Port Box

Table of Contents

• 1. About
  • Scope
  • Compatibility
• 2. Equipment Required for Operation
  • Power Adapter
  • Pass Thru Cable
  • Controller Port Jumper Cables
    • Controller Port Extension cables
    • DE-9 Ribbon Cables
    • Hybrid Cable Option
  • SIO Cable
• 3. Connecting the Test Assembly
• 4. Using UberSalt Diagnostic Software
  • Executive Menu
  • Menu Navigation
  • Performance Test
  • Extend Unit Test
  • Individual Tests
  • Change Test Opts
    • Option: Test
    • Option: Sequence
    • Option: Disp Time
    • Option: Show Test Group
  • Show Err Summary
• 5. SuperSALT Diagnostic Tests
  • 2-Way Clock Test
  • 6502 Test
  • ANTIC Stress Test
  • Bar Test
  • Color Bars
    • Color Verification and Adjustment
  • GTIA Diagnostics
    • GTIA Phase 1: PMG Sizing, Motion & Playfield Collisions
    • GTIA Phase 2: PMG Collision Detection
    • GTIA Phase 3: PMG/Playfield Priority
  • I/O Port Tests
    • Voltage Test
    • I/O Test Progress
    • PIA Ports Test
    • SIO Port
    • Trigger Lines
    • Pot Lines
    • Timers
  • OS ROM Checksum
  • RAM Test
    • RAM Test Methods
  • Tone Test
  • Video Test
  • Xternal Audio Test
• Interactive Diagnostic Utilities
  • Joystick Test
  • Keyboard Test
  • Paddle Test
  • Maintenance Mode
• 7. Fatal System Errors
• 8. Error Report Analysis
  • 8.1 System Error Summary
  • 8.2 6502 Error Summary
  • 8.3 OS ROM Error Summary
  • 8.4 RAM Error Summary
  • 8.5 GTIA Error Summary
  • 8.6 PIA Error Summary
  • 8.7 POKEY Error Summary
  • 8.8 Timers Error Summary
  • 8.9 Baud Error Summary
  • Baud Rate Report

List of Illustrations

• Figure 3-1. Enhanced CPS SuperSALT Diagnostic Software Splash Screen
• Figure 4-1. Executive Menu
• Figure 4-2. Performance Test
• Figure 4-3. Extend Unit Test
• Figure 4-4. Individual Tests
• Figure 4-5. Change Test Opts
• Figure 4-6. Show Test Group
• Figure 4-7. Error Summary
• Figure 5-1. 2-Way Clock Test
• Figure 5-2. 6502 Test
• Figure 5-3. ANTIC Stress Test
• Figure 5-4. Bar Test
• Figure 5-5. Color Bars
• Figure 5-6. GTIA Diagnostics Phase 1
• Figure 5-7. GTIA Diagnostics Phase 2
• Figure 5-8. GTIA Diagnostics Phase 3
• Figure 5-9. Atari 400/800 Voltage Test
• Figure 5-10. Atari 1200XL Voltage Test
• Figure 5-11. Atari XL/XE Voltage Test
• Figure 5-12. I/O Test Progress
• Figure 5-13. Atari 400/800 OS ROM Checksum
• Figure 5-14. RAM Test Screen
• Figure 5-15. RAM Test Summary Showing a Failure
• Figure 5-16. Tone Test
• Figure 5-17. Video Test
• Figure 5-18. Xternal Audio Test
• Figure 6-1. Joystick Test
• Figure 6-2. Keyboard Test
• Figure 6-3. Paddle Test
• Figure 7-1. Fatal System Error Screen
• Figure 8-1. Error Summary – System
• Figure 8-2. Error Summary – 6502
• Figure 8-3. Error Summary – OS ROM Checksum
• Figure 8-4. Error Summary – RAM Test
• Figure 8-5. Error Summary – GTIA Exercise Showing Error
• Figure 8-6. Error Summary – PIA Exercise
• Figure 8-7. POKEY Exercise
• Figure 8-8. Timers/Random Number Generation
• Figure 8-9. Error Summary – Baud Rate

List of Tables

• Table 5-1. Voltage Test Limits
• Table 7-1. Fatal System Errors
• Table 8-1. PIA Port Loop-back Configuration
• Table 8-2. SYNC Baud Error Bit Assignments
• Table 8-3. ASYNC Baud Rate Bit Assignments

1. About

Research performed while preparing this documentation and enhancing Atari’s CPS SuperSALT Rev. A software revealed numerous defects that produce incorrect or misleading diagnostic results. As these issues were investigated and corrected, the scope of the project expanded beyond its original intent. Consequently, this guide documents UberSALT, while details of the known Rev. A defects and their corrections are provided in the companion documentation included with the software distribution.

