations perform at 100 MIPS or more
 Mainframes now perform as fast as 981,024 MIPS
 Supercomputer processing speed is measured in flops
 Flops stands for floating point operations per second
Los Alamos Lab’s new Roadrunner cranks out 1 petaflop or 1,000 trillion operations per second

Memory Chip
1. RAM Random Access Memory chips are volatile and hold:
Software instructions
Data before & after the CPU processes it

2. ROM Read only memory

Cannot be written on or erased without special equipment
Are loaded at factory with fixed start-up instructions

3. CMOS Complementary Metal Oxide Semiconductor

Powered by a battery Contains time, date, calendar, boot password

4. Flash Nonvolatile memory that can be erased and reprogrammed more than once
Doesn’t require a battery
Used in newer PCs for BIOS instructions

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 1. DRAM Dynamic RAM must be constantly refreshed by the CPU or it loses its contents
2. SDRAM Synchronous Dynamic RAM is synchronized by the system clock and is much
faster than DRAM
3. SRAM Static RAM is faster than DRAM and retains its contents without having to be
refreshed by CPU
4. DDR / SDRAM Double-data rate synchronous dynamic RAM
5. SIMM Single Inline Memory Module has RAM chips on only one side
a. FPM is fast page mode type
b. EDO is extended data output; is faster than FPM
6. DIMM Dual Inline Memory Module has chips on both sides

Speeding up Processing
 The CPU works much faster than RAM
 So it could sit there waiting for information
 Cache temporarily stores instructions and data that the processor uses frequently to
speed up processing
 Level 1 cache is part of the microprocessor
 Holds 8 to 256 kb
 Faster than Level 2 cache
 Level 2 cache is SRAM external cache
 Holds 64 kb to 2 Mb
 Level 3 cache is on the motherboard
 Comes on very high-end computers

Ports
1. Serial Port Used to transmit slow data over long distances
a. Sends data sequentially, one bit at a time
b. Used to connect keyboard, mouse, monitors, dial-up modems
2. Parallel Port For transmitting fast data over short distances
a. Transmits 8 bytes simultaneously
b. Connects printers, external disks, backups
3. SCSI Port Small Computer System Interface
a. Connects up to 7 devices in a daisy chain
b. Transmits data 32 bits at a time
4. USB Port Universal Serial Bus can theoretically connect up to 127 peripheral devices in a
daisy chain

 Binary System: the basic unit of computing

 Uses just two numbers: 0 and 1
 All data and program instructions in the computer are represented as binary
 Bit: each 0 or 1 is a bit
 Byte: a group of 8 bits
 Kilobyte: ~1,000 (1,024) bytes
 Megabyte: ~1 Million (1,048,576) bytes
 Gigabyte: ~1 Billion (1,073,741,824) bytes

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  Terabyte: ~ 1 Trillion (1,009,511,627,576) bytes
 Petabyte: ~ 1 quadrillion bytes
 Exabyte: ~ 1 quintillion bytes
All the printed material in the world is ~ 5 exabytes
 Binary coding schemes assign a unique binary code to each letter
 EBCDIC
 Requires 8 bits per character
 Used for IBM mainframes
 ASCII
 Requires 7 or 8 bits per character, depending on the version
 8 bit Extended ASCII provides 256 characters
 Used for PCs, Unix hosts, Macs
 Unicode
 Requires 16 bits per character
 Handles 65,536 characters

Storage operation: Storage is of two types—temporary storage and permanent

storage, or primary storage and secondary storage. Primary
storage, or memory, is the internal computer circuitry that temporarily
holds data waiting to be processed. Secondary storage, simply called
storage, refers to the devices and media that store data or information
permanently. A hard disk or CD/DVD is an example of this kind of
storage. (Storage also holds the software—the computer programs.)

Floppies and Zip Disks

 Floppies
 Flat piece of mylar plastic inside a 3.5‖ plastic case
 Store about 1.44 MB
 Have a write-protect notch
 Data is recorded in tracks: concentric recording bands
 Formatting breaks the tracks into small wedge-shaped sectors
 Read/Write head transfers data between the computer and disk
 Floppies DO wear out!
 Zip Disks
 Disks with a high-quality magnetic coating
 Store 100, 250, or 750 MB
 Require a Zip drive; won’t work on floppy drives
 Used to store larger files than floppies can hold
 Zip disks wear out too!

Hard Disks
 Thin, rigid metal, glass, or ceramic platters covered with a substance that allows data to
be held in the form of magnetized spots
 The more platters there are, the higher the drive capacity

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  Store data in tracks, sectors, and clusters
 Formatting creates a file allocation table that maps files to clusters or inodes
 Typical file systems are VFAT & NTFS for Windows, HFS and ext2 for
Unix
 Drive heads ride on .000001‖ cushion of air, and can crash!
 Important data should always be backed up!
Hard Disk Types:
 External Hard Disks – a freestanding disk drive
 Removable Hard Disk – inserted into a cartridge drive on the PC
Hard Disk Controllers
 EIDE – Enhanced Integrated Drive Electronics
 Supports up to 4 disks at 137 GB per disk
 Marketed as SATA, Fast ATA, Ultra ATA, ATA-2, ATA/100
 SCSI – Faster than EIDE controllers
 Fibre Channel – used in large servers – faster and costlier than SCSI

Optical Disks
 CDs and DVDs are Optical disks
 Data is written and read using lasers, not a disk head
 CD-ROM is Compact Disk Read-Only Memory
 CD-R is used for recording only once
 CD-RW is an erasable optical disk that can both record and erase data over
and over again
 DVD is a CD-style disk with extremely high capacity
 Stores 9.4 or more GB
 DVD-R is used for recording only once
 DVD-RW, DVD-RAM, DVD+RW are reusable DVDs

Flash Memory
 Nonvolatile memory with no moving parts
 But the electronics can wear out
 Available as
 Flash memory cards
 Insert these into a flash port of a camera, handheld
PC, smartphone
 Flash memory sticks
 A form of flash memory that plugs into a memory stick port
 Flash memory drives
 A finger-sized module of flash memory
 Plugs into the USB port of most PCs and Macintoshes
 Higher Density Disks
 Blank CDs are replacing floppy disks since they hold up to 700 MB and cost < $1
each
 DVD disks hold up to 9.4 GB of data currently

[AHMED YASIR KHAN.] Page 21 of 91

  Perpendicular recording technology allows 25% - 100% more data to be stored on
the same disk
 Polymer memory creates chips that store data on plastics
 Nonvolatile memory
 Data is stored based on polymer’s electrical resistance

Output Hardware
Output is whatever is output from (―put out of‖) the
computer system—the results of processing, usually information. Examples
of output are numbers or pictures displayed on a screen, words
printed out on paper by a printer, or music piped over some loudspeakers.

 Softcopy
 Data that is shown on a display screen or is in audio or voice form; exists
electronically
 Output that is ephemeral in nature
 Hardcopy
 Printed and film output
 Output that is more permanent in nature

Display Screens
 Making a good choice when choosing a display
 Dot pitch (dp) is the amount of space between adjacent pixels (picture elements) on
screen
 The closer the pixels, the crisper the image
 Get .25 dp or better
 Resolution refers to the image sharpness
 The more pixels the better the resolution
 Expressed in dots per inch (dpi)
 Color depth or bit depth is the number of bits stored in a dot
 The higher the number the more true the colors
 24-bit color depth is better than 8-bit color depth
 Refresh rate is the number of times per second the pixels are recharged – a higher
rate gives less flicker

