"The main problem with current 7800 emulation (With respect to Dan Boris for his outstanding work), is that most of the Maria graphic stuff had to be more or less guessed out on how it worked."
This is incorrect. I had actual Maria programmers guide when I developed the emulator and didn't really have to guess at anything. The problems with the video emulation on the 7800, like most systems, is emulating the stuff that is NOT documented anywhere.
With that said, the document that Curt posted is very cool, I love getting a look at stuff like this. I will have to take some time to peruse this in detail.
Dan