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An electronic device that stores, retrieves,
and processes data or which manipulates
data according to a list of instructions and
which is composed of hardware and software.
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Computers are popular because of following characteristics:
Speed: Computer can perform a task much faster than done
manually.
Accuracy: Computer gives accurate results compared to task
done manually.
Storage: Computer stores the information in its main memory
and the same can be retrieved based on the requirement.
Multitasking: Computer performs multiple tasks simultaneously.
For example, one can use the computer to take a printout of an
inventory report and at the same time can use it to draft letters.
Communication: Computer can be used to exchange information
between two or more computers. Internet is the best example of
this.
Business Area
Entertainment Area
Education Area
Medicinal Area
Finance Area
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Bit
Byte
Kilobyte
(KB)
Megabyte
(MB)
Gigabyte
(GB)
Terabyte(T
B)
8 Bits = 1 Byte
1024 Bytes = 1 Kilo
Byte(KB)
1024 KB = 1 Mega Byte(MB)
1024 MB = 1 Giga Byte (GB)
1024 GB = 1 Tera Byte ( TB)
1024 TB = 1 Peta Byte ( PB)
1024 PB = 1 Exa Byte ( EB )
1024 EB = 1 Zetta Byte (
ZB)
1024 ZB = 1 Yotta Byte (
YB)
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0 = Off
1 = On
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7
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Input- Computer store the data in its input
devices like keyboard and mouse by the
users.
Process- Computer process the Data in its
processing unit like CPU
Output- Computer show the data in its
output screen(Monitor)
Storage- computer stores the data in its
storage device(HDD)
INPUT
CPU
STORAGE
OUTPUT
The physical components of a computer are
called computer hardware.
Devices connected internal are called the
primary components and connected external
are called the peripherals.
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Some of the devices that are attach internally are
called Primary Components.
i. Motherboard: It is a main circuit board that content
processor slot, chipset, front side bus(FSB), RAM’s slots,
PCI, Internal Components, ports, keyboard and mouse
connect USB port, display connector, speaker,
microphone etc.
ii. Hard Disk: It is a magnetic memory device used for
permanent storage.
iii. Optical Drive: Data used to read and write data from the
optical media is called CD/DVD ROM etc. the CD ROM
content 700 MB and DVD content 1.5 GB
iv. SMPS(Switch Mode Power Supply): It convert the AC
input into DC output.
v. Floppy Disk Drive: It is used to read drive floppy disk.
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The devices that are attached externally to the computer are
called peripherals
1. Keyboard: It is a input device. It consist rectangular or
near rectangular buttons called keys. The standard
keyboard consist of 101 to 104 keys.
2. Mouse: It is a Pointing device use to move a graphics
pointer on the screen this graphics pointer is called
cursor. Using mouse you can give commands, draw
images and perform other input task.
3. Scanner: It is a optical device that analysis images,
printing text, hand writing and digital images.
4. Joystick: It is commonly used for controlling player
movement.
5. Microphone: It is used for recording audio in a computer.
A sound cart converts and analog sound signal to digital
form.
6. Digital Camera: It is a input device used for capture and
storing still images. You can convert a digital camera to a
computer and transfer the images from others.
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Input Devices
Output Devices
Processor
Primary Memory(Main Memory)
Secondary Storage Devices
Internal Components
Software
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Mouse
Keyboard
Scanner
Digital Camera
Web Camera
Joysticks
Trackball
Touch Pad/Screen
Light Pen
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Bar Code Reader
Microphone
Graphics Tablets
Magnetic Ink
Character Reader
Optical Mask
Reader
Magnetic Card Read
Biometric Devices
Bluetooth
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Monitor
Printer
Projector
Plotter
speaker
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It is the main unit inside the computer this
unit is responsible for all event inside the
computer. It control all internal and external
devices to perform arithmetical and logical
operations. The CPU is a device that
interprets and execute instructions.
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RAM(Random Access Memory)
ROM(Read Only Memory)
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Hard Disk(Local Disk)
Optical Drive(CD Writer and DVD)
Pen Drive
Zip Drive
Floppy Disk
Memory Cards
External Hard Drive
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The Mother Board
Expansion Slots
CMOS Battery
Cooling Fan
Network Card
Graphics card
Power Supply Unit
Memory Slots
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Software is a program that enables a computer to
perform a specific task, as opposed to the
physical components of the system. Without
software, computers would be useless. This
includes application software such as a word
processor, which enables a user to perform a
task, and system software such as an operating
system, which enables other software to run
properly. Computer software has to be "loaded"
into the computer's storage (such as a hard drive,
memory, or RAM).
