7 INPUT AND OUTPUT CHAPTER Information and data gets in and out of a computer through input and output devices These devices are translators Competent end users need to know about the common input and output devices

Competencies Define input Describe keyboard entry, pointing devices, & scanning devices Discuss image capturing devices, digitizing devices, & audio input devices

Competencies cont. Define output Describe monitors, printers, and audio output devices Discuss combination input & output devices

What is Input? Any data or instructions used by a computer Input devices Hardware Keyboards Mice Scanners Other devices Translates data into a form that the system unit can process Input devices are hardware used to translate words, sounds, images, and actions that people understand into a form that the computer can understand Input allows user to put their information into computer language Most common are keyboard, mouse, “light” pens, and increasingly voice!

Keyboard Entry Keyboards Traditional keyboards Features Flexible keyboards Ergonomic keyboards Wireless keyboards PDA keyboards Features Typewriter keyboard with numeric pad Special purpose keys Toggle and combination keys Keyboards come in a variety of designs Range from full-sized to miniature and from rigid to flexible Common types Traditional Flexible – fold or roll up fore easy packing or storage Ergonomic keyboards – similar to traditional Keyboard arrangement is not rectangular and a palm rest is provided Wireless PDA - miniature keyboards

Traditional Keyboard Features Numeric key pad – used to enter numbers and arithmetic symbols Toggle keys Cap Locks Combination keys – perform an action when used with other keys CTRL key

Pointing Devices Mouse Joystick Touch Screen Light Pen Mechanical Optical Cordless or wireless Joystick Touch Screen Light Pen Direct entry creates machine-readable data that can go directly to the CPU. Pointing devices mouse, joystick, touch screen, light pen and stylus Mouse Mechanical – traditional type Optical – has no moving parts Emits and senses light to detect mouse movement Can be used on any surface Cordless – battery powered Uses radio waves or infrared light waves Joystick – input for computer games Touch Screen – a kind of monitor with a clear plastic outer layer Easy to use Commonly used at restaurants, ATMs, and information centers Light pen – a light sensitive pen-like device

Scanning Devices Optical scanners Bar code readers Flatbed Portable Handheld wand readers or platform scanners Contain photoelectric cells that read bar codes Scanners move across text and images Devices convert scanned data into a form the system unit can process Types Optical – known as a scanner Recognizes light, dark, and colored areas that make up individual letters or images Flatbed Portable Bar Code Readers You see these devices at the grocery store Wand scanner or platform scanner Reads bar codes or vertical zebra striped marks printed on product containers Products have a UPC (Universal Product Code)

Scanning Devices Character and mark recognition devices Scanners that recognize special characters & marks Magnetic ink character recognition (MICR) Optical-character recognition (OCR) Optical-mark recognition (OMR) Character and mark recognition devices MICR - used by banks to read magnetically encoded characters OCR - specially preprinted characters are read by OCR devices such as wand scanners OMR - devices sense the presence or absence of marks, common for test scoring

Image Capturing Devices Digital camera Images recorded digitally on a disk Images can be downloaded to a computer Digital video camera Records motion digitally Can take still images as well WebCams Specialized digital video cameras Broadcast images over the Internet These devices create or capture original images Digital camera – images downloaded to a computer Digital video camera – records motion digitally on a disk Can take still photos as well

Digitizing Devices Graphics Tablets Digital Notepads Graphics tablets record sketches and tracings of maps and other drawings Used by artist, mapmakers, and engineers Digital notepads record handwritten notes and drawings Similar to table PCs except that they typically use regular notepads and pens Notepad is positioned on top of an electronic pad or tablet Notes can later be processed, edited, and used with a word processing program

Audio Input Devices Voice Voice recognition systems Music Discrete-speech recognition systems Continuous-speech recognition system Music Musical Interface Digital Interface (MIDI) Convert speech into digital code; most common device is the microphone Voice recognition systems Microphone, bundled with sound card and software Some voice recognition systems must be trained for user’s voice Some can translate from one language to another Types Continuous speech - used to issue commands to special application programs Two well known systems Naturally-Speaking from Dragon Systems ViaVoice from IBM Discrete-word – able to recognize individual words based on their sound Cannot distinguish between same-sound words such as there, their MIDI – standard that allows musical instruments to connect to the system unit using MIDI ports

What is Output? Processed data or information Types of output Text Graphics Audio & video Output devices Monitors Printers Converts machine-readable information into people-readable form Four most common output devices used with microcomputers – text, graphics, audio, and video Monitors are commonly called display screens

Monitors Known as screens or display screens Output referred to as soft copy Features Resolution Dot pitch Refresh rate Size Standards indicate screen quality (resolution). Some monitors are used on the desktop, others are portable. Features Resolution – expressed as a series of dots or pixels Dot pitch – the distance between each pixel Refresh rate – indicates how often a displayed image is updated or redrawn on the monitor Size – is measured by the diagonal length of a monitor’s viewing area Common sizes are 15, 17, 19, and 21 inches

More on Monitors Cathode-ray tube or CRTs Flat-panel Other monitors Liquid crystal display (LCD) Portable and thinner than CRTs Other monitors E-books Data projectors High-definition television (HDTV) Cathode-Ray Tubes - similar to television technology Flat-Panel Monitors - or liquid display (LCD) monitors Passive-matrix or dual-scan - images created by scanning the entire screen Active-matrix - each pixel is individually activated eBook – hand-held, book sized; cost less than publishing and delivery of printed matter Data projectors – similar to slide projectors; extension of monitor HDTV – merger of microcomputer and TV; not taking off as much as developers had hoped; what is cost? What is availability? How many in classroom are participating?

