Objectives

1

• Objectives
• Identify the key components of a computer system
• Explain the role of input and output devices and
  describe the features of the most common types
  
• Describe the relationship and function of the
  central processing unit, memory, and storage
  

2

• Objectives
• 4. Describe the functions and purpose of and the
  most common types of storage devices
  
• 5. Explain the relationship and support value of
  each component of a computer system to teaching
  and learning

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How Computers Work

• A computer is made up of hardware and software
  that makes the computing cycle possible.
  
• Hardware includes all the physical components of
  a computer
  
• Software includes all the programs (set of
  computer instructions) that instruct the computer
  how to perform operations or tasks

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How Computers Work

• The computing cycle consists of
• Input
• Processing
• Storage (Temporary Permanent)
• Output
• Each stage of the cycle has specific hardware
  devices associated with it

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How Computers Work
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How Computers Work

• Input includes any data or programs that are
  entered into the machine by the user
  
• Input is directed to the CPU for processing
• The CPU chip controls data flowing through the
  computer and executes all necessary tasks to
  complete the requested process
  
• The CPU may use temporary memory (RAM) to store
  data during processing
  

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How Computers Work

• Or, if the data needs to be stored more
  permanently, the CPU may direct data to be placed
  on a storage media (disk)
  
• When processing is completed, the CPU moves data
  to the user as output
  
• This cycle is continuous as long as the machine
  is on

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How Computers Work - Hardware

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Input Devices

• Includes all devices used to put data or programs
  into the machine
  
• The most common devices are the keyboard and
  mouse
  
• Other input devices include alternative pointing
  devices such as track balls, joy stick or glide
  points

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Input Devices

• Scanners
• Convert printed copy or images into a digital
  version
  
• With Optical Character Recognition (OCR)
  software, scanned text can be saved as a word
  processing file
  
• Page scanner scan one page at a time
• Flat bed scanners can scan one page or multiple
  pages and can scan from a book

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Input Devices

• Digital Cameras
• Do not use film but instead capture images to a
  storage media
  
• May vary in resolution the higher the
  resolution the sharper the picture but also the
  larger the size of the file it creates
  
• Storage media vary from floppy disk to memory card

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Input Devices

• Digital Cameras
• Stored images are then downloaded to computer for
  viewing and editing
  
• Often come with small LCD screens on the back of
  the camera to preview images as you take
  pictures
  
• Digital photos can be used in any computer
  software or can be printed on photographic paper
  to create hard copy photos.
  

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Input Devices

• Graphics Tablets
• Use a stylus to draw on an electronic pad
• Pressure of the stylus on the pad is converted to
  images or commands
  
• Allow for greater control and can therefore be
  used for creating art work
  
• The digitizer, a graphics tablet adaptation, lets
  teachers add notations to a computer image

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Input Devices

• Sound Input Devices
• Personal microphones are a component of most
  multimedia computers
  
• Microphones plug into the sound card port on the
  back of the machine
  
• The microphone can be used to add commentary or
  record music to enhance a computer presentation
  or tutorial

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Input Devices

• Pen Input Devices
• Pen input is used with Personal Digital
  Assistants (PDAs)
  
• The stylus is pressed against the PDA screen to
  record commands or handwritten notes which can be
  later read as a word processing file
  
• The PDA can also provide management tools such as
  calendars and phone books

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Input Devices

• Touch Screens
• Computer monitor screens that are sensitive to
  touch
  
• Touch screens are best used to issue commands and
  make selections
  
• They can also be a useful assistive device for
  students with limited motor skills

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Input Devices

• Video / Digital Capture
• Video capture cards let you stop a video and
  capture single still images of each frame as a
  digital file
  
• Once digital, the sequence of images can be
  edited and used in sequence as a digital video or
  used singly as digital graphics

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Input Devices

• Electronic Whiteboards
• Like traditional whiteboards, dry erase markers
  can be used to write or draw on them
  
• Electronic whiteboards can then capture the
  writing or drawing and save it as a digital file
  
• Whiteboard files can then be printed or shared
  electronically

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Output Devices

• Includes all devices that move processed data
  from the computer to the user
  
• Monitors display data in the form of soft-copy
  output
  
• Monitors vary in the clarity (resolution) of
  their display as well as their size (measure
  diagonally across the screen)
  
• LCD monitors using a different display technology
  and offer flat, smaller hardware

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Output Devices

• Printers display data in hard-copy output
• Laser printers use heat to affix toner to paper
  to create clear, permanent images
  
• Most laser printers are black and white
• Inkjet printers blow small bubbles of ink on
  paper to create images
  
• Most Ink Jet printers print in color and black

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Output Devices

• Data Projection
• Data projectors display a room-size image of the
  computer screen to a large group
  
• LCD Projection Panel
• Sit on top of an overhead projector and are
  plugged into the computer
  
• Uses the overhead projectors light source for
  display so they are limited by the quality of the
  overhead

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Output Devices

• Data Projection
• Data Projector
• Uses LCD technology but has its own light source
• Can be fixed to the ceiling or used as a portable
  desktop unit
  
• Can usually display both digital (from computer)
  and video images (from VCR)
  
• Usually includes speakers and a remote control

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Output Devices

• Data Projection
• Converter
• Takes a digital computer signal and converts it
  for display on a television
  
• Very inexpensive compared to other digital
  display devices
  
• Resolution may not be as clear since most TV
  monitors to not have the display capacity of
  computer monitors

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Output Devices

• Speakers and Headphones
• Small speakers plug into the sound card port of a
  computer to play sound associated with software
  
