Music Porting

I have read through Sonic Retro's music hacking guide but still have no idea how to port music from any of the games on the data locations. e.g Phantasy star 4.

 

Every time I port the song "Under Magma" to marble zone, at a certain point I get an illegal instruction error!


Any help would be appriciated.

 

happens to me exactly the same

 

We need more information before help is at hand. Can you show us the line of the error (or the latest bit of ASM you have done)?

 

"Under Magma" is a Ristar song. Ristar uses two DAC channels -- you'll need to make sure you've converted it properly otherwise you will get unpleasant errors.

 

The coordination flags in Ristar also works in a different way. There are some values to add to the pointer stuff and also in some loop flags. He is getting this kind of problem certainly because he tried to port using the ErikJS's Music Pointer Fixer instead of the music hacking guide itself.

 

This is the error,


ILLEGAL INSTRUCTION$0007659E

 

That error report is no good to us, it displays the offset in the rom of where the processor read an instruction that was invalid, but we'd need to the rom to check this offset.


I'm going to take a guess here, the offset is around the 70000 area where the music in the original title is approximately, and yours is quite close (with the additions to any changes you may have made/added), and the fact that you mentioned porting a track, I'm going to assume the track has a flag that was unchanged resulting in the processor jumping on a table to an incorrect address, thus the possibility of hitting into code that is not a machine instruction.

 

Did you already check this tutorial? It might help you:


http://forums.retrohack.org/topic/109-s1-simple-music-guide/