A Plan Of Action; Resolving Hardware Conflicts On Your Own - Toshiba Satellite 1805 Series User Manual

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If Something Goes Wrong
Resolving a hardware conflict

A plan of action

The smooth operation of the system depends on the interaction of
all devices, programs, and features. If the system or one of its
attached devices isn't working, resolving the problem can be time-
consuming and frustrating.
The recommended procedure for getting multiple devices to work
together is to add and set up one device at a time. After you add
each device, test it to make sure it and all previously connected
devices work.
The device most recently connected to the system is the one most
likely to be causing a hardware conflict.

Resolving hardware conflicts on your own

Computer components need resources to accomplish a task. A
device, such as a CD-ROM drive or a modem, needs a channel to
the computer's Central Processing Unit (CPU). It also needs a
direct channel to the computer's memory to store information as it
works. These channels of communication are commonly referred
to as system resources.
Interrupt Request Channel
The channel to the CPU is called an Interrupt Request (IRQ)
because it interrupts what the processor is doing and requests
some of the processor's time. If two or more devices use the same
IRQ, the processor does not know which device is asking for
attention. This causes a hardware conflict.
Direct Memory Access
Similarly, the data required by the device is stored in a specific
place or address in memory called the Direct Memory Access
(DMA). The DMA provides a dedicated channel for adapter cards
to bypass the microprocessor and access memory directly. If two
or more devices use the same DMA, the data required by one