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Using Information Technology. Chapter 6, pages from 219 to 253 Hardware--Input & Output. Hardware--Input & Output Taking Charge of Computing & Communications. 6.1 Input & Output 6.2 Input Hardware 6.3 Output Hardware 6.4 The Future of Input & Output
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Using Information Technology Chapter 6, pages from 219 to 253 Hardware--Input & Output
Hardware--Input & OutputTaking Charge of Computing & Communications • 6.1 Input & Output • 6.2 Input Hardware • 6.3 Output Hardware • 6.4 The Future of Input & Output • 6.5 Input & Output Technology & Quality of Life: Health & Ergonomics
6.1 Input & Output • Input hardware - devices that translate data into a form the computer can process • Output hardware - devices that translate information processed by the computer into a form that humans can understand
6.2 Input Hardware • Keyboard - a device that converts letters, numbers, and other characters into electrical signals that can be read by the computer’s processor • Traditional keyboards… Braille keyboard One-handed keyboard
Keyboards • Specialty keyboards and terminals: Dumb terminal Intelligent terminal Internet terminal Dumb terminal
Specialty keyboards and terminals: Dumb terminal Intelligent terminal Internet terminal Examples of intelligent terminals: Automatic teller machine (ATM) Point-of-sale (POS) terminal Keyboards
Keyboards • Specialty keyboards and terminals: • Dumb terminal • Intelligent terminal • Internet terminal: • Web terminal • Network computer • Online game player • PC/TV • PDA PDA (Internet terminal)
Pointing Devices • Pointing devices - control the position of the cursor or pointer on the screen • Mouse • Trackball • Pointing stick • Touchpad Mouse for right-handed user
Pointing Devices • The mouse and its variants: • Mouse • Trackball • Pointing stick • Touchpad Ergonomic trackball
Pointing Devices • The mouse and its variants: • Mouse • Trackball • Pointing stick Touchpad Pointing stick
Pointing Devices • The mouse and its variants: • Mouse • Trackball • Pointing stick • Touchpad Touch pad
Pointing Devices • Touch screen - a video display screen that has been sensitized to receive input from the touch of a finger Touch screen
Pointing Devices • Pen input: • Pen-based computer system - allows users to enter handwriting and marks onto a computer screen by means of a penlike stylus rather than by typing on a keyboard Touch screen
Pointing Devices • Pen input: • Light pen - a light-sensitive penlike device connected by a wire to the computer terminal
Pointing Devices • Pen input: • Digitizer - converts drawings and photos to digital data using a mouselike device called a puck • Digitizing tablet - electronic plastic board on which each specific location corresponds to a location on the screen Digitizing tablet
Source Data-Entry Devices • Scanning devices - imaging systems: • Scanners - devices that use light-sensing equipment to translate images of text, drawings, photos, and the like into digital form
Source Data-Entry Devices • Scanning devices - bar-code readers: • Bar codes - vertical zebra-striped marks you see on most manufactured retail products • Bar-code readers - optical scanners that translate the symbols in the bar code into digital code
Source Data-Entry Devices • Scanning devices - mark- and character-recognition: • MICR - Magnetic-ink character recognition. Reads the strange-looking numbers printed at the bottom of checks • OMR • OCR
Source Data-Entry Devices • Scanning devices - mark- and character-recognition: • MICR • OMR - Optical mark recognition. Uses a device that reads pencil marks and converts them into computer-usable form • OCR
Source Data-Entry Devices • Scanning devices - mark- and character-recognition: • MICR • OMR • OCR - Optical character recognition. Uses a device that reads preprinted characters in a particular font and converts them to digital code
Source Data-Entry Devices • Scanning devices - fax machines… • Types of fax machines: • Dedicated fax machine • Fax modem Dedicated fax machine
Source Data-Entry Devices • Scanning devices - fax machines… • Types of fax machines: • Dedicated fax machine • Fax modem Fax modem
Audio-input devices Webcams and video-input cards Digital cameras Voice-recognition systems Record analog sound and translate it for digital storage and processing Require either an audio board or a MIDI board Other Source Data-Entry Devices
Other Source Data-Entry Devices • Audio-input devices • Webcams and video-input cards • Digital cameras • Voice-recognition systems
Other Source Data-Entry Devices • Audio-input devices • Webcams and video-input cards • Digital cameras • Voice-recognition systems
