This section lists error codes that might be returned if a system test diagnostic fails. When the system test fails while the animated boot icon is being displayed, you can display the text window containing the specific system test error message by typing the NMI key sequence (that is, by pressing the backquote key on the keypad while holding down both the left and right Command keys).
FPU Tests
Error Code Meaning
41 FPU data registers are faulty.
42 FPU and CPU intraprocessor data transfer test failed.
43 FPU arithmetic functional test failed.
SCC Channel Tests
Error Code Meaning
51 Port A SCC/DMA transmit interrupt didn't occur within 0.1 second.
52 Port A SCC chip didn't receive the loopback character within 0.1 second.
53 Port A loopback character doesn't match the character sent.
55 Port B Tx buffer not cleared after waiting for 0.1 second.
56 Port B non-DMA transmit not finished within 0.1 second.
57 Port B non-DMA loopback character doesn't match the one sent.
SCSI Channel Tests
Error Code Meaning
61 FIFO count doesn't match the number of characters loaded.
62 FIFO doesn't contain the data that was loaded.
63 FIFO count doesn't match number of characters left in FIFO.
Tests that produce the following error codes are executed only if a SCSI drive is installed and the p command's “SCSI test” parameter is enabled.
Error Code Meaning
64 FIFO flush command failed.
65 Cannot load counter with test pattern.
66 Cannot load counter with inversed test pattern.
67 Configuration register failed.
68 53c90 doesn't generate interrupt on illegal command.
Ethernet Channel Tests
Error Code Meaning
71 Couldn't set physical address.
72 Couldn't drain DMA receive buffer.
73 Physical packet not received.
74 Physical packet was garbled.
75 Received a packet with wrong address.
76 Broadcast packet not received.
77 Broadcast packet was garbled.
MO Drive ECC Tests
Error Code Meaning
81 DMA transfer of raw data to ECC failed.
82 DMA read of encoded data from the ECC failed.
83 DMA transfer of corrupted data back to ECC failed.
84 ECC error count is incorrect.
85 DMA transfer of corrected data from ECC failed.
86 ECC corrected data isn't correct.
Real-Time Clock Tests
Error Code Meaning
91 The RTC didn't tick after 0.3 seconds.
Two Bit Graphics Tests
Error Code Meaning
a1 Main memory TBG A*B function failed.
a2 Main memory TBG ceiling(A+B) function failed.
a3 Main memory TBG (1-A)*B function failed.
a4 Main memory TBG A+B-A*B function failed.
a1 Video memory TBG A*B function failed.
a2 Video memory TBG ceiling(A+B) function failed.
a3 Video memory TBG (1-A)*B function failed.
a4 Video memory TBG A+B-A*B function failed.
System Timer Tests
Error Code Meaning
c2 The system timer can't be set.
c3 The system timer interrupt doesn't work.
Event Counter Tests
Error Code Meaning
d1 The event counter didn't tick after 2 microseconds.