3. A World of Computers
• Computers are everywhere
– People use all types and size of computer for a variety
of reasons and in a range of places.
Search information
Listen to music
Home
Edit photos
Send
messages
Workplace
School
Pages 4 - 5
Figure 1-1 People use all types and sizes of computers in their daily activities
4. What is a computer?
• A computer is an electronic device, operating
under the control of instructions stored in its
own memory, that can accept data, process the
data according to specific rules, produce results,
and store results for future use.
Produce
results
Accept
data
Process
Store
results
Pages 6
5. Data and Information
Data
• Data is a collection of unprocessed items, which can
include text, numbers, images, audio and video.
Information
• Information conveys meaning and is useful to
people.
Data
Sally, 32, 24, 32
Computers
Process
Information
Sally Exam Results
Chinese 32 marks
Malay 24 marks
English 32 marks
8. Information Processing Cycle
1. Accepts raw data
Input
2. Process data into information 3. Produces results
Processing
Output
Storage
4. Stores results for
future use
Communications
Sending or retrieving data
Internet
5. Communicate with
other computers
9. The Components of a Computer
• A computer contains many electric, electronic, and
mechanical components known as hardware.
• These components include:
1.
2.
3.
4.
5.
Input devices
Output devices
System unit
Storage devices
Communication devices
10. The Components of a Computer
Input Device
• Allows you to enter data and instructions into a computer
Output Device
• Hardware component that conveys information to one or
more people
System Unit
Storage Device
Communications
Device
• Case that contains the electronic components of the
computer that are used to process data
• Holds data, instructions, and information for future use
• Enables a computer to send and receive data, instructions,
and information to and from one or more computers or
mobile devices
11. Input Devices
• It is a hardware component that allows people to
enter data and instructions into a computer.
• 5 widely used input devices are as below:
1.
2.
3.
4.
5.
Keyboard
Mouse
Microphone
Scanner
Webcam
14. Output Devices
• It is a hardware component that conveys
information to people.
• 3 commonly used output devices are below:
– Printer (produce text and graphics on a paper)
– Monitor (display text, graphics, video on a screen)
– Speakers (to hear music, voice, and other audio)
16. System Unit
• The system unit is a case that contains the
electronic components of the computer that are
used to process data.
• The circuitry of the system unit is connected to a
circuit board called the motherboard.
• 2 main components on the motherboard:
1. Processor (CPU – central processing unit)
2. Memory (E.g. RAM)
18. Storage Devices and Media
• Storage holds data, instructions, and information for
future use.
• Computers can store hundreds or millions of customer
names and address. Storage holds these items
permanently.
• Examples of storage media:
– USB flash drive, hard disk, optical disk, and memory cards.
• Examples of storage devices:
– DVD drive and CD ROM drive
20. Storage Device VS Storage Media
CD/DVD Drive
Storage device
Records and retrieves items to
and from storage media
Storage media
Physical material on which data,
instructions, and information
are stored
CD/DVD
21. Communication Devices
• It is a hardware components that enables a
computer to send and receive data, instructions,
and information to and from one or more
computer.
• Widely used communication device is a modem.
23. Advantages and Disadvantages
of using computers
• Advantages of
Using Computers
• Disadvantages of
Using Computers
Speed
Health Risks
Reliability
Violation of Privacy
Consistency
Public Safety
Storage
Impact on Labor Force
Communications
Impact on Environment
24. Advantages of using computers
Speed
Reliability
Consistency
Travel at incredibly fast speed
Have low failure rate
Given the a same input and process,
will produce the same results. This
phase called “garbage in, garbage out”
Storage
Store enormous amount of data and
make this data available for processing
anytime
Communication
Can share the store data, instructions,
and information
25. Disadvantages of using computers
• Health risks
– Prolonged or improper computer use can lead to injuries or disorder
of the hand, wrists, elbows, eyes, neck, and back.
