thread Unsurprisingly I know Ian Primus.
Other TV trickery came to light in the ZX Spectrum era with game designers coding games specifically for a 50Hz screen refresh giving 'flicker free' games, the first of which was Bug-Byte's 'The Birds And The Bees' which also was the first game to properly support Steve Currah's 'Microspeech' add-on which unfortunately resulted in a lot of melted Spectrums.

Early 80s technology in the 'computerphone' STC Executel relied on the 'gap' or pause while the electron gun moved back to the top of the screen during a complete refresh to update background screen memory with new information so you got an instant swap of screen content without waiting for it to update and redraw.

Teletext worked in a similar way
permalink I remember covetting a Currah Microspeech
when I were a lad.

My dad borrowed a light pen for drawing from somewhere, which I assume worked the same way. For a given value of 'worked' anyway.
permalink I swear that turrican 2 managed to get brown
on the spectrum, which is imposisble.

the person I was playing with was colour blind and didn't believe me either.