I wanted to do some more impressive animation with the 1K color mode, but ran out of time unfortunately. One tricky part about doing animation with this mode is that it suffers from the "CGA snow" bug (visual glitching when writing to video memory). To avoid that by writing to video memory only during the vertical retrace/overscan period means that it would take about a quarter of a second to update the entire screen.
Totally deterministic. I think there's even an emulator which models it (though without a cycle-exact emulation of the CPU the snow won't be in the same places as on real hardware).
