Saw a movie about atari software-driven graphic modes. Maybe some technics that are used on the atari could be utilized on the ep... Atari seems to also use something like the lpt (display list). Although I guess that some will use sprites for coloring up...
First "software-driven" (I don't know if I can say that) modes I could list are the "square-pixel" (well don't have to be "square" - just vertically stretched) modes like I'm trying to use... (atari seems to have the 4 color variant. Game "Yoomp!" uses it
https://www.youtube.com/watch?v=UqmyLKG1l-4).
Someone knows about another?
"Interlace demo" mode counts...
Zozolace demo has another one too...
Changing palette at every scanline (fix bias every two) could also count as such mode, I guess...
I think that one of such atari modes uses vbi to switch between two character sets every frame to get the illusion of more colors... Well actually wuoting the author:
"In my game "Gem Drop", I used a simple VBI to flip between two character sets (no palette changes or DLIs) to give the illusion of 13 colors in ANTIC 4 mode."
https://en.wikipedia.org/wiki/Software-driven_graphics_modes_for_the_Atari_8-bit_computers