Service manual

Troubleshooting Your Computer: Dell Latitude CP
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 your computer can
confirm whether or not these programs are the cause of the problem.
Other programs use specialized subroutines called device drivers that can cause problems in
your 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 - the creation of a boot file made especially for that program, for example. 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 3-4 to configure the device for one of the available IRQ
lines.
NOTES: Installed devices cannot share the same COM port address. The default address of
your computer's serial port is COM1.
To view IRQ line assignments in the Windows 95 operating system, select the Start button,
and point to Settings and then to Control Panel. Double-click the System icon. Select the
Device Manager tab, and then double-click Computer.
Table 3-4. IRQ Line Assignments
IRQ Line Reserved/Available
IRQ0 Reserved; generated by the system timer
IRQ1 Reserved; generated by the keyboard controller to signal that the keyboard output buffer
is full
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