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PUMA Station Board
System Interrupts
A NMI is an interrupt requiring immediate attention and
has priority over the normal interrupt lines (IRQX).
NMI interrupts are caused by the following conditions:
NMI Source
Parity #
Fail Safe Timer
IOCHK #
Bus Timeout
Write to Port 0462h
Interrupt Controller 1
Interrupt Controller 2
IRQ0-Timer Output 0 (Out 0)
IRQ8-Realtime Clock INT
IRQ1-Keyboard (Output Buffer Full)
IRQ9-Software Redirected
to INT 0AH (IRQ2)
IRQ3-Serial Port 2
IRQ10-Reserved
IRQ4-Serial Port 1
IRQ11-Reserved
IRQ5-Parallel Port 2
IRQ12-Reserved
IRQ6-Diskette Controller
IRQ14-Fixed Disk Controller
IRQ7-Parallel Port 1
IRQ15-Reserved
Note:
Any or all interrupts including NMI may be masked.
The 14 levels of system interrupts from high to low are
ordered as: IRQ0>IRQ1>IRQ8>IRQ9>IRQ10>IRQ11
>IRQ12>IRQ14>IRQ15>IRQ3>IRQ4>IRQ5
>IRQ6>IRQ7.
E-3
u
Appendix E