A Computer with Peripheral Devices

1. A Computer with Peripheral Devices Scanner Speaker Monitor External Drive Mouse Keyboard

2. Comparison of PC Keyboard Types XT Keyboard AT (Standard) AT (Enhanced)

3. Other Keyboards Ergonomic Keyboard Dvorak Layout

4. Keyboard DIN Connectors

5. How a Keyboard Works Scan code Interprets the key New scan code

6. Common Keyboard Problems • Keys stick. • User with physical limitation is currently unable to use the standard keyboard. • No input is sent when keys are pressed. • Keyboard-related messages or beep codes given during computer boot. • Wrong characters are displayed on the screen when user inputs information. • Multimedia buttons not working properly. • New keyboard won’t plug into the same port as the old keyboard.

7. Pointing Devices Mouse Touchpad Trackball

8. How a Mechanical Mouse Works Encoder wheel Click!

9. Common Pointing Device Problems • Mouse pointer jumps around on the screen. • Cordless mouse is in use and mouse pointer is jumping around or not moving. • Mouse works sometimes, but not others. • Mouse is not working. • USB mouse is not working properly.

10. A CRT Monitor

11. An LCD Flat-Panel Monitor

12. Virtual Reality Glasses

13. A Video Projector

14. A Touch Screen Monitor Data

15. Red Blue Green How Color CRT Monitors Work Horizontal & vertical deflection coils Magnetic yoke Electron guns Color dots

16. Electron Beam Positioning Technologies Used in Monitors

17. Display Characteristics

18. DB 15-pin High-Density VGA Connector 15 14 13 12 11 5 4 3 2 1 10 9 7 8 6

19. Relative Screen Sizes The aspect ratio of most computer monitors is 4:3

20. Display Properties

21. Monitor Distortions Pincushion Barrel Trapezoid

22. Monitor Test Pattern

23. Power Management

24. A VGA Connector

25. A DVI-I Receptacle Connector

26. Common Monitor Problems • No image displayed on the monitor. • Monitor flickers. • Monitor is dark or power indicator light is not lit. • Monitor turns itself off. • Screen is fine until a specific application is started, then the screen goes blank, flickers, or acts bizarrely. • Monitor is on, but rather than displaying an image or being black, it is white.

27. A Dot-Matrix Printer Cut sheet feeder Moves bail bar against or away from the platten Select Tractor or Friction Feed Creates images using pins that strike an inked ribbon Slot for font cards Adjust printer settings with these buttons Adjust gap between print head and paper Print head Manually advance the ribbon Ribbon

28. Tractor Feed Sprockets with prongs and latches fit over holes in the edge of the paper Continuous sheet paper with perforations to create individual sheets

29. Friction Feed Paper loaded in cut sheet feeder Lever set for cut sheet, friction feed Bail holding paper against the platten

30. How a Dot-Matrix Printer Works Paper Ink ribbon Tractor Electrical signals from microprocessor Print head Coils Pins Electrical signals cause pins to move out toward the ribbon

31. An Inkjet Printer Ink cartridges with integrated print heads Paper feeds straight through the same side up from cut sheet feeder at the top to the output tray at the lower front Separate black and color cartridges; color cartridge contains reservoirs for cyan, magenta, and yellow

32. How an Inkjet Printer Works Ink is sprayed onto the paper Paper Print head and reservoir Melted ink is forced out to spray against the paper; each droplet is about one one-millionth of a normal drop Print head nozzle detail Rollers Resistor creates heat that vaporizes some of the ink from the reservoir

33. A Laser Printer LocalTalk port Type B parallel port Type C parallel port Laser cartridge Output tray Input trays IR port

34. How a Laser Printer Works Corona wire charging the drum Laser Toner supply Fusing unit uses heat and pressure to adhere toner to paper EP drum Paper Corona wires charging the paper

35. Comparison of Printer Types

36. The Windows Print Process Application GDI Print driver Client-side spooler User prints document Server-side spooler 1 Calls printer driver Print router 2 Renders job 3 Returns control to application 4 Inserts job into print stream 5 Which print server? 6

37. The Windows Print Process (Cont.) Local print provider Print processor Separator page processor Port monitor Printer Inserts separator page Spools job and locates print processor Completes rendering Communicates with printer Produces output 7C 7D 7E 7A 7B To Windows 8 Remote print provider To NetWare

38. Common Print Problems • Nothing will print from any application. • Printer doesn’t print the way the user expects it to. • User can’t access network printer. • Printer prints part of a document then prints garbage for the rest of the document.

39. Common Dot-Matrix Printer Problems • Horizontal lines appear in the print so parts of characters are missing. • Flecks and smudges on the paper. • Poor print quality. • Continuous-feed paper jams.

40. Common Inkjet Printer Problems • Poor print quality. • No output; paper passes through printer but is blank. • Fuzzy output.

41. Common Laser Printer Problems • Smeared output or output rubs off the paper. • Low-quality image. • Repeating horizontal lines or white spaces. • Repeating vertical lines or white spaces.

42. Environmental Effects on Printing • A clean environment prolongs the life and usability of most equipment, including printers. • Relative humidity of 50 to 60 percent is good for computer equipment.

43. Scanners

44. Digital Camera

45. A Touch Screen Interface Connected via USB Touch sensor panel USB connector

46. Speakers

47. Microphones