2. Input and Output: Data In, Information Out Lesson 4 What You Will Learn The various types of input and output and their purposes The differences between a computer keyboard and a typewriter keyboard The special keys and their purpose The pros and cons of speech recognition as an alternative to keyboard use The various types of printers, monitors, mouse and pointing devices Devices used to get sound, video and images into the computer

3. What are the types of input? Software- Programs transferred from storage devices to the computer’s memory Data- Unorganized information (words, numbers, images or sounds) that the computer converts to meaningful information Commands- Instructions that tell the computer what to do Responses- Prompts requiring user feedback

4. What are input devices? Hardware that enable you to get programs, data, commands and responses into the computer’s memory Digital Cameras Microphone

6. What is the purpose of a keyboard? Allows the computer user to enter words, numbers, punctuation, symbols, and special function commands into the computer’s memory

7. What are the types of keyboards? Enhanced or Extended keyboard- Typically 101 keys laid out in the QWERTY fashion; Connected to the computer by a serial cable Cordless keyboard- Uses infrared or radio wave signals Ergonomic keyboard- Designed to help prevent cumulative trauma disorder (CTD) or damage to nerve tissues in the wrist and hand due to repeated motion Enhanced / Extended KeyboardErgonomic Keyboard

8. What is speech recognition? A type of input, in which, the computer recognizes words spoken into a microphone Special software and a microphone are required Latest technology uses continuous speech recognition where the user does not have to pause between words

9. What are pointing devices? Enable the user to control the movements of an on-screen pointer Enable the user to initiate commands and responses to the active program Are used to provide input in graphics programs Pointing Devices

10. What are the types of pointing devices? Mouse Joystick Touch pad Touch screen Trackball Pointing stick Pen

11. What are the types of mice? PS/2- Most commonly used; Connects to PS/2 port or USB port Serial- Not commonly used; Connects to a serial port Cordless- Uses infrared signals; Must be within sight of receiving port PS/2 Mouse Cordless Mouse

12. How does a mouse work? Mouse buttons- Enable the user to initiate actions  Clicking (left, right or double click)- Allows the user to select an item on the screen, open a program or dialog box  Click and drag- Holding down the left mouse button and moving the mouse enables the user to move objects on the screen Mechanical mouse- Uses rotating ball to position the pointer on the screen Optical mouse- Uses laser light to determine the pointer position

13. What are other pointing devices? Trackball Pointing stick Touchpad Joystick Touch Screen Pen

14. What are other pointing devices? Biometric Fingerprint Reader USB Tablet

15. Optical input devices Digital Cameras Digital Video VideoconferencingWeb cams Click on picture to play video

16. Other input devices Scanners Flatbed Handheld Fax Machines

17. Other input devices Image processing systems- Used in business, industry and science to input data without manually keying it in Magnetic-ink character recognition- Used by banks to process checks Bar code reader Biological feedback devices- Use body movements as input Chemical detectors- Molecules of chemicals are used as input

19. What are output devices? Peripheral devices that enable us to view or hear the computer processed data Visual output- Text, graphics and video Audible output- Sounds, music and synthesized speech

20. What is a visual display system? Composed of two parts  Video adapter- Responsible for video quality  Monitor- Displays video adapter’s output

21. What is a video adapter? Also called display adapter, video card, or graphics card Plugs into expansion slot on motherboard Contains memory called video RAM (VRAM) Designed to work with digital or analog monitors Converts digital signals to analog Determines a monitor’s maximum resolution (VGA/Super VGA) Determines a monitor’s refresh rate 3D graphics adapter- Enables 3 dimensional images Multi-display video adapter- Permits a connection of two monitors at a time

22. What is a monitor? A peripheral device which displays computer output on a screen Screen output is referred to as a soft copy

23. What are the types of monitors? Cathode-ray tube (CRT)- Resemble televisions; Use picture tube technology; Inexpensive, take up desk space and use a lot of energy Liquid Crystal Display (LCD or flat-panel)- Cells sandwiched between two transparent layers form images; Used for notebook computers, PDA’s, cellular phones and personal computers; Expensive, take up less desk space and use less energy CRTLCD

24. What’s the difference between a monochrome and color monitor? Monochrome  Only two colors; Either green or amber on black background  Grayscale colors are black and white and shades of gray Color  Capable of displaying 16.7 million colors

25. What are monitor specifications? Screen size- The diagonal measurement of the screen surface in inches (15, 17, 19, 21) Resolution- The sharpness of the images on the screen determined by the number of horizontal and vertical pixels that the screen can display (800x600, 1024x768, 1600x1200) Dot pitch- The distance between each pixel on the screen measured in millimeters (.22mm,.25mm,.28mm) Refresh rate- The speed in which the screen is redrawn (refreshed) measured in Hertz (Hz) (60Hz, 75Hz)

26. What is a printer? A peripheral device that produces a physical copy (hard copy) of the computer’s output Two basic types:  Impact printer  Nonimpact printer

27. What is an impact printer? A printer that has a print head that contacts the paper to produce a character Uses ink ribbon Noisy; Near-letter quality printouts; Not commonly used today Dot-matrix- Pins used to make characters Impact printerDot-matrix

28. What is a nonimpact printer? Quiet; Most commonly used Inkjet printer- Also called bubble-jet; Makes characters by inserting dots of ink onto paper; Letter-quality printouts; Cost of printer is inexpensive but ink is costly Laser printer- Works like a copier; Quality determined by dots per inch (dpi) produced. Color printers available; Expensive initial costs but cheaper to operate per page Inkjet Laser

29. What is a multifunction printer? A combination of nonimpact printer, scanner, fax machine, and copier in one unit

30. What is a plotter? A printer that uses a pen that moves over a large revolving sheet of paper Used in engineering, drafting, map making and seismotology

31. What is audio output? The ability of the computer to output sound Two components needed:  Sound card- Plays contents of digitized recordings  Speakers- Attach to sound card Plays various formats i.e. WAV, MPEG, MP3 and MIDI WMAMIDIMP3WAV Beethoven 1:15 min Rocky 2:56 min Hornsby 48 sec Cheers 15 sec Click on icon to play music Click on icon again to stop playing Try clicking on Cheers while playing music

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