Atari 2600 Quick start guide

2600/2600 A
VCS DOMESTIC (MD)
Field Service
Manual
FD100133
Rev. 02

E.C.R. NO. 0021
2600/2600A VCS DSMZSTIC FSM
I Error in Flowcharts and Parts Lists
JR
ATARI, INC.
consumer Product Services
845 W. Maude Avenue
Sunnyvale,
CA 94041
ATAR~ o~------
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8-3 and 8-7 with the attached corrected pages.
Re~lacecover page with new (Rev. 02) cover page.
Retain
this ECN as a record of these changes.
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I
PART NO. R EV.
Fill 00133 02
DATE
1-21 -83
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ATARI
VIDEO COMPUTER SYSTEMTM
FIELD SERVICE MANUAL
MODEL 2600/2600A DOMESTIC (M/N)

Atari believes that the information described in this manual is accurate and reliable, and much
care has been taken
in its preparation. However, no responsibility, financial or otherwise, shall
be accepted for
any consequences arising out of the use of this material. Information contained
herein is subject to change. Revisions may be issued to advise of such changes and/or additions.
Correspondence regarding this document
should be forwarded to Manager of Technical Support,
Consumer Product
Service, Atari, Incorporated, 845 W. Maude Sunnyvale, California 94086.
2600/2600A Domestic VCS

Table of Contents
P
Section Title
-
Page
INTRODUCTION
THEORY OF OPERATION
Introduction
Overview
Game Console
Outer Casting
Switchboard
:Motherboard
2600A Model Differences
- All Revisions
2600A Model Differences
- Revisions 14 and 15
2600A Model Differences - Revisions 16 and up
Summary
2 SCHEMATICS
AND SILKSCREENS
3 TESTING AND TROUBLESHOOTING
Equipment Requirements
Test Procedures and Methods
2600 Model Modifications
2600A Model Modifications
Testing with the Diagnostic Test Cartridge
(Version 2.6)
Initialization
RAM Test
Color Bar Test
Gray Bar Test
magnostic Matrix Test
Audio Tones Test
Paddle
Control Lines Test
2600 DIAGNOSTIC FLOWCHART
SYMPTOM CHECKLIST
2600 Symptom Checklist
2600A Symptom Checklist
2600A DIAGNOSTIC FLOWCHART
GAME CONTROLLERS
Overview
Joystick
(X-Y) Controller
Joystick
(X-Y) Controller Check
Paddle Controller
Paddle Controller Check
Driving Controller
Driving Controller Check
Keyboard Controller
Keyboard Controller Check
ATARI CX2600 (M/N) PARTS LIST
ATARI CX2600A
(M/N) PARTS LIST
iii 2600/2600A Domestic
VCS

Table of hntents
Section
9
Figure
Title
-
SERVICE BULLETINS
List of Illustrations
Title
-
2600 Functional Diagram
2600 Game Console
2600 Switchboard and Motherboard Assembly
TV Switchbox
2600A Game Console
2600A Board Layout
2600/2600A IC Pinouts
2600 Motherboard Silkscreen
2600 Channel 3 Switchboard Silkscreen
2600 Channel 3 Switchboard Schematic
2600 Channel 2-3 Switchboard Silkscreen
2600 Channel 2-3 Switchboard Schematic
2600A Motherboard Silkscreen (Revs. 1-1 3)
2600A Motherboard Silkscreen (Revs. 14 and 15)
2600A Motherboard Silkscreen (Revs. 16 and up)
Inserted in Front Pocket of Notebook:
2600 Motherboard Schematic
2600A Motherboard Schematic (Revs. 1-1 3)
2600A Motherboard Schematic(Revs. 14 and 15)
2600A Motherboard Schematic (Revs. 16 and up)
2600 Trigger Circuitry with Static Modification
2600 Static Modification Zener Diode
Location of Colored Dot Over Trace
2600 Switchboard Static Modification
2600A (Revs. 1-1 3) Static Modifications
Switch Initialization Positions
Defective
RAM Patterns
Color Bars Screen
Grav
Bars Screen
~iagnosticMatrix Screen (Shorting Plugs
OUT)
Diagnostic Matrix Screen (Shorting Plugs IN)
Audio Tone Test Screens
Page
9-1
Page
iv
2600/2600A Domestic VCS

