CS 177 Recitation

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CS 177 Recitation

• Jan 13, 2006 Week 1

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Important things to Remember

• Course Webpage www.cs.purdue.edu/cs177
• Course Recitations slides will be posted here.
• Projects will also be posted there.
• Contact details of everyone

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Von Neumann Architecture

• Computers solve math problems
• Solving is in a step-by-step manner (algorithmic)
• What makes a computer different from a
  calculator?
• Access to instructions Data
• Calculator we run/execute solution methodology
  (sequence of instructions)
• Computer runs them by itself!!

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Components of Von Neumann Arch
Memory stores both instructions data CPU
executes instructions on data I/O
takes input displays output
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Central Processing Unit

• CPU fetches executes instructions
• Simple individual instructions add, multiply
  etc.
• Speed of execution faster or slower
• 1 GHz 109 simple instructions per second.
• Made of electronic components wired together
• Very small in size 1 2 sq. inches

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Memory

• Stores data programs
• Storage capacity amount of data that can be
  held
• Specified in Bytes, KB, MB, GB
• Volatile Memory
• Permanent Memory

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Operating System

• OS controls the hardware (the actual devices CPU,
  Memory, I/O devices)
• It is a software
• Manages files and directories
• Modern OS have Graphical User Interface (GUI)
• Windows, Icons, Menus Clickable by Mouse

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Internet WWW

• Internet connected system of many computers
  (hardware)
• Web Service that runs over Internet (software)
• Internet enables communication and sharing
  between computers
• Web allows linking of documents and files on
  computers
• The rules that specify how two computers on
  Internet should communicate Protocol
• Several types of protocols

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HTML

• What is a Markup Language?
• Printed matter has italics, bold lettering
  other formatting
• Markup Language for Documents on Web HTML
• Can specify colors, fonts and several other
  things!!

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Uniform Resource Locator

• URL locate and identify web pages
• Each page has a URL (or Web Address)
• Parts of a URL
• Some URLs dont end up with a file name. How can
  that be?