1. © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Chapter 2A Input Devices

2. 2 2 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Learning Objectives 2.1Compare how to interact with an operating system using a graphical user interface and a command-line interface 2.2Summarize how to input information into a computer with a computer’s keyboard, mouse, and touch screen 2.3Describe other ways to input information into a computer 2.4Explain why and how computer users need to address the ergonomics of using a computer

3. 3 3 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. User Interfaces Operating system basicsOperating system basics Graphical user interfacesGraphical user interfaces Command-line interfacesCommand-line interfaces

4. 4 4 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Operating System Basics An operating system controls the system’s hardware and interacts with the user and application softwareAn operating system controls the system’s hardware and interacts with the user and application software It performs the following functions:It performs the following functions: –Displays the on-screen elements with which you interact— the user interface –Loads programs –Coordinates how programs work with the computer’s hardware and other software –Manages information storage and retrieval

5. 5 5 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Graphical User Interface Graphical user interface (GUI): Users launch programs and make choices with graphical objectsGraphical user interface (GUI): Users launch programs and make choices with graphical objects –Shortcuts - small pictures on the desktop which represent links to resources –Icons - pictures used to represent an object Elements on the Windows desktop:Elements on the Windows desktop: –Taskbar –Start button –Start menu –Quick Launch bar

6. 6 6 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Graphical User Interface When you right-click an object in Windows, a small menu usually appears called a shortcut menu or a context menuWhen you right-click an object in Windows, a small menu usually appears called a shortcut menu or a context menu The window currently in use is the active windowThe window currently in use is the active window Dialog boxes are windows that appear when the OS or application needs to give you status informationDialog boxes are windows that appear when the OS or application needs to give you status information Common GUI features of a windowCommon GUI features of a window –Title bar –Menu bar –Toolbars –Scroll bars

7. 7 7 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Command-line Interface The user enters typewritten commands rather than interacting with graphical objects to execute tasksThe user enters typewritten commands rather than interacting with graphical objects to execute tasks Users enter commands at a prompt on the screenUsers enter commands at a prompt on the screen –For example: in DOS, the prompt usually includes the identification for the active disk drive (a letter followed by a colon), a backslash (\), and a greater-than symbol (>), as in C:\>

8. 8 8 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Common Input Devices Input devices enable users to enter information and commandsInput devices enable users to enter information and commands Ports - connect input and output devices to the computer.Ports - connect input and output devices to the computer. –Many devices connect via USB ports Common input devices include:Common input devices include: –Keyboard –Mouse –Trackballs –Touchpads and pointing sticks –Touch screens

9. 9 9 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Keyboard The primary input device for entering text and numbersThe primary input device for entering text and numbers –Alphanumeric keys - Letters, numbers, the space bar, and the Tab, CapsLock, Backspace, and Enter keys –Modifier keys - Alt (Alternate), and Ctrl (Control) –Numeric keypad - A set of numbers, operation signs, and cursor movement keys –Function keys—Keys labeled F1, F2, etc. –Cursor-movement keys—Navigate the cursor around the screen

10. 10 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Mouse and Trackball Mouse - a pointing device that is widely used for entering data on a full-sized PCMouse - a pointing device that is widely used for entering data on a full-sized PC The pointer allows users to select the specific graphical objects they wish to activate or changeThe pointer allows users to select the specific graphical objects they wish to activate or change A mouse may be:A mouse may be: –mechanical - sensors read information from a rolling ball –optical - a sensor and image processor reads and interpret information from a beam of light Trackball – a pointing device in which you move the pointer by rolling a ballTrackball – a pointing device in which you move the pointer by rolling a ball

11. 11 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Using the Mouse Pointing is moving the pointer to a location on the screenPointing is moving the pointer to a location on the screen To click, press and release the button on the mouseTo click, press and release the button on the mouse –Double-clicking - pressing the primary mouse button twice –Right-clicking - pressing and releasing the non-primary button Dragging - pressing and holding the mouse button and continuing to hold it as you move the mouseDragging - pressing and holding the mouse button and continuing to hold it as you move the mouse Scrolling is moving a list of information up or down on the screenScrolling is moving a list of information up or down on the screen

12. 12 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Touchpads and Pointing Sticks Touchpad (or trackpad) – a pointing device operated by moving a finger across a small touch-sensitive surfaceTouchpad (or trackpad) – a pointing device operated by moving a finger across a small touch-sensitive surface A pointing stick is usually positioned near the middle of a portable computer’s keyboardA pointing stick is usually positioned near the middle of a portable computer’s keyboard –Generic terms include integrated pointing device and 3-D point stick

13. 13 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Touch Screens Accept input from a user’s fingertips directly on the computer screenAccept input from a user’s fingertips directly on the computer screen Computers and terminals with a single purpose use touch screens offering a menu of choicesComputers and terminals with a single purpose use touch screens offering a menu of choices Smart phones and tablet PCs have more sophisticated touch screensSmart phones and tablet PCs have more sophisticated touch screens

14. 14 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Inputting Data in Other Ways Devices for the handDevices for the hand Optical input devicesOptical input devices Audio input devicesAudio input devices Inputting musicInputting music Video input devicesVideo input devices Digital camerasDigital cameras

15. 15 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Devices for the Hand Pens are used for tablet PCs, PDAs, and other handheld computersPens are used for tablet PCs, PDAs, and other handheld computers Game controllers - input devices designed for a particular set of gamesGame controllers - input devices designed for a particular set of games –Game pads - small, flat devices designed to be held with both hands

16. 16 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Optical Input Devices Use light as a source of inputUse light as a source of input Bar code readers are scanners that read bar codesBar code readers are scanners that read bar codes –QR Codes are a new format for storing data visually Image scanners convert any printed image into electronic formImage scanners convert any printed image into electronic form –Text documents can be scanned with optical character recognition (OCR) software to translate the image into text Biometric scanners analyze physical patterns in humansBiometric scanners analyze physical patterns in humans

17. 17 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Audio and Visual Input Devices Audio Input Devices:Audio Input Devices: –Microphones are used to record speech –Speech recognition or voice recognition software translates spoken words into text Video Input Devices:Video Input Devices: –PC video cameras capture full-motion video images –A video capture card lets the user connect other video devices to the PC

18. 18 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Inputting Music Import files from CDs, MP3 players or tape playersImport files from CDs, MP3 players or tape players A built-in musical instrument digital interface (MIDI) port or MIDI adapter allows the connection of electronic instruments to your computerA built-in musical instrument digital interface (MIDI) port or MIDI adapter allows the connection of electronic instruments to your computer

19. 19 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Digital Cameras Digital cameras - portable, handheld devices that electronically capture still imagesDigital cameras - portable, handheld devices that electronically capture still images The images may be copied to a PC, where they may be edited, copied, printed, etc.The images may be copied to a PC, where they may be edited, copied, printed, etc. Most digital cameras can store dozens to hundreds of high-resolution imagesMost digital cameras can store dozens to hundreds of high-resolution images

20. 20 © 2013 by the McGraw-Hill Companies, Inc. All rights reserved. Ergonomics and Input Devices Ergonomics is the study of the physical relationship between people and their toolsErgonomics is the study of the physical relationship between people and their tools Repetitive stress injuries (RSIs) occur when repetitive, improper use of a muscle group leads to strain injuriesRepetitive stress injuries (RSIs) occur when repetitive, improper use of a muscle group leads to strain injuries –Carpal tunnel syndrome - a wrist or hand injury caused by using a keyboard for long stretches