Phnom Penh International University Quality Excellence Innovation Computer

ស កលវទយ លយភនព ញអនតរជ ត Phnom Penh International University Quality Excellence Innovation Computer Literacy 2011 -2012 1

Chapter 3 Classification of Computer: Purpose Type and Capacity 2

Objectives 3 After this chapter, students would be able to: • Advantages and Disadvantages of Computers • Purpose of Computer Classification • Type of Computers • Capacity of Computers • Input Devices • Output Devices • Input and Output Devices (Multi Functions Devices)

Chapter 3 Classification Advantages and Disadvantages of Using Computers Advantages of Using Computers Disadvantages of Using Computers Speed Health Risks Reliability Violation of Privacy Consistency Public Safety Storage Impact on Labor Force Communications Impact on Environment 4

Advantages and Disadvantages of Using Computers Green computing involves reducing the electricity consumed and environmental waste generated when using a computer Strategies include: Recycling Regulating manufacturing processes Extending the life of computers Immediately donating or properly disposing of replaced computers 5

Chapter 3 Cont’… A computer contains many electric, electronic, and mechanical components known as hardware Input Device • Allows you to enter data and instructions into a computer Output Device • Hardware component that conveys information to one or more people System Unit • Case that contains the electronic components of the computer that are used to process data Storage Device Communications Device • Holds data, instructions, and information for future use • Enables a computer to send and receive data, instructions, and information to and from one or more computers or mobile devices 6

Categories of Computers Personal computers Mobile computers and mobile devices Game consoles Servers Mainframes Supercomputers Embedded computers 7

Personal Computers A personal computer can perform all of its input, processing, output, and storage activities by itself Two popular architectures are the PC and the Apple Desktop computer 8

Mobile Computers and Mobile Devices Mobile Compute r Mobile Device Personal computer you can carry from place to place Computing device small enough to hold in your hand Examples include notebook computers, laptop computers, and Tablet PCs Examples include smart phones, PDAs, handheld computers, portable media players, and digital cameras 9

Mobile Computers and Mobile Devices Notebook computer Tablet PC Smart phone PDA 10

Mobile Computers and Mobile Devices Handheld computer Portable media player Digital camera 11

Game Consoles A game console is a mobile computing device designed for single -player or multiplayer video games 12

Servers A server controls access to the hardware, software, and other resources on a network Provides a centralized storage area for programs, data, and information 13

Mainframes A mainframe is a large, expensive, powerful computer that can handle hundreds or thousands of connected users simultaneously 14

Supercomputers A supercomputer is the fastest, most powerful computer Fastest supercomputers are capable of processing more than one quadrillion instructions in a single second 15

Embedded Computers An embedded computer is a special-purpose computer that functions as a component in a larger product • • • Consumer Electronics Mobile and digital telephones Digital televisions Cameras Video recorders DVD players and recorders Answering machines • • • Home Automation Devices Thermostats Sprinkling systems Security monitoring systems Appliances Lights Automobiles • Antilock brakes • Engine control modules • Airbag controller • Cruise control Process Controllers and Robotics • Remote monitoring systems • Power monitors • Machine controllers • Medical devices Computer Devices and Office Machines • • Keyboards Printers Faxes Copiers 16

Embedded Computers 17

Input Devices Input is any data and instructions entered into the memory of a computer 18

What Is Input? Instructions can be entered into the computer in the form of programs, commands, and user responses A program is a series of related instructions that tells a computer what tasks to perform and how to perform them Programs respond to commands that a user issues A user response is an instruction a user issues by replying to a question displayed by a program 19

What Are Input Devices An input device is any hardware component that allows users to enter data and instructions into a computer 20

The Keyboard A keyboard is an input device that contains keys users press to enter data and instructions into a computer 21

The Keyboard Most desktop computer keyboards have… A numeric Function keys, Between 101 keypad on the CTRL keys, and 105 keys right side of the ALT keys, and keyboard arrow keys WINDOWS key APPLICATION key Toggle keys 22

The Keyboard The insertion point, also known as the cursor, is a symbol on the screen that indicates where the next character you type will appear 23

The Keyboard Wired Keyboards Wireless Keyboards USB port Bluetooth Keyboard port Ir. DA 24

The Keyboard An ergonomic keyboard has a design that reduces the chance of wrist and hand injuries Ergonomics incorporates comfort, efficiency, and safety into the design of the workplace 25

The Keyboards on mobile devices typically are smaller and/or have fewer keys Some phones have predictive text input, which saves time when entering text using the phone’s keypad 26

Pointing Devices A pointing device is an input device that allows a user to control a pointer on the screen A pointer is a small symbol on the screen whose location and shape change as a user moves a pointing device 27

