I wonder if I can manage to hack the music of Doom, or anyone out there can manage to hack Doom's music.
Because I really want to do Doom SNES music hacks, I will share my knowledge that can be of any use for music hacking
Most importantly, The SNES port of Doom appears to use use standard N-SPC, or a slightly modified variant of N-SPC, I say this because of 2 things. 1. The N-SPC Engine in an SPC file always has 20 CD FF as the starting bytes. I checked the SPC files of Doom, and surely enough at offset 0x700 there was 20 CD FF in all of the files.
2. The SPC files play on ANY SPC player, Think about it. If Doom utilized a different music format (Like Wolfenstein 3D for the SNES, which used a different method of using the SPC, thus making SPC dumps unplayable) then it would not play.
Another very important thing. With the block of hex starting at 0x700 (SPC Engine, starts with 20 CD FF) I was tracing pointers after the 20 CD FF, but staying within the same block (it is noticably, but slightly seperated from other data by several FF bytes before and after the block) I got to a few locations. From the locations the pointers got me, I selected a big chunk of hex from the location the pointer got me to, and opened the Doom ROM and searched for that chunk. I found it. Exactly the same. I checked the bytes before and after, and compared with the SPC file and ROM, They matched, but only for several bytes more before not being the same anymore. I am guessing it was one of the pattern data blocks.
I will update this every now and then. Good luck to everyone trying to hack the Doom ROM.