There are several methods of generating video output from an Arduino or compatible board, however most of them use the analogue RF signal type which may prove to not have the best quality. However a VGA-type signal is also easily created, and by following the instructions provided by Arduino enthusiast Nick Gammon you can have good-quality text output without too much effort.
The tutorial in itself is quite interesting, as Nick has not only provided the code and schematic - but also explains the background of VGA, the signal types, refresh rates and how to generate various fonts. With a little work you can have all sorts of video effects, ideal for data displays or simpler gaming examples.
When adding your own VGA-output circuitry to your Arduino or compatible board - consider our range of ProtoShields. From the tiny LeoStick to the Mega range, we offer a complete range for you to work with.