Research conducted while documenting Atari’s CPS SuperSALT Rev. A software revealed numerous defects that produce incorrect or misleading diagnostic results. As these issues were investigated and corrected, UberSALT evolved from a documentation effort into an enhanced derivative of CPS SuperSALT designed to provide an accurate assessment of the console under test.

Research conducted during the development of UberSALT and the preparation of this documentation identified several defects in Atari’s CPS SuperSALT Rev. A software that can produce incorrect or misleading diagnostic results. Accordingly, this guide documents UberSALT behavior. The companion documentation included with the UberSALT software distribution describes the known Rev. A defects, their corrections, and the enhancements and functional improvements incorporated into UberSALT.

This guide describes the installation and operation of the 8YoRetro Port Box when used with the Atari CPS SuperSALT diagnostic software. It covers connecting the CPS SuperSALT Test Assembly (also referred to as the “test assembly” or “port box”), configuring the hardware, running the diagnostic tests, and interpreting their results.

The port box is an external hardware interface used by the CPS SuperSALT diagnostic software to exercise the external interfaces of an Atari 8-bit computer. Installed between the console and associated test cables, it provides the hardware resources required for the software to generate, route, and monitor signals, allowing comprehensive verification of the system’s external I/O functionality. It allows the diagnostic software to actively drive and measure signals that would otherwise require external test equipment.

Scope

This guide assumes the port box is fully assembled, calibrated and verified and focuses on its practical operation. For detailed information about calibration, design and operation of the test assembly, refer to the Port Box Technical Reference Manual.

Compatibility

The 8YoRetro Port Box is fully compatible with Atari’s original CPS SuperSALT diagnostic software and, when used with that software, behaves like the original Atari test assembly.

An enhanced version of the diagnostic software is available to support additional capabilities. This software is fully compatible with both the original Atari CPS SuperSALT Test Assembly and the 8YoRetro Port Box, including test assemblies equipped with the optional 8YoRetro Error Display Board.

Additional features provided by the enhanced software include:

• Automatic detection of the Port Box and Error Display Board during startup
• Support for the 8YoRetro Error Display Board
• The Port Box Hi-Z operating mode, which prevents conflicts with the 2-Way Clock test

Unless otherwise noted, the procedures and screen images in this manual assume the enhanced diagnostic software is being used.

2. Equipment Required for Operation

These are the items you will need to put the Port Box to use.

Power Adapter

Pass Thru Cable

Controller Port Jumper Cables

Four 9-conductor female-female DE-9 controller port jumper cables are required to connect the Port Box to a console’s controller jacks for diagnostic testing. Atari had supplied these with their original device, but they are virtually unobtainable today. The most practical alternative is to combine the following readily available items.

Controller Port Extension cables

DE-9 Ribbon Cables

Hybrid Cable Option

Optionally, DE-9 crimp connectors can be added to the aforementioned IDC header to female DE-9 IDC cables to create a hybrid IDC-header and gender-changer cable.

SIO Cable

A 13-conductor SIO cable is required to connect the Port Box to a console for testing. These are still fairly common on the second-hand market if you don’t already have one.

3. Connecting the Test Assembly

Perform the following steps exactly as described below to connect the test assembly.

1. Using 9-conductor controller cables, connect the corresponding controller ports between the console and the test assembly as follows:
   • Console controller port 1 to test assembly port 1
   • Console controller port 2 to test assembly port 2
   • Console controller port 3 to test assembly port 3 (if equipped)
   • Console controller port 4 to test assembly port 4 (if equipped)
2. Connect the test assembly to the console serial port using a 13-conductor SIO cable.
3. Connect the power adapter to the console:
   • 400/800/1200XL:
     • Insert the barrel connector from the console power adapter to the A/C power pass-thru jack on the test assembly.
     • Insert one end of the A/C pass-thru jumper cable into the other A/C pass-thru jack on the test assembly.
     • Insert the other end of the A/C pass-thru jumper cable into the console’s power input jack.
   • All other models:
     • Connect the power adapter directly to the console as described in the Atari owner’s manual.
4. Set the tone switch to the setting appropriate for the UUT. 400/800 vs XL/XE.
5. Connect the display/television cable as per the Atari owner’s manual.
6. Insert the SuperSALT diagnostic software cartridge.
7. Set the console power on – the splash screen should appear on the display (See figure 3-1).