List of Illustrations (Continued)
Figure
Title
Page
Table
-
4-1
Switch Initialization Positions
Color
Bars Screen
Defective
RAM Patterns
Gray Bars Screen
Defective Gray
Bars Screen
Diagnostic
Matrix Screen (Shorting Plugs OUT)
Diagnostic Matrix Screen (Shorting Plugs IN)
Diagnostic Matrix Screen with Defective Pattern
Audio Tone Test Screens
RC Waveforms
STC Address Line Waveforms
STC Data Line Waveforms
Joystick
(X-Y) Controller
Joystick
(X-Y) Schematic
Paddle Controller
Paddle Confroller Schematic
Driving Controller
Driving Controller Schematic
Keyboard Controller
Keyboard 'Xriring Diagram
Keyboard Schematic
4
List of Tables
~iile
Connected Pins on
VCS Motherboard
Page
4-47
2600/2600A Domestic VCS

sections:
a
a
a
0
0
a
a
a
.
a
INTRODUCTION
The Video Computer systemT' (VCS) Field Service Manual is organized in nine
THEORY OF OPERATION - overview of how the VCS works and what the
basic assemblies look like.
SILKSCREENS AND SCHEMATICS - electrical drawings and layouts of the
printed circuit boards.
TESTING AND TROUBLESHOOTING - overview of the procedures for
testing and repairing the VCS unit.
2600 DIAGNOSTIC FLOWCHART - thorough flowchart enabling the
technician to test and troubleshoot a defective 2600 unit.
SYMPTOM CHECKLIST - for the experienced technician, a list of the high
failure parts and the flowchart entry point for that particular problem.
2600A DIAGNOSTIC FLOWCHART - thorough flowchart enabling the
technician to
test and troubleshoot a defective 2600A unit.
GAME CONTROLLERS - overview of hand controller construction with
electrical schematics and recommended
test and repair procedures.
PARTS LIST - detailed breakdown of all parts used in both the 2600 and
2600A .
SERVICE BULLETINS - section to be used to hold service bulletins released
by the Manager of Technical Support. These bulletins will include changes
in recommended repair procedures and required modifications for units in
the field.
The manual is designed for use by both experienced and inexperienced service
personnel.
The Diagnostic Flowcharts (Sections 4 and 6) provide detailed diagnostic
and repair procedures for technicians who are not yet completely familiar with the
VCS. The Symptom Checklist (Section 5) provides a fast repair reference for the more
experienced technician.
2600/2600A Domestic VCS

SECTION 1
THEORY OF OPERATION
There are currently four types of ATARI Video Computer Systems. The original model
(2600) is composed of two
PC Boards connected by a 12-pin ribbon cable with the
motherboard surrounded by a heavy aluminum casting.
The other models (2600A: Revisions 1-13, Revisions 14-15, and Revisions 16 and up)
are composed of a single board with a light aluminum shield. The single board models
differ slightly in the video output circuitry. Component differences are:
Revisions 1-1 3 have no diodes on TIA lines LA41 and Sync.
a Revisions 14-15 have diodes and pull-up resistors on TIA lines LMl and
Sync.
e
Revisions 16 and up include the above mentioned diodes and resistors as
well as a timer chip.
The revision level
is etched directly on the PC board.
OVERVIEW
The ATARI Video Computer System (VCS) Models 2600/2600A are state-of-the-art
microcomputers. They receive instructions for the operation of different games from
individual Read-Only-Memory game cartridges and interpret data from the players'
hand-held controllers. They
also allow game players to select both a specific version
of
each game and the player difficulty (on a per player basis). Figure 1-1 is a block
diagram of the functional flow of the
VCS Model 2600. Section 7 describes the player
controllers.
-
.
brar
Ellmcutor
(AX, Adwmrt
120 VAC
Figure 1 -1. 2600 Functional Diagram
2600/2600A Domestic
VCS

