COMP 6005 An Introduction to Computing

1
COMP 6005 An Introduction to Computing

• Session Two Computer Hardware
• Input and Output

2
Introduction

• Input any data or instructions entered into the
  memory of a computer
• Output data that has been processed into a
  useful form

3
Input

• Instructions can be in the form of
• Program series of instructions telling a
  computer what to do and how to do it
• Command an instruction that causes a particular
  program to perform a specific action
• User response an instruction given by a user by
  replying to a question displayed by a program

4
Input Devices

• Any hardware component that permits users to
  enter data or instructions into a computer
• Popular devices light pen, keyboard, mouse,
  stylus, microphone, digital camera, scanner

5
Keyboards

• Issue 5-1, pg 232
• Describe the Dvorak keyboard and compare the
  differences between the commonly used QWERTY
  keyboard

6
Mouse

• Types
• Mechanical
• Rubber or metal ball on its underside
• Electronic circuits translate movements into
  signals that computer can process
• Optical
• Uses devices that emit and sense light to detect
  the mouses movements
• Can be placed on nearly any surface (except
  glass)
• Cordless
• Battery-powered device that transmits data using
  wireless techonology (radio wave or infrared
  light waves)

7
Other Pointing Devices

• Trackball
• Touchpad
• Pointing Stick

• Touch Screen
• Stylus and digital pen
• Cursor

8
Assignment

• What is a cursor in reference to input devices?
  Describe and include an image
• Compare and contrast the display pen and the
  stylus
• Discuss voice recognition and its applications

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Voice and Audio Input

• Voice input
• Process of entering data by speaking into a
  microphone
• Audio input
• Process of entering any sound into the computer
  speech, music, sound effect
• Inputs via microphone, tape players, CD/DVD
  players, radios being plugged into a port on the
  sound card

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Discussion

• Looking Ahead 5-1, pg 241
• Issue 5-3, pg 247

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Video Input

• Process of capturing full-motion images into a
  computer and storing them on a storage medium
• Types
• Digital video cameras
• PC video cameras
• Web cams

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Other Input Devices

• Scanners
• Optical
• Optical readers
• Bar code reader
• (Magnetic-ink Character Recognition) MICR Reader
• Data collection devices

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Terminals

• Point-of-Sale terminals
• Automated Teller Machines
• Smart Displays

14
Biometric Input

• Fingerprint scanner
• Face recognition system
• Hand geometry system
• Voice verification system
• Iris recognition system

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Biometric Input

• Issue 5-5, pg 261
• http//www.ibiometrics.net/BioBasics.htm

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Input Devices For Differently-Abled Users

• Limited hand mobility persons use a keyguard to
  stop them from accidentally pressing keys
• On-screen keyboard
• Trackballs attached to a table, whhelchair or
  held in users hand
• Head-mounted pointers can control the pointer or
  insertion point

17
Gesture Recognition

• Still in prototype stage
• Computer detects human motions
• Potential to recognize sign language, read lips,
  track facial movements, follow eye gazes

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Implants

• Paralyzed or speech impaired individuals can have
  a doctor implant a computerized device into the
  brain
• As the user thinks thoughts, the transmitter will
  send signals to the computer
• Looking Ahead 5-2, pg 264

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Output

• Users view output on
• Screens
• Via PDAs, monitors, notebooks, tablet PCs, smart
  phones
• Can view web sites, documents, videos, email, etc
• Print it
• Can view photographs, black-and-white documents,
  coloured graphics
• Hear it through speakers or headset
• Can listen to music, sounds, voice messages

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Output

• Four basic categories of output
• Sound
• Text
• Graphics
• Video

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Display Devices

• Output device that shows text, graphics and video
  information
• Types of display devices
• CRT monitor
• Flat-panel display

22
CRT Monitors

• CRT stands for Cathode-ray tube (large, sealed
  glass tube)
• Originally curved screens modern day uses flat
  screens (more ergonomic)
• Produce a small amount of electromagnetic
  radiation
• Issue 6-1, pg 297
• http//www.webopedia.com/TERM/C/CRT.html

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Flat Panel Display

• Device with a shallow depth that does not use CRT
  technology
• Examples LCD monitors, LCD screens, gas plasma
  monitors, many HDTVs
• Uses liquid crystal display to produce images
• Uses less power than CRT and less space
• Used in Tablet PCs, notebooks, smart phones,
  PDAs, e-books
• Issue 6-2, pg 299

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Flat-panel Display vs Flat Display

• Flat-panel display refers to a display with a
  shallow depth and uses LCD, gas plasma or some
  other technology
• Flat display refers to a CRT monitor that has a
  flat screen

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Some Other Output Devices

• Printers
• Speakers and headsets
• Fax machines and fax modems
• Multifunction peripherals act as several
  different devices in one printer, fax machine,
  scanner, copier
• Projectors Looking Ahead 6-2, pg 317
• Force-feedback joysticks and wheels provides
  resistance to the user in response to actions
  taken

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Printers

• Device that produces text and graphics on a
  physical medium (paper, transparencies, etc)
• Figure 6-16, pg 303
• Looking Ahead 6-1, pg 303
• Issue 6-3, pg 306

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Types of Printers

• Dot-matrix
• Ink-Jet
• Impact
• Line
• Nonimpact
• Photo
• Laser

• Thermal
• Mobile
• Label and postage
• Plotters and large-format
• Wireless

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Output Devices For Differently-Abled Users

• Hearing-impaired users will have programs display
  words and no sound
• Visually-impaired users can increase size, change
  colour
• Blind users can work with voice output instead of
  using a monitor computer reads what is
  displayed
• An alternative for blind users is a Braille
  printer information outputted onto paper in
  Braille

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Discussion

• Issue 6-4, pg 314
• Issue 6-2, pg 299
• Issue 6-5, pg 319

30
Assignment

• Read the Special Feature pg 334-345
• Read Chapter 7 for Class preparation

31
Links

• Reference
• Discovering Computers 2005 by Shelly, Cashman and
  Vermaat
• Of Interest
• http//www.indigoimage.com/count/
• http//www.hp.com/large/ipg/mobileprint.html
• http//wearables.cs.bris.ac.uk/index.htm