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 Monitors
 Cathode Ray Tube (CRT) is a vacuum tube used in a computer or terminal display screen
 Watch the PC ads to make sure your monitor is included
 Flat panel displays are made of 2 plates of glass separated by a layer of liquid crystals that
line up to transmit or block light
 Preferable to CRTs because they take up less room on the desktop
 Latency problems make them less desirable for online games players

liquid crystal display (LCD) is a thin, flat panel used for electronically
displaying information such as text, images, and moving pictures. Its
uses include monitors for computers, televisions, instrument panels, and
other devices ranging from aircraft cockpit displays, to every-day
consumer devices such as video players, gaming devices, clocks,
watches, calculators, and telephones. Among its major features are its
lightweight construction, its portability, and its ability to be produced in
much larger screen sizes than are practical for the construction of cathode
ray tube (CRT) display technology. Its low electrical power consumption
enables it to be used in battery-powered electronic equipment. It is an
electronically-modulated optical device made up of any number of pixels
filled with liquid crystals and arrayed in front of a light source (backlight) or
reflector to produce images in color or monochrome. The earliest discovery
leading to the development of LCD technology, the discovery of liquid
crystals
a printer is a peripheral which produces a hard copy (permanent readable
text and/or graphics) of documents stored in electronic form, usually on
physical print media such as paper or transparencies. Many printers are
primarily used as local peripherals, and are attached by a printer cable or, in
most newer printers, a USB cable to a computer which serves as a document
source. Some printers, commonly known as network printers, have built-in
network interfaces (typically wireless and/or Ethernet), and can serve as a
hardcopy device for any user on the network. Individual printers are often
designed to support both local and network connected users at the same time.
In addition, a few modern printers can directly interface to electronic media
such as memory sticks or memory cards, or to image capture devices such as
digital cameras, scanners; some printers are combined with a scanners
and/or fax machines in a single unit, and can function as photocopiers.
Printers that include non-printing features are sometimes called
Multifunction printers (MFP), Multi-Function Devices (MFD), or All-In-One
(AIO) printers. Most MFPs include printing, scanning, and copying among
their features.

[AHMED YASIR KHAN.] Page 23 of 91

  Impact Printers Form characters or images by striking a print hammer or wheel against an
ink ribbon
 Dot matrix printers Laser Printers Use drums and toner like in photocopiers
 Page Description Language (PDL)
 PostScript and PCL are PDL types
 Produce crisp, professional pages

 Inkjet Printers Spray ink from 4 nozzles at high speed

 Quiet, inexpensive color printers
 Often less precise than laser printers
 Thermal Printers Low to medium resolution printers that use thermal paper that darkens in
time

Token/ Ticket Printer

Auto Token/ Ticket Dispenser is Indigenously Built with the State of Art
Technology to Print and Issue Token/Ticket to the Incoming Customers who are to
be served in Queue.

[AHMED YASIR KHAN.] Page 24 of 91

As per the prevailing trend in electronic automation, this is the Advance
Token/Ticket Dispenser System that gives Host of new below said Advanced
Features than any conventional or hand written Token/Ticket System.
With this Auto Token/Ticket Dispenser System, Customer has to just select their
respective Queue and this Automatic Token Printer will Issue/Print the Sequential
Token/Ticket Automatically as per the Queue selected by the user with it's Queue
Series stored in the Memory. The Number is printed in Bold print along with the
Preset Alpha-Numeric Header & Footer Messages and the most importantly is the
Date and Time are also Printed on the Issuing Token/Ticket. The Issued Token/
Ticket Numbers Data is retained in the System Memory even after Power Off.
This System if Fully Stand Alone where no PC or any Software is required to
operated.

This New Token Printing System as Host of useable Features as follows :

Automatic Token/ Ticket Number issuing

Easy and User Friendly operations
Explicitly designed user panel
Blinking LEDs in each user key
Up to 4 Queues selection can be provided
Easy Supervisor Settings
Printer with Auto-Cutter
Supervisor selectable Header / Footer Messages
Alpha-numeric key-pad for Messages
Supervisor selectable Q-Code
Password Number for Supervisor Settings
Optional Automatic Next-Day Token Number Reset
Optional Dual Token/ Ticket Printing Facility
Optional Cut Between Dual Token Ticket Prints
Optional Header Message Print or Pre-printed Header

Plotters
 A specialized output device designed to produce large high-quality graphics in
a variety of colors
 The earliest output device that could produce graphics
 Pen plotters use one or more colored pens
 Electrostatic plotters lie partially flat on a table and use toner like photocopiers
 Large-format plotters are large-scale inkjet printers used by graphic artists

Mixed Output
 Sound output
 You need a sound card and sound software
 Good equipment can produce very high-quality 3-D sound

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  Voice Output
 TTS systems (text to speech) are becoming popular
 Requires a sound card and speakers with TTS software
 Video Output
 Requires a powerful processor and a video card
 Video files are large, so a lot of storage is needed too.

Future of Input and Output

 This is a fruitful area for research, including
 Intelligent sensors
 More data input from remote locations
 More source data automation
 Input help for the disabled
 More sophisticated touch devices
 Better speech recognition
 Improved digital cameras
 Gesture recognition
 Pattern-recognition and biometric devices
 Brainwave devices
 Better and cheaper display screens
 Improved video on PCs
 3-Dimensional output
 Miniaturization for improved data transfer speeds to I/O devices

Communications Hardware These days, most (though not all) computers

have communications ability, which offers an extension capability—
in other words, it extends the power of the computer. With
wired or wireless communications connections, data may be input
from afar, processed in a remote area, stored in several different locations,
and output in yet other places. However, you don’t need communications
ability to write letters, do calculations, or perform many
other computer tasks.

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 • Analog signals use variation of a wave form to send information
• In FM signals the Frequency is varied (Modulated)
• In AM signals the Amplitude is varied (Modulated)
• Radios send signals this way
• Light works this way
• Hearing and phones work this way
• Modems work this way

 Digital signals send data in terms of 1s and 0s

 The signal goes up and down abruptly because the only values that matter are 0 and 1 and
the timing of when they occur

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  Computers use digital signals
 Newspaper photographs are digital since they are made up of little dots

 Since computers use digital signals but phone lines use analog, modems must translate from
digital to analog, send the signal along the phone line, then translate back from analog to
digital at the other end
 The process is called ―modulation/demodulation‖
 Modulation means to translate from digital to analog
 Demodulation means to translate from analog to digital
 Modems have to do all this just to use standard analog voice phone lines
 Tape recorders, voices, and musical instruments are analog while CDs are digital
 To burn a CD from a jam session, the digital recording equipment must convert from analog
to digital
 The analog-to-digital converter samples the sound and converts the height of the
wave to a number
 Samples of the sound wave are taken at regular intervals – about 44,100 times each
second
 Because the digital samples are played back faster than our ears can react, it sounds
to us like a single continuous sound wave
 Digital sampling is similar to showing movies
 Movies show still pictures (frames)
 But they show them so fast that our eyes can’t react in time
 So to us the series of still pictures look like continuous motion
 Did you ever notice in movies when they show car tires in motion they sometimes
seem to move backwards?
 This is because the tires are moving at a rate that is incompatible with the
frame rate of the movie, so our eyes think the tires are really moving
backwards when the car is actually moving forward!

Networks
 LAN – Local Area Network Connects computers and devices in a limited geographic area
such as an office, building, or group of nearby buildings
 MAN – Metropolitan Area Network Covers a city or a suburb
 WAN – Wide Area Network Covers a wide geographic area, such as a country or the world

 Client/Server
 Consists of clients, which are computers that request data, and servers, which are
computers that supply data
 File servers act like a network-based shared disk drive
 Database servers store data but don’t store programs
 Print servers connect one or more printers and schedule and control print jobs
 Mail servers manage email
 Peer-to-Peer
 All computers on the network communicate directly with each other without relying
on a server
 For fewer than 25 PCs
 Cheaper than client/server since servers are typically more expensive than PCs

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  There are often problems with knowing who has the current version of documents
and files
 Too slow for use in larger offices
 Legal considerations
 Downloading copyrighted material without paying violates U.S. copyright laws
 Server-based online file sharing sites such as Napster have been shut down
 Peer-to-Peer file-sharing sites have been more difficult to control since there is no
central server to shut down
 So publishers are suing individual downloaders instead

Intranets, Extranets, VPNs

 Intranets
 An organization’s private network that uses the infrastructure and standards of the
internet and the web
 Extranets
 Private internets that connect not only internal personnel but also selected suppliers
and other strategic parties
 Virtual Private Networks
 Private networks that use a public network, usually the internet, to connect remote
sites

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 Components of Networks

 Connections
 Wired – twisted-pair, coaxial cable, or fiber-optic
 Wireless – infrared, microwave (Bluetooth), broadcast (Wi-Fi) or satellite
 Hosts & Nodes
 Host: the central computer that controls the network
 Node: a device that is attached to the network
 Packets
 The format for sending electronic messages
 A fixed-length block of data for transmission

