I'm sure someone somewhere has already answered this in detail, but I've been searching on this for some time now and I haven't stumbled upon it.
What I'm wondering is why the NES (and, similarly, the Sega Master System and Game Boy) decided to go with bit planes for its graphics format. Was it simply a hardware consideration for the PPU that had to do with fetching the data quickly enough by spreading it across multiple bytes? Or was it just because that was the simply more popular VRAM storage format of the time?
It makes sense to me why the SNES would stick with it even as the Genesis / Mega Drive moved to packed pixels, because of that system's multiple-choice screen modes that made use of varying bits-per-pixel. But even the Atari 7800, which came out a couple years after the NES, appears to have used a packed pixel format from what documentation I can find, so I'm guessing Nintendo's reasoning was tradition/familiarity and not raw speed. But I'm not knowledgeable enough of hardware in general to do much more than guess.
What I'm wondering is why the NES (and, similarly, the Sega Master System and Game Boy) decided to go with bit planes for its graphics format. Was it simply a hardware consideration for the PPU that had to do with fetching the data quickly enough by spreading it across multiple bytes? Or was it just because that was the simply more popular VRAM storage format of the time?
It makes sense to me why the SNES would stick with it even as the Genesis / Mega Drive moved to packed pixels, because of that system's multiple-choice screen modes that made use of varying bits-per-pixel. But even the Atari 7800, which came out a couple years after the NES, appears to have used a packed pixel format from what documentation I can find, so I'm guessing Nintendo's reasoning was tradition/familiarity and not raw speed. But I'm not knowledgeable enough of hardware in general to do much more than guess.