1 Introduction to Computers
What is a
Computer?
Mrs. Nedreberg
Living Without Computers
Do you realize
the implications
of computers in
your every day
life?
 2001 Prentice Hall
1.2
What is a Computer?
• An electronic device
“Consider
– Operating under control of instructions
the past
stored in its own memory
and you
shall know • What are the four functions of
every
computer?
the future.”
– Input
Chinese Proverb
– Output
– Processing
– Storage
 2001 Prentice Hall
1.3
The First Real Computers
Inventors of the first real computers include:
Konrad Zuse
John Atanasoff
Howard Aiken
John Mauchly &
J. Presper Eckert
 2001 Prentice Hall
1.4
Evolution and Acceleration
• First Generation
– Vacuum tubes
• Second Generation
– Transistors
• Third Generation
– Integrated circuit
• Fourth Generation
– Microprocessor
 2001 Prentice Hall
1.5
Where Are We Now?
Fourth-Generation Computers
• 1970s to present
• Switches of previous
generations reduced to
microprocessor
• Cost dropped so much
that “hobbyists” could
own them, and now nearly
everyone does!
 2001 Prentice Hall
1.6
Information-Processing Machine
Input
data
 2001 Prentice Hall
Processing
elements
Print
materials
1.7
Types of Computers
• Supercomputers
• Mainframes
• Workstations
• Personal Computers
• Portable Computers
• Embedded Computer
• Special-Purpose Computers
 2001 Prentice Hall
1.8
Basic Components of a Computer
Hardware
 Input devices
– Keyboards
– Pointing devices
• Output devices
 Monitor – CRT or LCD
 Printer – Inkjet or Laser
 Speakers
 2001 Prentice Hall
1.9
Basic Components of a Computer
Hardware, continued
 Central Processing Unit (CPU)
 Motherboard
 Memory
 Storage devices
 Hard Drive
 Other Magnetic disks – floppies, Zip disks, memory
stick
 Optical Storage
 CD ROMs, CD-R and CD-RW, DVDs
 2001 Prentice Hall
1.10
Software
•
Three Major Types of Software
1. Translation Software – Compilers, etc.
•
Change a programmer’s “program” into machine code, the 1s and 0s
that the computer understands
•
Programmers use high-level languages with English type
instructions – Fortran, (the first) BASIC, COBOL, C, C++, Java…
2. System Software
•
Operating System – every computer must have one
•
Many Tasks
–
•
Memory and data management – communication with input, output, and
storage devices - user interface (GUI)
Utility software – virus protection, etc.)
 2001 Prentice Hall
1.11
The third Type of Software
Consumer Application Software
A huge variety of applications are available:
– Word processing and
desktop publishing
– Telecommunication and
networking
– Spreadsheets and
databases
– Artificial intelligence
– Presentation graphics
– Computer graphics,
multimedia and
hypermedia
 2001 Prentice Hall
– General problemsolving
– Programming languages
1.12
Computer Connections
• Local Area Networks (LAN)
– designed to share resources
– allow communication between users
(usually in the same building)
• Wide Area Networks (WAN)
– designed to share resources
– allow communication around the globe
 2001 Prentice Hall
1.13
The Internet Explosion
• A network of networks
• Immense source of
information
• Electronic mail
• Audio/Video links
• Multimedia simulations
• On-line transactions
• World Wide Web
 2001 Prentice Hall
1.14
Electronic Mail (e-mail)
“The great
success of
the Internet
is not
technical,
but its
human
impact.”
Dave Clark
 2001 Prentice Hall
Why did E-mail lure people
to the Internet?
– Availability
• software made it easy to use
– Speed
• messages can be created and
delivered in minutes
1.15
World Wide Web
Web browsers help
locate information
on the Web
Information is
stored on Web pages
A group of Web pages
make up a Web site
 2001 Prentice Hall
1.16
World Wide Web
Enter a Web page’s unique
address (URL) to go to the Web page
http://www.prenhall.com/grauer
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1.17
World Wide Web
Click a hot link
to jump to
different Web
pages
 2001 Prentice Hall
1.18
The Internet Culture
Why do people connect to the Internet?
 To find
information
 Explore
research
material
 To get
instant
answers
 2001 Prentice Hall
1.19
The Internet Culture
 To shop
 Play games
 Track
stocks
 2001 Prentice Hall
1.20
Internet Growth
• 1994? 3 million people connected
• Today? Hundreds of millions, maybe
billions
• The United States leads the world in
Internet activity
– Approximately 1/3 of U.S. households
connected in 1999
– Today, over twice that number are connected
 2001 Prentice Hall
1.21
Connecting to the Internet
• Direct connection
– One that’s hard wired through an
organization
• Indirect connection
– Telephone system
• Cable TV connection
• Wireless connection
 2001 Prentice Hall
1.22
Living with Computers
What do you really need to know
about computers?
Explanations?
Applications?
Implications?
 2001 Prentice Hall
1.23
Clarifying Technology
Learn basic concepts of hardware and software
 2001 Prentice Hall
1.24
Social and Ethical Issues
Learn about the impact of computers on your life:
– Threat to personal
privacy
– Hazards of hightech crime
– Protecting
intellectual
property
 2001 Prentice Hall
– Risk of computer
failures
– Threat of automation
– Dehumanization of
work
– Abuse of information
1.25
Social and Ethical Issues
“For better
and for
worse, we’ll
be
coexisting
with
computers
till death do
us part.”
– Technology dependence
(remember the Y2K bug?)
– The Death of privacy
– Blurring of reality
– Evolution of intelligence
– Emergence of bio-digital
technology
George Beekman
 2001 Prentice Hall
1.26