CSCI N100

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CSCI N100

• Essence of Computation

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Definition of computer

• Universal
• Information
• Manipulator

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Universal

• Works with all kinds of information
• Does all kinds of stuff to it
• Very few limitations

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Information

• Seems to be able to work with anything
• Actually very limited
• Tiny pieces of data combined into complex
  information

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Manipulator

• Seem able to do anything with data
• Actually very limited
• Simple commands combined into complex instructions

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CSCI N100

• Essence of Computation

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Computers and Information

• Information limited to on/off impulses
• Like a light switch
• Infinite positions
• Two outcomes
• The light demo

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Working with Multiple Switches

• One switch - two messages
• Two switches - four messages
• Three switches - eight messages

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Assigning Values to messages

• Looking at the pattern
• 1, 2, 4, 8, 16, 32, 64, 128...
• Seeing how it works.
• The brick counter demo

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CSCI N100

• Converting from binary to Base 10

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Converting from Binary to base 10

• Start with Grid
• Right to left
• Powers of Two
• Substitute 1 with appropriate value

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CSCI N100

• The basic logic gates

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Definition of Computer

• Universal
• Information
• Manipulator

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The Information Part

• Computers only deal with on and off!
• Universality is a hoax.
• Lots of tiny values combined

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The Manipulation Part

• Computers can do very limited operations
• These operations are combined to make computer do
  complex things

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Three Logical Operations

• AND
• OR
• NOT

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How They are Used

• Test if two numbers are equal
• Add / subtract
• Refer to computers memory