Introduction to computers

Introduction To
Computer
Programming
Eng:Dhanik Maheshwari
dhanikvikrant@gmail.com
Civil Engineering QUEST Nawabshah

 Chapter 1: Introduction to Computer and Its components 3 Hours
 Chapter 2: Computer Operating System 2 Hours
 Chapter 3: Word Processing 3 Hours
 Chapter 4: Electronic Spread sheets 3 Hours
 Chapter 5: Electronic Presentation 2 Hours
 Chapter 6: Algorithm and Flowcharts 2 Hours
 Chapter 7: Introduction to Programming Language 11 Hours
Course Contents

A computer is an electronic device, operating under the control of instructions
(software) stored in its own memory unit, that can accept data (input),
manipulate data (process), and produce information (output) from the
processing. Generally, the term is used to describe a collection of devices
that function together as a system.
What Is A Computer?

 The computer is truly amazing machine.
 Few tools can help you perform so many different tasks
whether you want to track an investments, publish a
newspaper, design a building or practice landing on the
deck of an aircraft carrier, you use a computer to do it.
Why Study Computer Technology

 Equally amazing is the fact that the computer has taken
on a role in nearly every aspect of our lives.
 Consider the following examples.
 Tinny embedded computers control our alarm clocks,
 Entertainment centers, and
 home appliances.

 Today’s automobiles could not even start-let alone run
efficiently-without embedded computer system.
 In the united states, more than half of all homes have at
least one personal computer, and the majority of those
computers are connected to the internet.

 An estimated 10 million people now work from home instead of
commuting to traditional workplace, thanks to PCs and
networking technologies.
 People use e-mail for personal communication nearly 10 times
as often as ordinary mail, and nearly 5 times more than the
telephone.
 Routine daily tasks such as banking, using the telephone and
buying groceries are affected by computer technologies.

 Improved Employment Prospects:
 Computer-related skills are essential in many careers,
whether you plan a career in automotive mechanics, nursing,
journalism, or archaeology, having computer skills will make
you more marketable to prospective employers.
Advantages of Computer

 Skills that span different Aspects of life:
 Many people find their computer skills valuable
regardless of the setting-at home, work, school, or
play. Your knowledge of computer will be useful in
many places other than your work.

 Greater Self-sufficiency:
 Those people who truly understand computers know
that computers are tools, nothing more or less. We
do not give up control of our lives to computer
systems, rather we use computer system to suit our
needs. By knowing how to use computers, you can
actually be more self-sufficient, whether you use
computers for research , communications, or time
management.

 Foundation of knowledge for lifetime of learning:
 Basic computing principles have not changed over
the past few years, and will valid well in to the future.
By mastering fundamental concepts and
terminology, you will develop a strong base that will
support your learning for years to come.

 Speed:
 Since computer is an electronic machine and
electrical pulses travel at the rate of passage of
electric current. This speed enables the computer to
perform millions of calculations per second.
 Storage:
 A computer has too much storage capacity. Once
recorded, a piece of information can never be
forgotten.

 High accuracy:
 A computer can be considered as 100% accurate.
Checking circuits are built directly in to the
computer, so that computer errors that are
understood are extremely rare.
 Versatility:
 Computer can perform any task provided, it can be
reduced to a series of logical steps.

 Diligence:
 Computer never gets tired. It perform most boring
repetitive and monotonous tasks.
 Automatic Operation:
 Once a program is fed in to computer the individual
instructions are processed on after the other. Thus
computer works automatically without manual-
intervention.

 Obedient or obedience:
 The ability to take in and store a sequence of
instructions for the computer to obey. Such a
sequence of instructions is called program and it
must be written in the computer language.
 Decision making Capacity:
 Computer can take simple decisions, such as less
than, greater than or equal to. It also determine
whether a statement is true or false.

 Inflexible:
 The computers are not flexible.
 For example to a human being "addition of two numbers“,
"summing up of two numbers", or "totaling of two numbers"
means one and same thing. But computer is not so smart, it
understands only the symbol "+" and nothing else.
Limitations of Computer

 Need Details:
 The computer needs very detailed instructions. It
means that each step must be instructed to perform,
even it is very little and ignorable for human being.
 Expensive Equipment and Maintenance:
 The computers and their peripheral devices are
much expensive than the equipment required for
manual work. In the same way maintenance of these
equipment is very costly.

