Introduction to Computers

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 phone connector but larger Speaker and microphone General purpose USB ports Monitor port, older style VGA port shown here

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)

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

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

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

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

Print speed Ink jet and laser printer speeds Expressed in pages per minute (ppm) for B&W text Color prints slower than B&W Graphics prints 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

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

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 good choice for high volume printing

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

Dot matrix printers Once the dominant printing technology Slow, noisy, and low quality Supplanted by laser and ink jet printers Dot matrix printers still used by 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

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

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

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

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