1 Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

2 Technology in Action Chapter 2 Looking at Computers: Understanding the Parts Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

3 Chapter Topics Functions of a computer Data versus information Bits and bytes Input devices Output devices System unit Ergonomics Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

4 Major functions Gathers data (users input data) Processes data into information Outputs data or information Stores data and information Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

5 Data vs. Information Data: Representation of a fact, figure, or idea Information: Organized, meaningful data Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

6 Bits and Bytes Bit Binary digit 0 or 1 Byte 8 bits Each letter, number, and character = a string of eight 0s and 1s Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

7 How Much Is a Byte? Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

8 Computer Software Software: Programs that enable hardware to perform different tasks Application software System software Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

9 Computer Hardware Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

10 Input Devices Devices used to enter information or instructions into the computer Keyboard Mouse/ pointing device Stylus Scanner Digital camera Microphone Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

11 Keyboards The QWERTY layout is standard on most PCs. Enhanced keyboard features include number, function, and navigation keys. Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

12 Dvorak Keyboards Put the most commonly used keys on “home keys” Reduce the distance of finger stretches Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

13 Specialty Keyboards Notebook keyboard PDA stylus Tablet PCs Wireless keyboard Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

14 Mice Optical mouse Needs no mouse pad Doesn’t need cleaning Is more expensive Trackball Easier on wrists Stays stationary on desk Wireless Uses radio or light waves Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

15 New Mouse Features Instant viewer Magnifier Customizable buttons Web search Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

16 Other Input Devices Scanners Scanners Text Text Images Images Digital cameras Digital cameras Images Images Video Video Flatbed scanner Handheld scanner Digital camera Camcorder Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

17 Other Input Devices EPOS Digital Pen Webcam Live video Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

18 Inputting Sound Microphones are used for: Podcasts Video-conferencing Internet phone calls Speech recognition Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

19 Output Devices Send processed data out of the computer Monitors Printers Output devices make: Soft copies (video, sounds, control signals) Hard copies (print) Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

20 Monitor Types CRT (Cathode-Ray Tube) Less expensive Uses much more space Uses more energy Offers better viewing angles Legacy technology LCD (Liquid Crystal Display) More expensive Uses far less space More energy efficient Less viewable from an angle Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

21 How they work Screens are grids made up of millions of pixels. LCDs: Liquid crystal is sandwiched between two transparent layers to form images. CRTs: Pixels are illuminated by an electron beam that passes back and forth across the screen. Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

22 LCD Quality Factors Resolution Passive-matrix vs. active-matrix display Viewing angle Contrast ratio Brightness Response time Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

23 LCD vs. CRT LCD monitors: Take up less space Are generally brighter Cause less eyestrain Use less energy Emit less electromagnetic radiation Weigh less CRT monitors: Used to offer more resolutions Used to produce better color and clarity Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

24 Other Video Output Touch-screen monitors Double as both input and output devices Projectors Project a computer image to a large screen for sharing with large groups Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

25 Printers Impact printers Dot-matrix Nonimpact printers Inkjet Laser Specialty printers Multifunction Plotters Thermal printers Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

26 Nonimpact Printers Inkjet Less expensive device Print high-quality color images cost effectively Laser More expensive device Faster printing speed Less expensive per page in B&W Color lasers are becoming less expensive Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

27 Choosing a Printer Speed (ppm) Resolution (dpi) Color output Memory Use and cost Cost of consumables Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

28 Outputting Sound Speakers and headphones Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

29 The System Unit Box that contains the central electronic components of the computer : CPU/RAM/ motherboard Expansion cards Power supply Storage devices Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

30 The Front Panel Power control Drive bays Memory card reader Productivity ports Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

31 Power Controls Power-on button: Turns on system, should not be used to turn it off Other options: Sleep mode Hibernation Warm boot Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

32 Drive Bays Internal drive bays: Cannot be access from outside the system Are reserved for internal hard drives External drive bays: Can be accessed from outside the system CD or DVD drives Floppy and zip drives Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

33 Hard Disk Drive Permanent (nonvolatile) storage Internal or external versions Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

34 Flash Drives/Flash Memory Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall Flash drives (jump drives) Newer storage alternative Plug into USB ports Flash memory cards Slide into slots in the system

35 Storage Media Capabilities Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

36 On the Back Ports for peripherals Types of ports: Serial and parallel Audio and video USB FireWire Connectivity Ethernet Modem Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

37 Inside the System Unit Essential electronic components used to process data Types of components: Power supply Hard disk drive Motherboard CPU Expansion cards Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

38 The Motherboard CPU RAM Expansion cards and slots Built-in components Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

39 Central Processing Unit (CPU) Referred to as the “brains” of the computer Controls all functions of the computer Processes all commands and instructions Can perform billions of tasks per second Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

40 Memory Module Random access memory (RAM) Stores instructions and data Temporary (volatile) storage Operates in nanoseconds Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

41 Expansion Cards Add functions Provide new connections for peripheral devices Common types: Sound Modem Video (VGA) Network (NIC) Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

Specialty Computers Mainframes Supercomputers Embedded computers Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 42

43 Setting It All Up: Ergonomics Ergonomics: minimizing injury or discomfort while using the computer Steps to follow: Position monitor correctly. Use adjustable chair. Assume proper position while typing. Take breaks. Ensure adequate lighting. Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

Ergonomics and Mobile Devices Mobile devices present ergonomic challenges Ergonomic “Disease”Cause Blackberry thumbThumb typing without breaks or stretching can cause DeQuervains’ tendinitis in the thumbs. iPod deafnessListening through ear buds for prolonged periods at a volume of 80 decibels or more can cause deafness. Cellular blindnessExtended viewing on tiny screens can cause eye strain and/or dry eyes. Laptop thighsResting a laptop directly on your lap for extended periods of time can result in 1 st and 2 nd degree burns. Laptop shoulderLarge, heavy, one-strap laptop bags can result in neck, shoulder, and back pain and/or strain. Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 44

45 Chapter 2 Summary Questions What exactly is a computer, and what are its four main functions? What is the difference between data and information? What are bits and bytes, and how are they measured? What devices do you use to get data into the computer? Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

46 Continue… What devices do you use to get information out of the computer? What’s on the front of your system unit? What’s on the back of your system unit? What’s inside your system unit? How do you set up your computer to avoid strain and injury? Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

47 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Printed in the United States of America. Copyright © 2010 Pearson Education, Inc. Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall