2. Monitors

A monitor (or screen) is the most commonly used output device.

They come in many different shapes, sizes and forms. In an exam question, you will need to be able to choose the best type of monitor and then explain your reasons.

The picture on a monitor is made up of thousands of tiny coloured dots called pixels. The quality and detail of the picture depends on the number of pixels that the monitor can display. The higher the number of pixels, the better quality the output.

Larger monitors make working at the computer much easier on the eyes, but the larger the monitor, the more money it costs! Typical monitor sizes are 19 inches.

The two types of monitor that you need to know about are Cathode Ray Tube monitors (CRT) and Thin Film Transistor monitors (TFTs).

Cathode Ray Tube

CRT monitors are becoming outdated, although you will probably remember using them at school not very long ago.

They are large and bulky and have a glass screen which makes them fairly robust and difficult to damage.

They produce quite a lot of heat so when you have an office with lots of them it could get quite warm. They are also fairly noisy compared to newer TFT monitors.

Thin Film Transistor

TFT monitors used to be very expensive but now the price has come down they are beginning to replace all of the old CRT monitors. Not only do they look much nicer they take up a lot less space. They are quieter than CRT monitors and also create less heat.

On the down side they are easier to damage than CRT screens. A few sharp pokes at the screen with a pencil can cause lasting damage. Another disadvantage is that unless you have a very high quality TFT monitor, the colours and contrast are not so good as a CRT monitor and so the picture can look a bit dull.