Atari 400 Field Service Manual

Symptom
Possible
Cause
Diagram
Entry
Point
No Gray Bars
Upside
Down Alpha/
Numerics
or Player
Field
Some Keyboard
Keys
Faii
AU
Keyboard
Keys
Faii
Tones
Missing
During
Sound
or Games
Console
(Game)
Switches
Will
Not
Function
ROM
Test
Failed
RAM
Test
Failed
Hand
Controllers
Will
Not
Work
A301,
Alll,
Q107
R309
Adjustment
X101,Q103
&
if
Modulator
A302
on CPU Board,
A301
AU1,Q107
Modulator
Keyboard
Failure
AlOl,
Zl03ac*
AlOi,
R160,
R161,
R166, R170
C164,
C179,
CIS*,
Q105
LlOl,
Q106, L118, A203
A301
on CPU Board,
RU9-122
C^21-12i^
AW
I -403
on
ROM
Board
1*03
See
RAM
test
Matrix,
Figure
5
Table
5
See Port
Test
Matrix,
Table
5
HH
*00, Page
5-U
800, Page
7-1*
n
*00, Page
5-1
800,
Page
7-1
*
13
*00, Page
5-21
800, Page
7-21
KK
*00, Page
5-22
800, Page
7-22
LL
*00, Page
5-22
800, Page 7-22
MM
*00, Page
5-2*
800, Page
7-2*
NN
*00,
Page 5-28
800, Page
7-28
OO
*00, Page
5-29
800, Page
7-29
PP
*00, Page 5-31
800, Page
7-31
QQ
*00, Page
5-33
800, Page
7-33
ATARI
Home
Computer
6-2

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)