So I've finally gotten around to putting together full text dumps
from the game, with everything decoded except control codes (movement,
sound effects, music changes, and so on are all lumped in with the text,
instead of the text being in its own block and called by reference like
it is in most of the other games I've dealt with). Aided by a reasonably functional editor, and a gamefaqs message thread with a remarkable amount of technical data as reference, and BizHawk's RAM Watch functionality to test some things, the section is shaping up rather nicely.
It's not ready to be posted yet, but for now, here's a list of some findings I thought were interesting and possibly surprising.
