Copyright 2010 Pearson Education Inc Publishing as Prentice
Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 1
Technology in Action Chapter 2 Looking at Computers: Understanding the Parts Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 2
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 3
Computers Are Data Processing Devices • A computer’s four 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 4
Data vs. Information • Data: Representation of a fact, figure, or idea • Information: Organized, meaningful data Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 5
Bits and Bytes: The Language of Computers • Bit – Binary digit – 0 or 1 • Byte – 8 bits • Each letter, number, and character = a string of eight 0 s and 1 s 0000 1111 Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 6
How Much Is a Byte? Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 7
Computer Software • Software: Programs that enable hardware to perform different tasks – Application software – System software Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 8
Computer Hardware Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 9
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 10
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 11
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 12
Specialty Keyboards • • Notebook keyboard PDA stylus Tablet PCs Wireless keyboard Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 13
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 14
New Mouse Features • Instant viewer • Magnifier • Customizable buttons • Web search Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 15
Other Input Devices • Scanners – Text – Images Flatbed scanner • Digital cameras Handheld scanner – Images – Video Digital camera Camcorder Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 16
Other Input Devices • EPOS Digital Pen • Webcam – Live video Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 17
Inputting Sound • Microphones are used for: – Podcasts – Videoconferencing – Internet phone calls – Speech recognition Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 18
Input Devices for the Physically Challenged • Visual impairments – Voice recognition – Keyboards with large keys – On-screen keyboards • Motor control issues – Special trackballs – Head-mounted devices 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 • LCD (Liquid Crystal Tube) Display) – – Less expensive Uses much more space Uses more energy Offers better viewing angles – Legacy technology Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall – – More expensive Uses far less space More energy efficient Less viewable from an angle 21
Key Monitor Features • 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 • Flash drives (jump drives) – Newer storage alternative – Plug into USB ports • Flash memory cards – Slide into slots in the system Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 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 – Fire. Wire – 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 42
Specialty Computers • Mainframes • Supercomputers • Embedded computers Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 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 44
Ergonomics and Mobile Devices Mobile devices present ergonomic challenges Ergonomic “Disease” Cause Blackberry thumb Thumb typing without breaks or stretching can cause De. Quervains’ tendinitis in the thumbs. i. Pod deafness Listening through ear buds for prolonged periods at a volume of 80 decibels or more can cause deafness. Cellular blindness Extended viewing on tiny screens can cause eye strain and/or dry eyes. Laptop thighs Resting a laptop directly on your lap for extended periods of time can result in 1 st and 2 nd degree burns. Laptop shoulder Large, 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 45
Chapter 2 Summary Questions • What exactly is a computer, and what are its four main functions? Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 46
Chapter 2 Summary Questions • What is the difference between data and information? Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 47
Chapter 2 Summary Questions • What are bits and bytes, and how are they measured? Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 48
Chapter 2 Summary Questions • What devices do you use to get data into the computer? Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 49
Chapter 2 Summary Questions • What devices do you use to get information out of the computer? Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 50
Chapter 2 Summary Questions • What’s on the front of your system unit? Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 51
Chapter 2 Summary Questions • What’s on the back of your system unit? Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 52
Chapter 2 Summary Questions • What’s inside your system unit? Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 53
Chapter 2 Summary Questions • How do you set up your computer to avoid strain and injury? Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 54
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. Publishing as Prentice Hall Chapter 2 55
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