9/23/2011. The box that contains the central electronic components of the computer: 2008 Prentice-Hall, Inc Prentice-Hall, Inc.

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1 Computer Hardware 2008 Prentice-Hall, Inc. 1 THE SYSTEM UNIT 2008 Prentice-Hall, Inc. 2 The box that contains the central electronic components of the computer: CPU/RAM/ motherboard Expansion cards Power supply Storage devices The System Unit 2008 Prentice-Hall, Inc. 3 1

2 Drive bays Memory card reader Floppy drive Productivity ports Power button The Front Panel 2008 Prentice-Hall, Inc. 4 Ports for peripheral devices Types of ports: Serial Parallel VGA DVI USB FireWire The Back 2008 Prentice-Hall, Inc. 5 Inside the System Unit Essential electronic components used to process data Types of components: Power supply Hard disk drives Motherboard CPU Expansion cards 2008 Prentice-Hall, Inc. 6 2

3 The Motherboard The motherboard is the main circuit board holding the essential processing parts CPU RAM Expansion cards Built-in in components 2008 Prentice-Hall, Inc. 7 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 2008 Prentice-Hall, Inc. 8 Memory Module Random access memory (RAM) Primary storage Stores current instructions and data Temporary (volatile) storage Operates in nanoseconds 2008 Prentice-Hall, Inc. 9 3

4 Expansion Cards Adds new functions to your computer Provides new connections for peripheral devices Common types: Sound Modem Video (VGA/DVI) Network (NIC) 2008 Prentice-Hall, Inc. 10 STORAGE DEVICES 2008 Prentice-Hall, Inc. 11 Hard Disk Drive Stores data and program instructions Permanent (nonvolatile) storage Data stored magnetically Storage capacities 250 GB and higher Transfers data in milliseconds 2008 Prentice-Hall, Inc. 12 4

5 Optical Disc Systems Optical discs (such as CDs and DVDs) store data optically using laser beams Can be read-only, recordable, or rewritable CDs hold usually at least 650 MB DVDs hold 4.7 GB (single-sided); sided); 8.5 GB (double-sided) Burning: the process of recording data onto an optical disc Blue Laser Discs The newest rewritable technology uses blue lasers instead of infrared (CDs) or red lasers (DVDs) to store data more compactly (23 GB+); developed for high-definition content 5

6 Flash Memory Systems Use flash memory media No moving parts so more resistant to shock and vibration and require less power (solid state) Very small and so are very appropriate for use with digital cameras, digital music players, handheld PCs, notebook computers, smart phones, etc. 6

7 Flash Memory Media Flash memory card (main type of flash memory) a small card containing flash memory chips and metal contacts CompactFlash Secure Digital (SD) MultiMedia Card (MMC) xd Memory Stick Read by flash memory card reader Flash Memory Drives Flash memory drives consist of flash memory media and a reader in a single self-contained unit Typically small, portable drives that connect via a USB port 7

8 INPUT DEVICES 2008 Prentice-Hall, Inc. 22 Input Devices Devices used to enter data or instructions into the computer Keyboard Mouse / pointing device Microphone Scanner Digital camera Scanne r 2008 Prentice-Hall, Inc. 23 The QWERTY keyboard is standard on most PCs Enhanced features include number pad, function and navigation keys. Keyboard 2008 Prentice-Hall, Inc. 24 8

9 Dvorak Keyboard Puts the most commonly used keys at home keys Reduces distance of finger stretches 2008 Prentice-Hall, Inc. 25 Specialty Keyboards Laptops PDAs Wireless Ergonomic Gaming Laptop PDA Ergonomic 2008 Prentice-Hall, Inc. 26 Rollerball mouse Less expensive Harder to keep clean Trackball Harder to control Stationary on desk Optical mouse Needs no mouse pad Doesn t need cleaning More expensive Game pads Buttons and pointing devices Mouse Stan dard Trac kball Wirel ess Opti cal 2008 Prentice-Hall, Inc. 27 9

10 Other Input Devices Scanners Images Text Digital cameras Still images Video Flatbed Handheld Camera Camcorder 2008 Prentice-Hall, Inc. 28 Input for the Physically Challenged Visually Impaired Voice recognition Keyboards with large keys Touch-screen keyboards Motor control Special trackballs Head-mounted devices 2008 Prentice-Hall, Inc. 29 Inputting Sound Microphone Input Teleconferencing Voice over Internet Protocol (VoIP) Vonage Voice Recognition Microsoft Voice Recognition 2008 Prentice-Hall, Inc

11 OUTPUT DEVICES 2008 Prentice-Hall, Inc. 31 Retrieving information from the computer Output devices Softcopy (video, sounds, control signals) Hardcopy (print out) Output Devices 2008 Prentice-Hall, Inc. 32 Monitor Types CRT Cathode Ray Tube Less expensive Use much more space Uses more energy Better viewing angles LCD Liquid Crystal Display More expensive Uses far less space More energy efficient Less viewable from an angle 2008 Prentice-Hall, Inc

12 CRT Monitors Uses picture tube technology Screen size Diagonal measurement of the screen (15, 17, 19, 21) Resolution Sharpness of the image determined by the number pixels that the screen can display (800 x 600, 1024 x 768, 1600 x 1200) Refresh rate Speed at which the screen is refreshed (60Hz, 75Hz) Faster rate equals less flicker Prentice-Hall, Inc. 34 Liquid Crystal Display Liquid crystals sandwiched between two transparent layers form images Used for notebook computers, PDAs, cell phones, and personal computers Polarizer Color filter Liquid Crystal Color filter glass Glass polarizer Backlight 2008 Prentice-Hall, Inc. 35 Other Video Output Touch-screen monitors double as both input and output devices. Data projectors project a computer image to a large screen for sharing with large groups Prentice-Hall, Inc

13 Printers Impact printers Dot-matrix Nonimpact printers Inkjet Laser Multifunction Specialty printers Plotters Thermal printers Dot-matrix Laser Inkjet Multifunction Plotter Thermal printer 2008 Prentice-Hall, Inc. 37 Nonimpact Printers Inkjet Less expensive device Full color printing Slower in pages per minute (PPM) More expensive per page in B&W Laser More expensive device Black and White (Color lasers are very expensive) Faster in PPM Less expensive in B&W 2008 Prentice-Hall, Inc. 38 Speakers and Headphones Outputting Sound 2008 Prentice-Hall, Inc

14 Setting it all up: Ergonomics Ergonomics refers to minimizing injury or discomfort while using the computer Steps to follow: Position monitor correctly Use adjustable chair Assume proper position while typing Take breaks Ensure adequate lighting 2008 Prentice-Hall, Inc