1. Using Information Technology
Chapter 5
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
5.2 Input Hardware
5.3 Output Hardware
Key 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?

3. 5.1 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. 5.2 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
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.
One-handed keyboard

5. Keyboards Specialty keyboards and terminals:
Dumb terminal, VDT, display & keyboard, but no processing
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.
Dumb terminal

6. Keyboards Specialty keyboards and terminals:
Examples of intelligent terminals:
Automatic teller machine (ATM)
Point-of-sale (POS) terminal
Specialty keyboards and terminals:
Dumb terminal
Intelligent terminal
Has own memory & processor
Internet terminal
Intelligent 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.

7. PDA (Internet terminal)
Keyboards
Specialty keyboards and terminals:
Dumb terminal
Intelligent terminal
Internet terminal:
Web terminal
Network computer
Online game player
PC/TV
PDA
Internet 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)

8. Mouse for right-handed user
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!).
Mouse for right-handed user

9. Pointing Devices The mouse and its variants: Mouse Trackball
Pointing stick
Touchpad
Touch pad
Trackball - 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 trackball
Pointing stick

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

11. 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
Light pen - a light-sensitive penlike device connected by a wire to the computer terminal

12. 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

13. 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.

14. 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

15. Source Data-Entry Devices
Scanning devices - mark- & character-recognition:
MICR - Magnetic-ink character recognition. Reads the strange-looking numbers printed at the bottom of checks
OMR
OCR

16. Source Data-Entry Devices
Scanning devices - mark- & character-recognition:
MICR
OMR - Optical mark recognition. Uses a device that reads pencil marks and converts them into computer-usable form
OCR

17. Source Data-Entry Devices
Scanning devices:mark- & 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

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

19. Other Source Data-Entry Devices
Audio-input devices
Webcams and video-input cards
Digital cameras
Voice-recognition systems
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.

20. Other Source Data-Entry Devices
Audio-input devices
Webcams and video-input cards
Digital cameras
Voice-recognition systems
Human-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.

21. 5.3 Output Hardware
Softcopy - data that is shown on a display screen or is in audio or voice form
Hardcopy - printed output

22. 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

23. 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

24. 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

25. Softcopy Output: Display Screens
Standard resolutions
(horizontal x vertical)
640 x 480
800 x 600
1024 x 768
1280 x 1024
1600 x 1200
1920 x 1440
Screen clarity…
Resolution - the image sharpness of a display screen; the more pixels there are per square inch, the finer the level of detail
dpi = dots per inch

26. 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).

27. 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 - made up of two plates of glass separated by a layer of a substance in which light is manipulated
CRT stands for Cathode Ray Tube, and is used in television sets in addition to monitors.

28. 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 (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:
Brighter
Sharper
Do not leave “ghosts” when the display changes quickly
Passive-matrix display advantages:
Cheaper
Use less power

29. Softcopy 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 artists
SVGA (Super Video Graphics Array)
XGA (Extended Graphics Array)
SXGA (Super Extended Graphics Array)
UXGA (Ultra Extended Graphics Array)

30. 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

31. 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 (dot matrix printer)
Non-impact printer - forms characters and images without direct physical contact between the printing mechanism and paper
Laser printer - creates images on a drum which are treated with a magnetically charged toner, & then transferred from drum to paper
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 high quality images by burning dots onto special 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!

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

33. 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.

34. Concept Check
Which type of scanning technology reads the special characters printed at the bottom of checks?
Magnetic-ink character recognition (MICR)

35. Concept Check
What is the smallest unit on the screen that can be turned on and off or made different shades?
Pixel (short for picture element)

36. Concept Check
What is the measure specifying the number of times per second that screen pixels are recharged?
Refresh rate

37. Concept Check
How is screen resolution specified--vertical x horizontal, or horizontal x vertical?
Horizontal x vertical

38. Concept Check What is the measure of resolution for printers?
Dots per inch (dpi)

39. Concept Check
What is the amount of space between the centers of adjacent pixels?
Dot pitch (dp)

40. Concept Check
What type of scanning technology is used to read pencil marks, such as those made by students on examination forms?
OMR (Optical mark recognition)

41. Concept Check What is an example of an impact printer?
Dot-matrix printer

42. Concept Check
Which type of printer produces the very highest-quality color output?
Thermal printer

43. Concept Check
What 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

44. Concept Check
What is the term for printed output?
Hardcopy

45. Concept Check
Does 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)