During startup, the splash screen indicates the presence of supported hardware:

• SSA — SuperSALT Assembly
• EDB — Error Display Board

When hardware is present, these indicators cycle through the Atari color palette. If no indicators are shown, no test assembly or Error Display Board has been detected.

4. Using UberSalt Diagnostic Software

The diagnostic software contained in UberSalt is designed to test all areas of the system: MPU, RAM, ROM, SIO port, controller ports, ANTIC, GTIA, POKEY and keyboard, as well as video and audio logic.

The software provides three distinct test facilities, a sub menu where test parameters can be customized, and an error summary report. These are all accessible from the Executive Menu.

Executive Menu

The Executive Menu lies at the topmost navigation level. It provides access to the five primary diagnostic tools offered by the diagnostic software.

As shown in figure 4-1, the Executive Menu also displays the detected console family and installed RAM, along with on-screen prompts identifying the keys used to navigate the menu.

Menu Navigation

Use OPTION to execute the highlighted menu item, SELECT to move the highlight to the next item, and BREAK to return to the previous menu.

The Individual Tests, Change Test Opts, and Show Err Summary menus use different execution controls than the other test menus. Always refer to the instructions displayed at the bottom of the screen before proceeding.

During testing, pressing BREAK returns to the previous menu. Some tests must complete before the software responds to the BREAK key, so a brief delay is normal.

Performance Test

This is the default selection when SuperSALT starts and serves as the recommended starting point when evaluating a system of unknown condition. It executes a predefined sequence of tests designed to identify hardware faults in the console (see figure 4-2). The tests are listed on the screen and performed in the order displayed.

Note: Entering the Performance Test menu automatically resets the SEQUENCE and TEST GROUP options to their default values even if the test is not started. The DISP TIME and TEST:CONTINUOUS/SNGL PASS options are unaffected.

Extend Unit Test

This function executes a sequence of tests (see figure 4-3) that can be customized using the Change Test Opts menu. It is particularly useful for repeatedly exercising selected system functions when investigating intermittent faults.

This menu is static and does not reflect the current settings established through Change Test Opts. Nevertheless, the diagnostic tests execute according to the active test configuration.

Individual Tests

This menu provides direct access to individual tests, allowing each test to be selected and executed with a single keystroke (see figure 4-4). All tests operate according to the parameters configured in the Change Test Opts menu.

Change Test Opts

This menu provides additional control over the diagnostic test parameters (see figure 4-5). It is most commonly used with the Extend Unit Test to tailor individual tests or test sequences for troubleshooting, targeted functional verification, or long-duration burn-in testing.

Option: Test

Applies to: Extend Test • Performance Test • Individual Test

SNGL PASS	Terminates after one complete test cycle
CONTINUOUS	Repeats continuously until interrupted

Option: Sequence

Applies to: Extend Test

INCR	Runs tests in the defined order
RANDOM	Shuffles the test order before each cycle and repeats until interrupted

Option: Disp Time

Applies to: Extend Test • Performance Test • Individual Test

02–14	Delay (in seconds) after each test
RTN	Requires user input to continue at certain points

Option: Show Test Group

Applies to: Extend Test

This utility is used to define a custom test sequence (see figure 4-6) for the Extend Unit Test. A test group (also referred to as a test sequence) specifies both which tests are executed and the order in which they are executed.

The upper portion of the screen displays a list of available tests, each identified by a unique character shown as the first character of each entry. The current test sequence is shown near the bottom of the screen beside CURRENT SEQ as a string of these characters (for example, 26ABCGIORTVX), with each character corresponding to a test in the list.

