Atari 400 Basic Reference Manual

DECIMAL
HEXADECIMAL
LABEL
LOCATION
LOCATION
COMMENTS AND DESCRIPTIONS
PORTA 54016
D300
PIA Port A Controller jack I/0 ports.
PORTE
54017
D301 PIA
Port B Initialized to hex 3C.
PACTL
54018
D302
Port A Control Register (on Program Recorder 52
= ON,
60 = OFF).
PBCTL
54019
D303
Port B control register.
SKCTL
53775
D20F
Serial Port control register . Bit 2=0 (last key still
pressed).
App en dix 1-3

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)