CTIA/GTIA (Graphic Television Interface Adapter) reference

CTIA/GTIA register set:
|  | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
$D000 (R) | M0PF | unused ¹ | Missile 0 to playfield collision
$D000 (W) | HPOSP0 | Horizontal position of player 0
$D001 (R) | M1PF | unused ¹ | Missile 1 to playfield collision
$D001 (W) | HPOSP1 | Horizontal position of player 1
$D002 (R) | M2PF | unused ¹ | Missile 2 to playfield collision
$D002 (W) | HPOSP2 | Horizontal position of player 2
$D003 (R) | M3PF | unused ¹ | Missile 3 to playfield collision
$D003 (W) | HPOSP3 | Horizontal position of player 3
$D004 (R) | P0PF | unused ¹ | Player 0 to playfield collision
$D004 (W) | HPOSM0 | Horizontal position of missile 0
$D005 (R) | P1PF | unused ¹ | Player 1 to playfield collision
$D005 (W) | HPOSM1 | Horizontal position of missile 1
$D006 (R) | P2PF | unused ¹ | Player 2 to playfield collision
$D006 (W) | HPOSM2 | Horizontal position of missile 2
$D007 (R) | P3PF | unused ¹ | Player 3 to playfield collision
$D007 (W) | HPOSM3 | Horizontal position of missile 3
$D008 (R) | M0PL | unused ¹ | Missile 0 to player collision
$D008 (W) | SIZEP0 | unused | Player 0 size
$D009 (R) | M1PL | unused ¹ | Missile 1 to player collision
$D009 (W) | SIZEP1 | unused | Player 1 size
$D00A (R) | M2PL | unused ¹ | Missile 2 to player collision
$D00A (W) | SIZEP2 | unused | Player 2 size
$D00B (R) | M3PL | unused ¹ | Missile 3 to player collision
$D00B (W) | SIZEP3 | unused | Player 3 size
$D00C (R) | P0PL | unused ¹ | Player 0 to player collision
$D00C (W) | SIZEM | Missile 3 size | Missile 2 size | Missile 1 size | Missile 0 size
$D00D (R) | P1PL | unused ¹ | Player 1 to player collision
$D00D (W) | GRAFP0 | Player 0 graphic data
$D00E (R) | P2PL | unused ¹ | Player 2 to player collision
$D00E (W) | GRAFP1 | Player 1 graphic data
$D00F (R) | P3PL | unused ¹ | Player 3 to player collision
$D00F (W) | GRAFP2 | Player 2 graphic data
$D010 (R) | TRIG0 | unused ¹ | /Trigger
$D010 (W) | GRAFP3 | Player 3 graphic data
$D011 (R) | TRIG1 | unused ¹ | /Trigger
$D011 (W) | GRAFM | Missiles graphic data
$D012 (R) | TRIG2 | unused ¹ | /Trigger
$D012 (W) | COLPM0 | Chroma | Luma | unused
$D013 (R) | TRIG3 | unused ¹ | /Trigger
$D013 (W) | COLPM1 | Chroma | Luma | unused
$D014 (R) | PAL | unused ¹ | $F (NTSC) / $1 (PAL)
$D014 (W) | COLPM2 | Chroma | Luma | unused
$D015 (W) | COLPM3 | Chroma | Luma | unused
$D016 (W) | COLPF0 | Chroma | Luma | unused
$D017 (W) | COLPF1 | Chroma | Luma | unused
$D018 (W) | COLPF2 | Chroma | Luma | unused
$D019 (W) | COLPF3 | Chroma | Luma | unused
$D01A (W) | COLBK | Chroma | Luma | unused
$D01B (W) | PRIOR | GTIA mode ² | Overlap | 5th Pl. | Priority
$D01C (W) | VDELAY | P3 | P2 | P1 | P0 | M3 | M2 | M1 | M0
$D01D (W) | GRACTL | unused | Latch Tr. | enable P | enable M
$D01E (W) | HITCLR | unused
$D01F (R) | CONSOL | unused ¹ | /Option | /Select | /Start
$D01F (W) | CONSOL | unused | Reset? | unknown

¹ - Unused bits read back 0
² - Only available on GTIA
© 2009-2010 Graham