intro to info tech

1: 1 Intro to Info Tech I/O Equipment

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3: 3 Input Devices Devices that allow users to enter instructions and data Categories Those commonly used with computers Gaming and media Other

4: 4 Computer Input Devices Require a monitor Two types Keyboard Pointing devices Mouse Trackball Touch pad Pointing stick Light pen Touch screen Pen

5: 5 Keyboards Keys to represent A-Z and 1-10 Additional keys to: Change function of other keys Alt, Ctrl, Shift Perform special functions in apps PageUp, PageDown, Home, Delete, Tab, Esc, F1 �F12, arrows Perform OS function Delete, Windows (shows Start menu), Short Cut Menu key (next to right Ctrl)

6: 6 Keyboards Higher end keyboards will have keys: That perform browser functions Start applications Media controls (forward, back, pause, etc.) And ergonomic features: Palm rest Split keyboard Keys not in a straight line Some have built in scanners S

7: 7 Mouse Use to be: Connected by a wire to SU Left button, right button, scroll wheel Had a little trackball on bottom Getting crazy complicated. Now can have Side buttons Small keyboard Thumb buttons Instead of track ball and wire: Laser or Optical sensors

8: 8 Other Pointing Devices Trackball May also have some buttons Touch pad Flat area that can sense pressure Pointing stick Looks like a pencil eraser stuck in the middle of the keyboard Light pen - like a little flashlight Monitor senses where light is Duck Hunt

9: 9 Other Pointing Devices Touch screens react to human touch Heat sensitive Pressure sensitive Laser grid Pen input Flat area/screen/paper that can sense and record the pen movement Alternative: pressure sensitive pen that records movement Then download from pen to computer

10: 10 Gaming and Media Lots of specialty devices Gamepad � two handed device, with buttons, wheels, sticks. Talks to console. Joystick � stick with buttons on base Steering wheel � may have buttons and a footpad with pedals Light guns � fancy flashlight or a motion sensing device Dance pad � flat device (can be hard or pliable) that senses pressure Motion sensing device � like a Wii remote

11: 11 Other Input Devices Audio Input Devices (require a sound card) Microphone For voice input, need voice recognition s/w MIDI (musical instrument digital interface) devices Electronic piano Electric guitar Other computers PDAs, Smart Phones, etc.

12: 12 Other Input Devices Graphic Input Devices Digital Camera Can store a small amount Can use memory cards Video Cameras Can be used to do VOIP, video conferencing, as a web cam, etc. Need extra s/w to do these things

13: 13 Other Input Devices Scanners/readers Optical scanners � convert anything scanned into an image Optical readers: OCR (Optical Character Recognition) Recognizes numbers and letters OMR (Optical Mark Recognition) Like a Scantron machine Bar Code readers, lots of kinds

14: 14 Bar Codes Standard is one dimensional Lots of different standards Code 39, code 93, code 128 MaxiCode (created by UPS) 93 chars max Data Matrix 2335 alphanumeric chars QR (Quick Response) can store 7,089 numeric chars 4,296 alphanumeric chars 2,953 bytes

15: 15 Bar Codes Originally created to contain product/tracking info Being used to store much more info URLs, phone numbers User scans the QR Code with phone The phone's browser is launched and goes to the URL The phone dials the number QR reader app in Android OS

16: 16 Other Input Devices Scanners/readers RFID (Radio Frequency Identification) Very hot technology Magnetic Stripe Card readers A device that swipes a credit card-like object MICR (Magnetic Ink Character Reader) What industry uses this?

17: 17 Other Input Devices Biometric Devices Use other input devices (scanners, microphones, etc.) and extra s/w to detect physiological characteristics Retinal scanner Iris scanner Fingerprint scanner Face recognition Voice recognition Signature verification Soldier ids a Baghdad city council member with iris scanner.Soldier ids a Baghdad city council member with iris scanner.

18: 18 Output Devices Devices that allow users to receive output Categories of Devices Displays Printers Other

19: 19 Output Devices Types of output Text Graphics Audio Video One of the ways to compare output devices is by the types of output they support

20: 20 Displays TV like viewing screen that can display text, graphics and video Most allow control over brightness, contrast, etc. Monitor � a separate device that connects to the system unit Compared by their: Screen size, resolution, response time (aka refresh rate), brightness, contrast ratio

21: 21 Monitors Most are: 15-23 inches diagonally Laptops 8-20 PDAs 3-4 Desktop publishing systems will have monitors 30-40 inches Beware of monitor vs. viewable size

22: 22 Monitors Resolution measured in Pixels and lines Expressed as the number of pixels per line by the number of lines from the top to bottom of the screen Eg. 1280X1024 What's a Pixel?

