Editing Sad Mac Error Codes (section)

== Macintosh II Family (II, IIx, IIcx, IIci, IIfx, IIsi, IIvi, IIvx) ==

The Macintosh II family uses the expanded two-line format with a broader test set than the SE. The IIcx, IIci, and SE/30 actually share the same diagnostic ROM image, which is why a IIcx will boot happily with an SE/30 ROM SIMM swapped in (and vice versa).

In addition to all the SE-family tests above, the Mac II family adds:

{| class="wikitable"
|+ ''Additional test numbers — Mac II family''
! Test (TT) !! Meaning
|-
| 0008 || Data bus test at end of RAM (last 8 bytes used for the stack post memory-sizing)
|-
| 000E || Data bus test at start of RAM
|-
| 000F || System error before the error-message table was loaded — see exception subcode in the minor field
|-
| 0010 || Power Manager self-test (Portable/PowerBook only; see [[#Macintosh Portable Diagnostic Codes|Portable codes]])
|-
| 0011 || Memory sizing test
|-
| 0014 || Power Manager communication failure (Portable/PowerBook)
|-
| 0080 || Mapper RAM data test (Portable, normally non-critical)
|-
| 0081 || Mapper RAM uniqueness test (Portable, normally non-critical)
|-
| 0082 || VRAM data test
|-
| 0083 || VRAM address test
|-
| 0084 || SCC register test
|-
| 0085 || SCC loopback test
|-
| 0086 || SCC timer test
|-
| 0087 || VIA full test
|-
| 0088 || SCSI full test
|-
| 0089 || [[Apple Sound Chip|ASC]] (Apple Sound Chip) test
|-
| 008A || PRAM test (always reports failure; not actually run)
|}

=== ROM-chip identification on multi-ROM machines ===

The [[Macintosh II|II]], [[Macintosh IIx|IIx]], [[Macintosh IIcx|IIcx]], [[Macintosh SE/30|SE/30]], and several other models carry their ROM as ''four'' physical chips (often labelled MH, ML, LH, LL for the two bytes of each of the upper and lower word) rather than one or two. When the ROM checksum test (test 01) fails on these machines the minor code identifies the failing ROM:

* '''0000FFFF''' (all bits set) — at least one ROM mismatched and the per-chip identity could not be narrowed down. Typically printed before per-chip diagnostics have run, e.g. on an initial boot before [[#Test Manager (Serial Diagnostic Mode)|Test Manager]] is invoked.
* '''00000001''' — first ROM chip
* '''00000002''' — second ROM chip
* '''00000004''' — third ROM chip
* '''00000008''' — fourth ROM chip
* Mixed values (e.g. {{code|0009}} = chips 1 + 4) indicate multiple failing chips, or — more commonly — an address-line problem upstream that's making all the chips look bad simultaneously.

To narrow down ''which'' ROM chip is bad on a IIcx/IIci/SE/30 board with soldered ROMs, see [[#Test Manager (Serial Diagnostic Mode)|Test Manager]] below; the {{code|*T000400010000}} command runs the per-chip ROM checksum directly and returns a result of 1/2/4/8.

=== Worked example: IIcx, slow Chimes of Death, code 0000FFFF 00000001 ===

A recapped Mac IIcx displays the Chimes of Death at half speed (the characteristic "24-bit ROM in trouble" cadence) and a serial console shows:

  Line 1: '''0000FFFF'''
  Line 2: '''00000001'''

* Line 1 upper word '''0000''' — no Test Manager flags
* Line 1 lower word '''FFFF''' — ROM checksum test failed, all-bits indicator
* Line 2 '''00000001''' — minor code "1" = first ROM chip / generic ROM mismatch

The slow chime cadence specifically points to a 24-bit-clean ROM (which is what the IIcx ships with) failing checksum; 32-bit-clean ROMs (IIci, SE/30 v.late) tend to fail at normal tempo. Connecting a null-modem cable to the modem port and entering Test Manager confirms which of the four soldered ROMs (UH7, UH9, UH11, UH13 on the IIcx — labels vary by board revision) is at fault. A common quick-test is to lift the on-board ROM jumper and drop an SE/30 ROM SIMM into the SIMM socket; if the machine then chimes happily, the diagnosis is confirmed and the fix is to replace or re-flash the failing chip.