Presentation on theme: "Using Information Technology"— Presentation transcript:
1Using Information Technology Chapter 5Hardware--Input & OutputTo the instructor:This presentation attempts to cover every term in the text, sometimes via a slide, sometimes via the Notes page.Additional material beyond what is in the text is presented via:Occasional “FACTOID” notations on the Notes page, and;Occasional hyperlinks in the slides themselves. ScreenTip text has been added to each hyperlink allowing you to see in advance of selecting the hyperlink where that link will take you.In addition, the last ~20 slides are questions covering the material just presented. They can be used to increase interaction between the instructor and students at the end of each lecture, to ensure students understand the material just presented, etc.Finally, some of the Notes pages include “Discussion questions” for use in encouraging student interaction during the lecture.
2Hardware--Input & Output Taking Charge of Computing & Communications 5.2 Input Hardware5.3 Output HardwareKey Questions (from the text):5.1 Input & Output. How is input and output hardware used by a computer system?5.2 Input Hardware. What are the three categories of input hardware, what devices do they include, and what are their features?5.3 Output Hardware. What are the two categories of output hardware, what devices do they include, and what are their features?
35.1 Input & OutputInput hardware - devices that translate data into a form the computer can processOutput hardware - devices that translate information processed by the computer into a form that humans can understand
45.2 Input HardwareKeyboard - a device that converts letters, numbers, and other characters into electrical signals that can be read by the computer’s processorTraditional keyboards…Braille keyboardTraditional keyboards include Braille and one-handed keyboards for the physically challenged, plus left-handed keyboards for the 10% of the population that is left-handed, and many others.One-handed keyboard
5Keyboards Specialty keyboards and terminals: Dumb terminal, VDT, display & keyboard, but no processingIntelligent terminalInternet terminalDumb terminal - a display screen and a keyboard, which can input and output but not process data. Also called a video display terminal (VDT).The picture depicts dumb terminals used by airline reservations clerks.Dumb terminal
6Keyboards Specialty keyboards and terminals: Examples of intelligent terminals:Automatic teller machine (ATM)Point-of-sale (POS) terminalSpecialty keyboards and terminals:Dumb terminalIntelligent terminalHas own memory & processorInternet terminalIntelligent terminal - has its own memory and processor, as well as a display screen and keyboard.FACTOID: Some sources distinguish between an intelligent terminal and a merely smart terminal. The latter does not have as many processing capabilities as an intelligent terminal.
7PDA (Internet terminal) KeyboardsSpecialty keyboards and terminals:Dumb terminalIntelligent terminalInternet terminal:Web terminalNetwork computerOnline game playerPC/TVPDAInternet terminal - provides access to the Internet.Types of Internet terminals:Web terminal - displays Web pages on a TV set.Network computer - a cheap, stripped-down computer that connects people to networks.Online game player - allows users to play games and connect to the Internet.PC/TV - merges the PC with the TV.Personal digital assistant (PDA) - a handheld computer that can do two-way wireless messaging.PDA (Internet terminal)
8Mouse for right-handed user Pointing DevicesPointing devices - control the position of the cursor or pointer on the screenMouseTrackballPointing stickTouchpadDiscussion question:Why is the mouse pictured described as one “for right-handed user?”Answer: The left button, to be used with a right-handed person’s index finger, is larger than the right button, because it is expected that this button will be used more often, and a larger button is easier to select.By contrast, a left-handed person’s index finger would need the right button to be larger than the left (or at least equal size!).Mouse for right-handed user
9Pointing Devices The mouse and its variants: Mouse Trackball Pointing stickTouchpadTouch padTrackball - a movable ball, mounted on top of a stationary device that can be rotated using fingers or palm.Discussion question:Why is the trackball pictured described as “ergonomic?”Hint: Why is the trackball pictured intended for right-handed users?Answer: Because the stationary device that holds the trackball is molded to fit the contours of a right hand.Ergonomic trackballPointing stick
10Pointing DevicesTouch screen - a video display screen that has been sensitized to receive input from the touch of a fingerTouch screen
11Pointing 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 keyboardLight pen - a light-sensitive penlike device connected by a wire to the computer terminal
12Pointing Devices Pen input: Digitizer - converts drawings and photos to digital data using a mouselike device called a puckDigitizing tablet - electronic plastic board on which each specific location corresponds to a location on the screenDigitizing tablet
13Source 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 formSource data-entry devices - create machine-readable data on magnetic media or paper or feed it directly into the computer’s processor.Imaging system (or image scanner or graphics scanner) - device which converts text, drawings, and photographs into digital form that can be stored in a computer system and then manipulated, output, or sent via modem to another computer.Electronic imaging - the software-controlled integration of separate images, using scanners, digital cameras, and advanced graphic computers.
14Source Data-Entry Devices Scanning devices –bar-code readers:Bar codes - vertical zebra-striped marks you see on most manufactured retail productsBar-code readers - optical scanners that translate the symbols in the bar code into digital code
15Source Data-Entry Devices Scanning devices - mark- & character-recognition:MICR - Magnetic-ink character recognition. Reads the strange-looking numbers printed at the bottom of checksOMROCR
16Source Data-Entry Devices Scanning devices - mark- & character-recognition:MICROMR - Optical mark recognition. Uses a device that reads pencil marks and converts them into computer-usable formOCR
17Source Data-Entry Devices Scanning devices:mark- & character-recognition:MICROMROCR - Optical character recognition. Uses a device that reads preprinted characters in a particular font and converts them to digital code
18Source Data-Entry Devices Scanning devices - fax machines…Types of fax machines:Dedicated fax machineFax modemDedicated fax machineFax machine - scans an image and sends it as electronic signals over telephone lines to a receiving fax machine, which prints out the image on paper. Also called facsimile transmission machine.Dedicated fax machine - specialized device that does nothing except send and receive fax documents.Fax modem
19Other Source Data-Entry Devices Audio-input devicesWebcams and video-input cardsDigital camerasVoice-recognition systemsWebcam - a camera that attaches to a computer to record moving images that can then be posted on a website in real time.Video-capture card - a special digitizing card that converts the analog signals that come from a VCR or a camcorder into digital form.