 More Staff:
 It is required to appoint computer personal to
operate computers. It increases the expenses of
organization
 Loss of Data:
 In particular circumstances, stored data may be
completely lost. It could be impossible to recover.
Therefore back up copies of latest data must be
maintained

 A human can do anything which a computer can do.
But the reverse of this statement is not true because
computer can not do every thing a man or human can
do.
 The computer does only what it is instructed, and these
instructions must take in to account every possible set
of conditions relating to the action.
Capabilities Comparison between
computer and Human

 Man is rather poor processor. He is slow and not
completely accurate. But he can innovate and adapt
and he can learn by trial and error discovery.
 In short,
 A man is best suited to think, reasons, and discover.
 A computer is best adapted to calculate, manipulate
and compare.

Properties Human or Man Computer
1. Speed of execution Slow Extremely fast
2. Ability to remember of
retrieve information
Relatively in accurate Accurate
3. Accuracy of work Makes error Makes virtually no errors
4. Ability to continued
processing over an
extended period
Poor Excellent
5. Ability of consistently
follow instructions
Imperfect and depend on
nature
Perfect and obedient
6. Ability to innovate in new
situations
Good Lacking
7. Ability to learn by trial
and error
Very good Nil

 Playing games
 Solving problems
 Doing homework
 Watching movies
 Listening music
 Browsing
 Internet &
 E-mailing
Uses of computers

 C-> Commonly
 O-> Operated
 M-> Machine
 P-> Purposefully
 U-> Used for
 T-> Technical
 E-> Education
 R->Research
Expansion of computers

 Data processing has been a big problem for the man
since beginning.
 The man always wants to process a large amount of
data in a short time with high speed and accuracy.
 For this man invented many devices to assist him in
calculating and processing data.
 Basically three types of data processing devices have
been developed in the entire history of data processing.
HISTORY OF DATA PROCESSING/
COMPUTER DEVELOPMENT

 Manual Mechanical Devices
 Electro Mechanical Devices
 Electronic Devices
 The history of development of these devices is divided
into three ages:

 Dark ages.
 Middle ages.
 Modern ages.
 This is known as Mechanical Era (1623-1900)

 Abacus
 About 3000 B.C the “Abacus” was developed
 beads on rods to count and calculate
 still widely used in Asia
DARK AGES (3000 B.C – 1890 A.D)

 John Napier ‘s Bones
 In 1617 designed a device consisting of eleven bones of
rods with numbers marked on them.

 Slide Rule
 Slide Rule 1630 by English mathematician William Oughtred
 based on Napier’s rules for logarithms
 used until 1970s

 Pascal’s Calculator
 In 1642, great French mathematician Blaise Pascal invented a
calculator.
 It manipulates numbers by rotating cogwheel gear by one to ten
steps with carryover ratchet to operate next higher digit.
 This technique can be found in automobile odometer

 Leibniz’s Calculator
 In 1671 the German mathematician-philosopher Gottfried
Wilhelm von Leibniz designed a calculating machine called the
Step Reckoner.
 The Step Reckoner expanded on Pascal's ideas and did
multiplication by repeated addition and shifting

 Jacquard’s Loom
 The Jacquard loom is a mechanical loom, invented by
Joseph Marie Jacquard, first demonstrated in 1801
 The loom was controlled by a "chain of cards", a number of
punched cards, laced together into a continuous sequence

 Babbage’s Difference Engine
 In 1822, Charles Babbage designed an automatic mechanical
calculator to tabulate polynomial functions
 The name derives from the method of divided differences, a way
to interpolate or tabulate functions by using a small set of
polynomial coefficients
 Most mathematical functions commonly used by engineers,
scientists and navigators, including logarithmic and trigonometric
functions, can be approximated by polynomials, so a difference
engine can compute many useful tables of numbers

 Babbage’s Analytical Engine
 Proposed mechanical general-purpose computer designed
by English mathematician Charles Babbage
 It was first described in 1837 as the successor to Babbage's
difference engine, a design for a mechanical computer.
 The Analytical Engine incorporated an arithmetic logic unit,
control flow in the form of conditional branching and loops,
and integrated memory, making it the first design for a
general-purpose computer that could be described in
modern terms as Turing-complete.

