Table 3-1. Irq Line Assignment Defaults; Avoiding Interrupt Assignment Conflicts - Dell PowerEdge 2500 Installation And Troubleshooting Manual

monitor may require a special screen driver program that expects a certain kind of video mode or monitor. In such cases, you may have to develop an alternate method
of running that particular program—by creating a start-up file made especially for that program, for example. Call the support service for the software you are using to
help you with this problem.

Avoiding Interrupt Assignment Conflicts

Problems can arise if two devices attempt to use the same IRQ line. To avoid this type of conflict, check the documentation for the IRQ line's default for each installed
expansion card. Then consult Table 3-1

Table 3-1. IRQ Line Assignment Defaults

IRQ Line Used By/Available
IRQ0 Used by the system timer
IRQ1 Used by the keyboard controller
IRQ2 Used by interrupt controller 1 to enable IRQ8 through IRQ15
IRQ3 Used by serial port 2 (COM2 and COM4)
IRQ4 Used by serial port 1 (COM1 and COM3)
IRQ5 Available unless used by a secondary parallel port
IRQ6 Used by the diskette drive controller
IRQ7 Used by the primary parallel port
IRQ8 Used by the real-time clock
IRQ9 Used for power management functions
IRQ10 Available
IRQ11 Available
IRQ12 Used by the PS/2 mouse port unless the mouse is disabled in the System Setup program
IRQ13 Used by the math coprocessor
IRQ14 IDE CD-ROM controller
IRQ15 Embedded server management
NOTE: For the full name of an abbreviation or acronym used in this table, see the abbreviations and acronyms list at the end of this guide.
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to configure the card for one of the available IRQ lines.