EarthBound/Map Data/Compressed Tile Arrangement Data

This is a sub-page of EarthBound/Map Data.

Data blocks storing arrangements of four-tile-by-four-tile chunks for map tilesets. Data for a given map tileset is found using the Tile Arrangement Pointer Table.

Terminology note: In EarthBound modding, these four-tile-by-four-tile chunks are often referred to ambiguously as "tiles", while the individual 8x8 pixel tiles making up the tile chunks are often referred to as "minitiles".

Blocks

Block 1

Map Data: Compressed Tile Arrangement Data, Block 1
Game	EarthBound
Start Address	0x17C800
End Address	0x17FDE7
# of Entries	1
Entry Length	Varies
Total Length	13800 bytes (0x35E8), 26624 bytes (0x6800) after decompression
Back to the ROM map

Address	Tileset name	Tileset index	Compressed length	Decompressed length	Num chunks
0x17C800	Lost Underworld	00	13800 bytes (0x35E8)	26624 bytes (0x6800)	832

Block 2

Map Data: Compressed Tile Arrangement Data, Block 2
Game	EarthBound
Start Address	0x190200
End Address	0x19D051
# of Entries	4
Entry Length	Varies
Total Length	52818 bytes (0xCE52), 100192 bytes (0x018760) after decompression
Back to the ROM map

Address	Tileset name	Tileset index	Compressed length	Decompressed length	Num chunks
0x190200	Onett	01	13545 bytes (0x34E9)	27040 bytes (0x69A0)	845
0x1936E9	Twoson	02	13250 bytes (0x33C2)	26464 bytes (0x6760)	827
0x196AAB	Threed	03	9514 bytes (0x252A)	16768 bytes (0x4180)	524
0x198FD5	Fourside	04	16509 bytes (0x407D)	29920 bytes (0x74E0)	935

Block 3

Map Data: Compressed Tile Arrangement Data, Block 3
Game	EarthBound
Start Address	0x1A0200
End Address	0x1A7EA6
# of Entries	3
Entry Length	Varies
Total Length	31911 bytes (0x7CA7), 61152 bytes (0xEEE0) after decompression
Back to the ROM map

Address	Tileset name	Tileset index	Compressed length	Decompressed length	Num chunks
0x1A0200	Magicant	05	4930 bytes (0x1342)	9184 bytes (0x23E0)	287
0x1A1542	Outdoors	06	15201 bytes (0x3B61)	28000 bytes (0x6D60)	875
0x1A50A3	Summers	07	11780 bytes (0x2E04)	23968 bytes (0x5DA0)	749

Block 4

Map Data: Compressed Tile Arrangement Data, Block 4
Game	EarthBound
Start Address	0x1B0200
End Address	0x1BF4EA
# of Entries	6
Entry Length	Varies
Total Length	62187 bytes (0xF2EB), 124096 bytes (0x01E4C0) after decompression
Back to the ROM map

Address	Tileset name	Tileset index	Compressed length	Decompressed length	Num chunks
0x1B0200	Dusty Dunes Desert	08	9921 bytes (0x26C1)	20096 bytes (0x4E80)	628
0x1B28C1	Dalaam	09	15038 bytes (0x3ABE)	29856 bytes (0x74A0)	933
0x1B637F	Indoors 4	16	6819 bytes (0x1AA3)	12480 bytes (0x30C0)	390
0x1B7E22	Winters	17	5622 bytes (0x15F6)	10976 bytes (0x2AE0)	343
0x1B9418	Indoors 1	10	13492 bytes (0x34B4)	27872 bytes (0x6CE0)	871
0x1BC8CC	Indoors 2	11	11295 bytes (0x2C1F)	22816 bytes (0x5920)	713

Block 5

Map Data: Compressed Tile Arrangement Data, Block 5
Game	EarthBound
Start Address	0x1C0200
End Address	0x1CB222
# of Entries	6
Entry Length	Varies
Total Length	45091 bytes (0xB023), 85472 bytes (0x014DE0) after decompression
Back to the ROM map

Address	Tileset name	Tileset index	Compressed length	Decompressed length	Num chunks
0x1C0200	Stores 1	12	8138 bytes (0x1FCA)	14784 bytes (0x39C0)	462
0x1C21CA	Caves 1	13	14706 bytes (0x3972)	28224 bytes (0x6E40)	882
0x1C5B3C	Indoors 3	14	3903 bytes (0x0F3F)	6496 bytes (0x1960)	203
0x1C6A7B	Stores 2	15	2629 bytes (0x0A45)	4576 bytes (0x11E0)	143
0x1C74C0	Scaraba	18	7050 bytes (0x1B8A)	14240 bytes (0x37A0)	445
0x1C904A	Caves 2	19	8665 bytes (0x21D9)	17152 bytes (0x4300)	536

Format

Tile arrangement data for each map tileset is individually compressed. See Compression Format.

Decompressed Format

Each entry, once decompressed, consists of a variable number of tile arrangements (four-tile-by-four-tile chunks), each 32 bytes. Arrangements are found from an index using the formula arrangement_offset = arrangement_index * 32. The decompression buffer has capacity for up to 960 arrangements (30720 bytes), but in an unmodified EarthBound ROM, no entry contains more than 935 arrangements.

Each arrangement contains 16 tilemap entries, each 2 bytes. The 16 tilemap entries represent a 4x4 grid of background tiles with each row in left-to-right order, followed by the next row, etc. Thus, within a tile arrangement, the tilemap entry for a given 0-3/0-3 x/y coordinate can be found using the formula entry_offset = x * 2 + y * 8.

Tilemap Entry Format

See SNES Background Tilemap.

VH0PPP0CCCCCCCCC

• V (bit 0x8000): Vertical flip. If set, tile will be flipped vertically from how it is stored in Tileset Character Data.
• H (bit 0x4000): Horizontal flip. If set, tile will be flipped horizontally from how it is stored in Tileset Character Data.
• 0 (bit 0x2000): Always zero in tile arrangement data loaded from ROM. This represents the BG Priority Bit once loaded into the tilemap, but the EarthBound engine sets it automatically when loading foreground/background paired tileset characters. See Tileset Character Data Decompressed Format.
• PPP (bits 0x1C00): Palette selection. Always between 2 and 7 (inclusive), as those indices are where EarthBound loads map palettes into CGRAM. A palette selection value can be determined from an EarthBound map subpalette number using the formula palette_selection = subpalette_number + 2.
• 0CCCCCCCCC (bits 0x03FF): Tileset character selection. Character index into the currently loaded map tileset of a background tile. Always between 0 and 511 (inclusive) as those are the characters that EarthBound uses as background tiles. For characters paired with a foreground character, EarthBound will automatically generate the tilemap entry for the paired foreground tile. See Tileset Character Data Decompressed Format.