– Repetitive strain injury: pain to arms, elbows, fingers and wrists due
to repetitive motion of typing and sitting in fixed position
– Prevention: proper workplace design, good posture sitting at work
desk and timely work break.
• Violation of privacy
– Personal and confidential records were not protected properly,
individuals have found their privacy violated and identities stolen.
• Public safety
– Unsuspecting, innocent computer users have fallen victim to crimes
committed by dangerous strangers.
26. Disadvantages of using computers
• Impact on labor force
– The skills of millions of employees have been
replaced by computers.
• Impact on environment
– Computer manufacturing processes and computer
waste are depleting natural resources and polluting
the environment.
– When computers are discarded in landfills, they
release toxic materials.
27. Green Computing
• Green computing involves reducing the electricity
consumed and environmental waste generated when
using a computer
• Strategies include:
– Recycling
– Regulating manufacturing processes
– Extending the life of computers
– Immediately donating or properly disposing of
replaced computers
28. Categories of Computers
Category
Personal computer
Mobile computer & mobile
devices
Game consoles
Servers
Mainframes
Supercomputers
Embedded computers
Physical Size
Fits on desk
Fits on lap or in hand
Small box or handheld
device
Small cabinet
Partial room to a full room of
equipment
Full room of equipment
Miniature
29. Personal Computers (PCs)
• A personal computer can
perform all of its input,
processing, output, and storage
activities by itself
• 2 popular architectures are the
PC and the Apple
• 2 types of PC are desktop and
notebook computers.
30. Mobile Computers & Mobile Devices
Mobile
Computer
Personal computer
you can carry from
place to place
Examples include
notebook
computers, laptop
computers, and
Tablet PCs
Mobile
Device
Computing device
small enough to
hold in your hand
Examples include
smart phones,
PDAs, handheld
computers,
portable media
players, and
digital cameras
31. Mobile Computer: Notebook
•
•
•
•
Also called laptop computer.
It is portable, personal computer
designed to fit on your lap.
Size is thin and lightweight, yet
they can be as powerful as the
average desktop computer.
More expensive than desktop
computer with equal capabilities.
32. Mobile Computer: Tablets PCs
•
•
•
Resembling a letter-sized
slate
You can interact with by
touching the screen with
your finger or a digital pen
Useful for taking notes in
lectures, at meeting, and
conferences
33. Mobile Device: Smart Phones
• It is an internet enabled phone that usually
also provided personal information
management functions such as a calendar,
an appointment book, an address book, a
calculator, and a notepad.
• It also allow you to send and receive email
massages, and access to the Web.
• Communicate wirelessly with other
devices.
• As a portable media player and build in
digital cameras.
34. Mobile Device: PDAs
• Personal digital assistant (PDA)
provides personal information
management functions such as a
calendar, an appointment book, an
address book, a calculator, and a
notepad.
• The primary input device of a PDA is a
stylus.
• Many PDAs are Internet-enabled so
that users can check email and access
the Web.
• Some also provide phone capabilities.
35. Mobile Device: E-book Reader
• Handheld device that is
used primarily for
reading e-books.
• Have a touch screen and
are Internet-enabled.
• Size smaller than tablet
computers but larger
than smart phone.
36. Mobile Device: Handheld Computer
• Sometimes referred to as a Ultra Mobile PC.
• Is a computer small enough to fit in one hand.
• Can communicate wirelessly with other devices or
computers and also include a digital pen/ stylus.
• For mobile employees:
– Meter reader and parcel delivery people, whose jobs
require them to move from place to place.
37. Mobile Device: Portable Media Player
• It is a mobile device on
which you can store,
organize, and play digital
media.
• For example:
– Listen to music
– Watch video, movie, and
television shows
– View photos
The iPod is a popular portable media player
38. Mobile Device: Digital Cameras
• It is a device that allows users to take pictures
and store the photographed images digitally,
instead of on traditional film.
