Computer hardware

Understanding the Computer Hardware
The Computer System

COMPUTERS have become
a useful part of our
everyday lives. The types of
computers we use at home
or at work are referred to
by varied names such as
PCs, microcomputers,
workstations, laptops and
desktops. These computers
are most popularly referred
to as “personal computers”
or PCs, the most common
type of computer in the
world.
Hardware
People ware
Components of
a computer
system

Hardware
People ware
The physical, touchable, electronic and
mechanical parts of a computer system.
Components of
a computer
system
Refers to people involved in the data processing
operations such as the system administrator,
office workers, students and others.
Is the set of instructions (also called a
program) that guides the hardware to
operate effectively.

Categories of HARDWARE components of a computer
system
Major hardware
components of a computer
system
Input Devices
Accepts data and instructions
from the user or from another
computer system.
Output Devices
Any piece of computer hardware that
displays results after the computer has
processed the input data that has been
entered.
Ports
External connecting sockets on the outside of the
computer. This is a pathway into and out of the
computer. A port lets users plug in outside
peripherals, such as monitors, scanners and
printers.
Cables and Wires
A cable is most often two or more
wires running side by side and
bonded, twisted or braided together to
form a single assembly, but can also
refer to a heavy strong rope.
1 2 3 4 5

Major
hardware
components of
a computer
system
1
2
3
4
5
6
7
8
9
10
System Unit
CPU
Mother board
Primary Storage
Expansion Bus
Adapters
Digital Versatile Disc
Power Supply
HDD
Optical Drive

System Unit
The main part of a
microcomputer, sometimes
called the chassis. It includes
the following parts:
Motherboard, Microprocessor,
Memory Chips, Buses, Ports,
Expansion Slots and Cards.
Figure 1. Tower Type System Unit

Mother
Board
The main circuit
board of a computer.
It contains all the
circuits and
components that run
the computer.
Figure 2. Modern Motherboard

Central Processing Unit
(CPU)The processor is the main
“brain” or “heart” of a
computer system. It
performs all of the
instructions and
calculations that are
needed and manages the
flow of information
through a computer. Figure 3. Examples of CPU
(Intel Core 2 Duo and AMD Athlon)

Primary Storage
(internal storage, main
memory or memory) is
the computer's working
storage space that holds
data, instructions for
processing and processed
data (information) waiting
to be sent to secondary
storage. Physically,
primary storage is a
collection of RAM chips.
RAM
ROM
2 types
of memory
(Read Only Memory) ROM is non-volatile,
meaning it holds data even when the power
is ON or OFF.
(Random Access Memory) RAM is volatile,
meaning it holds data only when the power is on.
When the power is off, RAM's contents are lost.
.

Expansion Bus
A bus is a data pathway
between several hardware
components inside or
outside a computer. It
does not only connect the
parts of the CPU to each
other, but also links the
CPU with other important
hardware. Figure 5. Expansion Bus

Adapters
Printed-circuit boards (also
called interface cards) that
enable the computer to use a
peripheral device for which it
does not have the necessary
connections or circuit boards.
They are often used to permit
upgrading to a new different
hardware.
Figure 6. Network Adapter

Power Supply
Installed in the back corner
of the PC case, next to the
motherboard. It converts
120vac (standard house
power) into DC voltages
that are used by other
components in the PC.
Figure 7. Power Supply

Hard Disc Drive (HDD)
Also known as hard drive, is a
magnetic storage device that
is installed inside the
computer. The hard drive is
used as permanent storage
for data. In a Windows
computer, the hard drive is
usually configured as the C:
drive and contains the
operating system and
applications.
Figure 8. Hard Disc Drive (HDD)

Optical Drive
An optical drive is a
storage device that uses
lasers to read data on the
optical media. There are
three types of optical
drives: Compact Disc (CD),
Digital Versatile Disc (DVD)
and Blu-ray Disc (BD).
Figure 9. Optical Drive

Digital Versatile Disc (DVD)
Designed to optically
access data stored on a
DVD. A laser moves
back and forth near the
disk surface and
accesses data at a very
fast rate.
Figure 10. CD Drive

2 Input
Devices Types of Input Device
Keyboard Entry
• Data is inputted to the computer
through a keyboard.
• The first input device developed for the
PC.
• Data is transferred to the PC over a
short cable with a circular 6-pin Mini-
din connector that plugs into the back
of the motherboard.
Direct Entry Devices
• A form of input that does not require data
to be keyed by someone sitting at a
keyboard.
• Direct-entry devices create machine-
readable data on paper, or magnetic
media, or feed it directly into the
computer’s CPU.

