Drivers

Drivers and System Resources

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Chapter 6 - Drivers and System Resources
This section provides basic information about drivers and system IRQ s.
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, touchpa d,
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 co mputer 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 sign al 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 mos t 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 Tab le 7.
TABLE 7. IRQs
IRQ Windows 98 Windows NT 4.0 Windows 2000
0System timer System timer System timer
1Keyboard Keyboard Keyboard
2Internal Controller Internal Controller Internal Controller
3IrDA Port COM 2, COM 4 IrDA Port
4COM 1, COM 3 COM 1, COM 3 COM 1, COM 3
5Audio/USB Audio/USB Audio/USB
6Floppy controller Floppy controller Floppy controller
7LPT1 (parallel port) LPT1 (parallel port) LPT1 (parallel port)
8CMOS/Clock CMOS/Clock CMOS/Clock
9ACPI bus SCI IRQ Reserved ACPI bus SCI IRQ