Hi Tom, good news, now I have a method to decompress and compress the graphics. I'll send the details for you later. But I'm using a compressor made by neviksti with help of several other guys. For what I read people like DarkForce, neviksti, Byuu, and other guys, made an amazing job understanding the SPC7110.




I made a video showing this intro:
https://youtu.be/L_DhzaNhiagThe garbage in the gate is because I changed a tile that is used in other places. There are a lot of tile reuse and I didn't change any tilemap.
The "2016" that I put in that pillar has green and pink colors because seems that these tiles use a different pallete.
So with this compressor, and reading Bsnes code (the best source of information about Snes internals), I learned what needs to be done to translate the graphics. So the SPC7110 compression is not a problem anymore (hope so). Now a hacker can work the graphics in this game like any other game. Of course the SPC7110 has a particular way of working, but it's simple after you learn.
By the way, when I change the rom and load a previous save, after a reset the game shows the screen below:

What this text is saying? The game seems to work fine after that.
Like I said in my previous post I don't think I have the skills (yet) to work in a legendary game like Feoez. This game deserves a more experienced romhacker like the ones listed in this topic, but I can help with these minor stuff. Then if I find more information I'll send to you. And of course I'll send you all the details I found untill now.
Thanks
December 04, 2016, 11:57:46 pm - (Auto Merged - Double Posts are not allowed before 7 days.)
Maybe someone should ask Byuu about : "But I don't know if the real chip doesn't allow this writing to $50:0000, or if it was a Byuu's decision, assuming that it's not the supposed way to work."
There is no need anymore. And I really think you can't write in $50. The SPC7110 controls the bank mapping, so probably it's not allowed to write to $50. But who knows? If you can read from $50 maybe you can write too