 In middle ages the compilation of census data was the
biggest problem.
 Dr. Herman Hollerith, an American statistician developed a
mechanical tabulator based on 3x5 in punched cards to rapidly
tabulate statistics from millions of pieces of data. With that, 1890
census was processed in one-fourth time needed for 1880 census.
 In 1908, Dr. James Powers developed 20-column punching
machine.
 In 1908, Dr. Herman Hollerith developed vertical sorting machine
which processed about 200 cards per minute
 In 1911, Helloerith developed horizontal sorter machine which can
process almost 275 cards per minute
MIDDLE AGES (1890 A.D – 1937 A.D)

 Computers at various stages of their evolution are divided
into several generations.
 Every new generation has certain dramatic improvement
when compared to its previous generations.
 These improvements were the result of the technology use
for building the computers, programming languages used
and the computer system’s internal organization.
MODERN AGES (Since 1937)

 There are six generations of computers as:
 First-Generation Electronic Computers (1937-1953)
 Second-Generation (1954-1962)
 Third-Generation(1963-1972)
 Fourth-Generation(1972-1984)
 Fifth-Generation (1984-1990)
 Sixth-Generation (1990-till date)

 Duration 1937 – 1953
 Major invention of this period was vacuum tubes,
 Vacuum tubes are glass tubes with circuits inside.
 Vacuum tubes have no air inside of them, which
protects the circuitry.
 But unfortunately these vacuum tubes produced a lot of
heat which became a big problem
1st GENERATION OF ELECTRONIC COMPUTERS

 In 1942
 Professor John Vincent Atanasoff designed and built
the Atanasoff-Berry Computer (ABC)

 In 1944
 Harvard Mark-I was conceived by Harward Aiken. It was
designed and built by IBM. It was as big as room with
50 ft long, it was used for mathematical tables.
 IBM launched its new version as “Mark-II” in 1945

 In 1946
 ENIAC (Electronic Numerical Integrator And Calculator)
was developed as a result of military need.
 It took up wall space in a 20x40 square feet room and
used 19.000 vacuum tubes, 70,000 resistors and
5,00,000 solder connections.
 It could perform 5000 additions in a second.

 In 1951
 first fully electronic digital
computer named as UNIVAC
(Universal Automatic
Computer) was built in the U.S
 Created at the University of
Pennsylvania
 ENIAC weighed 30 tons
 contained 18,000 vacuum
tubes
 Cost approximately $487,000

 UNIVAC was Programmed by
Geace Hopper
 Recipient of Computer
Science’s first “Man of the
Year Award”
 Besides these, IBM also developed vacuum tube
computers IBM-650, IBM-702, IBM-705, IBM-709 and etc.

 Advantages
 Vacuum tubes were used as electronic components.
 Electronic digital computers were developed.
 These computers were the fastest calculating device of
their time.
 Computations were performed in milli Seconds

 Limitations
 Too large in size
 Unreliable
 Produce large amount of heat due to vacuum tubes
 Air conditioning required
 Frequent hardware failures
 Constant maintenance required
 Non-portable
 Commercial production 'was difficult and costly
 Limited commercial use'

 1954 - 1962
 During this period transistors were used for internal
logic 'circuits of computers.
 These computers could execute 200000 instructions per
second.
 The amount of main storage memory was increased.
 The input/output devices became‘ much faster by the
use of magnetic tape.
SECOND GENERATION OF ELECTRONIC COMPUTERS

 During this period the low level programming
languages were used, however the high level
programming languages, such as FORTRAN and
COBOL were also used.
 The problem of heat and maintenance were solved and
size of computer reduced, while speed and reliability
were increased.
 In second generation launched computers were IBM-
1401 introduced in 1960, IBM-1400 series, IBM-1600
series, UNIVAC-III, NCR 300, etc.

 Advantages
 Smaller in size as compare to first generation
 Much reliable
 Less heat generated
 Computations were performed in micro seconds
 Less hardware failures
 Better portability
 Commercially used

 Limitations
 Air conditioning required
 Frequent maintenance required
 Commercial production was costly

 1963-1972
 Transistors were replaced by integrated circuits(IC)
 An integrated circuit contains many electronic
components on a single chip.
 One IC could replace hundreds of transistors
 This made computers even smaller and faster.
 As a result of it, Computers could run about 5 million
instructions per second and store up to 8 million
characters.
THIRD GENERATION OF ELECTRONIC COMPUTERS

 There was a big flexibility with input/output devices.
The disk oriented systems were made at the end of this
generation.
 In 1969 the first microprocessor chip INTEL 4004 was
developed, but it was used only in calculators.
 The famous computers of this generation were IBM-360,
IBM-370, UNIVAC 9000 series etc.

