The Devices preference lets you add, configure,
and disable hardware devices. The Devices panel lists all hardware
devices (modems, various cards, mouse, keyboard, etc.) on your computer.
In addition to using the
Devices scrolling window to see what devices you have, you can highlight
a device, click Configure, and go to theInfo tab of the panel that
opens for basic information about the device. This includes whether
or not it's enabled, the type of device it is, which bus it's on
(ISA or PCI), whether or not a resources conflict exists, and so
on.
The information you see in Devices is not always reliable--devices
sometimes appear to be enabled when they're not. If you have a device
that shows up in the list as enabled, but that isn't working, check
"Troubleshooting Device Configuration Problems" below.
Configuring Devices
All devices have system resources associated with them. These resources
are IRQs (interrupt requests), DMAs (direct memory access), I/O
ports, and memory. Devices cannot generally share resources (with
the exception of PCI devices, which can share IRQs with each other).
When you boot, your system's configuration manager configures all
the devices in or attached to your computer so they don't conflict
with each other; that is, they don't try to share each other's resources.
Sometimes the configuration manager doesn't manage things successfully,
and one or more devices on your system will either turn up as disabled
(you'll know it's disabled because it appears in red in the devices
list) or just won't work. There are several reasons why this typically
occurs:
- There are more devices on your system than it has resources
to support (i.e., there's a resource conflict).
- There's an unknown device (or devices) on the system.
- The configuration manager isn't smart enough to figure out
the device configuration.
Identifying Resource
Conflicts
Resource conflicts should occur only between ISA and plug and play
devices. There are two perspectives from which to view such conflicts
when they occur--from the point of view of the device or from the
point of view of the resource:
- To identify the conflict by way of the device, double-click
on the disabled device in the Devices scrolling list to pop open
a device resources and info window.
Toggle open the Resources Conflicts section of the window (at
the bottom) to see which resources are in conflict.
- To identify the conflict by way of the resource, select Devices
> Resource Usage (Alt+U). The Resource Usage window opens at
the IRQ tab with the devices that are in conflict showing in red.
The troubleshooting section
that follows tells you how to deal with some device configuration
problems you might run into.
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