• Most sound card ports also have a headphone port
  to accommodate the use of headphones
  
• To accommodate multiple headphones, a splitter is
  required

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Storage Devices

• Hard Disks
• Are typically permanently fixed inside the
  computer
  
• Offer the largest storage capacity of all disks
• When installing programs, most of the program is
  stored on the hard disk for quick access
  
• Hard disks can crash so it is important to
  backup data on removable media

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Storage Devices

• Floppy Disks
• Are portable storage with a limited capacity of
  1.44 megabytes
  
• Are usually used to store smaller files for back
  up or for transportability
  
• Like hard disks, can store both electronic files
  and the electronic folders that organize them

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Storage Devices

• Floppy Disks
• Are useful in the classroom when each student is
  given their own disk on which to store work
  
• Floppy disks may inadvertently transport viruses
  as well as files
  
• It is important to use a virus checker program to
  protect classroom machines from possible
  infection via floppy disks

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Storage Devices

• External Hard Disks
• Some hard disks are designed to be movable and
  can be connected to the computer through as USB
  interface
  
• Removable hard disks vary in capacity from 100
  megabytes to 1 gigabyte
  
• These disks are good for backup and classroom
  storage of files too large for floppy disk
  

The 21st Century Classroom Technology in
Teaching and Learning
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Storage Devices

• USB Flash Drives
• They are typically small, lightweight, removable
  and rewritable. Memory capacity typically ranges
  from 128 megabytes up to 64 gigabytes
  
• USB flash drives have several advantages over
  other portable storage devices, particularly the
  floppy disk.

The 21st Century Classroom Technology in
Teaching and Learning
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Storage Devices

• USB Flash Drives
• They are more compact, generally faster, hold
  more data, and are considered more reliable (due
  to their lack of moving parts) than floppy disks.
  These types of drives use the USB mass storage
  standard, supported natively by modern operating
  systems such as Linux, Mac OS X, and Windows.

The 21st Century Classroom Technology in
Teaching and Learning
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Storage Devices

• CD-ROM
• Compact Disks (CD) that are read only (ROM) can
  be used only to read programs
  
• CD-ROMs cannot be used to store files
• CD-ROMs use a laser technology to store
  approximately 600 megabytes of data
  
• These optical discs are typically used by
  software manufacturers to store programs for user
  installation

The 21st Century Classroom Technology in
Teaching and Learning
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Storage Devices

• CD-R
• Compact Disks (CD) that can be read many times
  AND recorded only ONCE are Recordables
  
• CD-Rs are useful to archive (back up) large
  amounts of data
  
• CD-Rs require a specially designed disc (CD-R
  disc) and drive to record data
  
• Once recorded, data can be read on a CD-ROM drive

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Storage Devices

• CD-RW
• Compact Disks that can be read and recorded on
  many times are Compact Disc-ReWriteable (CD-RWs)
  
• CD-RWs can be used like a portable hard disk with
  up to 600 megabytes of space
  
• CD-RWs require a specially designed disc (CD-RW
  disc) and drive to record data
  
• Once recorded, data can be read by most newer CD
  drives

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Storage Devices

• DVD
• Digital Versatile Discs are optical discs that
  can store up to 17 gigabytes of data
  
• DVDs are typically used to store digital video
  since video files require large amounts of
  storage space
  
• DVDs require a DVD drive, but DVD drives can also
  play back CD technology
  
• DVD-Rs, recordable DVDs, are an emerging
  technology just becoming available

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Emerging Technologies

• Wireless Devices
• Computers and handhelds can be connected to a
  network via wireless technology
  
• Wireless networks eliminate the cost of
  retrofitting a school for network cables
  
• Wireless networks improve flexibility by freeing
  computers from cables that tether them to walls -
  computers can be moved to wherever learning is
  happening

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Emerging Technologies

• Palmtop Computers
• PDAs are fast becoming palmtop computers with
  scaled-down versions of the same software found
  on desk top machines
  
• Newer palmtops are expandable via small expansion
  cards that can add to their capabilities
  
• PDAs often come with sound, microphone and color
  for multimedia programs
  

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Emerging Technologies

• E-Books
• Electronic books are tablets that display an
  electronic multimedia version of a book
  
• A single tablet can store many books which can be
  read and/or listened to by using simple
  navigational controls
  
• Ebooks can let you take notes as your read
• Some PDAs include e-book capability

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Emerging Technologies

• Voice Activated Devices
• Speaking to the computer to input data rather
  than typing or clicking is accomplished via voice
  activation software
  
• Voice input technology is already widely used as
  an assistive device
  
• Voice activation can make computing more flexible
  by freeing users from proximity to keyboard or
  mouse

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Emerging Technologies

• Virtual Environments
• Virtual reality software and hardware can be used
  to create 3-D environments
  
• VR worlds can be representations of aspects of
  the real world or completely imaginary
  
• VR worlds can let students take virtual
  fieldtrips to places otherwise inaccessible

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Conclusion

• Computer hardware makes it possible to enhance
  teaching and learning in many ways
  
• Computer software focuses the hardware on
  specific tasks appropriate to the classroom
  
• Teachers should review and evaluate both hardware
  and software carefully to ensure they have
  selected the best tools for teaching and
  learning

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Conclusion

• Teachers need to be sufficiently aware of
  computer hardware and software to use both
  effectively in their classroom
  
• While teachers need not be technical experts,
  they do need to know enough to
  
• Use the technology appropriately
• Handle minor computer problem
• Help students use computers
• Recognize when technical support is needed