 Advantages
 Smaller in size as compared to previous generation
 Reliability increased
 Heat generation was rare
 Computations were performed in nano seconds.
 Hardware failure was very rare
 Low maintenance cost
 Very easy portable
 These computer were very general purpose
 Less electricity consumption
 Commercial production was easier and cheaper

 Limitations
 Air conditioning required in many cases
 Very advance technology was required to made IC

 1972 – 1984
 Integrated circuits' were more developed and called
Small Scale Integration (SSI), after some time the SSI
were more developed and termed as Large Scale
Integration (LSI).
 The major achievements were the increase in storage
capacity and speed, as well as the ability of
sophisticated programs for special applications.
FOURTH GENERATION OF ELECTRONIC COMPUTERS

 There was a great versatility of input/output devices
 In 1971, a powerful microprocessor chip INTEL 8008
was introduced.
 The first microprocessor which used in Personal
Computers. (PC) was INTEL 8080.
 The 8 inch floppy disk was also introduced in 1971,
while hard disk was introduced in 1973.
 The 5:25 inch floppy disk was first time used in 1978.

 The optical disk was developed in 1980.
 First portable computer "Osborne I" was marketed
in1981.
 Many other input/output devices were developed for
example optical reader, by which whole documents
could be fed into computer, audio response terminals,
by which an operator can vocally input data or
instructions and scanners by which an operator can
feed pictures into the computer.

 Advantages
 Smallest in size
 Very reliable
 Heat generated was negligible
 No air conditioning was required in many cases
 Much faster computations were possible
 Minimal maintenance was required
 Hardware failure was negligible
 Very easily movable
 Totally general purpose
 Very inexpensive

 Limitations
 Much sophisticated. technology was required to
fabricate IC

 1984 – 1990
 New technologies are adopted to fabricate IC chips,
such as electron beam, X-rays or Iaser rays
 Very Large Scale Integration, (VLSI) was developed, so
the computers became much smaller than ever before.
 Microsoft Corporation launched their new operating
system (MS-DOS)
5th GENERATION OF ELECTRONIC COMPUTERS

 3.5 inch floppy disk was developed in 1984.
 Intel's microprocessor 80286 was made in 1984, while
microprocessor 80386 was made in 1985.
 Compact Disk (CD-ROM) was also invented in 1985.
 New memory devices such as Tunnel Junctions and
Bubble Memories are expected to be used.
 New programming languages are designed such as
PROLOG, LISP, SQL, etc..

 Major difference between the fifth generation and
conventional computers is the best interaction between
user and computer.
 The "expert systems" were developed by using artificial
intelligence
 The ideas of fifth generation will gradually be adopted
along with other techniques for improving the utility of
computers and also to have the computer understand
natural language and to recognize voices.

 Advantages
 All the previous advantages
 Very huge storage capacity available
 long bit processors were built
 Laptop computers introduced
 Artificial intelligence languages developed

 1990 – To date
 In sixth generation, the ability to perform many complex
tasks at one time was expanded and revolutionized with
the introduction of the microprocessor in the early 70’s.
 Now what took up a whole room could rest gently on a
fingertip.
 Microprocessors were the beginning for a fury of
technological advancement that includes computerized
cars, appliances and smart phone.
6th GENERATION OF ELECTRONIC COMPUTERS

 Everything has become smarter, faster and smaller.
 They have also become integrated.
 With the advent of microprocessor came the ability to
link computers together in a network.
 The birth of the Internet and all of its wonders are
attributed to the birth of microchip.

 Hardware
 Software
 User
 Hardware:
 All physical components of computer are hardware
 Keyboard
 Printer
 Mouse
 Scanner
 Monitor
 Microphone
 Speaker
Resources of Computer

 Software
 Software is a computer program
 It gives step by step
instructions to the computer
what to do and how to do.
 It converts data into information

 USER
 User is one who knows how to use both hardware and
software

 Computers can perform four general operations, which
comprise the information processing cycle.
 Input
 Process
 Output
 Storage
Functional Process of Computer

 Input means to feed information into a computer words and
symbols in a document Numbers for a calculation pictures
 Data refers to the symbols that represent facts, ideas and
objects
 Processing is the way that a computer manipulates data
performing calculations sorting lists and numbers drawing
graphs
 A computer processes data in a device called the central
processing unit (CPU Computers can perform four general
operations, which comprise the information processing cycle.

