Generating video output with an Arduino or compatible board is generally limited - by the speed of the microcontroller, the I/O and of course the amount of memory available to the application. However there are some very good attempts, from basic composite video and so on. However a new method has been demonstrated by the folks of the "Don't Quit Your Day Job" website.
Their method involves several stages, including some interesting timer code by Nick Gammon and external digital logic circuits that are used to increase the clock rate for the video signal, which does work but due to the difference in the generated and required clock rate - does have a margin of error. However it's a fascinating experiment and an example of the results are shown in the following video:
For complete details on this method including code and hardware details, visit the DQYDJ website. And for more, we're on facebook, Google+, and twitter - so follow us for news and product updates as well.