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  Protocols
 The set of conventions governing the exchange of data between hardware and/or
software components in a communications network
 Built into the hardware or software you are using
 Govern the packet design and transmission standards
 Examples are:
 TCP/IP for LANs and internet
 AppleTalk for older Mac networks
 SIP for Voice over IP (VoIP)
 CDMA for cellphones
IPX for older Novell networks

Packets
 TCP/IP Packets carry four types of information
 Sender’s address (source IP number)
 Address of intended recipient (destination IP number)
 Number of packets the original data was broken into
 This happens because the amount of data the PC is sending can be much
larger than the space in a single packet
 So the data has to get broken up in one or more packets
 Then the packets have to be assigned a number like 1 of 6, 2 of 6, 3 of 6, 4 of
6, 5 of 6, and 6 of 6
 Packet number and sequence info for each packet
 Packets may arrive out of order (1, 6, 3, 2, 5, 4 for example)
 This information is used to resequence the packets and put them back in
the correct order (1, 2, 3, 4, 5, 6) so they can be read

Topologies
 Bus – all nodes are connected to a single wire or cable
 Ring – all nodes are connected in a continuous loop
 Star – all nodes are connected through a central host

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 Wired Communications Media
 Communications media carry signals over a communications path
 Twisted-Pair Wire
 2 strands of insulated copper wire twisted around each other
 Twisting reduces interference (crosstalk) from electrical signals
 Data rates are 1 – 128 Megabits per second
 Coaxial Cable
 Insulated copper wire wrapped in a metal shield and then in an external
plastic cover
 Used for cable TV and cable internet electric signals
 Carries voice and data up to 200 megabits per second
 Fiber-optic cable

[AHMED YASIR KHAN.] Page 32 of 91

  Dozens or hundreds of thin strands of glass or plastic that transmit beams
of light, not electricity
 Can transmit up to 2 gigabits per second
 More expensive than twisted-pair or coax
 Lighter and more durable than twisted-pair or coax
 More difficult to tap into than twisted-pair or coax
 Electromagnetic spectrum of radiation is the basis of all
telecommunications signals
 Includes the longest radio waves (9 kHz) and audio waves (sound), up

through gamma rays that come from nuclear decay (thousands of

gigahertz)
 Radio-frequency spectrum is the part of the electromagnetic spectrum that
we use for radio communication

Bandwidth
 Narrowband (or Voiceband)
 Used for regular telephone communications
 Transmission rate 1.5 megabits per second or less
 Medium Band
 Used for long-distance data transmission or to connect mainframe and midrange
computers
 Transmission rate 100 kb to 1 megabit per second
 Broadband
 For high-speed data and high-quality audio and video
 Transmission rate 1.5 megabits per second to 1 gigabit per second or more
 US households get 4 – 5 MB while Japanese get 63 – 64 MB per second

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  Infrared Transmission

 Sends signals using infrared light

 Frequencies are too low to see (1-16 Mbits per second)
 Broadcast Radio
 AM/FM, CB, ham, cellphones, police radio
 Sends data over long distances using a transmitter and a receiver

 Cellular Radio
 Form of broadcast radio
 Widely used in cell phones and wireless modems
 Does not interfere with other cellular phone calls
 Microwave Radio
 Superhigh-frequency radio waves (2.4 gigahertz or higher)
 Requires line-of-sight transmitters and receivers
 Communications Satellites
 ―sky stations‖
 Microwave relay stations in orbit around the earth
 Launch costs between $50 and $400 million
 Basis for Global Positioning Systems (GPS)

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 Global Positioning System
 24 to 32 earth-orbiting satellites continuously transmitting timed radio signals
 Each satellite circles earth twice each day at 11,000 miles up
 GPS receivers pick up transmissions from up to 4 satellites and pinpoint the
receiver’s location
 Accurate within 3 – 50 feet, with a norm of 10 feet accuracy
 GPS receivers contain map files that are displayed based on the GPS position to
guide users
 Many GPS receivers have speech chips too

Wireless Communications Media

One-way Pagers

 One-way pagers are radio receivers that receive data sent from a special radio transmitter
 Radio transmitter sends out signals over the special frequency
 Pagers are tuned to that frequency
 When a particular pager hears its own code, it receives and displays the message

Long-Distance Wireless
 Two-way pagers: Blackberry and Treo

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  1G: First Generation Cellular

 Analog cellphones
 Designed for voice communication using a system of hexagonal ground-area cells
around transmitter-receiver cell towers
 Good for voice – less effective for data due to handing off

2G: Second Generation Cellular

 Use same network of cell towers to send voice and data in digital form over the
airwaves
 Required digital receivers on original analog cell towers

 3G: Third Generation Cellular

 Broadband technology
 Based in the U.S.
 Carry data at high speeds

[AHMED YASIR KHAN.] Page 36 of 91

 4G: Fourth Generation Cellular

 A nationwide 4G network in development

 Uses the WiMax (Worldwide Interoperability for Microwave Access) standard
 Hope to provide broadband to rural areas

2G Wireless
 There are two competing, incompatible standards
 CDMA – Code Division Multiple Access
 Transmission rates 14.4 kilobits per second
 Used by Verizon and Sprint

 GSM – Global System for Mobile Communications

 Transmission rates of 9.6 kilobits per second
 Used by Cingular and T-Mobile, as well as Western Europe, Middle East
and Asia
 US GSM and European GSM use different frequencies

2.5G Wireless
 Data speeds of 300–100 kilobits per second
 GPRS – General Packet Radio Service
 An upgrade to 2.5G
 Speeds of 30 – 50 kilobits per second

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  EDGE is Enhanced Data for Global Evolution
 A different 2.5G upgrade
 Speeds of up to 236 kilobits per second

3G Wireless
 Third generation wireless
 High speed data: 144 kilobits per second up to 2 megabits per second
 Accept e-mail with attachments
 Display color video and still pictures
 Play music
 Two important upgrades:
 EV-DO – Evolution Data Only
 Average speeds of 400 – 700 kilobits per second, peaks of 2
megabits per second
 UMTS – Universal Mobile Telecommunications System
 Average speed of 220 – 320 kilobits per second

4G Wireless
 Fourth generation wireless
 The latest standard
 Uses WiMax (Worldwide Interoperability for Microwave Access) standard
 Transmission at a range of 6-10 miles
 Transmission speed up to 20 mbits/sec
 Transmits farther than Wi-Fi
 Two varieties: one fixed/one mobile
 Hoped to provide broadband in rural areas
 Several communications firms developing a nationwide
4G network
Short-range Wireless
 Local Area Networks
 Range 100 – 228 feet
 Include Wi-Fi (802.11) type networks
 Personal Area Networks
 Range 30 – 32 feet
 Use Bluetooth, ultra wideband, and wireless USB

[AHMED YASIR KHAN.] Page 38 of 91

  Home Automation networks
 Range 100 – 150 feet
 Use Instead, ZigBee, and Z-Wave standards

Wi-Fi (802.11) networks

 Wi-Fi b, a, and g correspond to 802.11b, 802.11a, and 802.11g
 802.11 is an IEEE wireless technical specification
 802.11b is older, transmits 11 megabits per second
 802.11a is faster than b but with weaker security than g
 802.11g is 54 megabits per second and transmits 50 ft
 Wi-Fi n with MIMO extends range of Wi-Fi using multiple transmitting and
receiving antennas – 200 megabits per second for up to 150 ft
 Warning! Security is disabled by default on Wi-Fi

 Wi-Fi Security
 Why is it disabled by default?
 So non-technical users can get Wi-Fi working more easily
 Why should this bother me?
 A person with a $50 antenna can eavesdrop on everything your computer
sends over wireless from a block or two away
 This is called ―wardriving‖
 To read more about this problem, follow this link
 http://www.webopedia.com/TERM/W/wardriving.html
Personal Area Wireless

Bluetooth
 Short-range wireless standard to link cellphones, PDAs, computers, and peripherals
at distances up to 30 ft
 Named after King Harald Bluetooth, the Viking who unified Denmark and Norway
 Transmits up to 3 megabits per second
 When Bluetooth devices come into range of each other, they negotiate. If they have
information to exchange, they form a temporary wireless network
 Bluetooth can also be used to eavesdrop on networks
 Turn it off on your cellphone unless you need it at that time

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 Ultra Wideband (UWB)
 Developed for military radar systems
 Operates in 480 megabit per second range up to 30 ft
 Uses a low power source to send out millions of bursts of radio waves each second
 100 times as fast as Bluetooth

Wireless USB
 USB is the most used interface on PCs
 The wireless version could be a hit
 Range of 32 ft and maximum data rate of > 480 megabits per second

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Software: Software, or programs, consists of all the electronic instructions
that tell the computer how to perform a task. These instructions
come from a software developer in a form (such as a CD, or
compact disk) that will be accepted by the computer. Examples are
Microsoft Windows and Office XP/Vista.