 A computer stores data so that it will be available for
processing
 Memory is an area of a computer that holds data that is
waiting to be processed and for later use
 Storage is the area where data can be left on a permanent
basis
 Computer output is the results produced by the computer
 Reports, documents
 Music, graphs and pictures
 An output device displays, prints or transmits the results
of processing

 All computer processing requires data, which is a collection of
raw facts, figures and symbols, such as numbers, words,
images, video and sound, given to the computer during the
input phase.
 Computers manipulate data to create information. Information
is data that is organized, meaningful, and useful.
 During the output Phase, the information that has been created
is put into some form, such as a printed report.
 The information can also be put in computer storage for future
use
Data and Information

 Earlier Days:
 Computers are categorized into categories from least to
most powerful:
 microcomputers
 minicomputers
 mainframe computers
 Super Computers
 Today:
 A computer is categorized based on its technology,
function, size, performance, and cost
Computer Categories

 A mainframe computer is a large and expensive computer
that is capable of passing data simultaneously to many
users Used by governments to provide centralized storage
 A supercomputer is one of the fastest computers in the
world
 Breaking codes
 Modeling weather systems
 Simulating nuclear explosions
Computer Categories

Desk top
Lap Top
Hand Held
computer
computer
Computer
computer

 A general purpose computer has four main sections: the arithmetic
and logic unit (ALU), the control unit, the memory, and the input and
output devices (collectively termed I/O). These parts are
interconnected by busses, often made of groups of wires. Figure
summarizes the concepts.
Computer System

 The control unit, ALU, registers, and basic I/O (and often
other hardware closely linked with these) are collectively
known as a central processing unit (CPU).
 Early CPUs were composed of many separate
components but since the mid-1970s CPUs have typically
been constructed on a single integrated circuit called a
microprocessor.

 Input devices.
 Central Processing Unit
(containing the control
unit and the
arithmetic/logic unit).
 Memory.
 Output devices.
 Storage devices.
82
What Are The Primary Components Of
A Computer ?

 Personal Computers can be assembled or built with
different components according to our needs.
 Basic Personal Computer (PC) can be grouped into
System Unit and other components connected to it.
 Table below provides the overall mapping of PC
components
Computer Components

Items Component(s) Notes
System Unit Casing, Power Supply,
Motherboard installed with CPU,
RAM and Drive Controller, Hard
Disk Drive (HDD) , CD-ROM Drive,
Floppy Disk Drive (FDD), Video
Card
All these components are assembled as
System Unit. HDD, CD-ROM Drive and
FDD are connected to the motherboard
using IDE cables.
Monitor Stand alone component Monitor is connected to the System unit
(video card)
Keyboard Stand alone component Keyboard is connected to the motherboard
USB connector
Mouse Stand alone component Mouse is connected to the motherboard
USB connector
Printer Stand alone component Printer is connected to the motherboard
USB connector
Scanner Stand alone component Scanner is connected to the motherboard
USB connector

85
Printer
(output)
Monitor
(output)
Speaker
(output)
Scanner
(input)
Mouse
(input)
Keyboard
(input)
System unit
(processor, memory…)
Storage devices
(CD-RW, Floppy, Hard
disk, zip,…)

 Casing or computer Case
 Casing or computer case is used to place components
such as Power Supply, motherboard installed with:
 Central Processing Unit (CPU) and Random Access Memory
(RAM),
 Hard Disk,
 Floppy Disk Drive (FDD) and
 Compact Disk (CD) Drive.
 Two models of casings are available in the market:
tower and desktop model.

 Tower model stands upright in a vertical position that
allows easy placement on the floor.
 Three towers design are available: mini-tower (2 CD
ROM Drive slots), mid-tower (3 CD ROM Drive slots),
and full tower case (5 CD ROM Drive slots).
 The selection on type of tower design usually depends
on the number of components required for each PC.
 For example, a user who required, two CD ROM Drives,
two hard Disk Drive and two CPU installed with the
motherboard will choose full tower case.

 The desktop model sits on a desk horizontally. The
monitor can be set on top of the casing and can be a
space saver.

 Power Supply
 Computer power supply comes with the case.
 Two types of power supply available are AT Model and ATX
model.
 AT power supply is an old model and has been replaced
with ATX model which enable the computer to be shutdown
using the operation system such windows XP.
 The old power supply model
(AT), required the user to
physically push the on/off
button to shut down the
computer.

