The GPU supports output via either the VGA port or an ILI9341 based LCD (Needs the parallel interface variant with 8 data lines). The selection is a constant parameter set in the VHDL to compile the needed interface.
| Name | Indices | Address |
|---|---|---|
| Render | 0 | $30000 |
| Horizontal Scroll | 1 | $30004 |
| Vertical Scroll | 2 | $30008 |
| Window X | 3 | $3000C |
| Window Y | 4 | $30010 |
| Palette | 5-20 | $30014 |
| Tile Data | 21-2068 | $30054 |
| Background Data | 2069-6164 | $32054 |
| Window Data | 6165-7364 | $36054 |
| Sprite Data | 7365-7428 | $37314 |
- 64 32-byte tiles. 4 bits per pixel allowing for a 16-color palette.
- Tile containing images with dimensions multiples of 8 can be converted to binary
- and header files for use in programs using the image_convert.py script.
- Subroutines and functions are provided for copying tiles into VRAM.
- 1 byte tile index for each tile in world (64 by 64 tiles)
- Scrollable vertically and horizontally
- 1 byte tile index for each tile in window (30 by 40 tiles)
- Moveable position
- Drawn over background and sprites
- 16 RGB888 colors
- GIMP palette file is provided for ease of use
- Composed of 4 sequential tiles in a 2 by 2 grid
- 9 bit x and 9 bit y coordinates
- 8 bits specifying for the first tile
- 2 bits for vertical/horizontal flip
- Priority is based on sprite index with lower ones drawn first
- Palette color zero is transparent