Output Devices

Monitors

VDU’S (VDU stands for Visual Display Unit)

This is a 17 inches standard monitor and cost around £160

This is a 17 inches flat screen monitor and cost around £660

RESOLUTIONS

How good a monitor is determined by its max resolution the resolution is how many pixels up and across the display unit has, the average monitor has a max resolution of about 1980 by 1024 this means that there are 1024 lots of 1980 pixels stacked vertically and 1980 lots of 1024 next to each other going across this means that there are 2,027,520 pixels in total. The more pixels you have the better the displayed image looks.

HOW TV’s DIFFER FROM VDU’s

First thing that’s is different between a TV and a VDU is the way that they refresh a normal TV fills in the picture from top to bottom missing every other line then once its hit the bottom it fills in the missing ones from top to bottom again this means that this device is interlaced. A VDU is non-interlaced this mean they refresh differently, instead of every other line a VDU refreshes from top to bottom and keeps doing this to keep the picture up.

DIFFERENT TYPES OF PRINTERS

Dot Matrix – A impact printer the only type of printer that the print heads actually makes contact with the paper now there largely obsolete because there very noisy and there are better printers are around, although they are still use mainly in industry when they need multiple copies of document when using carbon paper.

Ink Jet – A printer that uses liquid ink stored in cartages, the ink is squirted onto the paper with this printer and heat is used to do this, the ink flows in to the printer’s heads when it is headed and once it gets hot enough it squirts onto the page it does this very quickly and is very accurate.

Laser Printers – Are very big and expensive but they have to be the best printer you could ever buy they are very accurate printers and print the whole page in one when other printer only print line by line. These printers work by heating up the paper with a laser and running the paper through the toner and because of the heat on the paper the color sticks to the paper.

WHAT DPI IS

DPI stand for Dot Per Inch this the maximum amount of dot that the printer can print in every inch, the more dots per inch you have the better quality the image you print looks but it also depends on the image you printing. Is you printing a word document the you don’t need a very high DPI cause text doesn’t require a lot of DPI cause its not very complex and only uses 1 colour.

SPEAKERS

This output gives out sound most pc’s only have 2 speakers and there not very powerful but some people have other sets of speakers thing like 5.1 and 6.1 this means they have 5 or 6 speakers and a sub woofer and when used with the right sound card each one can produce a different sound from the others and this makes it good for games cause you can hear what’s behind you.