Pony Fantasy VI Remake

It looks like there's been some questions on how I hacked the battle backgrounds.

To edit a background, you'll typically be changing 3 things: The graphics tile pack, the tile assembly, and the palette.
If you are going to change which graphics pack, tile assembly, or palettes a background uses, you'll also need to change the background master list.  This list will also be useful locating the information you want to change.

Master List
The background master list is located at $E70000
Each background is 6 bytes long.

The first 3 bytes tell the game which graphics packs to use for the background.  This value * 2 + $E71380 will give a 2-byte pointer to the graphics pack.
I don't know where the bank is determined, so for locating the data, it might be faster to use this list:

Code:

Start      End                    Length   Description                                                
27ABE7     27B859                 3186     Compressed data: graphics from Narshe/Figaro background      SNES 4 bit colors
27B859     27BFE2                 1929     Compressed data: graphics from Thamasa background            SNES 4 bit colors
27BFE2     27C899                 2231     Compressed data: graphics from Narshe Mines background       SNES 4 bit colors
27C899     27CF04                 1643     Compressed data: graphics from Desert background             SNES 4 bit colors
27CF04     27D212                 782      Compressed data: battle backgrounds                          SNES 4 bit colors    
27D212     27DB78                 2406     Compressed data: battle backgrounds                          SNES 4 bit colors    
27DB78     27E2B5                 1853     Compressed data: graphics from Imperial Base background      SNES 4 bit colors
27E2B5     27E77B                 1222     Compressed data: graphics from Phantom Train Roof background  SNES 4 bit colors
27E77B     27EEC8                 1869     Compressed data: graphics from Phantom Train Interior background   SNES 4 bit colors
27EEC8     27F77F                 2231     Compressed data: graphics from Cave background               SNES 4 bit colors
27F77F     2802B3                 2868     Compressed data: battle backgrounds                          SNES 4 bit colors    
2802B3     280E49                 2966     Compressed data: battle backgrounds                          SNES 4 bit colors    
280E49     281A41                 3064     Compressed data: battle backgrounds                          SNES 4 bit colors    
281A41     282149                 1800     Compressed data: graphics from Colosseum background          SNES 4 bit colors
282149     282E58                 3343     Compressed data: battle backgrounds                          SNES 4 bit colors    
282E58     2835C1                 1897     Compressed data: graphics from Desert background             SNES 4 bit colors
2835C1     283ECA                 2313     Compressed data: battle backgrounds                          SNES 4 bit colors    
283ECA     2845AE                 1764     Compressed data: battle backgrounds                          SNES 4 bit colors    
2845AE     284A76                 1224     Compressed data: graphics from WoB Veldt background          SNES 4 bit colors
284A76     28512D                 1719     Compressed data: graphics from Ruined Castle background      SNES 4 bit colors
28512D     2858B6                 1929     Compressed data: graphics from Vector Palace background      SNES 4 bit colors
2858B6     285CB5                 1023     Compressed data: battle backgrounds                          SNES 4 bit colors    
285CB5     286960                 3243     Compressed data: battle backgrounds                          SNES 4 bit colors    
286960     2872BA                 2394     Compressed data: graphics from Opera stage background        SNES 4 bit colors
2872BA     2875DE                 804     Compressed data: graphics from Opera rafters background       SNES 4 bit colors
2875DE     287C67                 1673     Compressed data: battle backgrounds                          SNES 4 bit colors    
287C67     288858                 3057     Compressed data: battle backgrounds                          SNES 4 bit colors    
288858     288F6E                 1814     Compressed data: graphics from MAgitek Lab/Vector backgrounds     SNES 4 bit colors
288F6E     289625                 1719     Compressed data: graphics from ruined castle background      SNES 4 bit colors
289625     28A617                 4082     Compressed data: tentacles battle background                 SNES 4 bit colors
28A617     28AC6A                 1619     Compressed data: graphics from Zozo Indoors/Jidoor Paintings background     SNES 4 bit colors
28AC6A     28B3F3                 1929     Compressed data: battle backgrounds                          SNES 4 bit colors    
28B3F3     28BAB5                 1730     Compressed data: Sealed Cave bridge background               SNES 4 bit colors
28BAB5     28C1E7                 1842     Compressed data: Zozo outdoors background                    SNES 4 bit colors
28C1E7     28CC7F                 2712     Compressed data: battle backgrounds                          SNES 4 bit colors    
28CC7F     28D3CE                 1871     Compressed data: battle backgrounds                          SNES 4 bit colors    
28D3CE     28D566                 408      Compressed data: battle backgrounds                          SNES 4 bit colors    
28D566     28E620                 4282     Compressed data: final Kefka Espers part 1 battle background     SNES 4 bit colors    
28E620     28F74B                 4395     Compressed data: final Kefka Espers part 1 battle background     SNES 4 bit colors    
28F74B     29074A                 4095     Compressed data: final Kefka Espers part 2 battle background     SNES 4 bit colors    
29074A     29189D                 4435     Compressed data: final Kefka Espers part 2 battle background     SNES 4 bit colors    
29189D     2928D9                 4156     Compressed data: final Kefka Espers part 3 battle background     SNES 4 bit colors    
2928D9     2937D6                 3837     Compressed data: final Kefka Espers part 3 battle background     SNES 4 bit colors    
2937D6     29481E                 4168     Compressed data: final Kefka battle background               SNES 4 bit colors    
29481E     29582A                 4108     Compressed data: final Kefka battle background               SNES 4 bit colors    
29582A     295A63                 569      Compressed data: battle backgrounds                          SNES 4 bit colors    
295A63     29616D                 1802     Compressed data: Burning House background                    SNES 4 bit colors
29616d     2964C1                 852      Compressed data: Cyan Dream background                       SNES 4 bit colors

The next 2 bytes indicate the tile assembly to use.  In every existing case, they are identical.  I don't know what would happen if they weren't.  To get the address of the tile assembly, goto this *2 + $E71848.  The address referenced is in bank $E7.

The last byte is the set of 3 palettes.  The actual palette is at this * $60 + $E70150.

Graphics Pack
The actual graphics packs are compressed.  They can be decompressed with Peer Sprite Viewer and edited in any sprite editor.
Due to the complexity of backgrounds, I suggest something with a tile assembler, like Tile Layer Pro.

Tile Assembly
The tile assemblies are also compressed and can be decompressed in PSV, then edited with a hex editor.
Each tile is represented by 2 bytes.  
The first byte is the tiles.  Tiles 00-7F are in the first graphics pack. Tiles 80-FF are in the second graphics pack.  I'm not sure how this works for backgrounds that use 3 graphics packs.
The second byte is a set of bit flags.
    bit 0: Flip tile vertically
    bit 1: Flip tile horizontally
    bit 2-3: Unknown
    bit 4-5: Palette.  01 is the first palette. 10 is the second palette.  11 is presumably the 3rd palette.
    bit 6-7: Unknown

Palette
The palettes are just normal palettes and can be edited in something SNESPal



A few notes:
Some backgrounds share graphics packs or palettes.  Make sure you are aware of what other backgrounds change when you make an edit
The Ghost Train, Train Tracks, and Minecart backgrounds are animated.  I haven't checked how that's handled.
If the game crashes loading a background, try to copy the section to the buffer in PSV.  If it gives a bad compression error, your data isn't compressing small enough. You may need to make changes and recompress it