Introduction to Computers

1. Introduction to Computers

2. Expansion ports • Expansion ports provide connectivity for peripheral devices and include: • Mouse and keyboard ports (may look identical)USB ports often used instead of dedicated ports • Network port – like a phoneconnector but larger • Speaker and microphone • General purpose USB ports • Monitor port, older styleVGA port shown here

3. Usb ports • USB ports are the most frequently used by far • Desktops often have 6 ports (2 front, 4 back) • Most full-size notebooks have 4 USB ports • Smaller notebooks may only have 2 USB ports • Devices using USB connectivity include mouse, scanner, printer, and joystick • Windows detects USB devices when plugged in • Determines type of device and configures it for use • This capability referred to as Plug and Play (PnP)

4. Monitors • Most monitors are LCD flat panel displays • Screen size is measured diagonally • Resolution indicates highest number of pixels (distinct points of color) that can be displayed • Usually quoted as “width x height” in pixels, for example, 1024 pixels across & 768 pixels high • A larger resolution yields a smaller image • You may configure for a resolution less than the maximum to make text and images larger

5. Higher resolution = smaller image • Several resolutions may be used • Screen dimensions are fixed • So as resolution goes up, more pixels must fit in same space • Thus pixels must be smaller • If pixels are smaller, image size will be smaller as well • So to increase text or image size, select a lower resolution 800 x 600 resolution 1024 x 768 resolution

6. Monitor ports • A number of different types of monitor ports have been used over the years • VGA used extensively in years past • Some desktops still provide a VGA port • DVI provided higher resolution than VGA • Apple used mini & micro DVI versions • Does not carry audio while HDMI does • HDMI is the most recent standard • Also has both mini & micro versions

7. Printers • Print quality expressed in dots per inch (dpi) • More dots mean better print quality • Common types of printers • Ink jet – nearly always print in color • Laser – print in black & white or color • Thermal transfer – black & white only • Dot matrix – black & white only • Printers usually connect through a USB port • Older printers may use a Parallel port to connect • Many printers will also connect wirelessly

8. Print speed • Ink jet and laser printer speeds • Expressed in pages per minute (ppm) for B&W text • Color prints slower than B&W • Images and graphics print slower than text • 12 pages per minute is a typical print speed • Thermal printer speeds listed in linear millimeters per second • Dot matrix printer speeds listed in characters per second

9. Inkjet printers • Nozzles spray ink on to paper • Most popular home printing option • High quality results for both text and graphics • Very inexpensive to purchase • But costly to operate • Typically require 4 or 5 ink cartridges per printer • Cartridges are expensive and often used quickly • A poor solution for high volume printing needs

10. laser printers • Works like a copier with a light sensitive drum • Most popular business printing option • Very high quality results for text and graphics • More costly to buy but cheaper to operate • Black & white requires a single toner cartridge • Color more costly requiring 4 toner cartridges • Cartridges expensive but last far longer than ink jet • Most color lasers also require drum be replaced • B&W a great choice for high volume printing

11. Thermal printers • Uses special paper known as thermal paper • The ink is coated on the surface of the paper • Ink changes color from white to black when heated • Heavily used for receipts of all types • Gas stations, restaurants, stores, credit cards • Very convenient, no toner or ink to replace • Just replace the roll of paper when it runs out

12. Dot matrix printers • Once the dominant printingtechnology • Slow, noisy, and low quality • Largely replaced by laser and ink jet printers • Dot matrix printers still usedby companies to print multi-part carbon forms • These forms require an impact printer • Laser and ink jet printers do not strike the page • Very inexpensive to operate

13. Setting a Default printer • Several printers may be available to a computer • May be directly connected via parallel or USB port • Or mutiple printers may be available on a network • Can set one printer as the default printer • Go to Settings, Devices, Printers • Click printer name you wish to set as default, then the Manage button that appears for the printer • On Manage your device display, click Set as default • If you don’t see Set as default button • Return to the list of printers • Uncheck Let Windows manage my default printer button

14. Using a notebook as a desktop • Do you like the large screen & full keyboard of a desktop but also the portability of a notebook? • Get the best of both with a little extra money • Buy a notebook computer (if you don’t have one) • Buy a wireless keyboard and mouse for home • Buy a standalone monitor for home • Plug the notebook into the monitor and power • You get a full screen setup similar to a desktop • Also have a full keyboard and mouse • Just unplug and go to use again as a notebook

15. Desktop computer Expansion boards • A circuit board that provides additional functionality • Plugs into slot on motherboard • End of card exposed to back of system unit • System unit must have an open expansion slot in order to do this • Desktop system units provide expansion slots • “All in one” desktops & portable computers do not

16. Device drivers • Software that determines how a peripheral device communicates with a computer • Generally don’t need to install a device driver • Usually already included with the operating system • But if installing a new model of a peripheral device on an older computer, it may not have the driver • Or if installing a much less common device • CD with driver may be included with device • If not included, can usually download from Internet