One of the best demo screens for Atari ST. Created in 1990 Pure 68k assembler with a lot of direct hardware acess trickery More infos on https://wiki.hackerspace.lu/wiki/AtariSTknowhow with slides on how to do programming on the ST.
1 hour talk going with the slides from 2018: https://www.youtube.com/watch?v=CicttTq528I
see a video here: http://dhs.nu/video.php?ID=456 download the original demo here: http://pouet.net/prod.php?which=11349