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LOW LEVEL LANGUAGE
HIGH LEVEL LANGUAGE
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In computer science, a lowlevel programming language is a
programming language that provides little or
no abstraction from a computer's instruction
set architecture—commands or functions in
the language map closely to processor
instructions. Generally this refers to either
machine code or assembly language.
There is two type of low level languages:◦ Machine level language
◦ Assembly language
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These language instructions are directly
execute by CPU. Machine language, the
numeric codes for the operations that a
particular computer can execute directly. The
codes are strings of 0s and 1s, or Binary
digits.
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Assembly language is
one level above machine
language. Assembly language programs are
translated into machine language by a
program called an assembler. It uses short
codes for instructions and allows the
programmer to introduce names for blocks
of memory that hold data.
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A programming language such as C,
FORTRAN, or Pascal that enables a
programmer to write programs that are more
or less independent of a particular type of
computer. Such languages are
considered high-level because they are closer
to human languages and further from
machine languages. The user friendly
language.
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There are three basic kinds of computers.
This is based on the hardware structure and
the way physical quantities are represented in
a computer.
The following are the three types.
◦ Analog Computer
◦ Digital Computer
◦ Hybrid Computer
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Analog computers are used to process analog
data. Analog data is of continuous nature and
which is not discrete or separate. Such type of
data includes temperature, pressure, speed
weight, voltage, depth etc. These quantities are
continuous and having an infinite variety of
values. It measures continuous changes in some
physical quantity e.g. The Speedometer of a car
measures speed, the change of temperature is
measured by a Thermometer, the weight is
measured by Weights machine.
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A Digital Computer, as its name implies,
works with digits to represent numerals,
letters or other special symbols. Digital
Computers operate on inputs which are ONOFF type and its output is also in the form of
ON-OFF signal. A digital computer can be
used to process numeric. It can perform
arithmetic operations like addition,
subtraction, multiplication and division. The
most common examples of digital computers
are accounting machines and calculators.
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A hybrid is a combination of digital and
analog computers. It combines the best
features of both types of computers, i-e. It
has the speed of analog computer and the
memory and accuracy of digital computer.
Hybrid computers are used mainly in
specialized applications where both kinds of
data need to be processed. Therefore, they
help the user, to process both continuous
and discrete data.
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Different types and sizes of computer are
offering different services. The four basic
types of computer.
1. Super Computer
2. Mainframe Computer
3. Mini Computer
4. Micro Computer
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A supercomputer is a computer with great
speed and memory. This kind of computer
can do jobs faster than any other computer of
its generation. They are usually thousands of
times faster than ordinary personal
computers made at that time. These are
specialized and task specific computers used
by large organizations. These computers are
used for research and exploration purposes.
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A mainframe computer is a very
large computer capable of handling and
processing very large amounts of data
quickly. They are used by large institutions,
such as government agencies and large
corporations. It can also process and store
large amount of data. Banks, insurance
companies use mainframe computers to store
data.
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Mini computers are used by small businesses
and firms. These computers are not designed
for a single user. Individual departments of a
large company or organizations use mini
computers for specific purposes. For
example, a production department can use
mini computers for monitoring certain
production process.
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A microcomputer is a complete computer on a smaller
scale and is generally a synonym for the more common
term, personal computer. It is a computer with a central
processing unit (CPU) as a microprocessor. Designed for
individual use, a microcomputer is smaller than a
mainframe or a minicomputer. Desktop computers,
laptops, tablets and smartphone are all types of micro
computer.
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First Generation
Second Generation
Third Generation
Fourth Generation
Fifth Generation
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There are a number of third party anti virus products available.
Most of these are better than the rather
rudimentary products available within
DOS and Windows, but of course you do
have to pay for them!
Many companies supply updated disks on
a regular basis or allow you to receive
updates through an electronic, on-line
bulletin board.
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Advantages are :Vacuum tubes were the only electronic
component available during those days.
Vacuum tube technology made possible to
make electronic digital computers.
These computers could calculate data in
millisecond.
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Disadvantages are :The computers were very large in size.
They consumed a large amount of energy.
They heated very soon due to thousands of vacuum tubes.
They were not very reliable.
Air conditioning was required.
Constant maintenance was required.
Non-portable.
Costly commercial production.
Limited commercial use.
Very slow speed.
Limited programming capabilities.
Used machine language only.
Used magnetic drums which provide very less data storage.
Used punch cards for input.
Not versatile and very faulty.
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Advantages are:Smaller in size as compared to the first generation
computers.
The 2nd generation Computers were more reliable
Used less energy and were less heated.
Wider commercial use
Better portability as compared to the first generation
computers.
