INPUT/OUTPUT PRINTER,SCANNER AND MONITOR

1. INPUT/OUTPUT PRINTER,SCANNER AND MONITOR Introduction Computer Hardware Jess Role @UEAB 2006

2. What is input? Any data or instructions you enter into the memory of the computer Users can input data and instructions in a variety of ways What Is Input? Introduction Computer Hardware Jess Role @UEAB 2006

3. What are two types of input? Data A collection of raw unprocessed facts, figures, and symbols Instructions Programs Commands User responses USER RESPONSESYes, the timecard entries are correctNo, the timecard entries are not correct COMMANDSprint the timecard PROGRAMStimecard What Is Input? DATA Bradley Kinkade 42 hours $12.50 per hour hard disk INSTRUCTIONS Introduction Computer Hardware Jess Role @UEAB 2006

4. What are the three forms of instructions? Program A series of instructions that tells a computer how to perform the tasks necessary to process data into information User response An instruction you can issue by replying to a question that a computer program displays Command An instruction given to a computer program Users can issue commands by typing or pressing keys on the keyboard, clicking a mouse button, speaking into a microphone, or touching an area of a screen What is Input? Introduction Computer Hardware Jess Role @UEAB 2006

5. What are two features of most programs today? Menu-driven program Provides menus as a means of entering commands Menus contain a list of options from which you select icons menu icons buttons What is Input? • Graphical user interface (GUI) • Uses icons, buttons, and other graphical objects that allow you to select and issue commands Introduction Computer Hardware Jess Role @UEAB 2006

6. What is an input device? Any hardware component that allows you to enter data, programs, commands, and user responses into a computer voice input video input keyboard scanners and reading devices pointing device digital camera What are Input Devices? Introduction Computer Hardware Jess Role @UEAB 2006

7. What is a keyboard? An input device that contains keys you press to enter data into the computer Typing area Letters of the alphabet, numbers, punctuation marks, and other basic keys function keys typing area numeric keypad The Keyboard • Numeric keypad • Calculator-style arrangement of keys • Function keys • Special keys programmed to issue commands toa computer Introduction Computer Hardware Jess Role @UEAB 2006

8. What are some special types of keys? SHIFT, CTRL, ALT and others Used in combination with other keys to issue commands pointer insertion point The Keyboard • Toggle key • Switches between two different states such as the NUM LOCK or CAPS LOCK keys • Keys to position the insertion point • Insertion point is a symbol that indicates where on the screen the next character you type will display Introduction Computer Hardware Jess Role @UEAB 2006

9. What is an ergonomic keyboard? Designed to minimize strain on your hands and wrists The Keyboard • Ergonomics incorporates comfort, efficiency, and safety into the design of items in the workplace Introduction Computer Hardware Jess Role @UEAB 2006

10. What is a pointing device? An input device that allows you to control a pointer on the screen A pointer is a small symbol on the screen The pointer takes several shapes I-beam block arrow pointing hand Pointing Devices Introduction Computer Hardware Jess Role @UEAB 2006

11. What is a mouse? A pointing device that 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 Mouse Introduction Computer Hardware Jess Role @UEAB 2006

12. A rubber 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 How does a mechanical mouse work? mouse pad mouse buttons wheel button ball Mouse • A mouse pad provides better traction and protects the ball from a build up of dust and dirt Introduction Computer Hardware Jess Role @UEAB 2006

13. How does an optical mouse work? Uses devices that emit and sense light to detect the mouse’s movement Some use optical sensors; others use laser More precise than a mechanical mouse and does not require cleaning Slightly more expensive wheel button back button forward button optical sensor Mouse Introduction Computer Hardware Jess Role @UEAB 2006

