28C3 - Version 2.3.5

28th Chaos Communication Congress
Behind Enemy Lines

Ninja / The Dreams
Day Day 3 - 2011-12-29
Room Saal 3
Start time 21:45
Duration 01:00
ID 4814
Event type Lecture
Track Hacking
Language used for presentation English

Behind the scenes of a C64 demo

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.

This talk extends previous talks and documentation about the Commodore 64 and its demo effects by adding real-life challenges and experiences to it. What were the basic ideas? What obstacles were on the way? How did they get solved? 6502 assembly knowledge is really not required, some general understanding about assembly and low-level computing will be useful, though (think of stack, timer, cycles...). This isn't about theory, this is for real ;)

Topics include (but not limited to):

  • Explaining design choices
  • Basic ideas behind the effects
  • Data compression techniques
  • Load stuff while displaying effects
  • Dirty tricks which make your computer science professor run away
  • Synchronization and linking
  • how to keep it all in 64KB RAM