Other Source Data-Entry Devices • Audio-input devices • Webcams and video-input cards • Digital cameras • Voice-recognition systems
More Source Data-Entry Devices • Sensors • Radio-frequency identification • Human-biology input devices
More Source Data-Entry Devices • Sensors • Radio-frequency identification • Human-biology input devices
More Source Data-Entry Devices • Sensors • Radio-frequency identification • Human-biology input devices (biometrics)
6.3 Output Hardware • Softcopy - data that is shown on a display screen or is in audio or voice form • Hardcopy - printed output
Softcopy Output: Display Screens • Display screens - output devices that show programming instructions and data as they are being input and information after it is processed
Softcopy Output: Display Screens • Screen clarity… • Pixel (picture element) - the smallest unit on the screen that can be turned on and off or made different shades
Softcopy Output: Display Screens • Screen clarity… • Dot pitch (dp) - the amount of space between the centers of adjacent pixels; the closer the dots, the crisper the image
Screen clarity… Resolution - the image sharpness of a display screen; the more pixels there are per square inch, the finer the level of detail Standard resolutions (horizontal x vertical) 640 x 480 800 x 600 1024 x 768 1280 x 1024 1600 x 1200 1920 x 1440 Softcopy Output: Display Screens
Softcopy Output: Display Screens • Screen clarity… • Refresh rate - the number of times per second that the pixels are recharged so that their glow remains bright • The higher the refresh rate, the more solid the image looks (less flicker).
Softcopy Output: Display Screens • Two types of monitors: • CRT - a vacuum tube used as a display screen in a computer or video display terminal • Flat-panel display
Softcopy Output: Display Screens • Two types of monitors: • CRT • Flat-panel display - made up of two plates of glass separated by a layer of a substance in which light is manipulated
Softcopy Output: Display Screens • Active-matrix versus passive-matrix flat-panel displays… • Active-matrix - each pixel on the screen is controlled by its own transistor • Passive-matrix - a transistor controls a whole row or column of pixels
Softcopy Output: Display Screens • Color & resolution standards: • SVGA • XGA • SXGA • UXGA
Hardcopy Output: Printers • Printer - an output device that prints characters, symbols, and perhaps graphics on paper or another hardcopy medium • Dpi (dots per inch) - resolution measure for printers. Specifies the number of dots that are printed in a linear inch
Hardcopy Output: Printers • Impact printer - forms characters or images by striking a mechanism such as a print hammer or wheel against an inked ribbon, leaving an image on paper • Non-impact printer - forms characters and images without direct physical contact between the printing mechanism and paper
Hardcopy Output: Printers • Nonimpact printers: • Laser printer - creates images on a drum which are treated with a magnetically charged toner, and then transferred from drum to paper Replacing a laser toner cartridge
Nonimpact printers: Ink-jet printers - spray small, electrically charged droplets of ink from four nozzles through holes in a matrix at high speed onto paper Thermal printers - use colored waxes and heat to produce images by burning dots onto special paper Hardcopy Output: Printers
Hardcopy Output: Printers • Plotter - a specialized output device designed to produce high-quality graphics in a variety of colors
Hardcopy Output: Printers • Multifunction printer - output device that combines several capabilities, such as printing, scanning, copying, and faxing
Other Output • Sound output - devices which produce digitized sounds, ranging from beeps and chirps to music • Voice output - devices which convert digital data into speech-like sounds • Video output - photographic images which are played at 15-29 frames per second to give the appearance of full motion
6.4 The Future of Input & Output • More input devices in remote locations • More refinements in source data automation • More output in remote locations • Increasingly realistic--even lifelike--forms of output
Toward More Source Data Automation • More refinements in source data automation: High-capacity bar codes 3-D scanners More sophisticated touch devices Smarter smart cards More sensors
Toward More Source Data Automation • More refinements in source data automation: • Better voice recognition Smaller electronic cameras Pattern-recognition & biometric devices Brainwave devices Computer-read emotions
Toward More Output in Remote Locations • Electronic news tablet - a textbook-sized device for downloading a newspaper and then carrying around to read