23: 23 Monitors Dot pitch Distance between pixels Contrast Ratio Range of color intensity Compares the screens brightest white to it's darkest black Higher the contrast, better the color

24: 24 Monitors Lots of different types of monitors LCD (liquid crystal display) aka flat screen Built for a specific resolution Bigger the screen, higher the resolution 17 in usually 1280X1024 20 in usually 1600X1200 Response (time to change a pixel/bit) is 5 to 16 millisecs

25: 25 Monitors Brightness measured in nits Nit = 1 candle per square meter Candle = 1/60 of the luminous intensity per square centimeter of a black body radiating at the temperature of 2,046 degrees Kelvin All you have to know is "more nits = brighter picture" Dot pitch should be < .28 mm Static contrast ratios range from 400:1 to 800:1 Dynamic ratio is the ratio between the deepest blacks a display can show and the brightest whites it can handle over its entire operational range but not at the same time. Static measures the ratio between the darkest blacks and the brightest whites that a display can simultaneously support at any one time � the actual physical limit of the monitor. Dynamic contrast uses a processor inside the display to analyze the average, overall picture brightness and adjusts the backlight level on-the-fly. This helps render�deeper blacks in predominantly dark scenes and brighter whites in mostly bright picture content. Dynamic numbers are ridiculously high.Dynamic ratio is the ratio between the deepest blacks a display can show and the brightest whites it can handle over its entire operational range but not at the same time. Static measures the ratio between the darkest blacks and the brightest whites that a display can simultaneously support at any one time � the actual physical limit of the monitor. Dynamic contrast uses a processor inside the display to analyze the average, overall picture brightness and adjusts the backlight level on-the-fly. This helps render�deeper blacks in predominantly dark scenes and brighter whites in mostly bright picture content. Dynamic numbers are ridiculously high.

26: 26 Monitors Plasma Not as common as LCDs (for computers) Uses a gas instead of liquid Heavier than LCD Larger screen sizes than LCDs Richer colors More expensive 4th form of matter. plasma is ionized gas - a gas into which sufficient energy is provided to free electrons from atoms or molecules and to allow both ions and electrons to coexist. Example: the Sun.4th form of matter. plasma is ionized gas - a gas into which sufficient energy is provided to free electrons from atoms or molecules and to allow both ions and electrons to coexist. Example: the Sun.

27: 27 Monitors CRT (Cathode Ray Tube) Cheaper than LCDs Use more electricity than LCDs Resolution can be changed by OS Range from 2048X1536 to 1280X1024 Dot pitch should be < .27 Refresh rate How many times per sec image is changed 68 Hz means 68 times per sec Larger the number, less flicker

28: 28 Printers Produces text and graphics on some medium Paper, transparency, film Some have a camera dock or a memory card slot Images don't have to be transferred Lots of different types Can be categorized as Impact or Non-impact

29: 29 Impact Printers Component strikes the medium Well really the ink ribbon Don't see many anymore Line printers had solid font text Typewriter like keys A daisywheel A selectric ball Dot matrix

30: 30 Non-impact Printers Spray, attract ink or burn Compared by the Medium sizes accommodated 8.5X11.5, 3X5, 4X6 Print resolution DPI (dots per inch) Speed PPM (page per minute) Usually different PPM for color vs. B&W printing

31: 31 Non-impact Printers Ink Jet print head has two cartridges and little nozzles Relatively cheap (<$100) Ink's expensive! Supports many paper sizes 1200-4800 dpi 6 to 33 ppm

32: 32 Non-impact Printers Laser More expensive ($200 - $100,000) Uses powdered ink called toner Supports many paper sizes 1200-2400 dpi Faster than ink jet For home 8 to 35 ppm Business 150 ppm Laser draws the image/letters on the drum (where laser strikes drum turns to a negative charge). Positively charged toner (a fine powder) is then passed over the drum. (Like putting glue in the shape of letters on a soda can and rolling the can in flour. Paper is then negatively charged (more than the drum) and the drum in rolled of the paper and the toner is transferred to the paper. Paper is then run through a fuser that melts the toner onto the paper. (This is why the paper is always warm when it comes out of a laser printer.)Laser draws the image/letters on the drum (where laser strikes drum turns to a negative charge). Positively charged toner (a fine powder) is then passed over the drum. (Like putting glue in the shape of letters on a soda can and rolling the can in flour. Paper is then negatively charged (more than the drum) and the drum in rolled of the paper and the toner is transferred to the paper. Paper is then run through a fuser that melts the toner onto the paper. (This is why the paper is always warm when it comes out of a laser printer.)

33: 33 Non-impact Printers Photo Printer High quality Wide range of sizes More expensive May let you edit picture Often, can print without a computer connection

34: 34 Non-impact Printers Thermal Burns special paper Wide range of capability Cheapos � poor quality, like gas receipt High end � good quality Plotters Good for diagrams, charts Large format printers Blueprints, signs, posters

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39: 39 Points to Remember Input and output devices called peripheral devices Connect to the system unit either with a cable or wirelessly Infrared requires line of sight Radio (e.g. Bluetooth) Enable users to enter instructions and data and receive output