 Motherboard
 This is where the core components of the computer
reside. The cards for video, sound, networking and
more are also mounted into this board. Figure shows
the example of motherboard

 The major components on the motherboard include:
 Chipset,
 CPU socket,
 expansion sockets,
 Input/Output (I/O) support,
 Basic Input Output System (BIOS),
 RAM sockets,
 Power supply socket,
 Complementary Metal-oxide Semiconductor (CMOS) chip,
 Dipswitches and jumpers, and
 the memory cache

 Central Processing Unit (CPU)
 This is the brain of the personal computer. It performs commands
and instructions and controls the operation of the computer.
 Two main manufacturers of CPU in the market now are Intel
Corporation and Advanced Micro Devices (AMD) Corporation.
 Every year, both of them produces new CPU model and
specification which offer new design and faster processing
power.
 Four common specifications for CPU are: Processor type,
Processor speed (in Gigahertz (GHz)), Bus speed (Megahertz
(MHz)): and L2 Cache Size (in Kilobytes (KB)).
 As an example, a PC specification which related to the PC in the
market is listed in Table 1. Figure shows an example of Intel’s
Pentium II CPU

CPU
Specification
Values Explanation
Processor Type Xeon This is one of the Intel Corporation’s
Family of CPU
Processor Speed 1.4 GHz The CPU speed of 1.4 Gigahertz
Bus Speed 400 MHz The Bus Speed must be supported by the
motherboard
L2 Cache Size 256 KB Higher size of L2 Cache enhanced the
processing ability of the CPU

 Random Access Memory (RAM)
 The RAM in PC system is mounted on the motherboard.
 This is memory that must be powered on to retain its contents.
 Random Access Memory (RAM) is considered temporary, or
volatile memory.
 The contents of RAM are lost when the computer power is
turned off.
 RAM chips on the computer hold the data and programs that the
microprocessor is processing.
 In other words, RAM is memory that stores frequently used data
for rapid retrieval by the processor.

 A computer with higher RAM can hold and process large
programs and files.
 The amount and type of memory in the system can make a big
difference in the system performance.
 There are two classes of RAM that are commonly used today.
Static RAM (SRAM) and Dynamic RAM (DRAM).
 SRAM is relatively more expensive, but it is fast. It will maintain
data only as long as voltage is available. SRAM is used for cache
memory.
 DRAM is inexpensive and somewhat slow, but very dense for the
size. DRAM stores data in tiny capacitors that must be refreshed
to maintain the data. Once the power is turned off, the data is
lost.

 The current type of RAM available in the market is Double Data
Rate 3(DDR3) Synchronous Dynamic (SD) RAM.
 The advancement in the development of RAM and other PC
components are very fast and one model of RAM or other
components usually lasted less than two years.
 Table shows an example DDR3 SDRAM
RAM
Specification
Values Explanation
RAM Type DDR3 SDRAM New generation of RAM called Double Data
Rate 3 Synchronous Dynamic RAM.
Capacity 512 Megabyte Allows for RAM capacities of 512 Megabyte
(MB) to 8 Gigabyte (GB)

 Drive controllers
 The drive controllers control the interface of your system to hard
disk drives and the CD ROM Drives.
 The controllers let your hard drives and CD ROM Drives work by
controlling their operation.
 On most PCs, they are included on the motherboard and each of
their feature(s) is described in the motherboard manual which
comes with the PC when we purchased them.
 Additional controllers for faster or other types of drives such as
Small Computer System Interface (SCSI) can also be added to
the motherboard when SCSI Hard Disk is added to the PC.

 Every motherboard can support up to four hard disk drives if CD
ROM drive is not installed (One master and one slave at IDE1
and IDE2).
 Otherwise, three Hard Disk Drives can be installed with one CD
ROM Drive (One master and one slave HDD on IDE1) and one
master HDD on IDE2 and one slave CD-ROM Drive on IDE2.
 The setting for this configuration is usually available in the
motherboard manual supplied with each PC. Table gives
example of hard disk drive specification
Hard Disk Drive
Specification
Model Explanation
Model Quantum A common type of Hard Disk Drive
installed with PC
Capacity 80 Gigabyte (GB) The Hard Sizes is getting bigger as
the technology for this component
improves over time

