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Archived - Macintosh: "Sad Macintosh" Error Code Meaning

This article lists and explains the error codes that accompany the "sad Macintosh" icon that appears on the screen when a Macintosh computer does not start up.

This article has been archived and is no longer updated by Apple.
Products Affected

The "sad Macintosh" icon and its associated error codes exist only in older Macintosh computers. Newer models, such as those with Universal Serial Bus (USB) or Open Firmware, use a different mechanism for reporting such failures. For more information on newer systems, please see the following articles:

Article 58183: "Power-On Self-Test Beep Definition - Part 1"
Article 58442: "Power-On Self-Test Beep Definition - Part 2"
Article 95036: "Power Mac G4: Power-On Self Test"

Overview

The particular error code that appears with the "sad Macintosh" is not as important as when it occurs. If the Macintosh can start up from a different system disk then the fault is probably with the system software on the other disk. System faults are usually identified when you get a "happy Macintosh" face and the "Welcome to Macintosh" screen before the "sad Macintosh."

If the "sad Macintosh" appears immediately when you turn on the computer, that usually suggests an issue with the logic board or memory. Try starting up from a floppy disk before assuming it is a hardware fault.

Sad Mac Error Codes Description

On the Original ROMs (Macintosh 128K 512kK 512kK, Plus):

When you press the interrupt button on the side of your Macintosh when starting up, a sad Mac icon on the screen with '0F000D' and some bits cycling under the icon indicating it is performing a memory test.

This numeric code is in two parts:

  • The first two characters are the class code. The class code tells what part of the diagnostic program found the error.
  • The second four are the sub code. The sub class code tells what the error was. In the case of a bad RAM chip, the sub class identifies the bad chip (this was very helpful to homegrown upgraders).

Class Code
Sub Code
1=ROM test failedMeaningless
2=Memory test--bus subtestidentifies bad chips
3=Memory test--byte writeidentifies bad chips
4=Memory test--Mod3 testidentifies bad chips
5=Memory test--address uniquenessidentifies bad chips


Single Chip Identification
Data Bit
Location
Sub Code Bits
0
F5
0001
1
F6
0002
2
F7
0004
3
F8
0008
4
F9
0010
5
F10
0020
6
F11
0040
7
F12
0080
8
G5
0100
9
G6
0200
10
G7
0400
11
G8
0800
12
G9
1000
13
G10
2000
14
G11
4000
15
G12
8000


Class Code
Sub Code
Sub Code Meaning
F=Exception
0001
Bus error
0002
Address error
0003
Illegal Instruction
0004
Zero divide
0005
Check instruction
0006
Traps instruction
0007
Privilege violation
0008
Trace
0009
Line 1010
000A
Line 1111
000B
Other exception
000C
Nothing
000D
NMI (normal indication)
0064
Couldn't read System File into memory

Macintosh SE and Macintosh II ROMs

The "sad Macintosh" error codes for Macintosh SE and Macintosh II computers were changed to incorporate additional power for testing and to support the 32-bit world. Generally, the same codes are used for 68000 exceptions as the Macintosh but they are displayed differently.

Traditional

The traditional Macintosh error codes are displayed in hexadecimal notation like this: 0F0003

Where F indicates an exception occurred, and 3 indicates an illegal instruction occurred. On the Macintosh SE and Macintosh II, the display would appear:

0000000F
00000003

Power On

The power-on error codes have the following format:

XXXXYYYY
ZZZZZZZZ

Where XXXX is internal test manager state information (ignore this), YYYY contains codes that indicate either an exception code, or the test number for a power on test failure. The ZZZZZZZZ code contains additional failure information to help track down the fault.


