Test Manager

To enter the test manager, you can ground the VIA_TEST line located at pin 7 of the J22 edge connector. This must be done at boot before the cursor appears.
You also should be able to press the interrupt button to cause a "sad mac" to display and start the test manager, though it will go to sleep after some time unless you turn off sleep.

Connect a serial cable to the Modem port on the Portable.

Baud Rate: 9600
Parity: None
Data Bits: 8
Stop Bits: 2

Most examples here that involve additional input assume you are running in *A - ASCII Mode.
For example, before running a command like *T000100050000 make sure you've run *A at least once, or the system will assume the input is hex rather than ASCII.

*S - Service Mode

Stops the startup message if entered using VIA_TEST or enabled using *5, and disables the sleep timer which will normally shut down the computer after some time.

*L - Load A4

Load a value into address register A4, for use in other commands.

Input: 4 Bytes

Example Usage:

*L00900000

*B - Set Byte Count

Load a value into data register D4, for use in other commands such as *D or *M.

Input: 2 Bytes

Example Usage:

*B101F

Sets the byte count to 0x101F bytes.

*D - Get Data

Load data from the serial input at location A4, for a length of D4 bytes.

A checksum is placed in result register D6.

Example Usage:

*L00104000
*B00FF
*D
[Input Data]

Write data from serial input for 0xFF bytes to memory starting at location 0x104000.

*C - Checksum

Checksum data at location A4 for D4 bytes.

The checksum is returned in result register D6.

*G - Execute

Execute code from a provided memory address.

Input: 4 Bytes

Example Usage:

*G00900058

Run code starting at memory location 0x900058.

*0 - Load A0

Load a value into address register A0, for use in other commands.

Input: 4 Bytes

Example Usage:

*000100000

*1 - Load A1

Load a value into address register A1, for use in other commands.

Input: 4 Bytes

Example Usage:

*100200000

*4 - Clear Result Registers D6/D7

Clears the error result registers in D6 and D7.

*5 - Display Boot Message

Start the repeating boot message normally shown when entering Test Manager with VIA_TEST.

*7 - Prevent Sleep

Prevents the computer from sleeping automatically (typically only for computers on battery).

*A - ASCII Mode

Switch to ASCII input mode for commands like *D, *G, *T, etc.

*H - Hex Mode

Switch to Hexadecimal input mode for commands like *D, *G, *T, etc.

*R - Send Test Results

Outputs the D6 and D7 result registers.

*M - Memory Dump

Dump memory starting at the address in A4, for D4 bytes.

A4: Start address
D4: Number of bytes to dump

Example Usage:

*L000FFFF0
*B000F
*M

*E - Echo On

Enables echoing of command input.

*I - Restart Test Manager

Restarts Test Manager. This will cause the system to boot if VIA_TEST is not asserted and the system does not encounter any test errors.

*P - Power Manager Command

Send commands to the Power Manager.

Input: 2 + ? Bytes

Example usage:

*P100104

This command should turn off the hard drive power. (Untested)

*T - Run Critical Test

Run a test from the built in critical tests.

Input: 6 Bytes

Input structure:

2 bytes for the test number (Example: 0004 for the ROM Test)
2 bytes for the number of passes (Example: 00FF to run for 255 passes)
2 bytes for test options

Example Usage:

*T000400FF0000

Test 0: Memory Sizing Test

Location in ROM: 0x903EA6

Test 1: Data Bus Test

Write a pattern to 8 bytes starting at the address in A0. The first pattern is 00000001 FFFFFFFE which is rotated left 256 times (00000002 FFFFFFFD, 00000004 FFFFFFFB, etc.).

If a bit does not match at any point, it is reflected in the minor error register D6.

A0: Test address

Example Usage:

*000100000
*T000100010000

Location in ROM: 0x901CD6

Test 2: Modulo 3 RAM Test

A0: Start address
A1: End address

Example Usage:

*000000000
*100100000
*T000200010000

Location in ROM: 0x901D2A

Test 3: Address Line Test

Location in ROM: 0x901FEE

Test 4: ROM Test

This test calculates a checksum individually for the two ROM chips.

Location in ROM: 0x901F22

Test 5: Reverse Modulo 3 RAM Test

A0: Start address
A1: End address

Example Usage:

*000000000
*100100000
*T000500010000

Location in ROM: 0x901E2E

Test 6: March RAM Test

A0: Start address
A1: End address

Example Usage:

*000000000
*100100000
*T000600010000

Location in ROM: 0x901F90

*N - Run Non-critical Test

Input: 6 Bytes

Test 80: Mapper RAM Data Test

Test 81: Mapper RAM Uniqueness Test

Test 82: VRAM Data Test

Location in ROM: 0x9020E2

Test 83: VRAM Address Test

Location in ROM: 0x902068

Test 84: SCC Register Test

Location in ROM: 0x902322

Test 85: SCC Loop Test

Location in ROM: 0x90229A

Test 86: SCC Timer Test

Location in ROM: 0x90235A

Test 87: VIA Test

Location in ROM: 0x902444

Test 88: SCSI Test

Location in ROM: 0x9025C2

Test 89: ASC Test

Location in ROM: 0x9026A6

Test 8A: PRAM Test

This test does not do anything and always fails.

Location in ROM: 0x9027DE

Running from a Debugger

You can also run the tests from a debugger such as MacsBug or MicroBug.

As an example, here is running the March RAM Test on the 3rd megabyte of RAM:

Set the start memory address to test to the beginning of the 3rd megabyte of RAM:
A0 200000

Set the end address to the end of the 3rd megabyte:
A1 2FFFFF

Set the return address to the interrupt handler to return to the debugger:
A6 90380A

Set the Program Counter to the test location:
PC 901F90

Run the test:
G

Once the test is finished, you should be returned to the debugger.
You can now display the result from the appropriate register:
D6

Unimplemented Commands

Commands such as *U, *W, *Q, *2, *3, and *6 are valid Test Manager options but they are not implemented in the Portable's Test Manager, so they do nothing.