[circuit10]

These kinds of tricks were also very common on the NES, to create things like a HUD that doesn't scroll with the rest of the screen by changing the scroll values at the right time. Eventually they even started putting hardware in the cartridge to assist this by interrupting the CPU at the right time

[tuukkah]

Amiga may have taken this furthest with Copper, a co-processor that was synced with the CRT signal and programmed in a DSL for timed changes of register values in the other chips: https://en.wikipedia.org/wiki/Amiga_Original_Chip_Set#Copper