Were eating people

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Were eating people
http//www.imdb.com/title/tt0048960/

• Charlton Heston in Soylent Green (1973)

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Computer Science 101Lecture 29
author.handalak.com/.../ images/javascript.jpg

• Fall Semester 2008
• Monday, March 31
• Week 11/18
• Albert H. Carlson

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Announcements

• Your CSS is due Friday, April 4
• HW 5 is due Friday, April 11

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New Subject

• Now we have to discuss a new subject the
  environment where the software runs

The Operating System (OS)
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Operating Systems

• System software is software that controls a
  computer
• Officially, the operating system (OS) is a set of
  programs that coordinates all of the hardware
  activities in a computer
• It is transparent to the user. That is, you do
  not have to actually direct itself
• It is actually put on the hard disk

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Operating Systems

• The basic operating systems are
• Windows (pick your flavor IBM type)
• Mac OS (Apple)
• UNIX
• Linux
• History of OSs http//www.levenez.com/unix/histor
  y.html
• Windows is built on MS DOS
• Application Programs are written on the OS

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OS

• Each size machine has a different type of OS
• Even the same size machines can choose from a
  number of OSs. Mac has its own in several
  versions, so does Windows
• Among the functions we have for an OS is to start
  up a computer
• Warm
• Cold

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OS Types

• Mainframe
• Server
• Laptop/Desktop
• Mobile
• Palm
• Custom

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Networks

• Need to get information from one computer to
  another
• Used to do it by typing it in one computer at a
  time
• Sneakernet
• Wanted to do this using existing networks
• Power
• Phone

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Modems

• Needed a way to translate data from computer to
  electronic/voice signal
• Uses this as a translator
• Then it has to translate back to electronic
  signal again
• Started at 110 baud
• Now can go upwards of GB/s

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More Networks

• They also have some sort of control
• This is called a protocol
• Protocols are basically instructions about how
  something should work
• There are various levels of protocols

http//www.freesoft.org/CIE/Topics/15.htm
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Questions?