COMP 6005 An Introduction to Computing Session Two: Computer Hardware Input and Output

COMP 6005 An Introduction to Computing - Session Two: Computer Hardware2 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 Hardware3 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 Hardware4 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 Hardware5 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 Hardware6 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 Hardware7 Other Pointing Devices Trackball Touchpad Pointing Stick Touch Screen Stylus and digital pen Cursor

COMP 6005 An Introduction to Computing - Session Two: Computer Hardware8 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 Hardware9 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 Hardware10 Discussion Looking Ahead 5-1, pg 241 Issue 5-3, pg 247

COMP 6005 An Introduction to Computing - Session Two: Computer Hardware11 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 Hardware12 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 Hardware13 Terminals Point-of-Sale terminals Automated Teller Machines Smart Displays

COMP 6005 An Introduction to Computing - Session Two: Computer Hardware14 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 Hardware15 Biometric Input Issue 5-5, pg s.htmhttp:// s.htm

COMP 6005 An Introduction to Computing - Session Two: Computer Hardware16 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 Hardware17 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 Hardware18 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 Hardware19 Output Users view output on: –Screens Via PDAs, monitors, notebooks, tablet PCs, smart phones Can view web sites, documents, videos, , 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 Hardware20 Output Four basic categories of output –Sound –Text –Graphics –Video

COMP 6005 An Introduction to Computing - Session Two: Computer Hardware21 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 Hardware22 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

COMP 6005 An Introduction to Computing - Session Two: Computer Hardware23 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 Hardware24 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 Hardware25 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 Hardware26 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 Hardware27 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 Hardware28 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 Hardware29 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 Hardware30 Assignment Read the Special Feature pg Read Chapter 7 for Class preparation

COMP 6005 An Introduction to Computing - Session Two: Computer Hardware31 Links Reference –Discovering Computers 2005 by Shelly, Cashman and Vermaat Of Interest – – –