3 Categories
of Direct Entry
Device
3 Voice-Input
Devices
Audio input devices also known as
speech or voice recognition systems
that allow a user to send audio signals
to a computer for processing,
recording, or carrying out commands.
2 Scanning
Devices
A device that can read text or
illustrations printed on paper and
translates the information into a form the
computer can use.
Pointing
Devices
An input device used to move the
pointer (cursor) on screen.
1

Pointing Devices
1
Mouse
• The most common
'pointing device' used in
PCs.
• Every mouse has two
buttons and most have one
or two scroll wheels.

Pointing Devices
1
Touch Screen
• A display screen that is sensitive to
the touch of a finger or stylus.
• Used in myriad applications,
including ATM machines, retail
point-of-sale terminals, car
navigation and industrial controls.
• The touch screen became wildly
popular for smart phones and
tablets.

Pointing Devices
1
Light Pen
• A light-sensitive stylus wired
to a video terminal used to
draw pictures or select menu
options.
• The user brings the pen to the
desired point on screen and
presses the pen button to
make contact.

Pointing Devices
1
Digitizer
Tablet• A graphics drawing tablet
used for sketching new images
or tracing old ones.
• Also called a "graphics tablet,"
the user contacts the surface
of the device with a wired or
wireless pen or puck. Often
mistakenly called a mouse,
the puck is officially the
"tablet cursor."

Scanning Devices
2
Image Scanner
Barcode Reader

Voice-Input Devices
3
Audio input devices such as microphones allow users to speak to
the computer in order to record a voice message or navigate
software.

3 Output
Devices
1. Computer Display
Monitor
It displays information in visual form, using text and
graphics. The portion of the monitor that displays the
information is called the screen or video display terminal.
2. LCD Projector
3. Smart Board
A type of display screen that has a touch sensitive
transparent panel covering the screen, which is similar to
a touch screen.
4. Printer A device that prints text or illustrations on paper.
5. Speakers
Used to play sound. They may be built into the system unit or
connected with cables. Speakers allow you to listen to music
and hear sound effects from your computer.

Types of Computer Display Monitor
CRT Monitor
Cathode Ray Tubes
(CRT) were the only type
of displays for use with
desktop PCs. They are
relatively big (14" to 16"
deep) and heavy (over 15
lbs).

LCD Monitor
Liquid Crystal Display (LCD)
technology has been used in
laptops for some time. It
has recently been made
commercially available as
monitors for desktop PCs.

LED Monitors (Light Emitting
Diode)
A display and lighting
technology used in almost
every electrical and electronic
product on the market, from a
tiny on/off light to digital
readouts, flashlights, traffic
lights and perimeter lighting.

Types of Printer
Ink-Jet or Bubble-Jet printer
• Sprays ink at a sheet
of paper.
• Ink-jet printers
produce high-quality
text and graphics.

Types of Printer
Laser printer
• Uses the same technology
as copy machines.
• Laser printers produce
very high quality text and
graphics.

Types of Printer
LCD and LED Printer
Similar to a laser printer,
but uses liquid crystals or
light-emitting diodes rather
than a laser to produce an
image on the drum.

Types of Printer
Line Printer
• Contains a chain of
characters or pins that
print an entire line at one
time.
• Line printers are very fast
but produce low-quality
print.

Types of Printer
Thermal Printer
• An inexpensive printer that
works by pushing heated
pins against heat-sensitive
paper.
• Thermal printers are widely
used in calculators and fax
machines.

4 Ports
Intended for serial type
mouse and older camera
Serial Port
Types of Ports and their function
Type of Port Function Illustration
Also called as printer port.
This is only for old model
printer. It has 25 pins. It is a
female port.
Parallel Port

4 Ports
VGA Port
(Video Graphic Array)
Used to connect monitors. It
has 15 pins and it is a female
port.
USB Port
(Universal Serial Bus)
High speed serial interface that
is used with almost all devices.
It is used to connect latest
model printers, pen drives, cell
phones etc. it has 4 pins.

4 Ports
PS/2 Port
Simple, 6-pin, low-speed
serial connections commonly
dedicated to a keyboard and
mouse.
Power Port Intended for power
cord.

4 Ports
S-Video Port
S-Video connections are
available on certain source
components and video display
devices, and offer a higher
level of video performance over
composite video signals.

4 Ports
Audio Port
Intended for plugging in the
speaker or headset.
LAN Port
(Local Area Networking)
A physical interface often used
for terminating twisted pair
type cables used to connect
computers onto a local-area
networks (LAN), especially
Ethernet RJ-45 connectors

4 Cables and
Wires The Cables and Connectors
Function Illustration
These jacks are
intended for the PS/2
port specifically for PS/2
type of keyboard and
mouse.

4 Cables and
This type of jack is
intended for the audio
and microphone port.

4 Cables and
S-video jack is obviously
for S-Video port

4 Cables and
This monitor jack is
intended for the VGA
(Video Graphic Array)
port

4 Cables and
This printer cable jack
is intended for the
parallel port.

4 Cables and
Power cord is the most
important cord because
it connects the
computer to the main
source of electricity to
make it functional.

Computer hardware

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