YYYY Error Codes
Error Code
Meaning
$0001
The ROM checksum test failed. Ignore the Z field.
$0002
The first small chunk of RAM to be tested failed. The Z field indicates which RAM Bit(s) failed. This small chunk of RAM is always in Bank B. Using $AABBCCDD as a guide:

AA=8 bit mask for bits 31-24
BB=8 bit mask for bits 23-16
CC=8 bit mask for bits 15-8
DD=8 bit mask for bits 7-0

$0003
The RAM test failed while testing bank B, after passing the chunk tested for code $0002. The Z field indicates which bits failed as in code $0002.
$0004
The RAM test failed while testing bank A. The Z field indicates which bits failed as in code $0002.
$0005
The RAM External addressing test failed. The Z field indicates a failed address line.
$0006
Unable to properly address the VIA1 chip. The Z field is not applicable.
$0007
Unable to properly address the VIA2 chip (Macintosh II only). The Z field is not applicable.
$0008
Unable to properly access the Front Desk Bus. The Z field is not applicable.
$0009
Unable to properly access the MMU. The Z field is not applicable.
$000A
Unable to properly access NuBus. The Z field is not applicable.
$000B
Unable to properly access the SCSI Chip. The Z field is not applicable.
$000C
Unable to properly access the IWM chip. The Z field is not applicable.
$000D
Unable to properly access the SCC Chip. The Z field is not applicable.
$000E
Failed Data Bus test. The Z field indicated the bad bit(s) as a 32-bit mask for bits 0-31. This may indicate either a bad SIMM or data bus failure.
$000F
Reserved for Macintosh compatibility.
$FFxx
A 680xx exception occurred during power on testing. The xx indicates the exception:
$01 Bus Error
$02 Address Error
$03 Illegal Instruction Error
$04 Zero Divide
$05 Check Instruction
$06 cpTrapCC, Trap CC, Trap V
$07 Privilege violation
$08 Trace
$09 Line A
$0A Line F
$0B unassigned
$0C CP protocol violation
$0D Format exception
$0E Spurious interrupt
$0F Trap 015 exception
$10 Interrupt Level 1
$11 Interrupt Level 2
$12 Interrupt Level 3
$13 Interrupt Level 4
$14 Interrupt Level 5
$15 Interrupt Level 6
$16 Interrupt Level 7
$17 FPCP bra or set on unordered condition
$18 FPCP inexact result
$19 FPCP divide by zero
$1A FPCP underflow
$1B FPCP operand error
$1C FPCP overflow
$1D FPCP signalling NAN
$1E PMMU configuration
$1F PMMU illegal operation
$20 PMMU access level violation

Macintosh Portable ROMs

The startup code in the Macintosh Portable contains a series of startup tests that are run to ensure that the fundamental operations of the computer are working properly. If any of those tests fail, a "sad Macintosh" icon appears on the screen with a code below that describes what failure occurred. Here is a typical example of a Sad Mac display with an error code below it:

SAD MAC CODE

05460203 = (D7.L)
000OB6DB = (D6.L)

The two codes are actually the contents of the two CPU data registers D6 and D7. The upper word (upper 4 hexadecimal digits, in this case 0546) of D7 contains miscellaneous flags that are used by the start-up test routines and are unimportant to just about everybody except a few test engineers within Apple. The lower word of D7 is the major error code. The major error code identifies the general area the test routines were in when a failure occurred. D6 is the minor error and usually contains additional information about the failure, something like a failed bit mask.

SAD MAC CODE BROKEN DOWN

Test Flags Major Error

0546 0203

Minor Error Minor Error

0000 B6DB

The major error is further broken into the upper byte that contains the number of any 68000 exception that occurred ($00 meaning that no exception occurred), and the lower byte that usually contains the test that was being run at the time of failure. If an unexpected exception occurred during a particular test, then the exception number is logically ORed into the major error code. This way both the exception that occurred as well as the test that was running can be decoded from the major error code:

SAD MAC CODE FURTHER BROKEN DOWN

68000 Exception Test Code

02 03

In this example, the code says that an address error exception ($0200) occurred during the RAM test for Bank A ($03); $0200 ORed with $03 = $0203.

Major Error Codes

Below is a brief description of the various test codes that might appear in the major error code:

Important: Some of these codes may mean slightly different things in Macintosh models other than the Macintosh Portable. These descriptions describe specifically how they are used in the Macintosh Portable.

