Toshiba 8100 series, User Manual

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Part II: Technical Reference
Troubleshooting Guide
Resolving a hardware conflict
214
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 doesn’t 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
device overwrites the data required by the other, causing a
hardware conflict.
Plug and Play
TECHNICAL NOTE: Windows NT does not support Plug and
Play.
With Plug and Play and Windows 98 Second Edition, avoiding
hardware conflicts is easy. Plug and Play is a computer standard
that helps the system BIOS (basic input/output system) and
Windows 98 Second Edition to automatically assign system
resources to Plug and Play-compliant devices. In theory, if every
device connected to the computer is Plug and Play-compliant, no
two devices will compete for the same system resources. You
simply plug in the device and turn on your computer. Your
operating system automatically configures your system to
accommodate the new device.
However, if you install an older (legacy) device that Windows
cannot detect, Windows may have difficulty assigning system