Mouse A mouse is a pointing device that fits under the palm of your hand comfortably Most widely used pointing device on desktop computers A mouse can be wired or wireless 28

Mouse operations Point Click Right-click Double-click Triple-click Drag Right-drag Rotate wheel Free-spin wheel Press wheel Tilt wheel Press thumb button 29

• A touchpad is a small, flat, rectangular pointing device that is sensitive to pressure and motion Pointing Stick • A trackball is a stationary pointing device with a ball on its top or side Touchpad Trackball Other Pointing Devices • A pointing stick is a pressuresensitive pointing device shaped like a pencil eraser that is positioned between keys on a 30

Touch Screens and Touch-Sensitive Pads A touch screen is a touch-sensitive display device 31

Touch Screens and Touch-Sensitive Pads Microsoft Surface Touch-sensitive pads 32

Pen Input With pen input, you touch a stylus or digital pen on a flat surface to write, draw, or make selections 33

Other Input for Smart Phones 34

Game Controllers Video games and computer games use a game controller as the input device that directs movements and actions of on-screen objects Gamepads Joysticks and Wheels Dance pads Light guns Motionsensing controllers 35

Game Controllers 36

Digital Cameras A digital camera is a mobile device that allows users to take pictures and store them digitally Studio cameras Field cameras Point-and-shoot camera 37

Digital Cameras 38

Digital Cameras Two factors affect the quality of digital camera photos: Resolution Number of bits stored in each pixel • Resolution is the number of horizontal and vertical pictures in a display device • A pixel is the smallest element in an electronic display • Each pixel consists of one or more bits of data • The more bits used to represent a pixel, the more colors and shades of gray that can be represented 39

Voice Input Voice input is the process of entering input by speaking into a microphone Voice recognition is the computer’s capability of distinguishing spoken words 40

Voice Input Audio input is the process of entering any sound into the computer Speech Music Sound Effects 41

Voice Input Music production software allows users to record, compose, mix, and edit music and sounds 42

Video Input Video input is the process of capturing full-motion images and storing them on a computer’s storage medium Record video on a digital video (DV) camera or use a video capture card to convert analog signals to digital Connect the camera to a port on the system unit Transfer video and images 43

Video Input 44

Video Input A Web cam is a type of digital video camera that enables a user to: Capture video and still images Send e-mail messages with video attachments Broadcast live images over the Internet Add live images to instant messages Make video telephone calls 45

Video Input A video conference is a meeting between two or more geographically separated people 46

Scanners and Reading Devices Flatbed Pen or Handheld Sheet-fed Drum 47

Scanners and Reading Devices 48

Scanners and Reading Devices Optical character recognition (OCR) involves reading characters from ordinary documents A turnaround document is a document you return to the company that creates and sends it 49

Scanners and Reading Devices Optical mark recognition (OMR) reads hand-drawn marks such as small circles or rectangles An OMR device scans the documents and matches the patterns of light 50

Scanners and Reading Devices A bar code reader, also called a bar code scanner uses laser beams to read bar codes 51

Scanners and Reading Devices RFID (radio frequency identification) uses radio signals to communicate with a tag placed in or attached to an object An RFID reader reads information on the tag via radio waves RFID can track: Inventory Location of soldiers Gauging tire pressure and temperature Employee wardrobes Library books Airline baggage Prepaid tolls 52

Scanners and Reading Devices Magnetic stripe card readers read the magnetic stripe on the back of cards such as: Credit cards Entertainment cards Bank cards Other similar cards 53

Scanners and Reading Devices MICR (magnetic ink character recognition) devices read text printed with magnetized ink An MICR reader converts MICR characters into a form the computer can process Banking industry uses MICR for check processing 54

Scanners and Reading Devices Data collection devices obtain data directly at the location where the transaction or event takes place Used in: Restaurants Grocery stores Factories Warehouses The outdoors 55

Biometric Input Biometrics authenticates a person’s identity by verifying a personal characteristic Fingerprint reader Face recognition system Signature verification system Hand geometry system Iris recognition system Voice verification system Retinal scanners 56

Biometric Input hand geometry system iris recognition system fingerprint reader 57

Terminals A terminal is a computer that allows users to send data to and/or receive information from a host computer A POS terminal records purchases, processes payment, and updates inventory An automated teller machine (ATM) allows users to access their bank accounts A DVD kiosk is a self-service DVD rental machine 58

Input Devices for Physically Challenged Users Several input devices are available to assist physically challenged users: Keyguard Keyboards with larger keys Headmounted pointer On-screen keyboard Gesture recognition Various pointing devices Computerized implant devices 59

