Long-Word Translation - ZiLOG System 8000 Hardware Reference Manual

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Figure 4-14 Long-Word Translation
~.7.1.
Manual NMI:
A manual NMI can be generated in the
System 8000 from the START pushbutton on the front panel.
The NMI can be disabled by placing the ON/LOCK keylock
switch in the LOCK position. When the START pushbutton is
pressed immediately after a manual or power-up reset, the
system power-up diagnostics (SPUD) firmware is invoked. At
the conclusion of the diagnostic, if no errors have been
recorded, the message "POWER UP DIAGNOSTICS COMPLETE"
appears on the console screen and the ZEUS Operating System
is automatically booted.
4.7.2. Power-Fail NMI: A power-fail NMI will be sent to
the Z8001 CPU when the system power supply detects a
decrease in line voltage signifying a potential power
failure. After recelvlng a power-fail NMI, the system has
approximately 2 msec to power-down. When a power-fail NMI
identifier is read by the operating system, the operating
system generates a software reset which in turn, becomes a
hardware system reset. Therefore, the Winchester disk
drives are protected from crashing during a power failure.
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