To define or modify the sequence, enter the desired string of characters at the CURRENT SEQ prompt. The prompt accepts a valid test sequence character, or the following input:

DELETE	Removes the sequence character to the left of the cursor
RETURN	Accepts the sequence and returns to the previous menu. Submitting a blank entry sets the sequence to its default: 26ABCGIORTVX
BREAK	Discards changes and returns to the previous menu

Notes:

• The test sequence prompt provides only basic editing capability. Removing a test from the sequence may require deleting multiple characters and re-entering the remaining sequence.
• Twelve unique tests are available, but the test sequence prompt allows up to fourteen entries. Duplicate entries are permitted. The Error Summary counts each complete run of the test sequence as a single cycle, regardless of how many tests it contains; therefore, including duplicate entries may produce misleading statistical results.
• Unless the SEQUENCE option is set to RANDOM, the Extend Unit Test executes the test sequence from left to right.
• Entering the Performance Test resets the SEQUENCE option to its default INCR setting, and the Test Group to its default (26ABCGIORTVX).
• Submitting a null sequence reverts Test Group to its default (26ABCGIORTVX).

Show Err Summary

The Show Err Summary function displays the accumulated results of the diagnostic tests performed by the CPS SuperSALT software. The Error Summary consists of nine pages that can be viewed sequentially by pressing the RETURN key. Figure 4-7 shows the complete Error Summary report.

This section provides a brief overview of the Error Summary report. For a detailed explanation of each summary page and guidance on interpreting diagnostic results, refer to section 8, Error Report Analysis.

Note: The following tests are not represented in the Error Summary. Their results must be verified by the operator while the test is in progress.

• I/O Voltage Test
• ANTIC Stress Test
• 2-Way Clock Test
• Xternal Audio Test
• Bar Test
• Color Bars Test
• Tone Test
• Video Test

Note: The following diagnostic utilities require direct operator interaction and not represented in the Error Summary.

• Keyboard
• Joystick
• Paddle
• Maintenance Mode

5. SuperSALT Diagnostic Tests

This section describes each SuperSALT diagnostic test, including its purpose, operation, and any special requirements or observations needed to interpret the results. Where applicable, the test’s relationship to the automated test sequences and Error Summary is also discussed.

2-Way Clock Test

The 2-Way Clock test verifies operation of the serial port’s bidirectional clock line, referred to by the diagnostic software as the 2-Way Clock. The POKEY I.C. outputs a short 8-note melody on this line, which the port box routes to the console serial port’s audio input. As indicated in figure 5-1, hearing the melody through the A/V monitor or TV confirms that the console is capable of driving the 2-Way Clock line.

Troubleshooting: If the melody is faint or not heard, verify the port box tone switch position, all port box and A/V cable connections, and the TV/monitor volume before troubleshooting the console. These conditions are the most common causes of this symptom.

6502 Test

The 6502 Test verifies CPU operation by executing all 151 operation codes. Each cycle represents one complete execution of the instruction set, and each test pass consists of 100 cycles. Figure 5-2 shows the accumulated cycle and error counts displayed after each completed test pass.

Troubleshooting: A detected error may result from faulty low-memory RAM rather than the CPU. Run the RAM Test to verify memory operation before replacing the 6502. A severe CPU or related hardware fault may prevent the test from completing and cause the console to lock up.

ANTIC Stress Test

The ANTIC Stress Test verifies operation of the ANTIC I.C. by exercising the full range of ANTIC display modes. As shown in the animated display in figure 5-3, the operator determines whether the test passes by confirming that the display behaves as shown. Color is not significant; only the correct appearance and operation of each display element is required.

Bar Test

The Bar Test verifies that the GTIA I.C. is correctly generating the four luminance (LUM0-LUM3) bits by displaying an eight-step grayscale pattern. As shown in figure 5-4, the display consists of eight uniformly shaded horizontal bars progressing from black to white, with a thin white line immediately above the top bar. The operator determines whether the test passes by confirming that the display matches the figure.

Troubleshooting: Observe the display for at least 10 seconds to ensure that the bars remain steady and free of color. Missing bars, repeated or uneven shades, colored bars, or a display that shifts or flashes indicate a problem with the GTIA I.C. or its associated circuitry.

Color Bars

The Color Test verifies operation of the GTIA I.C.’s color generation circuitry and provides a means of adjusting the console’s color frequency. As shown in figure 5-5, the display consists of a 15-color rainbow scale separated from a single reference color bar by a gray reference bar. The operator determines whether the test passes by confirming that the upper and lower reference color bars are identical.

