You've seen 64kb demoscene productions. Hell, even 4kb is enough to generate a stunning seemingly-impossible variety of scenes. But Linus Akesson's entry in the Oldskool 4K Intro competition at Revision 2017 is generated by a program only 256 bytes long. There's an in-depth technical explanation. [via Metafilter]
The demo is driven by its soundtrack, so in order to understand what the program needs to do, it helps to have a schematic overview of the various parts of the song.
The three voices of the SID chip are used as follows: Voice 1 is responsible for the kick drum and bass, Voice 2 plays the melody and Voice 3 plays a drone that ducks on all beats, mimicking the genre-typical side-chain compression effect.
