Atari 400 Basic Reference Manual

APPENDIX D
ATARI 400/800
MEMORY MAP
ADDRESS CONTENTS
Decimal Hexadecimal
65535
57344
57343
55296
55295
53248
532 47
49152
49151
40960
40959
32768
32767
31755
10880
10879
9856
9855
4864
FFFF
EOOO
DFFF
D800
D7FF
DODO
CFFF
cooo
BFFF
AOOO
9FFF
8000
7FFF
7CIF
2A80
2A7F
2680
267F
1300
OPERATING SYSTEM ROM
F
LOATING POINT ROM
HARDWARE REGISTERS
NOT USED
CARTRIDGE
SLOT A
(may be RAM if no A or B cartridge)
CARTRIDGE SLOT B
(may be RAM if no B cartridg~ RAMTOP (MSB) l
(7FFF if 32K system )
DISPLAY
DATA (size varies)
DISPLAY LIST (size varies)
(7C1F if 32K system , (GRAPHICS ~ I OS MEMTOP I
FREE RAM
(size varies)
~BASIC MEMTO P I
BASIC program, buffers, tables , run-time stack.
(2A80 if DOS, ma y va ry)
DISK OPERATING SYSTEM (2A7F-700)
DISK I/0 BUFFERS (current DOS)
DISK
OPERATING SYSTEM RAM (current DO S)
Appendix D-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)