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hardware.pptx
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- 4. Physical Devices mouse trackballlight pen data tablet joy stick space ball
- 5. Input Modes Inputdevices contain a trigger which can be used to send a signal to the operating system Button on mouse Pressing or releasing a key When triggered, input devices return information (their measure) to the system Mouse returns position information Keyboard returns ASCII code
- 6. Incremental (Relative) Devices Devicessuch as the data tablet return a position directly to the operating system Devices such as the mouse, trackball, and joy stick return incremental inputs (or velocities) to the operating system Must integrate these inputs to obtain an absolute position Rotation of cylinders in mouse Roll of trackball Difficult to obtain absolute position Can get variable sensitivity
- 7. Keyboards The QWERTYlayout is standard on most PCs Enhanced keyboard features include number, function, and navigation keys. 7
- 8. Dvorak Keyboards Putsthe most commonly used keys on “home keys” Reduces distance of finger stretches 8
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- 10. Mouse 10 A pointing devicethat fits comfortably under the palm of your hand The most widely used pointing device on desktop Computers The mouse controls the movement of the pointer, also called the mouse pointer, on the screen
- 11. Mechanical Mouse Arubber or metal ball is on its underside When the ball rolls in a certain direction, electronic circuits in the mouse translate the movement of the mouse into signals the computer understands A mouse pad provides better traction and protects the ballfrom a build up of dust and dirt
- 12. Optical Mouse Usesdevices that emit & sense light to detect the mouse’s movement Some use optical sensors; others use laser More precise than a mechanical mouse & does not require cleaning Slightly more expensive 12
- 13. Track Ball &Space ball
- 14. Trackball and Spaceball Trackball It is a pointing device similar to a mouse. mainly used in notebook or laptop computer, instead of a mouse. This is a ball which is half inserted, and by changing fingers on the ball, the pointer can be moved. Spaceball similar to trackball, but can move in six directions where trackball can move in two directions only. movement is recorded by the strain gauge. Strain gauge is applied with pressure. It can be pushed and pulled in various directions. The ball has a diameter around 7.5 cm. The ball is mounted in the base using rollers. One-third of the ball is an inside box, the rest is outside.
- 15. Joysticks pointing deviceused to change cursor position on a monitor screen. Joystick is a stick having a spherical ball as its both lower and upper ends lower spherical ball moves in a socket. The joystick can be changed in all four directions. function of a joystick is similar to that of the mouse. mainly used in Computer Aided Designing (CAD) and playing computer games.
- 16. Data Glove inputdevice essentially a glove worn on the hand that contains various electronic sensors that monitor the hand's movements and transform them into a form of input applications such as virtual reality and robotics. Some datagloves enable and to apply fine-motion control. tactile sensing, allowing the user to seemingly feel a virtual object
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- 19. Touch Panels touchpanels allow displayed objects or screen positions to be selected with the touch of a finger. A typical application of touch panels is for the selection of processing options that are represented with graphical icons.
- 20. Light Pens lightsensitive pen-like input device used to select objects directly on the computer screen . used for making drawing, graphics and for menu selection. Figures and drawings can be made by moving the pen on computer screen.
- 21. Digitizers digitizer isan operator input device contains a large, smooth board (the appearance is similar to the mechanical drawing board) & an electronic tracking device, which can be changed over the surface to follow existing lines. The electronic tracking device contains a switch for the user to record the desire x & y coordinate positions. The coordinates can be entered into the computer memory or stored or an off-line storage medium such as magnetic tape. One type of digitizer is the graphics tablet
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- 23. Scanning Devices Copydata from a source Types of scanners Optical scanner Bar code readers Character and Mark recognition 23
- 24. Optical Scanners Copytext or images Can be displayed, printed, or stored Types of optical scanners Flatbed scanner Source placed on glass surface Image scanned from below Portable scanner Handheld device that slides across source 24
- 25. Bar Code Readers Photoelectric scanner Read bar codes Alternating black & white vertical bars Universal Product Code (UPC) Seen in grocery stores, retail stores 25
- 26. Character & MarkRecognition Magnetic-ink character recognition (MICR) Reads magnetically encoded characters Optical-character recognition (OCR) Reflects light off special preprinted characters Optical-mark recognition (OMR) Senses presence or absence of marks 26
- 27. Image Capturing Devices Create or capture original images Digital camera Image recorded digitally to memory Digital video cameras Capture motion Webcams Capture images for broadcast on Internet 27
- 28. Audio-Input Devices Convertsound into digital format Voice recognition system Operate computer by voice command Dictation Microphone, sound card, software Discrete Continuous 28
- 29. Voice Recognition SystemsTypes Recognize individual words based on sound Discrete-speech recognition Cannot distinguish same-sound words Continuous-speech recognition Can distinguish same-sound words Evaluates context of words 29
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- 31. Output Processed datafrom a computer Text, graphics, photos, audio, video Common output devices Monitor Printer Plotter Voice 31
- 32. Monitors Most frequentlyused output device Size is measured by diagonal of screen Common sizes: 15, 17, 19, 21 inches Clarity is indicated by resolution Measured in pixels More pixels = better clarity 32
- 33. Monitor Standards Resolutioncapabilities indicated by a monitor’s standard Super Video Graphics Array (SVGA) Extended Graphics Array (XGA) Super Extended Graphics Array (SXGA) Ultra Extended Graphics Array (UXGA) 33
- 34. Monitor Types Cathode-RayTubes (CRT) Most common Flat-panel monitors Passive-matrix Active-matrix eBook readers Data projectors High-definition television (HDTV) 34
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- 36. Printers Produces hardcopy output Ink-jet printer Sprays droplets of ink Laser printer Laser produced images Thermal printer Heated element produce image on heat sensitive paper 36
- 37. Other Printers Dot-matrix Series of pins on print head Inexpensive, not high quality Chain printer Used on networks Plotter Maps, architectural drawings High quality, larger sized output 37
- 38. Audio Output Devices Translate computer data into understandable sounds MP3 files Components Sound card Speaker system or headphones 38
- 39. Combination Input/Output Devices Devices are combined into one device Save room Specialized applications Fax machine Multifunctional device Telephony Terminals 39
- 40. Fax Machine Facsimiletransmission machine Sends and receives images across telephone lines Fax/modem board Give computer same capability 40
- 41. Multifunctional Device Combines Scanner Printer Fax machine Copying machine Cost effective Saves space Popular in small offices or home 41
- 42. Telephony Uses Internetrather than traditional communication lines Requires Internet telephone Internet Special service provider 42
- 43. Terminals Devices connectedto servers Input and output Types Dumb terminal Intelligent terminal Network terminal Internet terminal 43
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