This seems extremely useful. This guy talks about all kinds of different things about PSX hacking and how things work. Alot of it was above my head, but some of you more talented ASMer's may find this very enlightening... or not so much, idk. Either way, I strongly urge you to take a look
This is a link to a small document a guy named Klarth wrote about .TIM files. Again, it may shed some light on things... or maybe not.
http://mrclick.zophar.net/TilEd/download/timgfx.txt
Thanks, I've actually been looking for something like this, for dealing with palettes in SaGa Frontier.