[AHMED YASIR KHAN.] Page 41 of 91

 System Software
 Enables application software to interact with the computer
 Helps the computer to manage its own internal and external resources

Application Software
 Software developed to solve a particular problem for users
 Either performs useful work on a specific task
 Or provides entertainment
 We interact mainly with this software

System Software has 3 basic components

Operating System (OS)

 The principal component of system software
 Low-level, master system of programs to manage basic computer
operations
 Some hardware requires specific Operating Systems
 Macintosh computers run Macintosh OS
 PCs run Microsoft Windows, Linux, or BSD Unix
 IBM Mainframes run MVS or VM
 Cray supercomputers run COS or UNICOS

Device Drivers
 Help the computer control peripheral devices

Utility Programs
 Used to support, enhance, or expand existing programs in the computer

The Operating System: What It Does

Booting
 The process of loading an OS into the computer’s main memory
 The steps are:
1. Turn the computer on
2. Diagnostic routines test main memory, CPU, and other hardware

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 3. Basic Input/Output System (BIOS) programs are copied to main memory
 BIOS contains instructions for operating the hardware
 The computer needs those instructions to operate the hardware
and find a copy of the OS
4. Boot program obtains the OS and loads it into computer’s main memory
The Operating System: What It Does

Central Processing Unit (CPU) Management

 Kernel is the supervising software that manages CPU
 Kernel must remain in memory while the computer runs
 If another program uses the kernel’s memory when the kernel needs it, the
computer will crash
 Memory Management
 OS keeps track of memory locations to prevent programs and data from
overlapping each other
 Swaps portions of programs and data into the same memory but at
different times
 Keeps track of virtual memory

Queues, Buffers, Spooling

 Queue: First-in, First-out (FIFO) sequence of data or programs that waits
in line for its turn to be processed
 Buffer: The place where the data or programs sit while they are waiting
 To Spool: The act of placing a print job into a buffer
 Needed because the CPU is faster than printers
 The CPU can work on other tasks while the print jobs wait

File Management
 A file is either a
 Data File: a named collection of data
 Program File: a program that exists in a computer’s secondary storage
 The File System arranges files in a hierarchical manner
 Top level is Directories (aka Folders)
 Subdirectories come below Folders
 Find files using their pathname
 C:/MyDocuments/Termpaper/section1.doc

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 Task Management
 Required for computers that accommodate multiple users
 Required for computers that allow multiple simultaneous applications
 Methods of processing two or more programs
 Multitasking
 By one user on one processor
 Multiprogramming
 By multiple users concurrently on one processor
 Time-sharing
 By multiple users in round-robin fashion on one processor
 Multiprocessing
 By one or more users simultaneously on two or more processors
 Security Management
 Operating Systems permit users to control access to their computers
 Users gain access using an ID and password
 You set the password the first time you boot up a new computer
 System Administrators can set up new accounts and assign new passwords

[AHMED YASIR KHAN.] Page 44 of 91

 Other System Software: Device Drivers & Utilities

Device Drivers
 Specialized software programs that allow input and output devices to communicate
with the rest of the OS
 When you get a brand-new printer or monitor, you may also need to install the
device driver for it
 Device drivers come with new hardware, or download from the manufacturer’s
website, or sites like www.driverguide.com or www.windrivers.com

Utilities
 Service programs that perform tasks related to the control and allocation of
computer resources
 Some come with the OS, others can be bought separately like
 Norton SystemWorks, McAfee Utilities

 Practical Utility programs perform the following tasks

 Virus protection
 Data compression
 File defragmentation
 Disk scanner & disk cleanup
 Backup
 Data recovery

Common Operating Systems

 Mac OS
 The OS that runs on Apple Macintosh computers
 Pioneered the easy-to-use GUI
 Proprietary OS
 System 9 is OS from 1999, but still popular
 Mac OS X is based on BSD Unix kernel
 Leopard is 2007 release of Mac OS X; features include
 Spotlight – a desktop search engine for locating files on local hard
disk
 Dashboard – for creating desktop ―widgets‖
 Automator – automatically helps users to script repetitive tasks

Microsoft Windows
 Windows early versions
 95, 98 and ME
 Windows XP – 2001

[AHMED YASIR KHAN.] Page 45 of 91

  XP Home Edition
 Windows XP Media Center
 Windows Vista – 2007
 Windows 7 – in 2010
 Touch screen apps instead of mouse
 Uses a ―20 year-old Core‖
 Unix, Solaris, BSD
 Developed at AT&T Bell Laboratories in 1969 as minicomputer operating system
 Is a multitasking operating system with multiple users that has built-in networking
capability and a version for every platform
 Unix interface
 GUI – An optional shell program that starts after the kernel
 Command interface – starts when kernel loads
 Linux
 A flavor (version) of Unix
 A free, nonproprietary version of UNIX
 May legally be downloaded and used for free
 May legally be modified for free, as long as modifications aren’t
copyrighted
 In 2000, adopted by China as national standard OS
 Linux vendors produce Linux Distributions
 Software is distributed for free
 Support services are sold for a profit
 Many PCs are set up to dual-boot Linux and Windows

 Operating Systems for Handhelds

 Palm OS
 Dominant handheld OS
 Proprietary OS requires proprietary software
 Windows CE
 Has familiar Windows look and feel
 Can be directly programmed using Visual Basic 2005
 Symbian OS
 Symbian is world’s largest producer of smartphone software
 Software is open-source

Application Software
 There are 5 ways to legally obtain software
1. Commercial Software
 Copyrighted – license must be purchased
2. Public-domain software
 Not copyrighted – legal to copy
3. Shareware
 Copyrighted – download for free, then pay if you use it
4. Freeware
 Copyrighted – but available for free. Pay on honor system

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 5. Rentalware
 Copyrighted – lease for a fee

Software License Types

 Site licenses
 Allow software to be used on all computers at a specific location
 Concurrent-user license
 Allows a specified number of copies to be used at one time
 May require additional license-monitoring software
 Multiple-user license
 Specifies the number of people who may use the software
 Single-use license
 Limits the software to one user at a time

 Other software categories

 Pirated software
 Software obtained illegally in violation of copyright
 Software & Industry Information Association Anti-Piracy division
prosecutes violators of software copyright laws http://www.siia.net/piracy/
 Don’t pirate software!!!
 Abandonware
 Software that is no longer being sold or supported by its publisher
 Subject to copyright for 95 years from date of publication

 Importing files
 Getting data from another source and converting it into a format for the application
you are using
 Allows you to edit files from other applications
 Exporting files
 Transforming data into a format that can be used by a different application, then
transmitting it
 Common export files end in the .rtf extension
 Three types of data files
 Document, worksheet, database

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 Word Processing
 Software that uses computers to create, edit, format, print, and store text.
 Microsoft Word licensed for Windows and Mac OS
 Lotus Smart Suite licensed for Windows
 Sun Microsystems Star Office licensed for Windows- Linux- and
Solaris-based systems (was free)
 Corel Word-Perfect licensed for Windows
 Tools for creating documents
 Cursor is on screen to show you where to enter text
 Scrolling means moving quickly forward, up, down, or sideways
through document test display
 Word wrap automatically continues text to next line when you reach
the right margin
 Outline view puts tags on headings within a document to organize it
 Inserting is the act of adding text to documents
 Deleting is the act of removing text from documents

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  Find & Replace
 Find lets you go straight to any text in your document
 Replace lets you go to the text and automatically replace it with
something else
 Cut, Copy, & Paste
 Select the text you want to move
 Copy to clipboard, then paste in new location
 Or drag the text to the new location
 Spelling Checker
 Tests for incorrectly spelled words

