Final Fantasy/World map data

Final Fantasy I (and Final Fantasy II as well) uses a 256×256-tile world map in this data format. The map data is not stored raw, but uses simple compression in a kind of run-length encoding. The ROM (in iNES format) stores its world map data starting at $4010.

Row pointers

From $4010 to $4210 there are 256 little-endian 16-bit integer values representing addresses in the NES memory map (with the $4010 ROM bank currently in place) that mark the left-hand-side beginnings of each 256-tile row of the map. (Because memory pointers are used in this fashion, it is entirely possible for more than one pointer to point to the identical memory location if they use identical row data, such as a 256-tile row of ocean.) Since this bank will loaded into the NES memory map at readable address $8000, all memory pointers in the ROM must point to the row's ROM file address + 0x3FF0. To translate a memory pointer back into a ROM file address, you subtract 0x3FF0 instead.

Row data

Because the row pointers point to active NES memory in which the $4010 must be active, all of the map data is confined to this bank. Unrelated data begins at file address $7F50, so all row data referenced by pointers must be located starting at $4210 and ending before $7F50, giving you 0x3D40 bytes to store your map row data.

Row data is stored sequentially as such:

• Byte values indicate a row's tiles from the left-edge, from left-to-right through the tiles, ending at the row's right edge.
• A single byte ranging 0x00 to 0x7F describes a single tile of a specific value. The next byte describes the tile to its right.
• A byte ranging 0x80 to 0xFE is the same as its value subtracted by 0x80 (or exclusive-or'ed by 0x80), but the immediately following byte indicates repetition of the tile value. A repetition byte value of 0x01 means no repetition, 0x02 means repeat once, 0x03 means repeat twice, 0x04 means repeat three times, and so on. 0x00 means to repeat 256 times, so that it can fill an entire row. A repetition value of 0xFF is prohibited.
• A byte value of 0xFF after the row's final tile terminates the row data.

So, for example:

0x04

1 tile valued 0x04

0x73

1 tile valued 0x73

0x96 0x01

1 tile valued 0x16

0x96 0x05

5 consecutive tiles valued 0x16

0x96 0x00 0xFF

256 consecutive tiles (an entire row) valued 0x16, and a row terminator

FF1 Overworld Tile Values

00 = Grass
01 = First Castle - Lower Left
02 = First Castle - Lower Right
03 = Forest - Top Left
04 = Forest - Top
05 = Forest - Top Right
06 = Grass - Bottom Right
07 = Grass - Bottom
08 = Grass - Bottom Left
09 = First Castle - Top Left
0A = First Castle - Top Right
0B = Elf Castle - Top Left
0C = Elf Castle - Top Right
0D = Tower of Illusion - Top
0E = Grotto
0F = Dock - Vertical Left
10 = Mountain - Top Left
11 = Mountain - Top
12 = Mountain - Top Right
13 = Forest - Left
14 = Forest - Bottom
15 = Forest - Right
16 = Grass - Right
17 = Ocean
18 = Grass - Left
19 = First Castle - Middle Left
1A = First Castle - Middle Right
1B = Elf Castle - Bottom Left
1C = Elf Castle - Bottom Right
1D = Tower of Illusion - Bottom
1E = Tower of Illusion - Shadow
1F = Dock - Vertical Right
20 = Mountain - Left
21 = Mountain
22 = Mountain - Right
23 = Forest - Bottom Left
24 = Forest - Bottom
25 = Forest - Bottom Right
26 = Grass - Top Right
27 = Grass - Top
28 = Grass - Top Left
29 = Elf Castle - Bottom Left (again?)
2A = Elf Castle - Bottom Right (again?)
2B = Grotto
2C = Village Fence - Top Left
2D = Village Fence - Top
2E = Village Fence - Top Right
2F = Grotto

FF2 tile values

to do