Watching the sprites in vram while the game runs is really neat, and shows a bit about how the game is put together.
For instance in Kirby's Adventure, (IIRC)Kirby's walking sprites take up about half the available RAM, and they get swapped out for the flying sprites when he jumps.
Compare this to some of the early non bank switched games where the all sprites fit entirely in memory, with some creative tweaks (bushes are recolored clouds, etc).
It's a bit myopic of Nintendo that on-cartridge mappers had to be necessary, but on the other hand, it's early 80's consumer hardware; it was probably state of the art in the late 70's ... which makes it hilarious that Wario's Woods was released in 1994.
I wouldn’t call it “myopic,” if anything it was forward-thinking...the cost of memory in the early 80s was high enough that including more than the 2 KB of built-in RAM might have made the Famicom/NES way too expensive. They designed the machine with internals that could be extended with extra memory and additional chips inside the cartridges, so that over the ~15-year lifespan of the NES as technology advanced and the cost of memory dropped, the cartridges enabled ever more powerful, impressive games, but stayed about the same price ($40 iirc) the whole time.
In Battletoads, Rare went a step further and kept only a single frame for each player loaded in CHR RAM, copying over it for each frame of animation.
As for mappers, the 6502 (along with most other 8-bit CPUs from that era) has 16 address lines, imposing a hard-limit of 64 kilobytes of CPU-side address space. Without bank switching hardware somewhere, there was just no other practical way to access any more program ROM than that. Now, Nintendo could have pulled a PC-Engine/TurboGrafx-16 and embedded a bank switching unit somewhere in the console itself, but hindsight is 20/20.
I've coded a NES emulator for my C++ programming course (https://github.com/JaCzekanski/AnotherNES) and one of the features is live view of RAM and PPU registers (check out Screenshots at bottom of Readme). As for now only RAM can be changed during game play but I plan to carry on with development and create emulator with ability to change every register of console in realtime (like ICU64 here: https://www.youtube.com/watch?v=tjcvR5McmSg)
Compare this to some of the early non bank switched games where the all sprites fit entirely in memory, with some creative tweaks (bushes are recolored clouds, etc).
It's a bit myopic of Nintendo that on-cartridge mappers had to be necessary, but on the other hand, it's early 80's consumer hardware; it was probably state of the art in the late 70's ... which makes it hilarious that Wario's Woods was released in 1994.