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  Often shows them with a squiggly line underneath
 You may choose to use the ―Autocorrect‖ feature
 Grammar Checker
 Highlights poor grammar, wordiness, sentence fragments, and
awkward phrases
 Puts different-color squiggly line under suspect phrases
 Thesaurus
 Can be called up on-screen
 Offers suggestions for alternative words with the same meaning

 Formatting Documents using Templates & Wizards

 A template is a preformatted document that provides basic tools for
shaping a final document
 You can customize a template with your company’s name,
address, etc, then save it and use it again and again
 Use them when you have to repeatedly create the same basic
document
 A wizard is an interactive computer utility program that leads the
user through a task asking questions and using the user’s answers to
customize a solution
 Letter wizards create customized letters
Memo wizards help you to create memoranda
 Formatting
 Font
 The typeface, size, and color of your letters
 Also lets you specify underlined, italic, or bold
 Spacing & Columns
 Choose how far apart the lines will be (single- or double-
spaced)
 Choose single-column or multi-columned text for your
document
 Margins & Justification
 Indicate width of left, right, top, and bottom margins
 Justify text left, right, or center
 Headers, footers, page numbers
 A header is text printed at the very top of the page
 A footer is text (like page number) at the page bottom
 Other Formatting
 You can specify a border around a document or around a paragraph
– it can really highlight a point

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  You can also use shading, tables, and footnotes
 Default Settings
 These are the settings automatically used by the program unless you
change them
 Saving a document
 Store a document as an electronic file
 File  Save or click Floppy icon or Ctrl + S
 Save often, and save in two places
 Print
 Print individual pages, the whole document, or several copies
 File  Print or click printer icon or Ctrl + P
 Track Changes
 Save as Web Document

Spreadsheets
 Electronic spreadsheets were created in 1978 by Daniel Bricklin at Harvard
Business School and Daniel Fylstra at M.I.T. and HBS as a study tool
 Spreadsheets are organized into columns and rows
 Cells are where a row and a column meet
 Cell address is the position of the cell
 Range is a group of adjacent cells
 Values are numbers or dates entered into a cell
 Cell pointers or cursors are where the data is to be entered

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  Formulas, Functions, Recalculation, What-If
 Formulas are instructions for calculations
 They define mathematically how one cell relates to another cell
 Example: =SUM(A5:A15) sums the values of the cells A5, A6,
A7, and so forth up through cell A15
 Functions are built-in formulas, such as SUM()
 Recalculation is the process of recomputing values
 What-If analysis allows users to see what happens to totals when one
or more numbers change in cells
 This is the powerful feature of spreadsheets over manual
calculations

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  Charting and Analytical Graphics
 Spreadsheets allow you to automatically create graphs
 When the cells change, the graphs change too
 Charts are a type of graph that include
 Bar charts
 Column charts
 Line graphs
 Pie charts
 Scatter charts

Database Software

 A database is a structured collection of interrelated files in a computer

system with built-in data input and retrieval methods.
 In databases
 Data redundancy is minimized
 Data is integrated and stored in a structured fashion
 Data in databases has more integrity than does data stored in separate
files
 Data is organized into tables, records, and fields
 Data may include text, numbers, and graphics

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[AHMED YASIR KHAN.] Page 54 of 91
  Database features include
 Linking records using a key
 Tables that contain the same field are linked together by fields,
so the key can be updated just once
 Key fields can also be used to sort data
 Querying and displaying records
 Offer a quick way to locate records
 Saving, Formatting, Printing, Copying, Transmitting
 Database software allows you to create custom input forms,
custom reports, copy search results and paste them into Word,
print out addresses to mailing labels, or attach to email

Specialty Software
 Presentation Graphics
 Desktop Publishing
 Financial Software
 Drawing and Painting Software
 Project Management Software
 Video-audio Editing Software
 Animation Software
 Web Page Design Software

 Presentation Graphics Software

 Use graphics, animation, sound, data, or information to make visual
presentations
 This presentation is an example
 Contains
 Design and content templates
 Slide sorters
 Outline view
 Slide view
 Notes Page View

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[AHMED YASIR KHAN.] Page 56 of 91
 Financial Software
 Ranges from personal-finance managers to entry-level accounting
programs to business financial-management packages
 Common features
 Track income and expenses
 Allow checkbook management
 Do financial reporting
 Offer tax categories to assist with tax recordkeeping
 May also offer financial-planning and portfolio-management
features

Desktop Publishing
 Involves mixing text and graphics to produce high-quality output for
commercial printing
 Uses a mouse, scanner, printer, and DTP software
 Has the following features
 Mix of text with graphics
 Offers varied type and layout styles
 Allows import of files from other programs
 Drawing programs
 Graphics software used to design and illustrate objects and products

 Painting programs
 Graphics programs that allow users to simulate painting on-screen
 Produce bit-mapped or raster images
 Also called image-editing software
 Graphics file formats
 .bmp (bit-map)
 .gif (Graphic Interchange Format) – copyrighted format used
in web pages
 .jpeg (Joint Photographic Experts Group)- high-resolution
 .tiff (Tagged Image File Formats) – PC and Macs for high-
resolution images to print
 .png (Portable Network Graphics) – public domain alternative
to gif

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 Video editing software
 Allows import to and editing of video footage on PC
 Video editing examples include Adobe Premiere, Sony Pictures Digital
Vegas, Apple Final Cut Express, Pinnacle Studio DV, and Ulead
VideoStudio

Audio editing software

 Allows import to and editing of sound files on PC
 Sound editing examples include Windows Sound Recorder, Sony
Pictures Digital Sound Forge, Audacity (freeware), Felt Tip
Software’s Sound Studio (shareware), GoldWave, and WavePad.

Animation Software
 Simulates movement by rapidly displaying a series of still pictures, or
frames
 GIF is the first format to be widely used

Multimedia Authoring Software

 Combines text, graphics, video, animation, and sound in an integrated
way to create stand-alone multimedia applications
 Requires fast computer, lots of memory, and good, fast graphics card
 Macromedia Director and Macromedia Authorware are popular
examples

Web Page Design Software

 Used to create web pages with sophisticated multimedia features
 Not required to create simple web pages

Project Management Software

 A program used to plan and schedule the people, costs, and resources
required to complete a project on time
 Shows project broken down into steps and tasks
 Each task has a beginning and end date

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  Tasks can be scheduled concurrently or consecutively

Computer-Aided Design (CAD)

 Programs intended for design of products, structures, civil
engineering drawings, and maps
 Provide precise dimensioning and positioning of design
elements
 Examples include AutoCAD, ProEngineer, CorelCAD, CATIA

The Internet & the World Wide Web

 Internet History
 Began with 1969’s ARPANET for US Dept. of Defense
 62 computers in 1974
 500 computers in 1983
 28,000 computers in 1987
 Early 1990s, multimedia became available on internet
 To connect you need
 An access device (computer)
 A means of connection (phone line, cable hookup, or wireless)
 An Internet Service Provider (ISP)

Definition: Bandwidth is an expression of how much data – text, voice, video

and so on – can be sent through a communications channel in a given amount
of time.
Definition: Baseband is a slow type of connection that allows only one signal to
be transmitted at a time.
Definition: Broadband is a high speed connection that allows several signals to
be transmitted at once.

 Data Transmission Speeds

 Originally measured in bits per second (bps)
 8 bits are needed to send one character, such as A or a
 Currently measured in kilobits per second (Kbps)
 Kilo- stands for a thousand
 A 28.8 Kbps modem sends 28,800 bits per second
 How many characters per second would that be?

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  Mbps connections send 1 million bits per second
 Gbps connections send 1 billion bits per second

Modems
 Can be either internal or external to your PC
 Most ISPs offer local access numbers
 Need call waiting turned off; either manually or in Windows
 High-speed phone lines
 ISDN line
 DSL line
 Cable Modems
 Satellite
 Wi-Fi & 3G

 Modems
 28.8 Kbps takes 4 3/4 hours to download 6 minute
video
 High-speed phone lines
 ISDN line
 1 hour to download 6 minute video
 DSL line
 11 minutes to download 6 minute video
 Cable Modems
 Connects the PC to a cable-TV system
 2 minutes to download a 2 minute video
 Satellite
 Wi-Fi & 3G

Wi-Fi
 Name for a set of wireless standards set by IEEE
 Typically used with laptops that have Wi-Fi hardware

3G
 High-speed wireless that does not need access points
 Uses cell phones

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 How Does the Internet Work?

