Computers: A First Look

1
Computers A First Look

• In this lecture
• Syllabus
• Course overview
• What is a computer?
• Why computers?
• What are some characteristics of different types
  of computers?
• Explain the relationship between hardware and
  software
• Basic anatomy of a computer.

2
What will you learn?

• How computers internally represent the data you
  give them
• How memory and various hardware components work
• How programs make the computer do our bidding
• What operating systems do (to make our lives
  easier)
• How to program (toy examples)
• How computer networks work
• How the Internet works
• What hacking and computer security is all about
• What can we learn about computers from video
  games
• Computer Graphics
• Artificial Intelligence
• Ethics and legality in the digital millennium

3
What is a computer?

• What is a computer?
• by example
• Laptop computers
• Video Game Consoles
• Internet Routers
• ATM machines
• Personal Video Recorders (Tivo, etc)
• GPS
• Alarm clocks
• Microwaves
• Coffee makers

4
What is a computer?

• Computers are tools we use them to perform tasks
  that
• are repetitive
• involve calculation
• involve storage/retrieval of large quantities of
  information
• Theyre useful!
• Why learn about computers?
• They are ubiquitous
• You're curious?

5
What Is a Computer ?

• Definition
• A computer is a processor
• it takes data in one form, uses it, and produces
  a different form of information which is related
  to (but not the same as) the original data.
• Using this broad definition, many things we
  wouldnt usually consider computers qualify. . .

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What Is (and Isnt) a Computer

• A calculator ?
• Input
• Processing
• Output

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What Is (and Isnt) a Computer

• The Abacus?
• an early calculation device that holds numbers
  for the user
• Input
• Processing
• Output

8
What Is (and Isnt) a Computer

• A mechanical bathroom scale ?
• Input
• Processing
• Output

9
What Is (and Isnt) a Computer

• A speedometer ?
• Input
• Processing
• Output

10
The Many Kinds of Computers

• Computers can also be classified by compositional
  characteristics

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Purpose

• Special-purpose Computers
• Manufactured to perform a predetermined task or
  set of tasks.
• Some special purpose computers?
• Often attached to sensor to measure and/or
  control the physical environment
• examples?
• General-purpose Computer
• Was not manufactured to do any one thing.
• Changeable to do any task.
• (read programmable)
• examples?

12
Power

• Electronic Computer
• Needs an electrical source to function.
• Constructed from transistors and electrical
  circuits
• Mechanical Computer
• Produces its own intrinsic energy.
• Does not need electricity to function.
• Constructed of a combination of gears, levers
  and/or springs.

13
Analog Vs Digital

• Digital (Computer)
• One that functions in discretely varying
  quantities.
• Produces or gives results that are also
  discretely varying.
• Digital devices include
• A toggle (on/off) light switch
• A traffic light
• Stairs

14
Analog Vs Digital

• Analog (Computer)
• One that functions in continuously varying
  quantities.
• Produces or gives results that are also
  continuously varying.
• Analog devices include
• A dimmer light switch
• A ramp
• Acceleration pedal in a car
• Is digital data inherently better than analog
  data? Why would we make a computer digital or
  analog? Pros? Cons?