Format ASC (A? SCreen)
Binary format that contains background map tile information.
Specification
| Offset | Size | Description |
|---|---|---|
| 0x00 | 4 | Stamp ASC |
| 0x04 | 2 | Width |
| 0x06 | 2 | Height |
| 0x08 | 2 | Number of maps |
| 0x0A | 2 | Map data offset |
| 0x0C | 4 | Map data size |
| 0x10 | - | Standard NDS 16-bits map information |
It is not possible to confirm fields 0x08 and 0x0A as the game doesn't read
them. The offset to the map size is hard-coded in other code locations as
0x10. The content of these fields seem to be always the same 1 and 16.
The subroutine that copies the map is in overlay 62 at 0x020ec9fc. It gets the
map info given a pixel coordinate (x, y): it converts the pixel coordinate to
tile coordinate (tile size 8x8) and multiply by the map info size (2)
0x10 + (y / 8) * (width / 8) * 2 + (id0 / 8) * 2