20Other Source Data-Entry Devices Audio-input devicesWebcams and video-input cardsDigital camerasVoice-recognition systemsHuman-biology input devices (biometrics)Digital camera - uses a light-sensitive processor chip to capture photographic images in digital form on a small diskette inserted in the camera or on flash-memory chips.
215.3 Output HardwareSoftcopy - data that is shown on a display screen or is in audio or voice formHardcopy - printed output
22Softcopy Output: Display Screens Display screens - output devices that show programming instructions and data as they are being input and information after it is processed
23Softcopy 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
24Softcopy 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
25Softcopy Output: Display Screens Standard resolutions(horizontal x vertical)640 x 480800 x 6001024 x 7681280 x 10241600 x 12001920 x 1440Screen clarity…Resolution - the image sharpness of a display screen; the more pixels there are per square inch, the finer the level of detaildpi = dots per inch
26Softcopy Output: Display Screens Screen clarity…Refresh rate - the number of times per second that the pixels are recharged so that their glow remains brightThe higher the refresh rate, the more solid the image looks (less flicker).
27Softcopy Output: Display Screens Two types of monitors:CRT - a vacuum tube used as a display screen in a computer or video display terminalFlat-panel display - made up of two plates of glass separated by a layer of a substance in which light is manipulatedCRT stands for Cathode Ray Tube, and is used in television sets in addition to monitors.
28Softcopy Output: Display Screens Active-matrix versus passive-matrix flat-panel displays:Active-matrix - each pixel on the screen is controlled by its own transistor (brighter & sharper, but more expensive)Passive-matrix - a transistor controls a whole row or column of pixels (provides sharper image for single color screens but more subdued for color)Active-matrix display advantages:BrighterSharperDo not leave “ghosts” when the display changes quicklyPassive-matrix display advantages:CheaperUse less power
29Softcopy Output: Display Screens Color & resolution standards:SVGA – Super video graphics array (most common w/ 15” monitors)XGA – Extended graphics array (17-19” monitors)SXGA – Super extended graphics array (19”-21” monitors)UXGA - Ultra extended graphics array (popular w/ design & graphic artistsSVGA (Super Video Graphics Array)XGA (Extended Graphics Array)SXGA (Super Extended Graphics Array)UXGA (Ultra Extended Graphics Array)
30Hardcopy Output: Printers Printer - an output device that prints characters, symbols, and perhaps graphics on paper or another hardcopy mediumDpi (dots per inch) - resolution measure for printers. Specifies the number of dots that are printed in a linear inch
31Hardcopy 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 (dot matrix printer)Non-impact printer - forms characters and images without direct physical contact between the printing mechanism and paperLaser printer - creates images on a drum which are treated with a magnetically charged toner, & then transferred from drum to paperInk-jet printers - spray small, electrically charged droplets of ink from four nozzles through holes in a matrix at high speed onto paperThermal printers - use colored waxes and heat to produce high quality images by burning dots onto special paperDot-matrix printer - contains a print head of small pins, which strike an inked ribbon against paper to form characters or images.Advantage of dot-matrix printer:Can be used to print multi-part formsDisadvantage of dot-matrix printer:Noisy!
32Hardcopy Output: Printers Multifunction printer - output device that combines several capabilities, such as printing, scanning, copying, and faxing
33Other OutputSound output - devices which produce digitized sounds, ranging from beeps and chirps to musicVoice output - devices which convert digital data into speech-like soundsVideo output - photographic images which are played at frames per second to give the appearance of full motionVideoconferencing - another form of video output, in which people in different geographical locations can have a meeting--can see and hear one another--using computers and communications.
34Concept CheckWhich type of scanning technology reads the special characters printed at the bottom of checks?Magnetic-ink character recognition (MICR)
35Concept CheckWhat is the smallest unit on the screen that can be turned on and off or made different shades?Pixel (short for picture element)
36Concept CheckWhat is the measure specifying the number of times per second that screen pixels are recharged?Refresh rate
37Concept CheckHow is screen resolution specified--vertical x horizontal, or horizontal x vertical?Horizontal x vertical
38Concept Check What is the measure of resolution for printers? Dots per inch (dpi)
39Concept CheckWhat is the amount of space between the centers of adjacent pixels?Dot pitch (dp)
40Concept CheckWhat type of scanning technology is used to read pencil marks, such as those made by students on examination forms?OMR (Optical mark recognition)
41Concept Check What is an example of an impact printer? Dot-matrix printer
42Concept CheckWhich type of printer produces the very highest-quality color output?Thermal printer
43Concept CheckWhat type of input device consists of a small, flat surface over which you slide your finger, using the same movements as you would with a mouse?Touchpad
44Concept CheckWhat is the term for printed output?Hardcopy
45Concept CheckDoes a very crisp image require a small dot pitch or a large dot pitch?A small dot pitch (the closer the dots, the crisper the image)