Technical data

4-40 Fault Isolation
Table 4-6. Unexpected Use of (address) Failure Messages
3 Hex LSDs Unexpected Event
FFA
FF4
FFE
FE8
FE2
FDC
FD6
FCA
FC4
FBE
FB8
FB2
FAC
FA6
FA0
F9A
F3A-F94
F34
F2E
F28
F22
F1C
EEC - F16
EE6
EE0
Bus error
Address error
Illegal instruction
Zero by zero trap
Check trap
TRAPV trap
Privilege violation
1010 Op. Code
1111 Op. Code
Interrupt Level 1 (keyboard)
Interrupt Level 2 (not used)
Interrupt Level 3
Interrupt Level 4
Interrupt Level 5
Interrupt Level 6
Interrupt Level 7 (Reset from keyboard)
CPU traps
Reset from keyboard
Keyboard timeout (fast handshake)
Battery backup interrupt
Non-maskable interrupt from the backplane
Spurious interrupt
Vectored interrupt
Format error, co-processor violation, or unknown
Co-processor exception vectors
4.9.3 Failure Indications
As the self-test progresses, the LEDs display the current state. At the end of the test,
a power-up with no errors is indicated by all LEDs turned off and by immediate entry
into the boot scanner.
If a failure occurred during the self-tests, then that failure is indicated on the LEDs at
the end of the tests. If there was more than one failure, the highest priority failure is
indicated on the LEDs.