 CD-ROM Drive and DVD-ROM Drive
 This is normally a read only drive where files are permanently stored. There
are now read/write CD-ROM and DVD-ROM drives that use special software to
allow users to read from and write to these drives. CD-ROM Drive with
writable capability has become important for data backup purpose. Exiting
CD-ROM Drive can be used to backup data up 700 Megabytes (MB) of data in a
single CD. Slowly, CD-ROM drive is replacing the functionality of Floppy Disk
Drive (FDD). Figure shows example of CD-ROM drive

 Floppy Disk Drive (FDD)
 A Floppy Disk Drive uses floppy disk which is a small disk storage device that
today typically has about 1.4 Megabytes of memory capacity.
 The introduction of cheaper Thumb Drives (storage size can varies from 128
MB to 1 GB) has slowly replaced the usage of floppy disk as the common
device for storing data for backup purpose.

 Video Cards
 The video card or video adapter is the interface between the
computer and monitor.
 The video card tells the monitor which pixels to light up, what
color the pixels should be and the intensity of the color.
 The video card is either an expansion card (installed into one of
the motherboard expansion slots) or it can be built into the
motherboard.
 The display capabilities of a computer depend on both the video
adapter and the monitor.
 A 64-bit AGP video card with 4 MB of RAM should be enough,
but more graphic intensive games may perform better with a
video card having 32 MB or more video RAM.

 Some video cards even include a graphics coprocessor for
performing graphics calculations. These adapters are referred to
as graphics accelerators. A newer form of VRAM is WRAM
(Windows RAM).
 For Example:
 Pentium IV has an Accelerated Graphics Port (AGP) expansion
slot for installing a video card.
 AGP is designed exclusively for video cards.
 An AGP card allows game and 3D applications to store and
retrieve finer, more realistic textures in system memory rather
than video memory, without incurring any performance
problems.

 A significant advantage of the AGP is that the PCI bus is
relieved of handling graphics data, so that the PCI slot can
concentrate on other demanding duties.
 AGP also doubles the PCI transfer speed.

 Monitor
 This device which operates like a TV set lets the user see
how the computer is responding to our commands.
Monitors are available in different types, sizes, and
characteristics. Understanding the characteristics of a good
monitor will help determine which is best suited for a
specific system. Some key monitor-related terms are:
pixels, dot pitch, refresh rate, colour depth, resolution, and
size.
 Pixels are picture elements. The screen image is made of
pixels (tiny dots), which are arranged in rows across the
screen. Each pixel consists of three colors: red, green, and
blue (RGB).

 Dot pitch is a measurement of how close together the
phosphor dots are on the screen. The finer the dot pitch, the
better image quality you will have. Look for the smaller
number. Most monitors today have a 0.25mm dot pitch. Some
have a 0.22mm dot pitch, which gives a very fine resolution.
 The refresh rate is the rate per seconds that the screen image
is refreshed. Refresh rates are measured in Hertz (HZ), which
means times per second. The higher the refresh rate, the more
steady the screen image will be. It may look like a steady
picture, but actually it flickers every time the electron beam
hits the phosphor-coated dots. Refresh rate is also called
vertical frequency or vertical refresh rate.

 Colour Depth refers to the number of different colors each
pixel can display. This number is measured in bits. The higher
the depth, the more colors that can be produced.
 Resolution varies based on the number of pixels. The more
pixels in the screen, the better the resolution. Better
resolution means a sharper image. The lowest screen
resolution on modern PCs is 640 x 480 pixels, which is called
VGA (Video Graphics Array). There are now SVGA (Super
Video Graphics Array) and XGA (Extended Graphics Array)
with resolutions all the way up to 1600 x 1200.

 Some other devices are also important in personal
computer
 Keyboard used for entering commands into the computer.
 A Modem is a device that converts the digital data used by
computers into analog signals that are suitable for transmission
over a telephone line and converts the analog signals back to
digital signals at the destination
 A Network Interface Card (NIC), also known as a network
adapter, is used to connect a local computer to a group of other
computers so they can share data and resources in a networked
environment.

 Universal Serial Bus (USB) port allows user to connect up to 127
external PC peripherals, including USB keyboards, mice,
printers, modems, scanners, and external disk drives. Figure
1.11 shows example of USB port.
 A FireWire, also known as i.LINK or IEEE 1394 is a high-speed,
platform-independent communication bus that interconnects
digital devices such as digital video cameras, printers, scanners,
digital cameras, and hard drives.

Introduction to computers

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Introduction to computers