39. Game Consoles
• It is a mobile computing device designed for single
player or multiplayer video games.
• Standard game consoles use a handheld controllers
as an input device; a television screen as an output
device; and hard disk, optical disk / memory for
storage.
• Small enough to fit in one hand, portable.
• Example:
– Sony’s PlayStation Portable (PSP)
– Nintendo Wii
40. Servers
• A server controls access to the hardware,
software, and other resources on a network
and provides a centralized storage area for
programs, data, and information.
• It can support several thousand connected
computer at the same time.
41. Mainframes
• A mainframe is a large,
expensive, powerful computer
that can handle hundreds or
thousands of connected users
simultaneously.
• It can store tremendous
amount of data, instructions,
and information.
42. Supercomputers
• A supercomputer is the fastest, most powerful computer.
• Fastest supercomputers are capable of processing more than one
quadrillion instructions in a single second.
• Applications requiring complex, sophisticated mathematical
calculations use supercomputers.
– Online banking
– Weather forecasting
– Nuclear energy research
43. Embedded Computers
• An embedded computer is a specialpurpose computer that functions as a
component in a larger product
Consumer
Electronics
• Mobile and
digital
telephones
• Digital
televisions
• Cameras
• Video
recorders
• DVD players
and recorders
• Answering
machines
•
•
•
•
•
Home
Automation
Devices
Thermostats
Sprinkling
systems
Security
monitoring
systems
Appliances
Lights
Automobiles
• Antilock
brakes
• Engine control
modules
• Airbag
controller
• Cruise control
Process
Controllers and
Robotics
• Remote
monitoring
systems
• Power
monitors
• Machine
controllers
• Medical
devices
Computer
Devices and
Office Machines
• Keyboards
• Printers
• Faxes
• Copiers
44. Computer Applications in
Business and Society
Education
Business
Students have notebook
computers on their desks
during classroom lectures
Business users use computers
to generate business reports,
do presentations, business
planning, etc.
45. Computer Applications in
Business and Society
Finance
Health
Care
Government
Users access account balances, pay
bills, & copy monthly transactions
from the bank’s computer right
into their PC.
Medical staffs use computers
& computerized devices to
assist with medical tests
Law enforcement officials
have in-vehicle computers
& mobile devices to access
emergency, criminal records
in computer networks
46. Computer Applications in
Business and Society
Science
Scientists use computers to assist
them with collecting, analyzing, &
Modeling data.
Publishing
Many magazine & newspaper
publisher make the content of their
Publications available online
Travel
GPS gives users prompted directions to a
destination
Manufacturing
Automobile factories use
Industrial robots to weld
car bodies
47. Summary
Data vs. Information
Information Processing Cycle
What’s computer?
Education, business,
healthcare, etc.
Computer
applications in
business & society
Personal Computer
Mobile computer & device
Game console
Categories of
Server
computers
Mainframe
Supercomputer
Embedded computer
Input devices
Output devices
System Unit
Communication devices
Storage devices
Components of a
computer
Advantages &
disadvantages of using
computer
Speed, reliable,
consistent, etc.
Health risks,
violation of
privacy, etc.
Hinweis der Redaktion
Define the term computer, and describe the relationship between data and information.Describe the five components of a computer.Discuss the advantages and disadvantages that users experience when working with computersDifferentiate among types, sizes, and functions of computers in each categoryDiscuss how society uses computers in education, finance, government,, health care, science, publishing, travel, and manufacturing
A computer is a programmable electronic device that accepts input; performs processing operations; outputs the results; and provides storage for data, programs, or output when needed. This progression of input, processing, output and storage is called the information processing cycle. Most computers today also have communications capabilities, such as sending or receiving data via the Internet, accessing information located in a shared company database or exchanging data or email with others. Therefore, communications – technically an input or output operation, depending on which direction the information is going – is often considered the fifth primary computer operation.