Hardware of
Personal Computers
What are Basic Hardware of a Personal
Computer?
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Monitor
Motherboard
CPU (Microprocessor)
Primary storage (RAM)
Expansion cards
Power supply
Optical disc drive
Secondary storage
(Hard disk)
• Keyboard
• Mouse
What is a Hardware?
• Hardware is the general term that is used to describe physical
artifacts of a technology.
Classification of Hardware
What is an Input Device?
• A hardware mechanism that transforms information in the
external world for consumption by a computer.
Input Devices
Keyboard
for the input of text and
characters and also to
control the operation of
a computer .
Mouse
a pointing device by
detecting twodimensional motion
relative to its supporting
surface.
Scanner
a device that analyzes
images, printed text, or
handwriting, or an object
and converts it to a
digital image .
Input Devices
Microphone
an acoustic to electric
transducer or sensor
that converts sound into
an electrical signal.
WebCam
a real-time camera
(usually, though not
always, a video camera)
whose images can be
accessed using the World
Wide Web.
Digital Camera
an electronic device used
to capture and store
photographs
electronically in a digital
format
What is a Processing Unit?
• A central processing unit (CPU), is
the component in a digital
computer that interprets
computer program instructions
and processes data.
• There are 2 major CPU
manufacturers for personal
computers.
Figure 3. Intel Celern 2.66GHz CPU (Front)
Intel
http://www.intel.com/
AMD
http://www.amd.com
Figure 4. Intel Celern 2.66GHz CPU (Back)
How fast is a CPU?
• When you choose a CPU,
you should consider its
speed.
• The speed of a CPU is
determined by 2 main
factors.
• Clock frequency
• Amount of cache
memory
• The higher the value, the
faster the CPU will be.
The clock frequency of a
CPU
What is a motherboard?
• A motherboard is the
central circuit board
making up a personal
computer.
RAM
slot
CPU
Motherboard
• A personal computer is built with the CPU, main memory,
and other essential components on the motherboard.
• Other components such as external storage, controllers
for video display and sound, and peripheral devices are
typically attached to the motherboard via edge
connectors and cables.
• In modern computers it is increasingly common to
integrate these "peripherals" into the motherboard.
What is a Video Card?
• A video card is to
generate and output
images to a display.
A Video Card
• If the video card is integrated in the motherboard, it will use the
computer RAM memory (lower throughput). If it is not integrated,
the video card will have its own video memory which is called Video
RAM or VRAM.
• The VRAM capacity of most modern video cards range from 128 to
2048 MB (workstation graphics cards).
• In 2006, the VRAM was based on DDR technology, standing out
DDR2, GDDR3 and GDDR4. The memory clock rate is between 400
MHz and 1.6 GHz.
• A very important element of the video memory is the Z-buffer,
which manages the depth coordinates in 3D graphics.
What is a Sound Card?
A sound card is a
computer expansion
card that can input and
output sound under
control of computer
programs.
• Many computers have
sound capabilities built
in on the motherboard,
while others require
these expansion cards
if audio capability is
desired.
What are Types of Storage Devices?
What is Primary Storage?
• Primary storage is computer memory that is directly accessible
to the CPU of a computer without the use of computer's
input/output channels.
• Primary storage is used to store data that is likely to be in
active use.
What is ROM?
• Read-only memory
(ROM) is a class of
storage media used
in computers.
• Data stored in ROM
cannot be modified.
• ROM is a non-volatile
storage. Data
remains unchanged
even after switching
off the computer. E.g.
EPROM, EEPROM
What is RAM?
• Random access memory
(RAM) is a type of data
storage used in
computers.
• It takes the form of
integrated circuits that
allow the stored data to
be accessed in any order
(random).
• Data stored in RAM can
be modified.
• RAM is a volatile storage.
Data will lose after
switching off the
computer. E.g. DDRam,
DDR-2 Ram
What is Secondary Storage?
• Secondary storage is computer memory that is not
directly accessible to the CPU of a computer, requiring
the use of computer's input/output channels.
• It is used to store data that is NOT in active use.
• It is usually slower than primary storage but it always has
higher storage capacity.
• It is non-volatile. Data remains unchanged even after
switching off the computer.
