My implementation of a 2bpp bitmap mode inspired by :
Sverx :
https://t.co/U3awEHzsrY
Ben Ryves, bbc basic port on SMS:
https://benryves.com/journal/3763168
This allows, by sacrificing 12 colors, to be able to tile the entire screen while keeping sprites available and to be able to address each pixel individually.
NB: The illustration is just a placeholder to test the display of a 4 color .bmp