Dell 7500 manual Program Conflicts, Avoiding Interrupt Assignment Conflicts

result when other programs require use of all or part of the memory already occupied by these TSR programs.

Typically, the operating system’s start-up files contain commands to start TSR programs when you boot the computer. If you suspect that one of these TSR programs is causing a memory conflict, remove the commands that start them from the start-up file. If the problem you were experiencing does not recur, one of the TSR programs probably created the conflict. Add the TSR commands back into the start-up files one at a time until you identify which TSR program is creating the conflict.

Program Conflicts

Some programs may leave portions of their setup information behind, even though you have exited from them. As a result, other programs cannot run. Rebooting the computer can confirm whether or not these programs are the cause of the problem.

Other programs use specialized subroutines called drivers that can cause problems in the computer. For example, a variation in the way the data is sent to an external 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 alternative method of running that particular program—for example, the creation of a boot file made especially for that program. For help with this situation, call the support service offered by the manufacturer of the software you are using.

Avoiding Interrupt Assignment Conflicts

Problems can arise if two devices attempt to use the same interrupt request (IRQ) line. To avoid this type of conflict, check the documentation for the default IRQ line setting for each installed device. Then consult Table 3-2 to configure the device for one of the available IRQ lines.

NOTE: Installed devices cannot share the same COM port address. The default address of the computer’s serial port is COM1.

Table 3-2. Default IRQ Line Assignments

IRQ Line	Used/Available
IRQ0	Generated by the system timer
IRQ1	Generated by the keyboard controller to signal that the
	keyboard output buffer is full
IRQ2	Cascade to second interrupt controller
IRQ3	Reserved
IRQ4	Used by the communications port (COM1)
IRQ5	Used by the internal modem, audio controller, and USB

NOTE: For the full name of an abbreviation or acronym used in this table, see the Glossary

in the system Help.

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