1 / 50

Chapter Topics

Chapter Topics. Chapter 2 Looking at Computers: Understanding the Parts Functions of a computer Data versus information Bits and bytes Input devices Output devices System unit Ergonomics. Computers Are Data Processing Devices. Computer’s four major functions:

jonah
Télécharger la présentation

Chapter Topics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter Topics Chapter 2 Looking at Computers: Understanding the Parts • Functions of a computer • Data versus information • Bits and bytes • Input devices • Output devices • System unit • Ergonomics

  2. Computers Are Data Processing Devices • Computer’s four major functions: • Gathers data (users input data) • Processes data into information • Outputs data or information • Stores data and information

  3. Data vs. Information • Data: Representation of a fact, figure, or idea • Information: Organized, meaningful data

  4. Bits and Bytes: The Language of Computers • Bit • Binary digit • 0 or 1 • Byte • Eight bits • Each letter, number, and character = a string of eight 0s and 1s

  5. How Much Is a Byte?

  6. Metric prefixes

  7. Computer Hardware Hardware: Any part of the computer you can touch.

  8. Computer Software • Software: Programs that enable hardware to perform different tasks • Application software • System software

  9. Types of Computers • Notebook: Portable computer • Desktop: Used at a single location • Mainframe: Supports hundreds of users simultaneously • Supercomputer: Performs complex calculations rapidly • Embedded: Self-contained computer performing dedicated functions

  10. Input Devices • Devices used to enter information or instructions into the computer • Keyboard • Mouse/pointing device • Microphone • Scanner • Digital camera • Stylus

  11. Keyboards • The QWERTY layout is standard on most PCs • Enhanced keyboard features include number, function, and navigation keys.

  12. Notebook Keyboard • trackpoint • touchpad • number pad • Notebook keys – fn key in conjunction with function key does special function such as volume trackpoint Fn key Touchpad

  13. Dvorak Keyboards • Puts the most commonly used keys on “home keys” • Reduces distance of finger stretches • Not enough interest to change from QWERTY though

  14. Virtual laser, Tablet and stylus • Virtual laser keyboard • Configurable keyboard

  15. Digital pen • Stores what you “write”, later transfer to computer

  16. Wireless RF keyboard • With the RF (radio frequency) wireless technology, the keyboard contains a transmitter that transmits the radio waves to a receiver that sits next to the keyboard and is attached to the tower. (upto 100 ft) • Bluetooth wireless keyboard is a shorter range wireless RF keyboard

  17. Mice • Optical mouse • Doesn’t need as dirty • no mouse pad necessary • Trackball • Easier on wrists • Stays stationary on desk • Wireless • Use radio or light waves • Integrated pointing device • Touchpad • Trackpoint

  18. Other Input Devices • Scanners • Text • Images • Digital cameras • Images • Video Flatbed scanner Handheldscanner Digital camera Camcorder

  19. Other Input Devices • Game controllers • Touchscreens • DS game • Tablet PC (see pic) • Digital pens

  20. Image Input • Digital cameras, camcorders, and cell phones • Pictures • Video • Webcams • Live video

  21. Inputting Sound • Microphones used for: • Podcasts • Video-conferencing • Internet phone calls • Speech recognition

  22. Input Devices for the Physically Challenged • Visual impairments • Voice recognition • Keyboards with large keys • On-screen keyboards • Motor control issues • Special trackballs • Head-mounted devices

  23. Output Devices • Send processed data out of the computer • Monitors • Printers • Output devices make: • Soft copies (video, sounds, control signals) • Hard copies (print)

  24. CRT Cathode Ray Tube Less expensive Better viewing angles More adjusting allowed of of the resolution settings Better color accuracy Preferred for gaming A 17” monitor IS less than17” legacy LCD Liquid Crystal Display Price is dropping Uses far less space More energy efficient More environmentally friendly Less eye strain A 17’’ monitor IS 17” brighter Monitor Types and advantages

  25. LCD Monitor Features • Screens are grids made up of millions of pixels. • (pixel = picture elements, dots on screen) • Each pixel is composed of red, blue, and green subpixels • LCDs: Liquid crystal, light waves, etc result in variations of red, green blue colors of images formed n scrn (CRTs: Pixels illuminated by electron beam that passes back/forth across screen.)

  26. LCD Quality Factors (recommended measures in parentheses) : • Resolution - depends on # of pixels on screen; (native resolution is the maximum resolution) • Viewing angle - poorer angles than the CRT (degrades after 150 degrees) • Contrastratio - Diff between brightest white & darkest black (400:1 or 1000:1) • Brightness - amt of light when showing pure white(300 cd/m2) • Response time – time for pixel to change color (smaller # better; for movies, games)

  27. Screen Size • 21” monitor: 1680x1050 pixels (typical resolution) • 19” monitor: Some resolutions: 1440x900, 1280x1024 • Need 1920x1080 for hi-def movies • Wide screen vs. standard 4:3 ratio; wide good for 2 documents viewed at once... • Large resolution fits more on screen (images are smaller); Small res fits less (images are larger)

