Love these demos. The best one I've found, also 256 bytes, is Pyrit by Řrřola (Jan Kadlec, a Czech developer). It's frankly incredible, something I wouldn't have believed was possible:<p><a href="https://www.pouet.net/prod.php?which=78045" rel="nofollow">https://www.pouet.net/prod.php?which=78045</a><p>I ported it to a boot sector so you can run it with a single (rather long!) Linux command line in qemu:<p><a href="https://rwmj.wordpress.com/2019/12/08/pyrit-by-rrrola-incredible-raytracing-demo-as-a-qemu-bootable-disk-image/" rel="nofollow">https://rwmj.wordpress.com/2019/12/08/pyrit-by-rrrola-incred...</a><p>The source code for Pyrit is worth reading too (see first link). It's very clever and quite readable.