Interacting with computer (Input devices) Chapter 3 Interacting with computer (Input devices)

Using the Keyboard And Mouse Standard keyboard layout The Mouse Variants of the Mouse Ergonomics and Input Devices

1. The standard keyboard Layout The Alphanumeric keys (a, b, c,…) The Modifier keys (Shift, Ctrl, Alt) The Numeric keypad (1, 2, 3, …) The Function Keys (F1, F2, F3,…) The Cursor-Movement keys Special-Purpose Key (Delete, Esc, …)

Allows users to select objects Mechanical mouse 2. The Mouse Allows users to select objects Pointer moved by the mouse Mechanical mouse Rubber ball determines direction and speed The ball often requires cleaning Optical mouse Wireless Mouse

Mouse button configuration 2. The Mouse Mouse button configuration Configured for a right-handed user Can be reconfigured

Variants of the Mouse Trackballs Upside down mouse Hand rests on the ball User moves the ball Uses little desk space

Variants of the Mouse Trackpad Finger moves across the pad Popular on laptops

Variants of the Mouse TrackPoint Little joystick on the keyboard Move pointer by moving the joystick Insider information The term track point is copyrighted by IBM.

Ergonomics and Input Devices The study of the physical relationship between people and their tools Study of human and tool interaction Attempts to improve safety and comfort

Ergonomics and Input Devices Repetitive Strain Injury (RSI) Caused by continuous misuse of the body Many professions suffer from RSI E.g. carpal tunnel syndrome – a wrist or hand injury caused by using a keyboard for long periods of time Teaching tip Hairstylists often suffer from carpal tunnel. Bicyclists can suffer from overuse injuries of the knee. Page 116 of the text has a diagram of the carpal tunnel.

Ergonomics and Input Devices Office hardware suggestions Office chairs should have Adjustable armrests and height Lower back support Desks should have Have a keyboard tray Keep hands at keyboard height Place the monitor at eye level (Page 117)

Ergonomics and Input Devices Techniques to avoid RSI Sit up straight Have a padded wrist support Keep your arms straight Keyboard properly Take frequent breaks

Inputting Data In Other Ways Devices for the Hand Pen/Stylus, Touch Screens, Game Controllers Optical Input Device Bar code readers, Image scanners, OCR Audiovisual Input Devices Microphones, MIDI, Digital cameras

1. Devices for the Hand Pen (Stylus) based input Tablet PCs, PDA Pen used to write data Pen used as a pointer Teaching tip Microsoft has a demonstration of the tablet PC pen based input. Point your browser to http://www.microsoft.com/windowsxp/tabletpc/evaluation/tours/default.mspx and follow the tours.

1. Devices for the Hand Touch screens Use sensors to determine where finger points E.g. fast-food restaurants, supermarket … Discussion point Discuss the information kiosks at local malls. Many offer limited Internet access. Have students discuss what could happen to the computers if the malls were to provide keyboards to the mall shoppers.

1. Devices for the Hand Game controllers Enhances gaming experience Fall into two broad categories Joystick Game pad Teaching tip Microsoft’s Force Feedback joysticks vibrate. In driving games, when the player hits another car, the joystick will vibrate.

Allows the computer to see input Barcode readers 2. Optical Input Devices Allows the computer to see input Barcode readers Converts bar codes to numbers Works by reflecting light Scanners Converts printed media into electronic Insider information For more information on the UPC code and a searchable database, visit http://www.upcdatabase.com/. A working UPC is 071662000240, which represents a 24 count box of Crayola Crayons.

Optical character recognition (OCR) 2. Optical Input Devices Optical character recognition (OCR) Converts scanned text into editable text Each letter is scanned and compared to known letters Best match is entered into document Rarely 100% accurate Teaching tip Many companies ask for a plaintext resume. This is a resume, typed in Courier or other easy to read font, with no formatting. The intent is to allow the company to scan the resume for future searching. OCR technology makes this possible. For more information, see the website http://www.quintcareers.com/scannable_resumes.html.

3. Audiovisual Input Devices Microphones Used to record speech Speech recognition “Understands” human speech Allows dictation or control of computer Insider information Two common products are IBM’s Via Voice and Scansoft Dragon NaturallySpeaking. More information for ViaVoice can be found at http://www-306.ibm.com/software/voice/viavoice/. More information regarding Dragon is located at http://www.scansoft.com/naturallyspeaking/.

3. Audiovisual Input Devices Musical Instrument Digital Interface (MIDI) Connects musical instruments to computer Digital recording or playback of music Musicians can produce professional results

Audiovisual Input Devices Digital cameras Captures images electronically Image is stored as a JPG file

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