 Internet Backbone
 High-capacity, high-speed data transmission lines
 Use the newest technology
 Providers include AT&T, Cable & Wireless, Sprint, Teleglobe,
UUNET
 Internet 2
 Cooperative university/business research project
 New standards for large-scale higher-speed data transmission
 Requires state-of-the-art infrastructure

 Protocols
 The set of rules a computer follows to electronically transmit data.
 TCP/IP is the internet protocol
 Developed in 1978
 Used for all internet transactions
 Packets
 Fixed-length blocks of data for transmission
 Data transmissions are broken up into packets
 IP Addresses
 Every device connected to the internet has an address
 Each IP address uniquely identifies that device
 The address is four sets of 3-digit numbers separated by periods
 Example: 95.160.10.240
 Each number is between 0 and 255
 Static IP addresses don’t change
 Dynamic IP addresses don’t change
 Since addresses are limited, and most PCs are not connected a
lot of the time, dynamic addresses are common

The World Wide Web

 Browsers
 Software for web-surfing
 Examples: Internet Explorer, Netscape Navigator, Mozilla FireFox,
Opera, Apple Macintosh browser
 Website
 The location on a particular computer that has a unique address

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  Example: www.barnesandnoble.com, www.mcgraw-hill.com
 The website could be anywhere – not necessarily at company
headquarters
 Web Pages
 The documents and files on a company’s website
 Can include text, pictures, sound, and video
 Home page
 The main entry point for the website
 Contains links to other pages on the website
 Uniform Resource Locator (URL)
 A character string that points to a specific piece of information
anywhere on the web
 A website’s unique address
 It consists of
 The web protocol, http
 The domain name of the web server
 The directory or folder on that server
 The file within the directory, including optional extension

 Domain names
 Must be unique
 Identify the website, and the type of site it is
 www.whitehouse.gov is NOT the same as www.whitehouse.org
 .gov means government
 .org means professional or nonprofit organization
 HTTP
 The internet protocol used to access the World Wide Web
 HTTPS
 The secure version of HTTP
 Hypertext Markup Language (HTML)
 The language used in writing and publishing web pages
 The set of tags used to specify document structure, formatting, and
links to other documents on the web
 Hypertext links connect one web document to another

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  Web Browsers
 Your tool for using the internet
 Comes preinstalled on most PCs
 5 basic elements
 Menu bar
 Toolbar
 URL bar
 Workspace
 Status bar

 Home Page
 The page you see when you open your web browser
 You can change the Home Page on your browser
 Back, Forward, Home & Search
 Use the menu bar icons to move from one page to another

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  Web portals
 A gateway website that offers a broad array of resources and services,
online shopping malls, email support, community forums, stock
quotes, travel info, and links to other categories.
 Examples: Yahoo, AOL, Microsoft Network (MSN), Lycos, or Google
 Most require you to log in, so you can
 Check the home page for general information
 Use the subject guide to find a topic you want
 Use a keyword to search for a topic

 Search Services
 Organizations that maintain databases accessible through websites to
help you find information on the internet
 Examples: portals like Yahoo Search and MSN, and Google, Ask
Jeeves, and Gigablast
 Databases are compiled using software programs called spiders
 Spiders crawl through the World Wide Web
 Follow links from one page to another
 Index the words on that site

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  4 web search tools
 Keyword Indexes
 Type one or more search keywords, and you see web pages
―hits‖ that contain those words
 For phrases with two or more words, put phrase in quotes
 Examples are Google, Gigablast, HotBot, MSN Search, Teoma
 Subject Directories
 Search by selecting lists of categories or topics
 Example sites are Beaucoup, Galaxy, LookSmart, MSN
Directory, Netscape, Open Directory Project, Yahoo
 Metasearch Engines
 Specialized Search Engines

Email & Other Ways of Communicating over the Net

 Email Program
 Enables you to send email by running email software on your
computer that interacts with an email server at your ISP
 Incoming mail is stored on the server in an electronic mailbox
 Upon access, mail is sent to your client’s inbox
 Examples: Microsoft’s Outlook Express, Netscape’s Mail, Apple
Computer’s Apple Mail, QualComm’s Eudora
 Web-based Email
 You send and receive messages by interacting via a browser with a
website
 Advantage: You can easily send and receive messages while traveling
 Examples: Yahoo! Mail, Hotmail, Bluebottle, gmail.
 Using email
 Get an email address, following the format
Joe_Black@earthlink.net.us
 Type addresses carefully, including capitalization, underscores, and
periods
 Use the reply command to avoid addressing mistakes
 Use the address-book feature to store email addresses
 Sort your email into folders or use filters
 Email Attachments
 A copy of a file or document that you send attached to an email to one
or more people
 Be careful about opening attachments

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  Many viruses hide in them
 Know who is sending it to you before you open it
 The recipient must have compatible software to open the attachment.
If they don’t have Excel, they probably can’t read the spreadsheet you
sent them.
 FTP – File Transfer Protocol
 A software standard for transferring files between computers with
different Operating Systems
 Microsoft Windows  Linux
 Unix  Macintosh OS, and so forth
 You can transfer files from an FTP site on the internet to your PC
 Know your FTP site!
 If the FTP site is offering copyrighted material such as music
and movies for free, you are breaking US law if you download
files!
 You may also get a virus or spyware on your PC from them

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 Databases & Information Systems

 A database is a logically organized collection of related data designed and

built for a specific purpose
 Data is stored hierarchically for easier storage and retrieval
 Files: collections of related records
 Records: collections of related fields
 Field: unit of data containing 1 or more characters
 Character: a letter number or special character made of bits
Bit: a 0 or 1
 Key Field – the field that identifies a record
 Often an identifying number, such as social security number
 Primary keys must be unique
 Keys are used to pick records out of a database
 Unique keys make records stand out from each other
 If two records had the same key, then you might not pick the
correct one
 keys are used to sort records in different ways
Foreign keys are fields that appear in two different tables and are used to
relate one table to another

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 This example shows a sample database in Microsoft Access. Products is a
table. ProductID is the primary key of the Product table. ProductID is also a
foreign key in the Orders table

 Data files are files that contain data such as words, numbers, pictures, or
sounds
 These are the files that are used in databases
 They have extensions such as .txt .mdb, and .xls
 Graphics files have extensions like .tiff, .jpeg, and .png
 Audio files have extensions such as .mp3, .wav, and .mid
 Animation/video files have extensions such as .qt, .mpg, .avi, and .rm
 Data files are often compressed to save space and transmit them faster
 Compression removes repetitive elements from a file

 Software written specifically to control the structure of a database and access

to the data
 Reduced data redundancy
 Redundant data is stored in multiple places, which causes
problems keeping all the copies current

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  Improved data integrity
 Means the data is accurate, consistent, and up to date
 Increased security
 Limits who can create, read, update, and delete the data
 Ease of data maintenance
 Offer validation checks, backup utilities, and procedures for
data inserting, updating, and deletion
 Data Dictionary
 A repository that stores the data definitions and descriptions of the
structure of the data and the database
 DBMS Utilities
 Programs that allow you to maintain the database by creating,
editing, deleting data, records, and files
 Also include automated backup and recovery
 Report Generator
 Program for producing an on-screen or printed document form all or
part of a database
 Database Administrator (DBA)
 A high-paid, responsible position within an organization
 Coordinates all related activities and needs for an organization’s
database
 Ensures the database’s
 Recoverability
 Integrity
 Security
 Availability
 Reliability
 Performance

Database Models
 Hierarchical database in a family Fields or records are arranged tree, with
child records subordinate to parent or higher-level records
 Network database Like a hierarchical database, but each child record can
have more than one parent record
 Relational database Relates, or connects, data in different files through the
use of a key, or common data element
 Object-oriented database Uses objects (software written in small, reusable
chunks) as elements within database files

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  Multidimensional database Models data as facts, dimensions, or numerical
measures for use in the interactive analysis of large amounts of data