14. Point Click Right-click Double-click Drag Right-drag Rotate wheel Press wheel button What are some common mouse operations? Point Click Right-click Double-click Move the mouse across a flat surface until the pointer on the desktop rests on the item of choice Press and release the primary mouse button, which usually is the left mouse button Point to an item, hold down the left mouse button, move the item to the desired location on the screen, and then release the left mouse button Press the wheel button while moving the mouse on the desktop Point to an item, hold down the right mouse button, move the item to the desired location on the screen , and then release the right mouse button Press and release the secondary mouse button, which usually is the right mouse button Quickly press and release the left mouse button twice without moving the mouse Roll the wheel forward or backward Drag Right-drag Rotate wheel Press wheel button Other Pointing Devices Introduction Computer Hardware Jess Role @UEAB 2006

15. What is a trackball? A stationary pointing device with a ball on its top To move the pointer, you rotate the ball with your thumb, fingers, or the palm of your hand trackball Other Pointing Devices? Introduction Computer Hardware Jess Role @UEAB 2006

16. What is a touchpad? Also called a trackpad touchpad Other Pointing Devices • A small flat, rectangular pointing device that is sensitive to pressure and motion • Typically built onto keyboards of laptop or notebook computers Introduction Computer Hardware Jess Role @UEAB 2006

17. What is a stylus? Used in professional graphical applications A graphics tablet, also called a digitizer or digitizing tablet, is a flat rectangular, electronic plastic board used with a stylus stylus or pen Other Pointing Devices • Looks like a ballpoint pen, but uses pressure to write text and draw lines • Originally called a pen or electronic pen Introduction Computer Hardware Jess Role @UEAB 2006

18. What is handwriting recognition software? Some notebooks and many handheld computers have touch screens that allow you to input data using a stylus Other Pointing Devices • Software translates handwritten letters and symbols into characters that the computer understands Introduction Computer Hardware Jess Role @UEAB 2006

19. What is audio input? The process of entering any sound into the computer such as speech, music, and sound effects Requires a sound card Input sound via a device such as a microphone, tape player, CD player, or radio Windows stores audio files as waveforms Called WAV files with a .wav extension Voice Input Introduction Computer Hardware Jess Role @UEAB 2006

20. How does voice recognition work? You’re right! Natural Language Engine your, you’re right, write …Your write…You’re right…Your right Matches Voice Input Step 1: User dictates text into microphone. Step 2: An analog-to-digital converter (ADC) translates sound waves into digital measurements the computer can understand. Measurements include pitch, volume, silences, and phenomes. Phenomes are sound units such as aw and guh. Step 3: The software compares the spoken measurements to those in its database to find a match or list of possible matches. Step 4: To narrow a list down, the software presents the user with a list of choices or uses a natural language component to predict the most likely match. The user may correct any wrong selection made by the software. Introduction Computer Hardware Jess Role @UEAB 2006

21. What is MIDI? An external device such as an electronic piano keyboard used to input music and other sound effects Music is stored in the computer Voice Input Introduction Computer Hardware Jess Role @UEAB 2006

22. What is a digital camera? Allows you to take pictures and store the photographed images digitally Images are viewable immediately on the camera Digital Cameras • You can download, or transfer a copy of the pictures from the camera to the computer • Images can be edited, printed, or posted on a Web site or photo community Introduction Computer Hardware Jess Role @UEAB 2006

23. What is resolution? The sharpness and clearness of an image The higher the resolution, the better the image quality, but the more expensive the camera A pixel (picture element) is a single point in an electronic image Digital Cameras • In digital images the pixel is a tiny square • The greater the number of pixels, the better the quality of the image Introduction Computer Hardware Jess Role @UEAB 2006

24. What is video input? The process of entering a full-motion recording into a computer and storing it on a storage medium Also called video capture digital video camera video-in plug analog video camera Video Input • A video capture card is an expansion card that converts the analog video signal into a digital signal that a computer can understand • A digital video (DV) camera is a video camera that records video as digital signals Introduction Computer Hardware Jess Role @UEAB 2006

