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Drivers
Drivers and System Resources
71
Chapter 6 - Drivers and System Resources
This section provides basic information about drivers and system IRQs.
Drivers
A driver is a program that enables the Operating System to work with a hardware
device. Your computer includes drivers for the audio, video, infrared, touchpad,
keyboard, CD-ROM drive, hard drive, floppy drive, and PC Card controller. When
you add a device to your computer, such as a printer, you install a driver for that
device. Different drivers are used by different Operating Systems.
IRQs
Most of the devices in your computer are connected to your computer need their
own IRQ (interrupt request line). The IRQ is a hardware line that a device can use
to send signals to the microprocessor. When the device needs the
microprocessor’s service, the device sends an interrupt request signal to the
microprocessor.
The number of IRQs available for any computer is limited by industry standards.
Because it ships with numerous features, this computer uses most of the available
IRQs. If you add another device to your computer, you may need to disable an
existing device to free up an IRQ for the new device. IRQ resources are of
particular concern when the computer is attached to a docking device.
The default IRQ settings that are used by your computer are listed in Table 7.
TABLE 7. IRQs
IRQ Windows 98 Windows NT 4.0 Windows 2000
0 System timer System timer System timer
1 Keyboard Keyboard Keyboard
2 Internal Controller Internal Controller Internal Controller
3 IrDA Port COM 2, COM 4 IrDA Port
4 COM 1, COM 3 COM 1, COM 3 COM 1, COM 3
5 Audio/USB Audio/USB Audio/USB
6 Floppy controller Floppy controller Floppy controller
7 LPT1 (parallel port) LPT1 (parallel port) LPT1 (parallel port)
8 CMOS/Clock CMOS/Clock CMOS/Clock
9 ACPI bus SCI IRQ Reserved ACPI bus SCI IRQ