> Fiendishly clever stuff. Common opinion was that someone must have been counting CPU cycles per opcode /execution path to get that right.
Definitely clever, but I think it was a fairly common trick, at least on the 8-bit Atari and Commodore machines, with all their fancy (but still deterministic) graphical hardware.
And on a slight tangent, people have been doing similar cunning stuff on the ZX Spectrum. This infamously suffered from colour clash since it used a character-mapped display, and you could only have two colours per "text cell" - foreground and background.
However, with some very clever hackery, some people have managed to put together engines which lets you change the colours on each pixel-line. Giving you the ability to set colours in 8*1 or even 4*1 blocks, rather than 8*8.
It's a bit of a shame these were developed after the ol' Speccy's commercial decline. Still, it's a pretty impressive bit of engineering!