Map format and raw data

The main maps for the game are stored in a 26,584 byte file called bl_maps. The following article breaks down the format of this file and extracts the data.

1. File layout
2. $0: Header
3. $5a: Maps
4. Tile key
5. $205a: ? (71 x 4)
6. $2176: Text strings, signs
7. $28da: Teleporters
8. $29fe: Pits
9. $2be2: Signs
10. $30ae: Pressure plates
11. $369a: Traps / Triggers
12. $3a76: Locked doors
13. $3bea: Switches
14. $3e8a: NPCs
15. $41fa: Monsters
16. Monster IDs
17. $5de2: Items

File layout

The file is the following format:

$0: Header

The file begins with a 90-byte header, mostly consisting of an index to the sections of the file:

$5a: Maps

There are eight maps in the game. Each is 32 x 32 tiles in size, and each tile is represented by a single byte. The maps in order are:

• Forest area
• Quest Three: Sword of Freedom, floor 1
• Quest Three: Sword of Freedom, floor 2
• Quest Three: Sword of Freedom, floor 3
• Quest Two: Cup of Life
• Quest One: Shield of Justice
• Quest Four: Crown of Glory, various
• Quest Four: Crown of Glory, floor 1

All maps are automatically surrounded by solid walls. This differs from the Dungeons of Avalon II map format, where the map wraps north-south and east-west, allowing for more dynamic map shapes.

Full maps for each quest will be found at the relevant pages; see the main index.

Tile key

Additionally, any square appears to be able to add 0x80 to signify that the square is occupied by a monster and cannot be entered. For example, 0xa0 is just an occupied 0x20.

The following tile IDs are not used in any map: 03, 07, 09, 0c, 0d, 14, 15, 16, 17, 1b, 1c, 1d, 1f, 23, 24, 25, 28, 29, 2b, 2d, 2f, 32, 35, 37, 38, 39, 3a, 3b, 3f, 4f, 5f, 60, 61, 62, 67, 6d, 6e. Additionally, no maps use 14 to 17 (open hatches) or 50 to 5e (open doors); all start closed.

$205a: ? (71 x 4)

Possibly summoned monsters.

$2176: Text strings, signs

A set of 63 text strings, of variable length. The structure is as follows: two bytes for the length of the string (including all its headers), two bytes for the map offset address, four unknown bytes, and the text in ASCII terminated by null bytes. Non-standard control codes are used for newlines.

These text strings are used for the Treguard messages on the walls.

$28da: Teleporters

73 4-byte locations of teleporter doors. Two bytes each for the map coordinates.

$29fe: Pits

80 6-byte entries, plus a 4-byte footer. Two bytes source map address, two bytes destination address, two other bytes.

$2be2: Signs

For things like the Treguard signs. 307 4-byte rows: two bytes for map coords, one byte unknown, one byte padding always 00.

$30ae: Pressure plates

Another variable-bytes field. The first two bytes is the length of the entry, including itself. The second two bytes are the address for the map location of the switch. The next byte appears to determine the type of effect, and the remaining bytes are parameters.

There are 214 entries in the list, corresponding to the 214 pressure plates (154 regular and 60 hidden).

For the trigger type field, the first hexadecimal digit appears to represent the effect, and the second digit the number of parameters minus one. For example, 80 has one parameter and 83 has 5.

$369a: Traps / Triggers

A series of four-byte entries for things like fireball traps. Two bytes for the map address, and two more bytes to define the trap. Accounts for things like fireballs, disappearing walls, etc.

Trap effects:

03 / 83

Disappear a block.

07

Fireball shooter. The parameter can be 00, 40, 80, or c0 for direction of fire: north, east, south, or west.

0a

Toggle the block each time it’s triggered. Parameter determines the block type toggled with.

0b

Spawns a monster. Parameter determines the monster spawned.

0f

Win the game.

01, 02, 04, 05, 0c, 0d, 81, 82, 84

Unknown.

$3a76: Locked doors

62 6-byte entries. Two bytes for the map address of the door, two bytes for the address of the keyhole, one byte unknown, and one byte which is always zero.

The only three data bytes used are 81, 83, and 89. The number does not appear to relate to the type of key required.

$3bea: Switches

112 6-byte entries, consisting of two bytes each for a map address, target block, and effect.