  28. Other Video Output • Touch-screen monitors • Double as both input and output devices • Monitors w/ built-in cam, mic, card reader, USB hub • Data projectors • Project a computer image to wall for sharing with group

  29. Printers • Impact printers • Dot-matrix • Nonimpact printers • Inkjet • Laser • Specialty printers • All-in-one • Plotters • Thermal printers

  30. Inkjet Less expensive device Print high-quality color images cost effectively Laser More expensive device Faster printing speed Color lasers are becoming less expensive Nonimpact Printers

  31. Inkjet (spray tiny drops of ink. ) Entry level model is less expensive Full color printing – excellent choice for photo printing Laser (uses toner) There are B & W laser printers and color laser printers (Color lasers very expensive) Excellent quality, quiet Nonimpact PrintersInkjet and Laser • When purchasing a printer consider price of consumables (ex: cartridges and toner), speed (ppm, pages per minute), resolution (dpi, dots per inch) , memory, color

  32. The Motherboard • CPU • RAM (S+T) • Expansion cards and slots • Built-in components

  33. Expansion Cards • Add functions • Provide new connections for peripheral devices • Common types: • Sound • Modem (telephone) • Video (VGA or graphics) • Network (NIC=network interface card)

  34. RAM vs. ROM • Random access memory (RAM): • Stores instructions and data • Temporary (volatile) storage • Consists of several memory cards or modules • Read-only memory (ROM): • Stores start-up instructions • Permanent storage

  35. Memory Module • Random access memory (RAM) • Stores instructions and data temporarily • (copy of program instructions and current files goes into RAM) • Temporary (volatile) storage • Operates in nanoseconds • Common size: 2-8GB

  36. Central Processing Unit (CPU) • Referred to as the “brains” of the computer • Controls all functions of the computer • Processes all commands and instructions • Can perform billions of tasks per second • Common speed: 2-3 ghz (gigahertz) • 3 ghz = ~ 3 billion machine cycles per sec

  37. CPU Performance Measures • Speed - common 2-3 ghz • 3 GHz ~ 3 billion machine cycles per sec • Megahertz (MHz) • Gigahertz (GHz); • Cores (simultaneous paths executing instruct’s; see picture on right) • Single • Dual • Quad

  38. Drive Bays • Internal drive bays: • Cannot be accessed from outside the system • Are reserved for internal hard drives • External drive bays: • Can be accessed from outside the system • CD or DVD drives • Floppy and Zip drives (legacy technology)

  39. The Front Panel • Power control • Drive bays • Memory card reader • Productivity ports

  40. Hard Drive • Permanent storage • Internal or external versions • Stores data, program instructions as they are running • (Completes tasks in millisecsvs RAM’s nanosecs.) • (Spin rate: 5400, 7200 rpm) • Common: 500 GB, 640 GB, 1TB, 2TB • (T=Tera, trillion)

  41. Optical Storage • Compact discs (CDs) • Digital video discs (DVDs) • Blu-ray discs (BDs)

  42. StorageMediaCapabilities See p71 (8e), teacher notes Typo: DVD DL is 8.5 GB not 88.5

  43. Flash Drives/Flash Memory • Flash drives (jump drives) • Newer storage alternative • Plug into USB ports • Flash memory cards • Slide into slots in the system

  44. Types of Ports • USB • Serial and parallel • Audio and video • FireWire • Connectivity • Ethernet • Modem

  45. Ports for peripheral devices • Types of ports w/ speeds (= transfer rates): • Serial 115K bps, • Parallel 500K bps • USB 480Mbps (2.0) • USB 4800M bps (3.0) • Ethernet 100M,1000M bps • Tele. modem 56K bps • FireWire (or 1394) • 400M bps, 800M bps, and • 3.2G bps (= 3200M bps) • Audio ports • VGA (monitor), DVI, s-video • HDMI

  46. Adding Ports • Expansion cards: • New port standards • Expansion hubs: • Enable several devices to be connected to a port

  47. Power Controls Power-on button: Turns onsystem; Use Shut Down procedure or may use Power button to turn off. • Called a cold boot when turned on for the first time that day (Warm boot is restart) • Keep computer on but use conservation of energy:Sleep mode, Hibernate • Only turn off computer if use it very little • Change power settings: Control Panel (icon view) > Power Options

  48. Ergonomics (1) • Ergonomics – procedures, equipment for minimizing injury or discomfort while using the computer (minimize RSI - repetitive stress injury) • Steps to follow: • Position monitor correctly (eyse at top of monitor) • Use adjustable chair (back of knees not pressed against chair that is too high, feet on floor) • Wrists flat over keyboard, not presses on edge of table • Take breaks • Ensure adequate lighting

  49. Ergonomics (2) • Play PMPs (personal media players) at 60 decibels or less • Small screens – blink often, take a break to focus at 8ft • Backpack – place over both shoulders not one

  50. Chapter 2 Summary Questions • What are the 4 main functions of a computer? • What is the difference between data and information? • What are bits and bytes, and how are they measured? • What devices do you use to get data into the computer? • What devices do you use to get information out of the computer? • What’s on the motherboard? • Where are programs and information stored? • How are devices connected to the computer? • How do you set up your computer to avoid strain and injury?

More Related