C64 "demos" were the root of the whole demo-scene-thing and they are still the main force keeping the C64 alive today. Audiovisual pleasure, still pushing hardware limits, still exploring different ways of expression. But what is typically happening inside the machine when you watch a demo? What effort is needed to entertain the audience? This talk will give you an inside look at the steps taken for the award winning demo "Error 23" given first hand by one of its main programmers.