1. Semester One 2001/2002 Sheffield Hallam University1 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

2. Semester One 2001/2002 Sheffield Hallam University2 Input Devices

3. Semester One 2001/2002 Sheffield Hallam University3 Storage

4. Semester One 2001/2002 Sheffield Hallam University4 Output Devices

5. Semester One 2001/2002 Sheffield Hallam University5 Communications

6. Semester One 2001/2002 Sheffield Hallam University6 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

7. Semester One 2001/2002 Sheffield Hallam University7 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

8. Semester One 2001/2002 Sheffield Hallam University8 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

9. Semester One 2001/2002 Sheffield Hallam University9 More Ports Keyboard ports Games ports USB - Universal Serial Bus –allows several devices to be connected via only one port –fast data transfer rate

10. Semester One 2001/2002 Sheffield Hallam University10 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)

11. Semester One 2001/2002 Sheffield Hallam University11 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