Atari 400 Hardware Manual

B. ALPHABETICAL ORDER
Hardware Register
OS Shadow
Address
Address
Name
Description Hex
Dec
Name
Hex Dec
ALL POT Read 8
line Pot Port State D208
53768
AUDCl
Audio Channel 1
Control
D201
53761
AUDC2
Audio Channel 2
Control
D203
53763
AUDC3
Audio
Channel
3
Control
D205
53765
AUDC4
Audio
Channel 4 Control
D207
53767
AUDCTL
Audio
Control
D208 53768
AUDFl
Audio Channel 1 Frequency D200 53760
AUDF2
Audio
Channel 2
Frequency D202
53762
AUDF3
Audio Channel
3
Frequency D204
53764
AUDF4
Audio Channel 4
Frequency
D206 53766
CHACTL Character Control
D401 54273 CHART
2F3
755
CHBASE
Character base address D409 54281 CHBAS
2F4 756
COLBK Color-Luminance
of Background
DOlA
53274
COLOR4
2C8 712
COLPFO
Color
Luminance of Playfield 0
D016 53270
COLORO 2C4 708
COLPFl Color Luminance of
Playfield 1
D017 53271
COLORl
2C5 709
COLPF2 Color Luminance of Playfield 2
D018
53272 COLOR2
2C6 710
COLPF3
Color
Luminance
of Playfield 3 D019
53273
COLOR3 2C7 711
COLPMO
Color
Luminance of
Player-Missile 0
D012 53266 PCOLRO
2CO 704
COLPMl Color Luminance of Player-Missile 1 D013
53267
PCOLRl
2Cl 705
COLPM2 Color Luminance of Player-Missile 2 D014
53268
PCOLR2
2C2
706 ~
COLPM3
Color
Luminance of Player-Missile
3
D015
53269
PCOLR3 2C3 707
CON SOL Console Switch Port DOlF 53279 Set to
8 during
VB LANK
DLISTH Display List Pointer (high byte) D403 54275 SDLSTH
231 561
DLISTL Display List Pointer (low byte)
D402
54274 SDLSTL 230 560
DMACTL
Direct Memory Access (DMA) Control D400 54272
SDMCTL 22F 559
GRACTL Graphic Control
DOlD
53277
GRAFM Graphics for all Missiles DOll 53265
GRAFPO
Graphics for
Player
0 DOOD 53261
GRAFPl Graphics for Player 1 DOOE 53262
GRAFP2 Graphics for
Player
2 DOOF 53263
GRAFP3 Graphics for Player
3 DOlO
53264
HITCLR Colission Clear DOlE 53278
HPOSMO Horizontal Position of Missile
0 D004 53252
HPOSMl
Horizontal
Position
of
Missile 1 D005 53253
HPOSM2 Horizontal Position of Missile 2 D006 53254
HPOSM3
Horizontal
Position of Missile 3 D007 53255
HPOSPO
Horizontal Position of
Player 0 DOOO
53248
HPOSPl Horizontal Position of Player 1 DOOl 53249
HPOSP2
Horizontal Position
of
Player 2 D002 53250
HPOSP3 Horizontal
Position of Player
3
D003 53251
HSCROL Horizontal
Scroll D404
54276
IRQ EN
Interrupt Request
(IRQ) Enable D20E 53774 POKMSK 10 16
IRQST IRQ Status
D20E 53774
KBCODE Keyboard Code
D209 53769 CH 2FC
764
MOPF
Missile 0 to
Playfield Collisions DOOO 53248
MOPL
Missile
0 to
Player Collisions
D008
53256
MlPF Missile
1
to
Playfield Collisions
DOOl
53249
MlPL Missile
1 to
Player Collisions
D009 53257
M2PF
Missile 2
to
Playfield Collisions
D002
53250
M2PL Missile 2 to
Player Collisions DOOA 53258
v. 5

Atari 400 Specifications

General

Manufacturer	Atari
Model	400
Type	Home Computer
Release Year	1979
CPU	MOS Technology 6502
CPU Speed	1.79 MHz
ROM	10 KB
Operating System	Atari OS
Keyboard	Membrane keyboard
RAM	8 KB (expandable to 48 KB)
Graphics	ANTIC and GTIA chips
Sound	4 channels
Display	RF output for connection to TV
Storage	Optional cassette tape drive or floppy disk drive
Ports	Cartridge
Display Resolution	320x192 (16 colors)