25. What are some factors related to video input? Video files can require huge amounts of storage space Video compression is used to decrease the size of the files Files can be compressed using software or hardware video digitizer Used to capture an individual frame from an analog video and then save the picture in a file video decoder A card that decompresses video data Video Input Introduction Computer Hardware Jess Role @UEAB 2006

26. What is a scanner? A device that captures data directly from source documents A source document is the original form of the data Scanners and Reading Devices Introduction Computer Hardware Jess Role @UEAB 2006

27. What is an optical scanner? Usually called a scanner A light-sensing input device that reads printed text and graphics and then translates the results into a form the computer can use Scanners and Reading Devices • A flatbed scanner, a more popular type, works similarly to a copy machine except it creates a file of the document in memory instead of a paper copy Introduction Computer Hardware Jess Role @UEAB 2006

28. What is optical character recognition (OCR)? A technology that involves reading typewritten, computer-printed, or handwritten characters from ordinary documents and translating the images into a form that the computer can understand Software Works with an optical scanner to convert a scanned image into a text file that can be edited OCR device Includes a small optical scanner for reading characters and sophisticated software for analyzing what is read Scanners and Reading Devices Introduction Computer Hardware Jess Role @UEAB 2006

29. What is a bar code scanner? Uses laser beams to read bar codes Scanners and Reading Devices Introduction Computer Hardware Jess Role @UEAB 2006

30. Why are computers important for those with physical limitations? Americans with Disabilities Act (ADA) requires any company with 15 or more employees make reasonable attempts to accommodate the needs of physically challenged workers Many input devices address the needs of users with physical limitations Input Devices for Physically Challenged Users Introduction Computer Hardware Jess Role @UEAB 2006

31. What is a keyguard? A metal or plastic plate placed over the keyboard Input Devices for Physically Challenged Users • Allows users to rest their hands on the keyboard without accidentally pressing any keys • Also guides a finger or pointing device so a user presses only one key at a time • For users with limited hand mobility Introduction Computer Hardware Jess Role @UEAB 2006

32. What is an on-screen keyboard? A graphic of a standard keyboard that displays on the user’s screen A pointing device is used to press the keys Input Devices for Physically Challenged Users Introduction Computer Hardware Jess Role @UEAB 2006

33. What options are available for users with motor disabilities? A handheld switch can be used as a pointing device A portable computer or pointing device can be mounted to a wheelchair People with limited hand movement can use a head-mounted pointer Input Devices for Physically Challenged Users Introduction Computer Hardware Jess Role @UEAB 2006

34. What are new developments in computing that will benefit physically challenged users? Developments now in the prototype stage attempt to provide users with a natural computer interface • Implantation • For paralyzed or speech impaired individuals • A doctor will implant a computerized device containing a transmitter into the brain • As the users thinks, the transmitter will send signals to the computer • Gesture recognition • Computer will be able to detect human motions • Computers with this capabilities have the potential to recognize sign language, read lips, track facial movements, or follow eye gazes Input Devices for Physically Challenged Users Introduction Computer Hardware Jess Role @UEAB 2006

35. What is output? Data that has been processed into a useful form, called information A computer generates several types of output What is Output? Text Graphics Video Audio Introduction Computer Hardware Jess Role @UEAB 2006

36. What is text? Consists of characters that create words, sentences, and paragraphs What is Output? What is a graphic? • Also called a graphical image • A digital representation of non-text information such as a drawing, chart, and photograph Introduction Computer Hardware Jess Role @UEAB 2006

37. What is audio? Music, speech, or any other sound What is Output? • Consists of full-motion images that are played back a various speeds • Most video also has accompanying audio What is video? Introduction Computer Hardware Jess Role @UEAB 2006

38. What is an output device? Any hardware component that can convey information to a user monitor speakers printer What are Output Devices? Introduction Computer Hardware Jess Role @UEAB 2006

39. What is a display device? Also called a display An output device that visually conveys text, graphics, and video information Information on a display device is sometimes called soft copy Display Devices Introduction Computer Hardware Jess Role @UEAB 2006

