Atari 400 Hardware Manual

V. HARDWARE REGISTER LISTS
A. ADDRESS ORDER
CTIA ADDRESSES
WRITE
READ
Address Name Description
Name
Description
DOFF
}
l
REPEAT AS BELOW
7 MORE TIMES
D020
DOlF
CON SOL Write Consol SW.Port
CON SOL Read Consol SW. Port
DOlE
HITCLR
Collision Clear
DOlD
GRACTL Graphic Control
DOlC
VDELAY Vert.
Delay
D91B PRIOR
Priority Select
DOlA COLBK
Col-lum Bkgnd
D019
COLPF3
Color-lum of 3
D018
COLPF2
Pla_yfield 2
D017
COLPFl
Playfield 1
D016
COLPFO
Playfield
0
D015 COLPM3 Color-lum of 3
D014
COLPM2 Player-Missile 2
PAL READ PAL/NTSC bits
D013
COLPMl Player-Missile 1
TRIG3
Read Joystick
D012
COLPMO Player-Missile 0 TRIG2 Trigger
DOll GRAFM
Graphics All Missiles TRIGl Buttons
DOlO GRAFP3
Graphics
Pla_yer
3
TRIGO
DOOF
GRAFP2
Graphics Player
2 P3PL Read Player
DOOE
GRAFPl
Graphics Player
1 P2PL to Player
DOOD
GRAFPO
Graphics Player
0 PlPL Collisions
DOOC SIZEM
Size All Missiles
POPL
DOOB
SIZEP3 Size
Player
3
M3PL
Read Missile
DOOA SIZEP2 Size
Player
2 M2PL
To Player
D009 SIZEPl Size
Player
1 MlPL
Collisions
DOOB SIZEPO Size
Player
0 MOPL
D007 HPOSM3
Horz.
Posit. Missile 3
P3PF Read
Player
D006 HPOSM2 Horz. Posit. Missile 2 P2PF To Playfield
DOOS HPOSMl Horz. Posit. Missile 1
PlPF
Collisions
D004 HPOSMO Horz. Posit. Missile 0
POPF
D003
HPOSP3 Horz.
Posit.
Player
3
M3PF Read Missile
D002
HPOSP2 Horz.
Posit.
Player
2 M2PF To Playfield
DOOl HPOSPl Horz. Posit.
Player
1 MlPF Collisions
DOOO
HPOSPO Horz.
Posit.
Player
0 MOPF
v .1

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)