GAME CONSOLE
The VCS game console is composed of an outercasting that houses the switchboard and
the RF radiation shielded motherboard.
Outer Cast inq
The casting consists of three pieces of plastic (see Figure 1-2). The pieces include the
base, which holds the switchboard and motherboard assembly; the top; and the bezel.
Figure 1-2. 2600 Game Console
2600/2600A Domestic VCS

Switchboard
The switchboard assembly holds the player option switches, the power supply, and the
RF modulator (See Figure 1-3).
0 PLAYER OPTION SWITCHES
Switches SlOL thru SL04 are double-pole, single-throw. Switches SL05 and
5106 are double-pole, double-throw. All switches are connected between
the switchboard and the motherboard
by 1 2-conductor flexible ribbon
cable.
POWER SUPPLY
The power supply is composed of
a +5 voltage regulator, filter capacitors,
and the power on/off switch. Unregulated
DC is supplied to the board from
the battery eliminator.
A supply of +5 volts is routed through a filter
circuit to the RF modulator. The motherboard also receives its power
(+5
volts Vcc) from the switchboard via the same 12-conductor ribbon cable
referenced above.
0 RF MODULATOR
The RF modulator. converts the signal received from the Television
Interface Adaptor chip on the motherboard to
a frequency that a television
can receive and interpret. Data between the RF module and the Television
Interface Adaptor chip is passed via the 12-conductor ribbon cable which
connects the motherboard to the switchboard.
A coaxial cable passes this
siqnal from the
RF module to the switch box mounted on the bac!c of the
television.
Ilarq-
v mchm
(Amml
mrd
hm.r.1~
Figure 1-3. 2600 Switchboard and Motherboard Assembly
1-3 2600/2600A Domestic
VCS

Motherboard
The motherboard is composed
of a PC board containing a microprocessor (MPU) chip, a
combination Random Access Memory - Input/Output (RAM-110) chip, and a Television
Interface Adaptor
(TIA) chip (see Figure 1-3). The board also contains numerous
capacirors, resistors, transistors, and other assorted electronic components. These
parts are
all listed in Section 8, PARTS LIST.
a MICROPROCESSOR CHIP
The heart of the
VCS is the 6507 microprocessor chip (MPU). This device
makes decisions for
the VCS based upon information it receives from the
game cartridge and the
RAM-I/O (discussed in the next paragraph).
RANDOM ACCESS MEMORY-INPUT/OUTPUT CHIP
Temporary storage of data from the MPU is provided by the 6532 Random
Access ~emory-Input/Output (RAM-1/01 chip. This chip also scans the
option switches and the joystick 1/0 lines for information and maintains
time accounting for the
MPU.
0 TELEVISION INTERFACE ADAPTOR CHIP
This ATARI proprietary
chip generates audio and video signals which are
required
by the RF modulator. The Television Interface Adaptor (TIA) chip
also contains the analog-to-digital converter circuitry that allows the
MPU
to understand signals originating in the handheld paddle controllers.
TIA outputs are processed by additional circuitry into a composite video,
sound, and color signal which
is routed to the RF module on the switch-
board via the 12-conductor ribbon
cable. The RF module converts the
composite signal to
a RF signal acceptable to the television. A coaxial
cable transmits this
RF signal from the console to a selection box that can
be mounted on the T.V. This switchbox (Figure 1-41 allows you to display
either
a signal received by the antenna (for normal T.V. viewing) or a signal
from the
VCS (for playing a game).
Figure 1-4. TV Switchbox
1-4 2600/2600A Domestic VCS

