Atari 400 Field Service Manual

ROM
CARTRIDGE
The Atari
ROM Program
Cartridge contains two ROM
chips designed
to provide
a
specific program
application (See Figure 1-16).
The
6502
microprocessor
reads
the
information contained within
the
ROM
chips by
addressing
memory
locations
SOOO thru
BFFF Hex.
When
the ROM
Program
Cartridges are inserted
in the motherboard,
they
disable the RAM
address
locations 8000
thru
BFFF,
in SK increments.
The
left
ROM
Cartridge
overlays
memory
locations AOOO
to BFFF,
and the right ROM
Cartridge
overlays
locations
8000
to
9FFF.
ACCESSORIES
AC
Power
Adaptor
The AC
Power
Adaptor
plugs
into a standard
wall outlet
to provide
the 9Vac
used by
the
Consoles. The
other
end of the
power
adaptor plugs
into the power
jack
on either
Console.
TV
Switch
Box
The TV
Switch Box
allows
the
Console
to be connected
to the
300 ohm RF
antenna
or
75 ohm
cable inputs
on
a typical televison
set.
'BASIC
Program
Cartridge
The 'BASIC
Program
Cartridge
(provided)
is
a standard
feature for
both
Consoles
and
contains
the ATARI
BASIC
Interpreter.
ATARI
Home
Computers
1-17

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)