Input Devices for Physically Challenged Users Keyboard with larger keys Head-mounted pointer 60

Output Devices Output is data that has been processed into a useful form 61

What Is Output? An output device is any type of hardware component that conveys information to one or more people Display devices Printers Interactive whiteboards Speakers, headphones, and ear buds Forcefeedback game controllers Data projectors Tactile output 62

Display Devices A display device visually conveys text, graphics, and video information A monitor is packaged as a separate peripheral LCD monitor Widescreen 63

Display Devices Liquid crystal display (LCD) uses a liquid compound to present information on a display device Active-matrix display Passive-matrix display 64

Display Devices The quality of an LCD monitor or LCD screen depends primarily on: Resolution Response time Dot pitch Brightness Contrast ratio 65

Display Devices Resolution is the number of horizontal and vertical pixels in a display device A higher resolution uses a greater number of pixels 66

Display Devices The graphics processing unit (GPU) controls the manipulation and display of graphics on a display device LCD monitors use a digital signal and should plug into a DVI port, and HDMI port, or a Display. Port 67

Display Devices Plasma monitors are display devices that use gas plasma technology and offer screen sizes up to 150 inches 68

Display Devices Televisions also are a good output device Require a converter if you are connecting your computer to an analog television Digital television (DTV) offers a crisper, higherquality output HDTV is the most advanced form of digital television 69

Display Devices A CRT monitor is a desktop monitor that contains a cathode- ray tube Have a much larger footprint than do LCD monitors 70

Printers A printer produces text and graphics on a physical medium Printed information is called a hard copy, or printout Landscape or portrait orientation 71

Printers 72

Printers A nonimpact printer forms characters and graphics on a piece of paper without actually striking the paper Ink-jet printers Photo printers Mobile printers Label and postage printers Laser printers Thermal printers Plotters Largeformat printers 73

Printers An ink-jet printer forms characters and graphics by spraying tiny drops of liquid ink onto a piece of paper Color or black-and-white Printers with a higher dpi (dots per inch) produce a higher quality output 74

Printers 75

Printers A photo printer produces color photo-lab-quality pictures • Most use ink-jet technology • Pict. Bridge allows you to print photos directly from a digital camera • Print from a memory card and preview photos on a built-in LCD screen 76

Printers 77

Printers Highspeed Blackandwhite Laser printer Highquality Color 78

Printers 79

Printers A multifunction peripheral (MFP) is a single device that prints, scans, copies, and in some cases, faxes Sometimes called an all-in-one device 80

Printers A thermal printer generates images by pushing electrically heated pins against the heat-sensitive paper Thermal wax-transfer printer Dye-sublimation printer 81

Printers A mobile printer is a small, lightweight, battery-powered printer that allows a mobile user to print from a mobile device 82

Printers A label printer is a small printer that prints on adhesive-type material A postage printer prints postage stamps Postage also can be printed on other types of printers 83

Printers Plotters are used to produce high-quality drawings Large-format printers create photo-realistic quality color prints on a larger scale 84

Printers Impact printers form characters and graphics on a piece of paper by striking a mechanism against an inked ribbon that physically contacts the paper Dot-matrix printer Line printer 85

Printers A dot-matrix printer produces printed images when tiny wire pins on a print head mechanism strike an inked ribbon A line printer prints an entire line at a time 86

Speakers, Headphones, and Ear buds An audio output device produces music, speech, or other sounds Most computer users attach speakers to their computers to: • Generate higher-quality sounds for playing games • Interact with multimedia presentations • Listen to music • View movies 87

Speakers, Headphones, and Ear buds Headphones are speakers that cover your head or are placed outside of the ear Earbuds (also called earphones) rest inside the ear canal 88

Speakers, Headphones, and Ear buds Some speakers are specifically designed to play audio from a portable media player Wireless speakers 89

Speakers, Headphones, and Ear buds Voice output occurs when you hear a person’s voice or when the computer talks to you through the speakers • Some Web sites dedicate themselves to providing voice output • Often works with voice input • Vo. IP uses voice output and voice input 90

Other Output Devices Other output devices are available for specific uses and applications Data projectors Interactive whiteboards Force-feedback game controllers Tactile output 91

Other Output Devices A data projector is a device that takes the text and images displaying on a computer screen and projects them on a larger screen Digital light processing (DLP) projector 92

Other Output Devices An interactive whiteboard is a touch-sensitive device, resembling a dry-erase board, that displays the image on a connected computer screen 93

Other Output Devices Force-feedback sends resistance to the device in response to actions of the user Tactile output provides the user with a physical response from the device 94

Output Devices for Physically Challenged Users Many accessibility options exist for users with various disabilities 95