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Looking_at_Computers___Chapter_2 - Looking at Computers...

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Unformatted text preview: Looking at Computers: Looking at Computers: Understanding the Parts Introduction to Business Systems MAN 2812 Dr. Suarez I/O Devices I/O Devices Way we communicate with computers Input Translate our data and communications into a form that computer understands Computer processes information Output Translates information back into form that users can understand Your Computer’s Hardware Your Computer’s Hardware Parts you can actually touch System Unit Peripheral Devices Monitors and Printers Together perform four main functions: •Input Data •Process that Data •Output •Store the Data Traditional Input Devices Traditional Input Devices Keyboard Point and Draw Devices GUI Mouse Trackball Digitizer tablet and pen Joy stick Other Input Devices Other Input Devices Speech Recognition Vision­Input Systems Speak to the computer with basic vocabulary System accepts your spoken words and executes task Specialized tasks – few images are encountered Digital camera – computer digitizes images of all objects to be identified, stores in a database Computer compares new object to images in database Digital Cameras Digitized image processed on diskette, CD or memory to be uploaded and manipulated Input Devices (cont.) Input Devices (cont.) Handheld Data Entry Devices Small computer Limited external keyboard or soft keyboard Small display Storage capability for data Scanning devices Output Devices Output Devices Enable us to view or hear the processed data Types of output devices: Monitors Printers Speakers Output Devices Output Devices Monitors and Graphics Adapters Graphic Adapters Resolution (detail of the display) pixels, number of bits used to represent each pixel the Dot pitch of the monitor – distance btw centers of pixels Pixel – addressable point on the screen (dot pitch) Flat panel monitors – less than ½ inch thick LCD – active or passive matrix Device controller for monitor Electronic link between monitor and computer Video RAM – min of 8 MB Active – high refresh rates and better contrast Touch screen monitors CRT Monitors 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) LCD Monitors LCD Monitors Liquid crystal sandwiched between two transparent layers form images Used for notebook computers, PDAs, cellular phones, and personal computers Polarizer Color filter Color filter glass Liquid Crystal Glass polarizer Backlight CRT vs LCD CRT vs LCD CRT MONITOR ADVANTAGES Images viewable from all angles (LCD monitors often have limited viewing angle) Resolution can be adjusted more completely Better color accuracy and clarity Less expensive than LCD monitors Better for gaming and watching DVDs due to quicker pixel response time and higher color accuracy LCD MONITOR ADVANTAGES Take up less space and weigh less than CRT monitors Cause less eyestrain than CRT monitors More environmentally friendly than CRT monitors Larger viewable area compared with similar sized CRT (17­inch viewable area on 17­inch monitor compared with 15­inch viewable area) Desktop Printers Desktop Printers Laser printers Ink­Jet printers Print head moves back and forth 4 to 12 ppm Dot­Matrix printers 4 to 32 pages per minute dpi ­ # of dots printed per linear inch Very quiet – most expensive Impact printer Forms images one character at a time Multi­function peripheral Printer, fax, scan and copy Choosing a Printer Choosing a Printer Speed: Pages per minute (ppm) Inkjets print 2­6 ppm Lasers print 20­30 ppm Resolution: Image clarity Dots per inch (dpi) 300 dpi for general printing 1200 dpi for printing photos Color output: Quality of color images Inkjets use 4 or 6 color cartridges Lasers use separate color toner cartridges Memory: Inkjets need 4­8 MB Lasers need 16 MB Cost: Inkjets are inexpensive Lasers are more expensive NEXT SLIDE Presentation Graphics Presentation Graphics Multi­media projectors Two categories: LCD panels – Notebook size used with overhead projectors LCD projectors – Use own built­in lens and light source to project image on screen Terminals Terminals Video Display Terminal (VDT) General purpose – traditional Input – keyboard Output – monitor Special Function ATM POS – point of sale – Used by clerks and salespeople in retail stores Keypad for input, monitor and printer – Check Sales Price – Gift Registry The System Unit The System Unit Processes data into information The system unit components: Front panel Back Power supply Hard disk drive Motherboard Expansion cards The Front Panel The Front Panel Power controls Drive bays Drive bays Ports Floppy drive Power button Memory card reader Productivity ports The Back The Back Ports for peripheral devices Types of ports: e us o Serial Parallel VGA USB Connectivity M /2 S P y Ke b d ar o l ria Se l lle a ar P GA V w et N rk o B / US ker one ah pe rop S ic m The Motherboard The Motherboard Click on the motherboard components for details NEXT SLIDE Memory Module Memory Module Random access memory (RAM) Primary storage Stores instructions and data Temporary (volatile) storage Operates in nanoseconds Central Processing Unit (CPU) 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 Expansion Cards Expansion Cards Augment the computer’s basic functions Provide connections for peripheral devices Common types: Sound Modem Video (VGA) Network (NIC) Expansion Slots Expansion Slots Provide connections for expansion cards Types include: Industry Standard Architecture (ISA) Peripheral Computer Interconnect (PCI) Video Graphics Adapter (VGA) Hard Disk Drive Hard Disk Drive Stores data and program instructions Permanent (nonvolatile) storage Storage capacities up to 250 GB Transfers data in milliseconds NEXT SLIDE Setting it all up: Ergonomics 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 NEXT SLIDE ...
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