Major Error Codes
Error Code
Meaning
$01
ROM test failed. Minor error code is $FFFF, which means nothing.
$02
RAM test failed. Minor error code indicates which RAM bits failed.
$05
RAM external addressing test failed. Minor error code indicates a failed address line.
$06
Unable to properly access the VIA 1 chip during VIA initialization. Minor error code not applicable.
$08
Data bus test at location eight bytes off of top of memory failed. Minor error code indicates the bad bits as a 16bit mask for bits1500. This may indicate either a bad RAM chip or data bus failure.
$0B
Unable to properly access the SCSI chip. Minor error code not applicable.
$0C
Unable to properly access the IWM (or SWIM) chip. Minor error code not applicable.
$0D
Not applicable to Macintosh Portable. Unable to properly access the SCC chip. Minor error code not applicable.
$0E
Data bus test at location $0 failed. Minor error code indicates the bad bits as a 16bit mask for bits 1500. This may indicate either a bad RAM chip or data bus failure.
$10
Video RAM test failed. Minor error code indicates which RAM bits failed.
$11
Video RAM addressing test failed. Minor error code contains the following:

upper word = failed address (16-bit)

msb of lower word = data written

lsb of lower word = data read

Data value written also indicates which address line is being actively tested.

$12
Deleted
$13
Deleted
$14
Power Manager processor was unable to turn on all the power to the board. This may have been due to a communication error with the Power Manager. If so, the minor error code contains a Power Manager error code, explained in the next section.
$15
Power Manager failed its self-test. Minor error code contains the following:

msw = error status of transmission to power manager.

lsw = Power Manager self-test results (0 means it passed, non-zero means it failed)

$16
A failure occurred while trying to size and configure the RAM. Minor error code not applicable.

Minor Error Codes; Power Manager Processor Failures

If a communication breakdown occurs during communication with the Power Manager, the following error codes appear somewhere in the minor error code (usually in the lower half of the code, but not always):

Minor Error Codes
Error Code
Meaning
$CD38Power Manager was never ready to start handshake.
$CD37Timed out waiting for reply to initial handshake.
$CD36During a send, Power Manager did not start a handshake.
$CD35During a send, Power Manager did not finish a handshake.
$CD34During a receive, Power Manager did not start a handshake.
$CD33During a receive, Power Manager did not finish a handshake.

Diagnostic Code Summary

Below is a summarized version of the Sad Mac error codes:

Diagnostic Code Summary
Test Codes
Meaning
$01
ROM checksum test.
$02
RAM test.
$05
RAM addressing test.
$06
VIA 1 chip access.
$08
Data bus test at top of memory.
$0B
SCSI chip access.
$0C
IWM (or SWIM) chip access.
$0D
No applicable to Macintosh Portable; SCC chip access.
$0E
Data bus test at location $0.
$10
Video RAM test.
$11
Video RAM addressing test.
$14
Power Manager board power on.
$15
Power Manager self-test.
$16
RAM sizing.


Power Manager Communication Error Codes
Error Code
Meaning
$CD38
Initial handshake.
$CD37
No reply to initial handshake.
$CD36
During send, no start of a handshake.
$CD35
During a send, no finish of a handshake.
$CD34
During a receive, no start of a handshake.
$CD33
During a receive, no finish of a handshake.


CPU Exception Codes
(as used by the startup tests)
Error Code
Meaning
$0100
Bus error exception code.
$0200
Address error exception code.
$0300
Illegal error exception code.
$0400
Zero divide error exception code.
$0500
Check inst error exception code.
$0600
cpTrapcc,Trapcc,TrapV exception code.
$0700
Privilege violation exception code.
$0800
Trace exception code.
$0900
Line A exception code.
$0A00
Line F exception code.
$0B00
Unassigned exception code.
$0C00
CP protocol violation.
$0D00
Format exception.
$0E00
Spurious interrupt exception code.
$0F00
Trap inst exception code.
$1000
Interrupt level 1.
$1100
Interrupt level 2.
$1200
Interrupt level 3.
$1300
Interrupt level 4.
$1400
Interrupt level 5.
$1500
Interrupt level 6.
$1600
Interrupt level 7.
Last Modified: Feb 18, 2012
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  • Last Modified: Feb 18, 2012
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