4-2 Dell PowerEdge 4200 Systems Installation and Troubleshooting Guidemessage that is not listed in Chapter 3, check the operat-ing system or application program documentation.Input ErrorsIf a specific key or set of keys is pressed at the wrongtime, a program may give you unexpected results. See thedocumentation that came with the application program tomake sure that the values or characters you are enteringare valid.Make sure that the operating environment is set up toaccommodate the programs you use. Keep in mind thatwhenever you change the parameters of the computer’soperating environment, you may affect the successfuloperation of the programs. Sometimes, after modifyingthe operating environment, you may need toreinstall a program that no longer runs properly.Program ConflictsSome programs may leave portions of their setup infor-mation behind, even though you have exited from them.As a result, other programs cannot run. Rebooting thesystem can confirm whether or not these programs arethe cause of the problem.There are also programs that use specialized subroutinescalled device drivers that can also cause problems with thecomputer system. For example, a variation in the way thedata is sent to the monitor may require a special screendriver program that expects a certain kind of video mode ormonitor. In such cases, you may have to develop an alter-native method of running that particular program—bycreating a boot file made especially for that program, forexample. Call the support service for the software you areusing to help you with this problem.Avoiding Interrupt AssignmentConflictsProblems can arise if two devices attempt to use the sameinterrupt request (IRQ) line. To avoid this type of con-flict, check the documentation for the default IRQ linesetting for each installed expansion card. Then consultTable 4-1 to configure the card for one of the availableIRQ lines.Table 4-1. Default IRQ Line AssignmentsIRQ Line Used/AvailableIRQ0 Used by the system timerIRQ1 Used by the keyboard to signal thatthe output buffer is fullIRQ2 Used by interrupt controller 1 toenable IRQ8 through IRQ15IRQ3 Used by serial port 2IRQ4 Used by serial port 1IRQ5 AvailableIRQ6 Used by the diskette drive controllerIRQ7 Used by the parallel portIRQ8 Used by the RTCIRQ9 AvailableIRQ10 AvailableIRQ11 AvailableIRQ12 Used by the mouse portIRQ13 Used by the math coprocessor(if applicable)IRQ14 AvailableIRQ15 AvailableNOTE: For the full name of an abbreviation or acronymused in this table, see the abbreviation and acronym list.
