[Gabriel Gambetta] knows a few things about ray tracers, being the author of Tiny Raytracer, a raytracer written in just 912 bytes of JavaScript. As a long-time fellow sufferer of the UK-designed Z… ...

As detailed in his blog post on the project, Gambetta ported the basic ray tracing code from his book into BASIC—the programming language that powers the ZX Spectrum. Without too much tweaking ...

At the end of the bonus material is a strange noise that turns out to be a ZX Spectrum Basic program. [OooSLAJEREKooO] managed to find it, play it, and record it for all of us (see video below).