1. Using Information Technology
Lecture 3
Hardware--Input & Output
To 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.

2. Hardware--Input & Output Taking Charge of Computing & Communications
3.2 Input Hardware
3.3 Output Hardware
3.4 The Future of Input & Output
Key Questions (from the text):
6.1 Input & Output. How is input and output hardware used by a computer system?
6.2 Input Hardware. What are the three categories of input hardware, what devices do they include, and what are their features?
6.3 Output Hardware. What are the two categories of output hardware, what devices do they include, and what are their features?
6.4 The Future of Input & Output. What are some examples of the future of input and output technology?
6.5 Input & Output Technology & Quality of Life: Health & Ergonomics. What are the principal health and ergonomic issues relating to computer use?

3. 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

4. 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…
Traditional 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.

5. Keyboards Specialty keyboards and terminals: Dumb terminal
Intelligent terminal
Internet terminal
Dumb 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.

6. Pointing Devices
Pointing devices - control the position of the cursor or pointer on the screen
Mouse
Trackball
Pointing stick
Touchpad
Discussion 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!).

7. Pointing Devices
Touch screen - a video display screen that has been sensitized to receive input from the touch of a finger

8. 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

9. Pointing Devices Pen input:
Light pen - a light-sensitive penlike device connected by a wire to the computer terminal
The light pen has a button which the user presses when the pen is pointing to a desired location on the screen.

10. 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

11. 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 - 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.

12. 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

13. 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 - Optical mark recognition. Uses a device that reads pencil marks and converts them into computer-usable form
OCR - Optical character recognition. Uses a device that reads preprinted characters in a particular font and converts them to digital code

14. Source Data-Entry Devices
Scanning devices - fax machines…
Types of fax machines:
Dedicated fax machine
Fax 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.

15. Source Data-Entry Devices
Scanning devices - fax machines…
Types of fax machines:
Fax modem
Fax modem - a circuit board installed inside the computer’s system cabinet. It is a modem with fax capability that allows you to send signals directly from your computer to someone else’s fax machine or computer fax modem.

16. Other Source Data-Entry Devices
Audio-input devices
Record analog sound and translate it for digital storage and processing
Require either an audio board or a MIDI board
Audio board - an add-on circuit board that converts analog sound to digital sound and stores it for further processing and/or plays it back, directly to speakers or an external amplifier.
MIDI (Musical Instrument Digital Interface) board - provides a standard for the interchange of musical information between musical instruments, synthesizers, and computers.

17. Other Source Data-Entry Devices
Webcams and video-input cards
Webcam - 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.

18. Other Source Data-Entry Devices
Digital cameras
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.

19. Other Source Data-Entry Devices
Voice-recognition systems
Voice-recognition system - uses a microphone (or telephone) as an input device, then converts a person’s speech into digital signals by comparing the electrical patterns produced by the speaker’s voice with a set of prerecorded patterns stored in the computer.
Voice-recognition systems allow one to accomplish two tasks:
Turn spoken words into typed text; and
Issue oral commands to control your computer.

20. More Source Data-Entry Devices
Sensors
Sensor - an input device that collects specific data directly from the environment and transmits it to a computer.
The image depicts an earthquake sensor in southern California.

21. More Source Data-Entry Devices
Radio-frequency identification
Radio-frequency identification devices - based on an identifying tag bearing a microchip that contains specific code numbers, which are read by the radio waves of a scanner linked to a database. Also known as RF-ID tagging.
The image depicts a cat being scanned for an implanted microchip which would contain its owner’s name, address, and phone number.

22. More Source Data-Entry Devices
Biometrics - the science of measuring individual body characteristics.
The picture depicts line-of-sight systems, which enable you to use your eyes to point at the screen. You operate the computer by looking at icons on the screen and “press a key” by looking at one spot for a specified period of time.
Human-biology input devices (biometrics)

23. 6.3 Output Hardware
Softcopy - data that is shown on a display screen or is in audio or voice form
Hardcopy - printed output

24. 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

25. 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

26. 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

27. Softcopy Output: Display Screens
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

28. 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).

