This https://www.youtube.com/watch?v=ewoDLDDgHkI https://www.youtube.com/watch?v=ewoDLDDgHkI Goes into excruciating detail of many of the anti-piracy measures

This https://www.youtube.com/watch?v=ewoDLDDgHkI https://www.youtube.com/watch?v=ewoDLDDgHkI Goes into excruciating detail of many of the anti-piracy measures in Tempest, and probably covers what the parent is talking about. All "writing" was executable code in Tempest because everything being drawn is by telling the electron gun where to aim, so you have commands like a "Turtle" graphics library. There were sections of anti-piracy code that would check magic numbers and perturb those copyright drawing routines if the check failed.