40. Contains a cathode ray tube (CRT), a large sealed, glass screen The screen is coated with tiny dots of phosphor material A pixel, or picture element, is a single point in an electronic image Three dots (red, blue, and green) combine to make up each pixel What is a CRT monitor? cathode ray tube CRT monitor screen Display Devices Introduction Computer Hardware Jess Role @UEAB 2006

41. What are typical sizes for CRT monitors? 15, 17, 19, 21, and 22 inches Monitor measured diagonally from one corner of the casing to the other The viewable size is the diagonal measurement of the actual viewing area provided by the monitor screen size viewable size Display Devices Introduction Computer Hardware Jess Role @UEAB 2006

42. What is a liquid crystal display (LCD) monitor? A type of flat-panel display Uses liquid crystals between two sheets of material to present information on a screen An electric current passes through the crystals which creates the images on the screen Display Devices Introduction Computer Hardware Jess Role @UEAB 2006

43. Where are some features of LCD screens? Lightweight and compact Consumes less than one-third of the power than does a CRT monitor Come in a variety of sizes Ideal for notebook and handheld computers Display Devices Introduction Computer Hardware Jess Role @UEAB 2006

44. What is display resolution? Describes the sharpness and clearness of an image Resolution of a display device stated as dots, or pixels 800 x 600typically the standard 800 horizontal pixels 1280 x 1024maximum resolution of most monitors 600 vertical pixels 2048 x 1536maximum for high-end monitors Display Devices Total of 480,000 pixels on screen Introduction Computer Hardware Jess Role @UEAB 2006

45. What is dot pitch? Another factor used to measure image clarity Sometimes called pixel pitch The distance between each pixel on a display The smaller the distance between the pixels, the sharper the image Use a monitor with a dot pitch of .29 millimeters or lower to minimize eye fatigue Display Devices Introduction Computer Hardware Jess Role @UEAB 2006

46. What is refresh rate? Another factor in a monitor’s quality Also called vertical frequency or vertical scan rate The speed that a monitor redraws images on the screen Measured according to hertz, which is the number of times per second the screen is redrawn Should be fast enough to maintain a constant, flicker-free image A high-quality monitor will provide a refresh rate of at least 75 hertz The image on the screen redraws itself 75 times in a second Display Devices Introduction Computer Hardware Jess Role @UEAB 2006

47. What is a video card? Converts digital output from the computer into an analog video signal Sends the signal through a cable to the monitor Controls how the display device produces the picture Also called a graphics card or video adapter Display Devices Introduction Computer Hardware Jess Role @UEAB 2006

48. How does video travel from the processor to a CRT monitor? Step 1 Step 1 Step 1 Step 1 Step 1 Step 1 Step 2 Step 2 Step 2 Step 2 Step 2 Step 3 Step 3 Step 3 Step 3 Step 4 Step 4 Step 4 Step 5 Step 5 Step 6 Display Devices Step 1: The processor sends digital video data to the video card. Step 2: The video card’s digital-to-analog converter (DAC) converts the digital video data to an analog signal. Step 3: The analog signal is sent through a cable to the CRT monitor. Step 4: The CRT monitor separates the analog signal into red, green, and blue signals. Step 5: Electron guns fire the three color signals to the front of the CRT. Step 6: An image displays on the screen when the electrons hit phosphor dots on the back of the screen. Introduction Computer Hardware Jess Role @UEAB 2006

49. What is a printer? An output device that produces text and graphics on a physical medium such as paper or transparency film A hard copy, or printout, exists physically Two orientations portrait orientation landscape orientation Printers Introduction Computer Hardware Jess Role @UEAB 2006

50. What is an ink-jet printer? A type of nonimpact printer that forms characters and graphics by spraying tiny drops of liquid ink onto a piece of paper Usually uses individual sheets of paper stored in a removable or stationary tray The most popular type of color printer for use in the home Printers Introduction Computer Hardware Jess Role @UEAB 2006