Introduction to Computers

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Introduction to Computers

• Renee Felts
• Assistant Professor, IST

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What is a Computer?

• An electronic device, operating under the control
  of instructions stored in its own memory unit,
  that can accept data (input), manipulate the data
  (process), produce information (output) from the
  processing and store results (storage) for future
  use.

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Parts of the computer

• Look at the picture on page COM-2 of your
  textbook
• Mouse
• Mouse, Trackball, Touchpad
• Keyboard
• System Unit
• CPU Central Processing Unit
• Memory
• Storage (CD, Floppy Disk, Hard Drive)
• Monitor
• Two types are CRTs and LCDs (flat panel)
• Printer
• Communication devices (modems)

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Main Functions of a Computer

• Information Processing Cycle
• Input - way to get information into a computer
• Peripheral (external) device used to get
  information from the outside world into the
  computer
• Floppy disks, CDs, DVDs, modems are NOT input
  devices
• Output - getting information out of a computer
• Processing changing / translating the inputs to
  outputs,
• Storage - saving the information for future use

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Example devices for the main functions
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Storage

• Differences between storage devices include
• Size
• Speed
• Portability
• Ability to backup a computer

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Measuring Storage

• 1 byte 1 character, letter or number
• My Name (Patti) takes 5 bytes
• KB - kilobyte 1024 bytes
• MB -megabyte 1 million bytes
• GB - gigabyte 1 billion bytes
• 1 MB about 500 pages of information

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Hard Drive

• Inside system unit
• Stores operating system, programs
• Not portable
• Typical hard drives range from 40 GB to 200 GB

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Floppy Disk

• Portable
• Inexpensive
• Types of floppy disks (3.5" and 5.25")
• 3.5 is the most common today
• Look at picture in textbook on page COM-9 of
  inside of floppy disk to see why it is called
  floppy
• Computer vendors are starting to ship computers
  without floppy drives
• Be careful with magnets around floppy disks
• They can erase information on the disk

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CD-ROM

• Compact Disk
• Larger capacity than floppy disks
• Good for multimedia (sound, video, data,
  graphics)
• Holds about 650 MB
• 450 to 700 times more than a floppy disk
• About 4.75 in diameter
• CD-R, CD-RW
• Requires a special drive to write to these disks.
  Many drives are read only
• RW is read / write
• Sometimes used for backups

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DVD

• Over 4.7 GB of data and up to 17 GB
• About 4.75 in diameter
• Can store a full length motion picture
• Larger capacity than floppy disks and CD-Roms
• Good for multimedia (sound, video, data,
  graphics)
• Good for backups
• DVDRW
• Requires a special drive to write to these disks.
  Many drives are read only
• RW is read / write

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Zip Drive

• Holds 100 MB to 750 MB
• 100 MB Zip disk is equal to about 70 floppy disks
  
• Needs a special zip drive
• The drive can be internal or external
• Portable Storage
• Sometimes used for backups

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USB Flash Drives

• Many sizes 16MB, 32MB, 64MB, 128MB, 256MB
• Plug-in to USB port
• Windows XP automatically recognizes
• You have to install drivers on Windows 98
• Work like a floppy disk but hold a lot more
• Portable storage
• Bookstore, Wal-mart, Best Buy, Office Max, etc
  sell these drives
• Not too expensive
• http//reviews-zdnet.com.com/USB_Flash_Drives/4520
  -3240_16-5128560.html

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Tape Drives

• Good for backups
• Slower to find items later
• Have to start at beginning and read until you
  find what you are looking for (like an audio tape)

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Storage Comparisons

• What is the difference between floppy disk and
  CD-ROM and DVD?
• What is the difference between the floppy disk
  and hard drive?

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Drive Letters for Storage Devices

• Drive Letters you can see the drive letters in
  My Computer (Start, My Computer)
• Floppy almost always Drive A
• Hard Drive usually Drive C (depending on your
  computer you may have additional hard drives)
• Network drives F, T, H on our network (this
  will be different on other networks)
• CD-ROM usually drive D (depends on computer).
  It will have a picture of CD/DVD

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Memory

• RAM (Random Access Memory)
• Information stored here until written to disk
• Can holds information while your computer has
  power
• When the computer loses power the information
  in memory is lost

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Purchasing and Installing a PC

• These topics are covered in the textbook
• A lot of good information for your use
• You will not be expected to know the information
  on these pages

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Using and Taking care of diskettes

• Do not let label cover the silver piece when you
  put label on disk
• Do not remove when green light is on
• Green light indicates computer is writing to the
  disk
• If you remove when the light is on it can corrupt
  your files making them unusable
• Keep in their original box or floppy box
• Protect from getting in dust, dirt or silver
  piece gets bent
• Potential damage
• Dust, dirt
• Heat, sunlight
• Magnetic fields can erase files on disk (be
  careful with cell phones and floppy disks)
• Silver piece
• If it gets bent it may get caught in computer
• Copy information off disk and throw disk away

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Formatting a Disk

• Be very careful formatting disks !!!!
• Only need to do once for each disk
• Erases everything on the disk
• Prepares and lays out the disk so the computer
  can write to it
• We recommend formatting the disk the first time
  you use it on a Windows XP computer even if you
  use pre-formatted disks
• Some problems with students using diskettes in
  the lab and then on a Windows 95/98/ME computer

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Graphical User Interface

• Most systems today use a Graphical User Interface
• GUI (Graphical User Interface)
• Pictures (graphics) are used to allow us (users)
  to communicate (interface) with the computer
• Icons
• Another name for the pictures or graphics

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Software vs. Hardware

• Hardware
• Physical devices (parts of the computer)
• Mouse, Keyboard, Monitor, System Unit
• Software
• Software is the programs that we use
• Usually stored on the hard drive
• Two types of software
• Applications
• System Software

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Application Software

• Internet Explorer used browse the WWW
• Word Processing - create letters, papers, memos
  (figure 27)
• Spreadsheet allows you to add, subtract, create
  charts (figure 28)
• Database keep track of customers, contacts
  (figure 29)
• Presentation used to organize a presentation
  and create handouts (figure 30)
• E-mail - send messages electronically
• Games

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System Software

• Operating system
• Controls the Hardware
• Computer cant do anything without an operating
  system
• Interprets our actions so the computer can
  understand
• Need operating system to be able to run
  applications
• Computer cannot run without an operating system
• Important to understand the difference between
  operating system and application software
• Examples of Operating Systems
• Windows XP, Windows 95, Windows 98, Windows
  2000, Windows NT, Windows 3.1, OS/2, Mac, UNIX

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Cursor (Insertion Point) vs. Mouse Pointer

• Cursor or Insertion point
• Two names for the same thing
• Blinking line where your typing shows up
• Different from the mouse pointer
• Mouse pointer
• I-Beam in areas where you can type
• Used to change the location of the cursor
• Can be used to point and select items

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What is a Virus?

• Computers can get viruses
• They are spread like a cold
• Through contact such as using disks on multiple
  computers or sending files through the internet
• What can it do?
• Cause annoyances or destroy information on your
  computer
• Virus Protection Software
• Critical to have this software installed on your
  computer
• Important to update virus patterns at least every
  day
• Most virus protection software provides a way to
  do this. Usually have to be connected to the
  internet
• Dynamic virus protection
• Automatically detects viruses on files that you
  use on your computer