Color Verification and Adjustment

1. Allow the console to warm up for at least 15 minutes.
2. Compare the color bar immediately above the gray reference bar with the single color bar below it.
3. If necessary, adjust the GTIA color potentiometer until the two bars are identical.
4. Verify that each color bar is uniform across its entire width. Minor edge glitches are acceptable.

Troubleshooting: If the colors cannot be matched or the display contains missing bars or little to no color, verify the color adjustment before suspecting a faulty GTIA or ANTIC I.C. An incorrect or defective color crystal (Y1) may also produce incorrect colors.

GTIA Diagnostics

The GTIA Diagnostics test comprehensively exercises the GTIA I.C. by verifying Player/Missile Graphics (PMG), playfield priority, and collision-detection functions. The test is performed in three phases, shown in figures 5-6 through 5-8. While the software automatically verifies and tabulates collision-detection failures, the operator must observe each phase to confirm that the graphics appear and behave as described.

GTIA Phase 1: PMG Sizing, Motion & Playfield Collisions

As shown in figure 5-6, four horizontal playfields labeled PLAYFIELD ZERO through THREE span the screen while groups of player- and missile-generated rectangles move between them. This phase verifies player and missile sizing, movement, and collision detection as the objects traverse the playfields.

GTIA Phase 2: PMG Collision Detection

Figure 5-7 shows two groups of rotating vertical bars. The narrow bars represent missiles, while the wide bars represent players. Each player is moved through the player and missile positions to verify player-to-player and missile-to-player collision detection in the absence of playfield graphics.

GTIA Phase 3: PMG/Playfield Priority

Figure 5-8 verifies GTIA display priority by displaying the words UNDER and OVER intersected by vertical bars. The words indicate the expected position of the vertical bars relative to the text. Accordingly, the bars should appear behind the word UNDER and in front of the word OVER. The text window at the bottom of the screen identifies the player, missile, and playfield priority relationship currently being verified.

Troubleshooting: Missing or malformed graphics, incorrect player or missile sizing, improper movement, incorrect priority relationships, or reported collision failures indicate a problem with the GTIA I.C. or its associated circuitry.

I/O Port Tests

The I/O Port Test verifies operation of the controller and serial I/O interfaces. A properly connected and operational port box is required to perform the following tests:

• Voltage Verification: Verifies the +5 V and ground lines on each I/O port.
• Controller Port Data Lines: Verifies bidirectional operation of the controller port data lines.
• Trigger Lines: Verifies operation of the trigger inputs on each controller port.
• Potentiometer Lines: Verifies operation of the potentiometer inputs on each controller port.
• Serial Interface: Verifies the serial motor control, command, interrupt, data input, and data output lines.
• Serial Communications: Verifies asynchronous and synchronous serial communications over the full range of supported baud rates.

Voltage Test

Because the Voltage Test is not tabulated by the CPS SuperSALT software, the operator must determine the pass/fail condition by observing the real-time test results displayed on-screen. The Voltage Test screen (figures 5-9 through 5-11) displays the measured voltages applicable to the console under test. Measurements within the acceptable limits are displayed in green, while measurements outside those limits are displayed in red. The corresponding voltage limits are provided in table 5-1 for reference.

VI+ and VI- apply only to the Atari 400, 800, and 1200XL, where they represent the positive and negative outputs of the current-to-voltage converter. These values do not indicate current directly, but rather the converter output voltage, which is calibrated to a nominal value of 2.50 for a healthy, unmodified Atari 800 (48K) operating at idle.

When testing other console configurations, modest deviations from the 2.50 baseline are normal and may result from hardware upgrades, modifications, or memory configuration. However, large deviations or significant differences between VI+ and VI- may indicate abnormal current consumption.

Enhanced Software: On XL/XE consoles, the software normally omits the VI+, VI-, and +12 V measurements because those signals are not present. However, the enhanced software automatically performs these tests whenever it detects voltages above a predefined threshold, allowing modified systems such as a 1200XL configured to emulate an 800XL to be fully tested.

Troubleshooting: If all or most voltage measurements fail, first verify that the port box is properly connected, powered, and configured before troubleshooting the console. After correcting any setup problems, rerun the I/O Port Test.

Important: When using the original Atari diagnostic software, the Error Display must be disabled. Otherwise, the Voltage Test will report errors.

