comp 6005 an introduction to computing session two: computer hardware input and output
TRANSCRIPT
COMP 6005 An Introduction to ComputingSession Two: Computer HardwareInput and Output
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 2
Introduction
• Input – any data or instructions entered into the memory of a computer
• Output – data that has been processed into a useful form
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 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
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 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
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 5
Keyboards
• Issue 5-1, pg 232
• Describe the Dvorak keyboard and compare the differences between the commonly used QWERTY keyboard
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 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 mouse’s 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)
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 7
Other Pointing Devices
• Trackball
• Touchpad
• Pointing Stick
• Touch Screen
• Stylus and digital pen
• Cursor
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 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
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 9
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
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 10
Discussion
• Looking Ahead 5-1, pg 241
• Issue 5-3, pg 247
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 11
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
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 12
Other Input Devices
• Scanners– Optical– Optical readers
• Bar code reader
• (Magnetic-ink Character Recognition) MICR Reader
• Data collection devices
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 13
Terminals
• Point-of-Sale terminals
• Automated Teller Machines
• Smart Displays
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 14
Biometric Input
• Fingerprint scanner
• Face recognition system
• Hand geometry system
• Voice verification system
• Iris recognition system
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 15
Biometric Input
• Issue 5-5, pg 261
• http://www.ibiometrics.net/BioBasics.htm
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 16
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 user’s hand
• Head-mounted pointers can control the pointer or insertion point
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 17
Gesture Recognition
• Still in prototype stage
• Computer detects human motions
• Potential to recognize sign language, read lips, track facial movements, follow eye gazes
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 18
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
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 19
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
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 20
Output
• Four basic categories of output– Sound– Text– Graphics– Video
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 21
Display Devices
• Output device that shows text, graphics and video information
• Types of display devices– CRT monitor– Flat-panel display
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 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
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 23
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
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 24
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
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 25
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
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 26
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
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 27
Types of Printers
• Dot-matrix• Ink-Jet• Impact• Line• Nonimpact• Photo• Laser
• Thermal• Mobile• Label and
postage• Plotters and
large-format• Wireless
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 28
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
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 29
Discussion
• Issue 6-4, pg 314
• Issue 6-2, pg 299
• Issue 6-5, pg 319
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 30
Assignment
• Read the Special Feature pg 334-345
• Read Chapter 7 for Class preparation
COMP 6005 An Introduction to Computing - Session Two: Computer Hardware 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