29. Softcopy Output: Display Screens
Two types of monitors:
CRT - a vacuum tube used as a display screen in a computer or video display terminal
CRT stands for Cathode Ray Tube, and is used in television sets in addition to monitors.

30. Softcopy Output: Display Screens
Two types of monitors:
Flat-panel display - made up of two plates of glass separated by a layer of a substance in which light is manipulated
Liquid crystal display (LCD) - one technology used in flat-panel displays. Molecules of liquid crystal line up in a way that alters their optical properties, creating images on the screen by transmitting or blocking out light.
Flat-panel displays cost far more than CRT displays.

31. 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
Active-matrix display advantages:
Brighter
Sharper
Do not leave “ghosts” when the display changes quickly
Passive-matrix display advantages:
Cheaper
Use less power

32. Softcopy Output: Display Screens
Color & resolution standards:
SVGA
XGA
SXGA
UXGA
SVGA (Super Video Graphics Array)
XGA (Extended Graphics Array)
SXGA (Super Extended Graphics Array)
UXGA (Ultra Extended Graphics Array)

33. 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

34. 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
Dot-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 forms
Disadvantage of dot-matrix printer:
Noisy!

35. 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
PDL (Page Description Language). Software which tells the printer how to lay out the printed page.
Two types of PDL:
PostScript - developed by Adobe.
PCL (Printer Control Language( - developed by Hewlett-Packard.
Replacing a laser toner cartridge

36. Hardcopy Output: Printers
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
Advantages of ink-jet printers:
Cheaper than laser
Quieter than laser
Disadvantages of ink-jet printers:
Slower than laser
Lower resolution than laser
Thermal printers produce the highest-quality color output of any printer, but are expensive and require expensive paper.
Discussion Question:
What is the future of printers in light of the talk about “the paperless office,” a term that has been around for some time? Do you think the paperless office is a good idea? Do you think it’s possible? Why do you think it has not yet been achieved?

37. Hardcopy Output: Printers
Plotter - a specialized output device designed to produce high-quality graphics in a variety of colors

38. Hardcopy Output: Printers
Multifunction printer - output device that combines several capabilities, such as printing, scanning, copying, and faxing

39. 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 frames per second to give the appearance of full motion
Videoconferencing - 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.

40. 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
Discussion Question:
<Either describe the Verichip developed by Applied Digital Solutions, or show and read together the article linked to above.>
Currently the device is being developed as a medical aid with ID information, but might it be bundled with a GPS unit and used for identifying and locating missing children, kidnapping victims or Alzheimer patients who have wandered off? What are the medical and ethical implications? Might it be abused? Could parents use it to find out what their teenage kids are up to?

41. 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
High-capacity bar codes can be read vertically, as well as horizontally, allowing them to store more than 100 times as much data.
3-D scanners can make online shopping for clothing much more reliable.
Touch devices linked to mobile electronic “yellow pages” may be installed in cars.
Smart cards may evolve into all-purpose cards containing everything from medical records to frequent flier program information.
Sensor examples: a “smart needle” with embedded sensors can be inserted into a tumor to provide more information about it; a “canary on a chip” can be used to detect and identify chemical and biological agents;, etc.

42. Toward More Source Data Automation
More refinements in source data automation:
Better voice recognition
Smaller electronic cameras
Pattern-recognition & biometric devices
Brainwave devices
Voice recognition possibility: a translation device for travelers which could take your spoken English and instantly translate it into spoken French, Japanese, etc.
Smaller electronic cameras: Camera-on-a-chip?
Pattern-recognition & biometric devices: See image.
Brainwave devices: Users moving a cursor through sheer power of thought!

43. Toward More Output in Remote Locations
Electronic news tablet - a textbook-sized device for downloading a newspaper and then carrying around to read

44. Toward More Realistic Output
Display screens--better and cheaper
Audio--higher fidelity
Video--movie quality for PC’s
Three-dimensional display