I/O Test Progress

Following the Voltage Test, the I/O Test Progress screen (figure 5-12) displays the result of each remaining I/O subtest as it is completed. Each subsequent test name appears in green if the test passes, or red if one or more failures are recorded. In figure 5-12, TRIGGER LINES is shown in red because the test recorded at least one trigger-line failure. Detailed results can later be reviewed using the Error Summary.

PIA Ports Test

The PIA Ports Test verifies that each programmable input/output data line connected to the console’s controller ports functions properly as both an input and an output. Detailed results are retained for the Error Summary, where failures are identified by the affected PIA bit.

SIO Port

The SIO Port Test verifies the console’s ability to communicate through its Serial Input/Output (SIO) port using asynchronous and synchronous data transfers. This test requires the test assembly to be properly connected and powered.

Asynchronous reception is tested at six baud rates: 300, 600, 1200, 2400, 4800, and 9600. At each rate, the test assembly transmits a fixed $55 data pattern to the console, which checks the received character for timeout, framing, and data errors.

Synchronous communication is tested at 19,200 baud in two configurations. The first uses a clock generated by the console under test; the second uses an external clock supplied by the test assembly. Together, these tests verify the console’s ability to transmit and receive synchronous data with either clock source.

Detailed results are retained for the Error Summary, where failures are reported in the following categories:

• SYNC BAUD: synchronous communication failures
• ASYNC DATA: incorrectly received asynchronous data
• ASYNC FRAMING: asynchronous framing errors
• ASYNC TIMEOUT: asynchronous data not received within the permitted time

The software retries certain communication failures to distinguish persistent faults from transient errors. A failure is recorded when the applicable retry limit or receive timeout is reached.

Trigger Lines

The Trigger Lines Test verifies that each applicable controller-port trigger input responds correctly in both states when driven through the test assembly. All four trigger lines are tested on Atari 400/800 computers, while the two available trigger lines are tested on XL/XE computers. A failure may indicate a fault in the console’s trigger-input circuitry, the controller-port connection, the SIO Motor Control path used to operate the test assembly, or the test assembly itself. Detailed results are retained for the Error Summary, where failures are identified by trigger line.

Pot Lines

The Pot Lines Test verifies that each applicable controller-port potentiometer input produces a reading within the expected range when connected through the test assembly. All eight pot lines are tested on Atari 400/800 computers, while the four available pot lines are tested on XL/XE computers. A failure may indicate a fault in POKEY’s potentiometer-input circuitry, a controller-port connection, the connecting cables, or the test assembly itself. Detailed results are retained for the Error Summary, where failures are identified by pot line.

Timers

The Timers Test verifies POKEY Timers 1, 2, and 4 by confirming that each timer generates its interrupt within the expected interval. It also verifies that POKEY’s random-number generator produces changing values. A failure may indicate a fault in POKEY, its clock source, or the associated interrupt circuitry. Detailed results are retained for the Error Summary, where failures are reported separately for Timers 1, 2, and 4 and the random-number generator.

OS ROM Checksum

This test verifies the integrity of the system ROMs by calculating a checksum for each ROM and comparing it to the checksum value stored within the ROM. If the calculated and stored values match, the test passes (see figure 5-13). A mismatch indicates a fault in the ROM or associated circuitry.

RAM Test

The RAM Test verifies the integrity of system memory by performing a series of diagnostic patterns designed to detect addressing, data, and memory refresh faults. During portions of the test, the display is temporarily blanked while video memory is tested and refresh timing is verified. The duration depends on the amount of installed memory; for example, a 48KB system typically blanks the display for approximately 33 seconds before the results screen appears (figures 5-14 through 5-16).

Note: The message “DO NOT PRESS BREAK UNTIL SUMMARY“ is displayed only on consoles with 32KB or more of installed RAM. Because the RAM Test temporarily overwrites display memory and restores it upon completion, pressing BREAK before the summary screen appears will interrupt the process, leaving the display corrupted.

RAM Test Methods

The RAM Test performs the following diagnostic procedures:

• Marching 1’s through memory to test internal chip decoding.
• Marching 0’s through memory to test internal chip decoding.
• Fill memory with a variable data pattern.
• Fill memory with the complement of the previous pattern.
• Test using constant data patterns.
• Test using random data patterns.
• Verify memory refresh timing during the blank-screen interval.

