||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 [COLPM0]...\\PF0-PF3 Playfield colors [COLPF0]...\\BAK background or border color [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