Hierarchical Databases
 Fields or records are arranged in related groups resembling a family
tree with child (low-level) records subordinate to parent (high-level)
records
 Root record is the parent record at the top of the database, and data is
accessed through the hierarchy
 Oldest and simplest; used in mainframes

Network Database
 Similar to a hierarchical database, but each child record can have
more than one parent record
 Used principally with mainframe computers
 Requires the database structure to be defined in advance

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 Relational Database
 Relates or connects data in different files through the use of a key, or
common data element
 Examples are Oracle, Informix, Sybase
 Data exists independently of how it is physically stored
 Users don’t need to know data structure to use the database
 Uses SQL (structured query language) to create, modify, maintain,
and query the data
 Query by Example uses sample records or forms to allow users to
define the qualifications for choosing records

Object-oriented Databases
 Use ―objects‖, software written in small, manageable chunks, as
elements within data files
 An object consists of
 Data in any form, including audio, graphics, and video
 Instructions on the action to be taken with the data
 Examples include FastObjects, GemStone, Objectivity DB, Jasmine
Object Database, and KE Texpress
 Types include
 Web database

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  Hypermedia database

Multidimensional Database
 Models data as facts, dimensions, or numerical answers for use in the
interactive analysis of large amounts of data for decision-making
purposes
 Allows users to ask questions in colloquial English
 Use OLAP (Online Analytical Processing) software to provide
answers to complex database queries

Data Mining

 Is the computer-assisted process of sifting through and analyzing vast

amounts of data to extract hidden patterns and meaning and to discover new
knowledge
 Data is fed into a Data Warehouse through the following steps
 Identify and connect to data sources
 Perform data fusion and data cleansing
 Obtain both data and meta-data (data about the data)
 Transport data and meta-data to the Data Warehouse
 Data Warehouse is a special database that shows detailed and summary data
from multiple sources
 Methods for searching for patterns in the data and interpreting the results
 Regression analysis
 Develops a formula to fit patterns in the data that has been
extracted
 Formula is applied to other data sets to predict future trends
 Classification analysis
 A statistical pattern recognition process that is applied to data
sets with more than just numerical data

Using Databases to Help Make Decisions

 What are the qualities of good information?

 Correct and verifiable
 Complete yet concise
 Cost effective

[AHMED YASIR KHAN.] Page 72 of 91

  Current
 Accessible
 Most organizations have 6 departments to which information must flow
 Research and development
 Production (operations)
 Marketing and sales
 Accounting and finance
 Human resources (personnel)
 Information systems (IS)
 Information flows horizontally between departments

 Besides the 6 departments, many organizations also have 3 levels of

management
 Strategic-level management
 Top managers concerned with strategic or long-term planning
and decisions
 Tactical-level management
 Middle level managers who make decisions to implement the
strategic goals set for the organization
 Operational-level management
 Low-level supervisors make daily operational decisions
 Information flows vertically between management levels

 Decentralized Organizations – a new structure

 Employees increasingly telecommute – some staff have no desk or
office at work
 Employees communicate with each other more via email than in
person
 Companies use Groupware CSCW (computer-supported cooperative
work) systems to enable cooperative work by groups of people
 The management structure is flattened as employees are given more
authority to make day-to-day decisions
 6 computer-based information systems
 Office information systems
 Transaction processing systems
 Management information systems
 Decision support systems
 Executive support systems
 Expert systems

[AHMED YASIR KHAN.] Page 73 of 91

 Transaction Processing System (TPS)
 Transactions are recorded events of routine business activities such as
bills, orders, and inventory
 TPS systems keep track of the transactions needed to conduct a
business
 TPS systems are used by operational managers to track business
activities
 Transactions database provides the basis for management
information systems and decision support systems
 Management Information Systems (MIS)
 Computer-based information system that uses data recorded by a
TPS as input to programs that produce routine reports as output
 Features
 Inputs are processed transaction data. Outputs are
summarized structured reports
 Designed for tactical managers
 Draws from all departments
 Produces several kinds or reports: summary, exception,
periodic, and demand

Decision Support Systems (DSS)

 Computer information system that provides a flexible tool for analysis
and helps management focus on the future
 Features
 Inputs are external data and internal data such as summarized
reports and processed transaction data. Outputs are demand
reports

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  Mainly for tactical managers
 Produces analytic models
 Developed to support the types of decisions faced by managers in
specific industries

Executive Support Systems

 An easy-to-use DSS made especially for strategic managers to support
strategic decision-making
 Might allow executives to call up predefined reports
 Includes capability to browse through summarized information on all
aspects of the organization and drill down for detailed data
 Allows executives to perform ―what-if‖ scenarios

Artificial Intelligence

Expert System
 One of the most useful applications of Artificial Intelligence (AI)
 AI is a group of related technologies used to develop software and
machines that emulate human qualities such as learning, reasoning,
communicating, seeing, and hearing
 Areas include
 Expert systems
 Natural language processing
 Intelligent agents
 Pattern recognition
 Fuzzy logic
 Virtual reality and simulation devices
 Robotics

 Three components of an expert system

 Knowledge base
 An expert system’s database of knowledge about a particular
subject
 Inference engine
 The software that controls the search of the expert system’s
knowledge base and produces conclusions
 User interface
 The display screen the user used to interact with the expert
system

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  Natural language processing
 Allows users to interact with a system using normal English
 The study of ways for computers to recognize and understand human
language
 Intelligent agents
 A form of software with built-in intelligence that monitors work
patterns, asks questions, and performs work tasks on your behalf
 Pattern recognition
 Involves a camera and software that identify recurring patterns in its
vision and maps the pattern against patterns stored in a database
 Fuzzy logic
 A method of dealing with imprecise data and uncertainty, with
problems that have many answers rather than one
 Has been applied in running elevators to determine optimum times
for elevators to wait
 Virtual reality
 A computer-generated artificial reality that projects a person into a
sensation of 3-D space
 Often used with simulators to represent the behavior of physical or
abstract systems
 Robotics
 The development and study of machines that can perform work that
is normally done by people
 Commonly found in manufacturing plants and also in situations
where people would be in danger
 Nuclear plants
 Assembly lines, especially paint lines
 Checking for land mines
 Fighting oil-well fires

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 Systems Analysis & Programming

Systems Development

 Organizations can make mistakes, and big organizations can make really big
mistakes
 Murphy’s Law: Whatever can go wrong, will go wrong,
and at the worst possible time

 A system
 A collection of related components that interact to perform a task in
order to accomplish a goal
 Systems Development

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  6-phase process of gathering information about system requirements
and using that to develop a new system that improves productivity

 The three kinds of users of a project are:

 Users
 The new system must ALWAYS be developed in consultation
with the people who will be using the completed system
 Management
 Managers within an organization should be consulted about
the system, as they control the budget and resources
 Technical staff
 The Information Systems or IT staff must be involved so they
can make sure the technology is there
 Systems Analyst
 An information specialist who performs systems analysis, design, and
implementation
 His or her job is to study the information and communications needs
of an organization and determine what changes are needed to deliver
better information to the people who need it
 The 6 phases of systems analysis & design are:
 Preliminary investigation
 Systems analysis
 Systems design
 Systems development
 Systems implementation
 Systems maintenance
 Information systems are frequently revised and upgraded
 Steps in the cycle often overlap

 Phase 1: Conduct a preliminary investigation

 Conduct a preliminary analysis
 Propose alternative solutions
 Interview people within the organization
 Study what competitors are doing
 Decide to leave the system as is, improve it, or develop a new
system
 Describe costs and benefits
 Submit a preliminary plan with recommendations
 This should be a written report

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  Get management approvals for next phase
 Phase 2: Analyze the system
 Gather data
 Interview employees and managers
 Develop, distribute, analyze questionnaires
 Review current written documents
 Observe people and processes at work
 Analyze the data
 Use system modeling tools, such as CASE tools
 Create a data flow diagram to show how data flows through
the system
 Write a report and get approvals for next phase
 Document how the current system works
 Document problems with the current system
 Describe the requirements for the new system
 Phase 3: Design the system
 Notice that you don’t design the new system until you have done
phase 2 since that establishes the requirements it must meet!
 Do a preliminary design
 Often involves prototyping
 Do a detail design, showing:
 Input requirements
 Output requirements
 Storage requirements
 Processing requirements
 System controls
 Backup
 Write a report and get approvals for next phase
 Phase 4: Develop the system
 Develop or acquire the software
 Acquire and integrate the hardware
 Test the system
 Unit testing
 Systems testing with both analysts and end-users
 End-user testing is critical, as they don’t know the software
and will show the developers where they forgot something
 Phase 5: Implement the system
 Choose a strategy to convert to the new system
 Direct implementation
 Parallel implementation