Tone Test

The Tone Test verifies operation of the four POKEY sound registers by generating a descending sweep of tones through each register in succession. As each register is tested, its corresponding label is highlighted on the screen (figure 5-16). Brief pauses separate the tone sweeps, allowing the operator to distinguish between the four sound registers. Missing or incorrect tones indicate a fault in the POKEY or the audio output circuitry. If the console is connected to a television through the RF output, the 4.5MHz circuitry should also be considered as a possible cause.

Video Test

The Video Test exercises the console’s video circuitry using a variety of display patterns. The screen shown in figure 5-17 consists of wide and narrow vertical color bars, a horizontal color bar, diagonal line patterns, and a solid square. All elements should appear stable, properly aligned, and free of missing, distorted, or incorrectly colored regions. The vertical bars are generated using both playfield and Player/Missile Graphics and should appear as continuous, uniform lines with no visible discontinuities or misalignment.

Xternal Audio Test

This test uses the test assembly to simulate an external audio source, such as a cassette recorder or other audio device connected to the serial I/O (SIO) port. If a short melody is heard, the test passes. Figure 5-18 shows the Xternal Audio Test screen.

If no melody is heard, verify the following before troubleshooting the console:

• TV or monitor volume is turned up.
• Test assembly is properly connected.
• Test assembly is powered on.
• Test assembly Tone switch is set correctly.
• Inspect the UUT SIO connector for corrosion or damage.
• Verify the SIO cable has continuity across all 13 conductors.

If the problem persists, possible causes include:

• Incorrect 4.5MHz oscillator adjustment (RF output only).
• Faulty audio mixer IC (U8) or associated support circuitry.
• Faulty POKEY IC.

Interactive Diagnostic Utilities

The following utilities are available only from the Individual Tests menu and require operator interaction. Unlike the automated diagnostic tests, they are intended to evaluate external accessories or provide specialized service functions.

Joystick Test

This test verifies the operation of a joystick and its trigger button. It is intended for testing a joystick accessory using a known functional console.

Connect the joystick to controller port 1. The asterisk (*) shown in figure 6-1 should remain centered when the joystick is at rest and should move in the corresponding direction as the joystick is operated. Verify all eight joystick positions and confirm that the asterisk returns to the center when the joystick is released. Pressing the trigger should cause a red asterisk to appear beside FIRE BUTTON. Failure of any of these checks indicates a faulty joystick.

Keyboard Test

This utility verifies the operation of the console keyboard, including the special function keys. All keys may be tested except BREAK and RESET, which are verified by their normal operation.

The keyboard layout display (see figure 6-2) is fixed and always represents an Atari 1200XL keyboard, regardless of the console under test. Consequently, some displayed keys are not applicable to all console models.

As each key is pressed, the corresponding key on the display flashes in inverse video and a tone is heard. When testing modified keys, hold CONTROL or SHIFT while pressing the desired key.

Pressing RESET should reset the console and return to the software splash screen. Pressing BREAK should return to the Individual Tests menu.

Failure of a key to register or produce a tone may indicate:

• Faulty keyboard switch.
• Faulty keyboard cable/membrane.
• Faulty keyboard decoder circuitry.
• Faulty POKEY IC.

Paddle Test

This utility verifies the operation of a paddle controller using a known functional console.

Maintenance Mode

This utility assists in verifying and adjusting the console’s RF modulator alignment. Upon entering Maintenance Mode, a solid black screen is intentionally displayed to facilitate measurement and adjustment of the Channel 2 video carrier frequency (61.25MHz).

Pressing any key enables a continuous audio tone that may be used to verify and adjust the 4.5MHz sound carrier frequency.

Note: Alignment procedures and adjustment points vary between console models. Refer to the appropriate Atari Field Service Manual for the console under test before making RF modulator adjustments.

7. Fatal System Errors

The SuperSALT software rigorously tests and monitors the two lowest pages of RAM for faults during both idle periods and normal operation. If a fault is detected, the system halts and displays a fatal system error code in full-screen format (figure 7.1). Table 7.1 describes the conditions associated with each error code.

Note: A continuous tone accompanies this screen. Press any console key to silence it.

