I was working with some large graphics in a test program and found I couldn't fit all of the graphics inside a single bank. That alone isn't too big a deal so I went back to the graphic I was cutting up to fit.
While I was freeing up space, the overflow wasn't falling into the proper bank as quickly as I expected it to. I did some extra testing and found for some reason the last 8 bytes (32 pixels) of the bank refused to accept graphics despite the next graphic to be added was smaller than 8 bytes. (I had to keep chopping up a larger graphic til it fit.)
I tried making a quick test prog, attached below, to see if it would always leave 8 open. But it didn't. The test program simply tries to add (with mode 320B) 256 4-pixel graphics. That should completely fill the bottom bank. However, while it won't leave 8 free like it was doing with my graphics tests, it left 1 open. (I added a 257th sprite as well which should always carry over, which it does - but it should be the only graphic that does that.)
Not sure if this is an Issue, or if I'm just misunderstanding something.
The program itself does nothing - it's just a list of graphics includes for the most part.