Dell Latitude CPx J User Manual download pdf (Page 152)

4-4-1 Serial port failure. Run the Serial/Infrared Ports tests in the Dell Diagnostics.

5-1-2 No usable memory. Run the System Memory tests in the Dell Diagnostics.

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 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 Microsoft® Windows® 95 and Windows 98 operating systems, click the Start button,

point to Settings, and click Control Panel. Double-click the System icon. Select the Device Manager tab, and then double-

click Computer.

Table 3. 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

IRQ2 Reserved; generated internally by the interrupt controller to enable IRQ8 through IRQ15

IRQ3 Available for use by a PC Card unless the integrated serial port or infrared port is configured for COM2 or COM4

IRQ4 Available for use by a PC Card unless the integrated serial port or infrared port is configured for COM1 (the default) or

COM3

IRQ5 Available for use by the audio controller

IRQ6 Generated by the diskette drive controller to indicate that the diskette drive requires the attention of the microprocessor

IRQ7 Available for use by a PC Card or audio controller if the parallel port is disabled

IRQ8 Reserved; generated by the system I/O controller's RTC

IRQ9 Reserved; generated by the video controller

IRQ10 Available for use by a PC Card or audio controller unless the C/Port Family APR or C/Dock Family Expansion Station is

attached

IRQ11 Generated by USB, PC Card, and audio controllers; available for use by a PC Card

IRQ12 Reserved; generated by the keyboard controller to indicate that the output buffer of the DualPoint integrated pointing

device or the external PS/2 mouse is full

IRQ13 Reserved; generated by the math coprocessor

IRQ14 Reserved; generated by the hard-disk drive to indicate that the drive requires the attention of the microprocessor

IRQ15 Reserved; generated by CD-ROM drive in the modular bay to indicate that the drive requires the attention of the

microprocessor

Memory Allocations

Table 4 provides a map of the conventional memory area. When the microprocessor or a program addresses a location within the

conventional memory range, it is physically addressing a location in main memory.

1 2 ... 147 148 149 150 151 152 153 154 155 156 157 ... 171 172

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Dell Latitude CPx J User Manual Page 152