Note: Fatal system errors often result from corruption of the system RAM used by the diagnostic software. As a result, the fatal error display itself may be incomplete or contain corrupted characters. This effect is more likely when using the enhanced version of the SuperSALT software because it makes more extensive use of page 1 stack RAM during program execution.

8. Error Report Analysis

The Error Report Analysis section supplements the individual test descriptions by explaining how to interpret the diagnostic information reported by the CPS SuperSALT software. Topics include the Error Summary screens, test-specific error reports, and reference data used to analyze diagnostic failures.

8.1 System Error Summary

The System Error Summary is the first page of the Error Summary report and provides an overview of the diagnostic session. It displays the total number of completed test sequences and the cumulative number of errors recorded during testing. The remaining Error Summary pages provide a detailed breakdown of the recorded errors by diagnostic category.

The next portion of the screen lists the cumulative error counts for each of the remaining eight Error Summary pages. Each entry corresponds to the total errors reported on its respective detail page.

8.2 6502 Error Summary

The 6502 Test verifies the operation of the console’s 6502 microprocessor by executing a comprehensive diagnostic routine that exercises the processor’s complete instruction set. In addition to validating individual instructions, the test verifies addressing modes, register transfers, stack operations, arithmetic and logical operations, branching instructions, and processor status flags.

The 6502 Error Summary reports the cumulative results of the 6502 diagnostic test. The screen consists of the CYCLES and ERRORS fields.

8.3 OS ROM Error Summary

The OS ROM Error Summary screen (figure 8-3) displays the cumulative results of the OS ROM Checksum Test. In addition to the total number of test executions and checksum failures, the screen displays the calculated and stored checksum values for the most recent test, allowing the operator to identify which ROM failed verification.

8.5 GTIA Error Summary

The GTIA Error Summary displays the cumulative results of the GTIA Diagnostics test. The summary provides detailed diagnostic information by summarizing failures detected during the various phases of the test for the GTIA collision registers and trigger inputs.

In the example shown in figure 8-5, the GTIA Exercise has been executed once, resulting in a single detected failure. The ERROR BITS value of C080 reported for Missile 0 identifies collision-register test failures associated with that object. The first two hexadecimal digits represent errors detected during player-to-player or missile-to-player collision testing, while the last two digits represent errors detected during player/missile-to-playfield collision testing. A value of 0000 indicates that no collision errors were recorded.

ERROR BITS displays a four-digit hexadecimal bitmask identifying collision-test failures recorded for each player or missile. The first two digits represent errors detected during player-to-player or missile-to-player collision testing, while the last two digits represent errors detected during player/missile-to-playfield collision testing. A value of 0000 indicates that no collision errors were recorded for that entry.

TRIGGER LINE ERRORS display the cumulative number of errors detected for each GTIA trigger input during all GTIA Exercise test executions. A value of 0000 indicates that no trigger line failures were recorded.

8.6 PIA Error Summary

The PIA Error Summary displays the cumulative results of the PIA diagnostics performed during the I/O Port Tests. The summary records failures detected while verifying the PIA data and control line loop-back paths through the port box.

In the example shown in figure 8-6, the I/O Port Tests have been executed ten times, resulting in forty detected failures. The errors reported for PORT A-B BIT 4 through PORT A-B BIT 7 indicate failures detected while verifying the corresponding PIA data-line loop-back paths. The displayed values are cumulative decimal error counts. A value of 0000 indicates that no errors were recorded for the corresponding signal path.

8.7 POKEY Error Summary

The POKEY Error Summary displays the cumulative results of the POKEY diagnostics performed during the I/O Port Tests. The summary records failures detected while testing the POKEY potentiometer inputs, serial interface signals, and clock interface signals.

8.8 Timers Error Summary

intro figure 8-8

8.9 Baud Error Summary

intro figure 8-9

Baud Rate Report

The following tables provide a reference for interpreting baud rate error code information reported by the Error Summary. Together, they define the error types, error codes, and corresponding baud rates used to identify serial communication failures.

The Error Type values indicate the number of failures detected in each baud rate test category. The Error Code values are not error counts. Instead, they are 8-bit diagnostic codes displayed as two hexadecimal digits with leading zeros. Each bit represents one or more specific failure conditions that can be decoded using the following tables.

Table 8-3. ASYNC Baud Rate Bit Assignments

Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
–	9600	4800	2400	1200	600	300	–