Default Tilemap Attribute Register
From SpecNext official Wiki
| Number | $6C |
|---|---|
| Readable | Yes |
| Writable | Yes |
| Short Description | Default tile attribute for 8-bit only maps. |
| Bit | Function |
|---|---|
| 7-4 | Palette Offset (copied as bits 7-4 in final palette index) |
| 3 | X mirror |
| 2 | Y mirror |
| 1 | Rotate |
| 0 | If in 512-tile-mode: bit 8 of tile-id else draw priority: 1 = ULA over tilemap, 0 = tilemap over ULA |
This attribute is used for all tiles if bit 5 of Tilemap Control Register ($6B) is set.
When bit 1 of Tilemap Control Register ($6B) is set, the bit 0 of tile attribute works as ninth bit of tile-id (allowing 512 tiles in total), and the priority of layers is then "ULA over Tilemap" as default.
When bit 3 of Tilemap Control Register ($6B) is set, the bits 7-1 works as Palette offset (copied to bits 7-1 in final palette index, bit 0 comes from pixel data) (there are no mirror/rotate bits in the "text mode").