I have been getting into NES programming using NESASM3 to better understand computers in a lower level.
Right now I'm having a hard time wrapping my head around games like Kirby and Battletoads that use multiple screens and yet hardly use nametables at all. Particularly Battletoads.
How is Battletoads able to display dozens of backgrounds even though the nametables show nothing but the status bar and the pattern tables don't have any of those background tiles either?!
I know for 4-screen data you need extra VRAM addresses in the ROM file, but even if thats how it works that doesn't explain how the tiles get on the screen.
With Kirby, it's a little different.
The tiles are loaded into the PPU and you can see the actual screen scroll in the nametable, but then the status bar tiles are not in the PPU, even though theres a bunch of garbage tiles that show the status bar is there!
I have google searched questions and looked at dozens of NES programming sites, but nobody seems to ask those questions or even talk about it in an official or satisfying way.
If anyone can PLEASE explain this or direct me to any mapper or site where I can read up on this, I will greatly appreciate it.
Right now I'm having a hard time wrapping my head around games like Kirby and Battletoads that use multiple screens and yet hardly use nametables at all. Particularly Battletoads.
How is Battletoads able to display dozens of backgrounds even though the nametables show nothing but the status bar and the pattern tables don't have any of those background tiles either?!
I know for 4-screen data you need extra VRAM addresses in the ROM file, but even if thats how it works that doesn't explain how the tiles get on the screen.
With Kirby, it's a little different.
The tiles are loaded into the PPU and you can see the actual screen scroll in the nametable, but then the status bar tiles are not in the PPU, even though theres a bunch of garbage tiles that show the status bar is there!
I have google searched questions and looked at dozens of NES programming sites, but nobody seems to ask those questions or even talk about it in an official or satisfying way.
If anyone can PLEASE explain this or direct me to any mapper or site where I can read up on this, I will greatly appreciate it.