| ADR | HEXADR | NAME | Description | shadow of | OS |
|---|
| 623 | $026F | GPRIOR | Priority Selection Register | PRIOR | all |
Priority Settings#
| Bit | Description |
|---|
| 0 | P0-P1-P2-P3 PF0-PF1-PF2-PF3 BAK |
| 1 | P0-P1 PF0-PF1-PF2-PF3 P2-P3 BAK |
| 2 | PF0-PF1-PF2-PF3 P0-P1-P2-P3 BAK |
| 3 | PF0-PF1 P0-P1-P2-P3 PF2-PF3 BAK |
| 4 | Four Missiles add up to be 5th player |
| 5 | Overlapping Players have 3rd color |
| 6 | GTIA Mode see next table |
| 7 | GTIA Mode see next table |
P0-P3 Players
PCOLR0.../
COLPM0...
PF0-PF3 Playfield colors
COLOR0.../
COLPF0...
BAK background or border color
COLOR4/
COLBAK
A logical OR is done to the colors of players 0/1 and 2/3 when they overlap. Only the 0/1, 2/3 combinations are allowed; you will not get a third color when players 1 and 3 overlap, for example (you will get black instead).
You can also use this location to select one of GTIA GRAPHICS modes nine, ten, or eleven.
GTIA Modes#
| GTIA Mode* | Bit 6 | Bit 7 | Description |
|---|
| 9 | 0 | 1 | 16 different luminances of the same hue (color) |
| 10 | 1 | 0 | 9 different colors |
| 11 | 1 | 1 | 16 different hues (colors) of the same luminance |
* the same as GRAPHICS x in BASIC