Perhaps it would be best to leave everything just the way it is. Too many changes would only ruin the retro experience
The reason I asked was to see if an enhanced 7800 could be made, rather than a mod for existing 7800 consoles.
I get the impression that programmers can achieve all kinds of things that the original designers didn't think possible, the only problem being that enhancements such as displaying higher resolutions or more colours aren't really practical in games as there isn't enough power to perform hardware tricks and play games at the same time. Even the 7800's 320 x 200 resolution seems to be too much for it's humble processor.