A Brief Introduction to Computers

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A Brief Introduction to Computers
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What is a computer?

• mechanical device
• capable of
• performing computations
• making decisions
• consists of
• hardware
• software
• operating system

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Computer Hardware

• Input devices
• keyboard, mouse, scanner, etc.
• allow the user to input data for storage or
  calculation
• Memory
• temporarily stores information, both program
  instructions and data
• A CPU (Central Processing Unit)?
• the "brain" that performs the calculations,
  executes the instructions, etc.
• Storage devices
• hard drive, CD-ROM, thumb drive
• allow program instructions and data to be store
  more permantently
• Output devices
• monitor, printer, speaker
• allow data to be displayed in a manner a human
  can understand

4
Software

• Definition
• the applications that users run on a computer
• Examples
• Microsoft Word, Mozilla Thunderbird, Adobe
  Reader, etc.

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Operating System

• Examples
• Windows, Unix, Linux, Mac, etc.
• Purpose
• control the components of the computer and
  software
• It is a bridge between the software and the
  hardware.
• example When a printer is attached to a
  computer, a driver for that printer is installed
  into the operating system. An application, such
  as Microsoft Word, can then print to the printer
  and the operating system will take care of the
  details and Word can focus on word processing.

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Computer Speak

• Remember that a computer is a mechanical device.
  It only understands electrical impluses, on and
  off. On is represented by a 1 and off is
  represented by a 0.
• Since the language a computer understands has
  only two "words", it is called binary.
• A binary "word" is called a bit and is considered
  a binary digit.
• The smallest addressable unit of memory is called
  a byte and consists of 8 bits. A byte represents
  a single character (such as the letter 'Y').
  ASCII provides the standard representation of
  the 256 possible combinations of a byte this
  includes each lowercase letter of the alphabet,
  each uppercase letter of the alphabet, the
  numbers 0 - 9, and all the other characters
  visible on the keyboard along with additional
  characters both printing and non-printing. The
  letter 'Y' would appear as 1011001 to the
  computer.
• A kilobyte (KB) consists of 1024 bytes.  A
  megabyte (MB) consists of 1024 kilobytes.  A
  gigabyte (GB) consists of 1024 megabytes. As an
  example of what this means, consider that if a
  byte can represent a single character (letter),
  then a kilobyte would represent 1024 characters,
  etc.

American Standard Code for Information
Interchange
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Storage Devices

• In the beginning, there was the 8" floppy
  diskette it was followed by the 5 ¼" floppy
  diskette which was proceeded by the 3 ½" floppy
  diskette. None of which were ideal due to
  physical size, storage size, and reliability.
• CDRs, CDRWs, and DVDRs offer greater storage
  capacity and increased reliability.
• care and tips
• Do not leave valuable CDs in automobiles in the
  summer as the heat can cause warping.
• Do not write on a CD with a ball point pen as
  this can destroy data.
• Do not place warped CDs into a drive, especially
  the higher speed drives - CDs have been known to
  shatter in and explode out of drives.
• If a CD will not eject while in one of ASU's
  labs, locate an administrator.
• Thumb drives (aka jump drive, memory stick, etc.)
  offer excellent storage capacity and reliability
  all in a very compact physical size.
• care and tips
• Try not to lose it.

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Computer Protection

• Spyware and Adware
• Spyware consists of programs and cookies that
  keep track of what you do while on the Internet.
• Adware consists of programs that are freely
  downloadable, but generate ads which the user
  must endure in order to use the free
  application.
• Try Spybot Search and Destroy to remove spyware
  and adware already on a computer. (Available via
  www.download.com a reliable source of
  applications and utilities.)?
• Try SpywareBlaster for real-time protection
  against spyware. Also available from
  download.com.
• Viruses
• Viruses spread through email as well as some
  infected websites.
• AVG Anti-Virus offers a free version of their
  anti-virus program as well as free updates.
  www.grisoft.com
• Other forms of attack (such as Trojans, Worms,
  etc.)?
• Many hackers search for computers with open
  ports. A firewall can help "hide" a computer.
• Microsoft Windows XP comes with a built-in
  firewall, but it does not provide user
  modifications and only controls access into the
  computer.
• Zone Labs offers a free version of their firewall
  as well as notifications of upgrades. ZoneAlarm
  allows the user to control what can get in as
  well as what can get out. www.zonelabs.com

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Data Protection

• Backup
• Viruses, Trojans, and Worms are not the only ways
  to lose data. Electrical failure, electrical
  surges, age, flood, fire, etc. can also cause
  data loss.
• Periodically copy data onto a second hard drive,
  CDs, etc. and place the copies in a secure place.
  (If the data is valuable, place a copy in a
  different physical location in case of fire,
  flood, etc. or invest in a fire safe.)?