2600A MODEL DIFFERENCES - ALL REVISIONS
The major difference between the newer single board VCS (2600A) and the original
VCS (2600) is that all of the components formerly on the switchboard are now located
on the motherboard
(See Figure 1-5). This includes the player control function
switches (Power
ON/OFF, COLOR/BW, GAME SELECT and GAME RESET), RF
modulator and power supply circuitry. The single board design eliminates the need for
the ribbon cable, which connected the switchboard to the motherboard on the 2600
VCS.
Gone, too, are the luminescence and RF output buffers and the two TIA input buffers,
all
of which were contained in chip A203. In the oscillator circuit, one of the
transistors and its associated network has been eliminated and R227-R230 (paddle
control lines)
are no longer present. C239, going to pin 7 on J202 and 3203, has been
replaced by C236
and C237 (See Figure 1-6).
Figure 1-5. 2600A Game Console
2600/2600A Domestic VCS

Figure 1-6. 2600A Board Layout (Revs 1-13)
In addition to the component changes, the physical location of several parts has also
been changed. Instead of having the right and left difficulty switches placed on top of
the game, they are located
at the rear of the console next to the game controller
plugs. The channel selector switch is also located
at the rear of the console. The
game cartridge socket is no longer angled, but is mounted vertically on the board.
2600A MODEL DIFFERENCES - REVISIONS 14 AND 15
Revisions 14 and 15 contain the model differences described above, and in addition
have new components on the TIA lines, LM1 and
Sync. There are two IN914 diodes to
prevent feedback on the lines and two additional pull-up resistors to insure the signal
is at
+5v.
To compensate for any signal loss, R215 and 217 have been changed to 47K
(R215) and
24K (R217).
2600A MODEL DIFFERENCES - REVISIONS 14 AND UP
Revisions 16 and up contain the model differences described above; they also include a
timer chip (A205) added to the reset circuitry of the MPU chip. This chip eliminates
the problem of power-on reset failures.
2600/2600A Domestic
VCS

SUMMARY
The VCS is a microcomputer that receives its operational instructions from same
cartridges, the game console, and player controllers. The
2600 switchboard and
motherboard assemblies are housed within
an outer casting and are the principle
assemblies addressed in
the remainder of this manual. The boards are connected by a
12-conductor ribbon cable which passes not only power, but also data between the two
boards.
Three chips of the notherboard allow for the interaction between the game
and the
player.
These chips are the microprocessor (MPU), the Random Access Memory-
Input/Output
(RAM I/O), and the Television Interface Adapter (TIA) chips.
The 2600A model differs primarily in the location of the components formerly located
on the switchboard. They are attached directly to
the motherboard and eliminate the
need for the switchboard
and the ribbon cable. The 2600A Revisions 14 and up include
even further additional components to improve the performance of the output
circuitry.
2600/2600A Domestic VCS

SECTION 2
SILKSCREENS AND SCHEMATICS
On the following pages are representative silkscreens and switchboard schematics for
the ATARI Video Computer System. The motherboard schematics for all 2600/2600A
VCS models are located in the pocket at the front of this binder. Minor variations in
design
may be encountered depending on the production date of the game, but these
schematics provide all details required for an in-depth understanding of all 2600 units,
including the various
2600 A model revisions..
2600/2600A Domestic VCS

NAT. L.kt3kO
T.I. 78MC5C
VOLTAGE REGULATOR
(Tap View)
A203
(Top View)
win version
(Channel 2 or 3)
RF Moduiator
RF Mod. (TOO View)
Figure 2-1. 2600/2600A IC Pinouts
2600/2600A Domestic VCS

Figure 2-2. 2600 Motherboard Silkscreen
2600/2600A Domestic VCS

The following variations may appear on the 2600 switchboard:
CHANNEL 3 SWITCHBOARD:
C102 may or may not be in place.
C103 and/or C104 may or may not be in place.
C103 and/or ClO4 may be mylar dipped .22 uf.
C103 and/or ClO4 may be ceramic .Oluf (See Figures 2-3 and 2-4).
CHANNEL 2 OR 3 SWITCHBOARD:
The holes on the PC board
for the CAME RESET and GAME SELECT
switches may not be wide enough apart for the switch legs. To
correct this
the legs of the switch must be bent in so they fit into the holes (See Figures
2-5 and 2-6).
2600/2600A Domestic VCS

Figure 2-3.
2600 Channel 3 Switchboard Silkscreen
2600/2600A Domestic VCS