tepples wrote:
What do you plan to do with NSFs that rely on the value of $8000?
The value of $8000 storing the current song number is only when the main routine ROM is turned on. When the main routine ROM is disabled, it becomes other ROM (if FDS is not used) or RAM (if FDS is used). When the music is playing, them ain routine ROM is always disabled.
(That still doesn't necessarily mean it is best idea to put RAM there, or that it shouldn't be mirrored since the main routine ROM could probably be much smaller.)