Atari 400 Hardware Manual

VI.
FIGURES
A.
MEMORY MAP
ADDRESS
FFFF
D800
D000-D7FF
CFFF
BFFF
8000
7FFF
2000
lFFF
FUNCTION
Operating System
And
Math Routines
Hardware
Addresses
Reserved for Future
0. S • ex_I:lans ion
ROM Cartridge
(Colleen
left and right
slot and Candy single
slot all address
this
space)
RAM
Expansion
*
RAM initially
supplied in the
product
to
SIZE
lOK
2K
4K
16K
8K
* RAM expansion can actually exten to BFFF. However, the ROM cartridges
will deselect the RAM. Deselection occurs on 8K boundaries. Atari 400
units are RAM expandable only at the factory. They can accept RAM up
to 2FFF (16K) when fully extended.
VI .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)