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  Phased implementation
 Pilot implementation
 Train the users
 Document the system
 Give classes or train the trainers
 Phase 6: Maintain the system
 Perform periodic evaluations
 Make changes to the system based on new conditions
 Document those changes

Programming: A Five-Step Procedure

 A program is a list of instructions that the computer must follow to process
data into information
 The five steps are
1. Clarify/define the problem
a. Clarify the program objectives & users
b. Clarify outputs
c. Clarify inputs
d. Clarify processing tasks
e. Study the feasibility of the program
f. Document the analysis
2. Design the program
3. Code the program
4. Test the program
5. Document and maintain the program
 Step 2: Design the program
1. Create an algorithm or set of steps to solve the problem
a. Traditional structured programming approach
 Determine program logic using top-down approach &
modules
 Design details using pseudocode or flow charts
b. Alternative object-oriented approach
 Use ―Use Case‖ approach to determine program
objects, object inheritance, and actions or functions
each object can perform
 Identify major program components and organize
related functions and associated data into object classes
 This is the approach used by object-oriented languages
such as Java, C#, Lisp, Visual Basic, and C++

[AHMED YASIR KHAN.] Page 80 of 91

  For more information on object-oriented programming,
visit http://oopweb.com/ or
http://java.sun.com/docs/books/tutorial/java/concepts/

 A hierarchy chart

 Pseudocode

[AHMED YASIR KHAN.] Page 81 of 91

[AHMED YASIR KHAN.] Page 82 of 91
Example of a program flowchart and explanation of flowchart symbols
This example represents a flowchart for a payroll program

[AHMED YASIR KHAN.] Page 83 of 91

Programming: A Five-Step Procedure
Iteration and sequence
control structures

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  Step 3: Code the program
 Translate the logic requirements into a programming language
 Programming language is a set of rules that tells the computer what
operations to do
 Each programming language has a syntax, or set of grammatical rules
to follow to write valid expressions
 Syntax rules must be followed or there will be syntax errors
 Computers don’t understand what you want, only what you
type in
 Step 4: Test the program
 Desk checking is done by the programmer who checks for syntax
errors and logic errors
 Debugging is the process of detecting, locating, and removing all
errors in a computer program
 Beta testing is the process of testing the program using real data
 One phase of testing uses correct data
 Once the program works, the next phase of testing uses invalid
data and untrained users to root out hidden errors
 Step 5: Document & Maintain the program
 Documentation is written descriptions of what a program is and how
to fix it
 There are several types of documentation that should be written
 User documentation – for the people who will use your
program
 Operator documentation – for the people who run the large
computers the program runs on – so they know what to do if
the program or computer malfunctions
 Programmer documentation – for the next programmer who
must modify and maintain what you have written
 Maintain the program
 Fix any errors that are noticed once the program is in
production
 Update the program to reflect new requirements
st
 1945 – 1 Generation – Machine Language
 The basic language of the computer – all zeros and ones
 Each CPU architecture had a different machine language
 Mid-1950s – 2nd Generation – Assembly Language
 Mnemonic version of machine language
 Faster to program in than machine language
 Each CPU architecture had a different assembler

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  Mid-1950s to 60s – 3rd Generation – High-level Languages (procedural
languages) such as FORTRAN, COBOL, BASIC, C
 These languages are portable (the same across all CPUs)
 The programmer writes, then interprets or compiles the programs
 The compiler or interpreter translates the code into the CPU-specific
assembler
 Early 1970s – 4th Generation – Problem-oriented Languages such as Intellect,
NOMAD, FOCUS
 Easier to program in than 3rd generation languages
 Three types are:
 Report generators
 Query languages
 Application generators
 Early 1980s – 5th Generation – Natural Languages
 Programming languages that use human language to give people a
more natural connection with computers
 Part of the field of artificial intelligence

Object-Oriented & Visual Programming

 In Object oriented Programming (OOP) data and processing instructions are

combined into an object that can be reused
 Object
 Self-contained module consisting of reusable code
 Message
 The instruction received by the object indicating it is time to
perform an action
 Method
 The processing instructions within the object to perform the
specified action

 Black Box
 Objects are like a black box in that the
actions and the objects are specified, but
the methods used are internal to the object
 This means the programmer that uses an object does not need to
know how the program inside the object does what it does
 For example, Microsoft Excel is like an object
 Most of us use Excel without understanding what the
programmers at Microsoft did to make Excel work

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  If we had to know that, it would take a lot longer to learn how
to use Excel!
 Programmers who use objects can write programs a lot faster,
because objects save so much work
 3 basic concepts of OOP
 Encapsulation
 One object contains (encapsulates) both
 Data
 Relevant processing instructions
 Inheritance
 One object can be used as the foundation for other objects
 Objects can be arranged in hierarchies – classes and subclasses
 Objects can inherit actions and attributes from each other
 Polymorphism
 Allows a single definition to be used with different data types
and different functions
 Means a message produces different results depending on the
object it is sent to

Doors
Have a Handle
open
close

Patio doors Front doors Car doors

Have a slider Have locks Have locks
slide open Have windows
slide closed

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  Visual Basic is an example of visual programming
 Using a mouse, the programmer drags and drops objects on screen
 The objects are arranged to make up the graphical user interface for
the program being written
 By double-clicking on those objects, the programmer can get into a
coding window and write the programs to control the actions and
behaviors of those objects
 This makes it fast and easy to build prototype user interfaces and get
end-user approval before doing a lot of programming

 Visual Basic .NET (VB.NET) is an object-oriented computer

programming language that can be viewed as an evolution of
Microsoft's Visual Basic (VB) which is implemented on the Microsoft
.NET Framework. Microsoft currently supplies Visual Basic free of
charge.

[AHMED YASIR KHAN.] Page 88 of 91

Markup & Scripting Languages

 A markup language is a kind of coding or ―tags‖ inserted into text that

embeds details about the structure and appearance of the text.

<body bgcolor = "yellow">

<h2> <p>My name is </h2>
<b><i><font color=―red‖>your name</font></i></b></p>
And I <b><h1>love</h1></b> this class!!!
</body>

 Open up a text editor such as Notepad or WordPad, and enter the following
text:
 Then save the file on your desktop. Name it sample.htm
 Now open your internet browser and view it by clicking ―file open‖ and
navigating to your desktop
 HTML
 Hypertext markup language

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  Used to create web pages
 Also lets you insert a hypertext link in a web page
 VRML
 Virtual Reality Modeling for Markup Language is used to create
three-dimensional web pages including interactive animation
 Requires special VRML browser to view those pages
 XML
 eXtensible Markup Language is a metalanguage written in SGML
that allows one to facilitate easy document interchange on the internet
 XML lets you create your own tags
 XML statements define data content
 JavaScript
 Not the same language as Java
 An object-oriented scripting language that adds interactive functions
to web pages
 ActiveX
 Developed by Microsoft as an alternative to Java for creating
interactivity on web pages
 A set of controls or components that enable programs or content of
almost any type to be embedded in a web page
 Often used by crackers to propagate viruses and/or trojans
 Before you allow an ActiveX component to download from your
browser to your PC, make sure you trust that website!
 CGI (Common Gateway Interface)
 Standard protocol
 Interfaces external application software with a web server
 Manages the exchange of information
 TCL (Tool Command Language)
 Created for the Unix platform
 Interpreted script language from Sun Microsystems
 Comparable to JavaScript and Visual Basic
 Ruby
 Basic and completely object-oriented
 Open-source language
 Can be compiled and run on most operating systems
 PHP (Personal Home Page, or PHP Hypertext Preprocessor)
 Allows creation of dynamic content that interacts with databases
 Normally found on Linux servers with MySQL databases
 Free software

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ASP.NET Web Applications

• ASP.NET AJAX increases the responsiveness of Web pages

• Example ASP.NET applications:
 Product Catalog
 Shopping Cart

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