Better speed and could calculate data in microseconds
Used faster peripherals like tape drives, magnetic disks,
printer etc.
Used Assembly language instead of Machine language.
Accuracy improved.
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Disadvantages are :Cooling system was required
Constant maintenance was required
Commercial production was difficult
Only used for specific purposes
Costly and not versatile
Punch cards were used for input.
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Advantages are :Smaller in size as compared to previous generations.
More reliable.
Used less energy
Produced less heat as compared to the previous two generations of
computers.
Better speed and could calculate data in nanoseconds.
Used fan for heat discharge to prevent damage.
Maintenance cost was low because hardware failure is rare.
Totally general purpose
Could be used for high-level languages.
Good storage
Versatile to an extent
Less expensive
Better accuracy
Commercial production increased.
Used mouse and keyboard for input.
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Disadvantages are :Air conditioning was required.
Highly sophisticated technology required for
the manufacturing of IC chips.
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Advantages are:More powerful and reliable than previous
generations.
Small in size
Fast processing power with less power consumption
Fan for heat discharging and thus to keep cold.
No air conditioning required.
Totally general purpose
Commercial production
Less need of repair.
Cheapest among all generations
All types of High level languages can be used in this
type of computers
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Disadvantages are:-
The latest technology is required for
manufacturing of Microprocessors.
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ADVANTAGE:
It is very portable.
Easy to use and maintenance.
Not hit.
Computers are popular in a number of
applications because of its speed of
operation, high storage capacity of media like
hard disk, CD and so on, consistency and
accuracy in computations and support to
other electronic devices for engineering
applications.
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A computer is an electronics device each
requires electrical power for its functioning.
The electrical power that is coming in your
home is called Alternating current(AC) and
the electrical power that the computer system
require is called Direct current(DC).
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Ferro Resonant Power Supply
Linear Power Supply
Switch Mode Power Supply(SMPS)
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It is very large and heavy and give out large
amount of heat and can not be use internally
in PC. It is also called constant voltage
transformer. It is a low cost and highly
reliable power supply because of its simple
circuit design.
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It consume less power require while input
voltage range, low noise and fast response.
But it have a some disadvantage. It’s power
efficiency and it’s hudge size.
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It’s frequency range is 50 kHz to 1 MHz the
most common type of power supply used
today internally in PC is called SMPS. It is a
highly frequency which is actually a transistor
internally.
The Advantage:◦
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Smaller in size
Greater power conservation
Generate low heat
Reduce over all power loss.
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-12 volt: Use for serial ports and not provided in
a new system and rarely used in old system.
-5 volt: It is use for floppy controller.
0 volt: It is used for base voltage.
+3.3 volt: It is used for computer memory, new
processor and motherboard components.
+5 volt: It is used for computer memory
processor and motherboard.
+12 volt: It is used for disk drive, fans and other
cooling devices.
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AT Style SMPS: It is a pair of 6 pins connector.
ATX Style SMPS: It is a single 20 pins
connector.
PIN NUMBER
WIRE COLOUR
SIGNALS
1
ORANGE
+3.3 VOLT
2
ORANGE
+3.3 VOLT
3
BLACK
GROUND
4
RED
+5 VOLT
5
BLACK
GROUND
6
RED
+5 VOLT
7
BLACK
GROUND
8
GREY
POWER GOOD
9
PURPLE
+5 VOLT STAND BY
10
YELLOW
+12 VOLT
PIN NUMBER
WIRE COLOUR
SIGNALS
11
ORANGE
+3.3 VOLT
12
BLUE
-12 VOLT
13
BLACK
GROUND
14
GREEN
POWER ON
15
BLACK
GROUND
16
BLACK
GROUND
17
BLACK
GROUND
18
WHITE
-5 VOLT
19
RED
+5 VOLT
20
RED
+5 VOLT
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The power supply is responsible for
connecting internal hard disk, floppy disk,
CD, DVD and other drives that is two types:◦ Molex Connector
◦ Mini Molex Connector
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It is a D shaped connector or large size and
connecting for internal drive like hard drive,
CD, DVD and earlier 5.25 inch floppy disk
drive
PIN NUMBER
WIRE COLOUR
SIGNAL
1
YELLOW
+12 VOLT
2
BLACK
+12 VOLT+GROUND
3
BLACK
+5 VOLT +GROUND
4
RED
+5 VOLT
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It is a small size connector and use for 3.5
inch floppy disk drive.
PIN NUMBER
WIRE COLOUR
SIGNAL
1
RED
+5 VOLT
2
BLACK
+5 VOLT+GROUND
3
BLACK
+12 VOLT +GROUND
4
YELLOW
+12 VOLT