Secondary Storage
3.5” Floppy Disk
• Data can be read or
write
• Data capacity:
1.44 MB
Secondary Storage
Hard Disk
• Data can be read or
write
• Speed of disk
rotation
usually 7200 rpm
• Data capacity :
80GB, 160GB, 250GB,
300GB etc
Secondary Storage
CD-ROM
CD-R
CD-RW
Data can be
Read only
Read but write
once
Read & write
Data Capacity
(MB)
650
650
650
Secondary Storage
DVD
DVD-R /
DVD+R
DVD-RW /
DVD+RW
Data can be
Read only
Read but write
once
Read & write
Data Capacity
Single layer: 4.7
Double layer:8.5
Single layer: 4.7
Double layer:8.5
Single layer: 4.7
Double layer:8.5
What are the difference between
DVD-R and DVD+R?
• The DVD-R format was developed by Pioneer in the
autumn of 1997. It is supported by most DVD players,
and is approved by the DVD Forum.
• DVD+R was developed in 2002.
• This format is a competing format to the DVD-R format,
which is developed by the DVD Forum, it has not been
approved by the DVD Forum, which claims that the
DVD+R format is not an official DVD format.
Secondary Storage
Secondary Storage
Secondary Storage
USB flash drives
• They are flash memory
data storage devices
integrated with a USB
interface.
• They are typically
small, lightweight,
removable and
rewritable.
• Data capacity:
512MB, 1GB, 2GB, 4GB,
etc
Secondary Storage
Memory Cards
• e.g. SD card, CF card,
xD card, Microdrive,
Memory Stick
• Data can be read or
write
• Data capacity:
512 MB, 1GB, 2GB,
4GB etc
Various Types of Memory Cards
SM Card
SD Card
CF Card
XF Card
Memory Stick
Microdrive
What is an output device?
• Output devices include any hardware that translate
information processed by the computer into a form that
humans can understand.
Output Devices
A monitor is a piece of
electrical equipment
which displays texts
and images.
• It generated a
temporary record
because the record
disappear when power
off.
• There are 2 major
types of monitors:
Cathode Ray Tube
(CRT) and
Liquid Crystal Display
(LCD)
The performance parameters of a monitor are:
1.Luminance
2.Size, measured diagonally
For CRT the viewable size is one inch smaller then the
tube itself.
3.Dot pitch
Describes the distance between pixels of the same color.
In general, the lower the dot pitch (e.g. 0.24), the
sharper the picture will appear.
4.
5.
6.
7.
Response time
The amount of time a pixel in an LCD monitor takes to
go from active (black) to inactive (white) and back to
active (black) again. It is measured in milliseconds (ms).
Lower numbers mean faster transitions and therefore
fewer visible image artifacts.
Refresh rate
The number of times in a second that a display is
illuminated.
Power consumption
Display resolution
The number of distinct pixels in each dimension that
can be displayed.
Output Devices
A printer produces a hard copy (permanent humanreadable text and/or graphics) of documents stored in
electronic form, usually on physical print media such as
paper.
• There are 2 major types of printers. They are inject
printer and laser printer.
• The resolution of a printer is measured in dots per inch
(dpi). The higher the value, the better the quality.
Output Devices
Inkjet printers operates
by propelling tiny
droplets of liquid ink
onto paper.
• They are the most
common type of
computer printer for
the general consumer
due to their low cost,
high quality of output,
capability of printing in
vivid colour, and ease
of use.
Output Devices
Laser printer
• Laser printers employ
a xerographic
printing process.
• Laser printers are
available in both
colour and black &
white varieties.
Output Devices
• A loudspeaker is an
electromechanical
transducer which
converts an electrical
signal into sound.
References
• HP. (2007a). HP Officejet Pro K5400dn. Retrieved July 7,
2007, from
http://h10010.www1.hp.com/wwpc/hk/zh/sm/WF06b/109
0037-1090093-1095469-1095469-12224252-1297329478107983.html
• HP. (2007b). HP Olaser Jet 1022. Retrieved July 7, 2007, from
http://h10010.www1.hp.com/wwpc/hk/zh/ho/WF05a/1090
037-1090121-1090401-1090401-1091129-12094322.html