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What does a PC do?. computers collect , process , store , and communicate information Collect via input devices: mouse, keyboard, scanner, digital camera Process via CPU Store onto storage devices: hard disk, CD ROM, tape drive
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What does a PC do? • computers collect, process, store, and communicate information • Collect via input devices: mouse, keyboard, scanner, digital camera • Process via CPU • Store onto storage devices: hard disk, CD ROM, tape drive • Communicate via output devices: monitor, printer, speakers, robot Sheffield Hallam University
Input Devices Sheffield Hallam University
Storage Sheffield Hallam University
Output Devices Sheffield Hallam University
Communications Sheffield Hallam University
Important Units • Bit (Binary Digit, 0 or 1) is the smallest unit of info a computer can process • Byte is eight bits - amount needed to represent one alpha-numeric character. • Kilobyte (KB) is 1024 bytes, roughly half a page of text • Megabyte (MB) is 1024 kilobytes • Gigabyte (GB) is 1024 megabytes Sheffield Hallam University
Power Supply • converts mains (AC) electricity to DC • PC uses 200 Watts, one unit of electricity every five hours • Fan prevents parts from overheating and keeps case size as small as possible • Surge Protectors (optional) protect against voltage spikes • Uninterruptable Power Supply (UPS, also optional) protects a computer from loss of power Sheffield Hallam University
Ports • Connectors at the back of the computer where you plug in a peripheral device • modem, printer, mouse, keyboard • Serial ports have 9 pins • Labelled COM1, COM2 • Connect to mouse or modem • Parallel ports have 25 connections • Labelled LPT1, LPT2 • Connect to printers or tape drives Sheffield Hallam University
More Ports • Keyboard ports • Games ports • USB - Universal Serial Bus • allows several devices to be connected via only one port • fast data transfer rate Sheffield Hallam University
Expansion Cards/Boards • circuit boards that let you add a new feature to the computer • PCs have a number of expansion slots • Buy a PC with plenty of slots spare • Most cards go into the motherboard • Some plug into the back (Notebooks and Laptops) Sheffield Hallam University
Types of Expansion Card • Video - generates images to display on monitor • Modem - allows computers to exchange information via telephone lines • Sound - play and record audio • Network - to allow connected computers to share information and peripherals Sheffield Hallam University