Printers Translates information that has been processed by the system unit Output referred to as hard copy Features Resolution Color capability Speed Memory Printers translate information that has been processed by the system unit and present the information on paper Output is called hard copy Features Resolution – measures the clarity of images produced Measured in dpi (dots per inch) Most printers use an average of 1200 dpi Color – more expensive to print in color Speed – measured in the number of pages printed per minute 10-15 pages per minute is the average for a single color page; 5 to 10 pages per minute for color Memory – used to store printing instructions and documents waiting to be printed

Printers Ink-jet printer Laser printer Thermal printer Other printers Personal laser printers Shared laser printers Thermal printer Other printers Dot-matrix Plotters Photo printers Three major types of printers: ink-jet, laser and thermal; most people are familiar with these Inkjet printers spray ink at high speed onto the surface of paper Laser printers uses a laser light beam to produce images More expensive than ink jet printers Thermal printers – uses heat elements to produce images on heat sensitive paper Used to produce high quality art work Other Printers Dot-matrix – slow and not used much any more; poor quality but faster than some of newer printers Very noisy Inexpensive Photo printers – designed to print photographs from digital cameras Plotters – special purpose for maps, images, architectural & engineering drawings

Audio Output Devices Translates audio information into sounds that people can understand Common devices Speakers Headphones These devices produce sounds for people Connected to a sound card in the system unit Creating voice output is not as difficult as recognizing and interpreting voice input

Combination Input and Output Devices Fax machines Multifunction devices Internet telephones Telephony Voice-over IP (VoIP) Terminals Combination devices include fax machines, multifunction devices, Internet telephones, and terminals Internet telephone – specialized input and output devices for receiving and sending voice communication Connect to the system unit through a USB port Telephony – the transmission of telephone calls over computer networks Known as Voice over IP Uses Internet rather than traditional Requires Internet telephone Internet Special service provider Sound card Special software Terminal is an input and output device that connects to a mainframe or a host computer

Terminals An input and output device Connects to a mainframe or server Types of terminals Dumb terminal Intelligent terminal Network terminal Internet terminal Terminals - input and output device connecting users to mainframe computers Dumb terminal - no processor or local storage Intelligent terminal - CPU, memory and storage; Net PC, or network computer Network terminal - low cost alternative to intelligent terminal Internet terminal - or Web terminal, accesses and displays Web pages on a television set

A Look to the Future Neural Signals Inc. Brain machine interface Allows humans to control machines with their thoughts Individuals incapable of communication Physically immobile people Researchers have begun human trials that allow humans to control machines with their thoughts Brain machine interface is currently pursued as a way to allow those with certain disabilities to become functional

Key Terms active matrix monitor (190) audio input device (185) audio-output device (193) bar code (183) bar code reader (183) bar code scanner (183) cathode ray tube monitor (CRT) (189) character recognition device (183) clarity (189) color capability (printer) (191) combination device (193) combination key (175) continuous-speech recognition system (188)

Key Terms cordless mouse (180) data projector (190) digital camera (184) digital notepad (185) digital video camera (184) digitizing device (185) discrete-speech recognition system (188) display screen (189) dot-matrix printer (192) dot pitch (189) dots-per-inch (dpi) (191) download (184) dual-scan monitor (190) dumb terminal (195) e-book (190) e-book reader (190)

Key Terms facsimile (fax) machine (194) flat-panel monitor (190) Flatbed scanner (183) graphics tablet (185) hard copy (191) Headphones (193) high-definition television (HDTV) (190) host computer (195) image capturing device (184) ink-jet printer (191) input device (178) input (178) intelligent terminal (195) Internet telephone (194) Internet telephony (194)

Key Terms Internet terminal (195) IP Telephony (194) joystick (181) keyboard (178) laser printer (192) light pen (182) liquid crystal display (LCD) (190) Magnetic-ink character recognition (MICR) (183) mark recognition device (183) mark sensing (183) mechanical mouse (180) memory (printer) (191) Musical Interface Digital Interface MIDI (188)

Key Terms MIDI device (188) monitor (189) mouse (180) mouse pad (180) mouse pointer (180) multifunction device (MFD) (194) network computer (195) network terminal (195) numeric keypad (178) optical character recognition (OCR) (183) Optical-mark recognition (OMR) (183) optical mouse (180) optical scanner (182) output (188) output device (188)

Key Terms passive-matrix monitor (190) PC/TV (190) personal laser printer (192) photo printer (192) pixel (picture element) (189) platform scanner (183) plotter (192) pointing (180) pointing device (180) pointing stick (180) portable scanner (183) printer (191) reader/sorter (183) refresh rate (189) resolution (monitor)(189)

Key Terms resolution (printer) (191) roller ball (180) scanner (182) scanning device (182) screen (189) server (195) shared laser printer (192) size (viewable size) (189) soft copy (189) speakers (193) speed (printer) (191) telephony (194) terminal (195) thermal printer (192) thin client (195) thin film resistor monitor (TFT) (190) toggle key (179)

Key Terms touch pad (180) touch screen (181) touch surface (180) trackball (180) Universal Product Code (UPC) (183) voice recognition system (185) voice-over IP (VoIP) (194) wand reader (183) Web appliance (195) WebCam (184) Web camera (184) Web terminal (195) wireless mouse (180)

FAQs What are pointing devices? I would like to insert several images in a document. How can I capture the images? What are digitizing devices? What is voice recognition? What is the difference between a CRT and an LCD display? What is HDTV?

Discussion Questions Describe the three different mouse types designed for input. How does Internet telephony work? Discuss. Discuss the features of multifunctional devices. Describe the features of a monitor that help to make images appear clearer on the screen. What are MIDI devices and how are they used?