PT-2010 Mainboard Manual
Functionality
As you read through this manual, you will see the term IRQ on a number of
occasions. It is important for you to know what this term means, particularly if
you intend to upgrade your system.
IRQ stands for Interrupt Request, the process in which an input or output device
tells the processor to temporarily interrupt its current task and immediately
process something from the source of the interrupt. When it has completed this,
the processor returns to the task it was already processing. Devices that need an
IRQ line to operate sometimes need to have exclusive use of that line.
A large number of add-on cards, such as sound cards and LAN cards, require
the use of an IRQ line to function. Some of
may already be in use by
components in the system such as the keyboard and mouse. Add-on cards that
need to use an IRQ draw from the unused group of
When installing a card
that uses an IRQ, it will have a default IRQ setting which you might have to
change if that IRQ is already in use and cannot be shared.
Both ISA and
add-on cards may need to use
System
are
available to add-on cards installed on the ISA bus first; the remaining ones can
be used by cards installed on the
bus. There are two categories of ISA
on cards: so-called Legacy ISA cards, which need to be configured manually
and then installed in any available ISA slot; and Plug and Play
ISA cards,
which are configured automatically by the system. As a result, when you install
Legacy ISA cards, you have to carefully configure the system to ensure that the
installed cards do not conflict with each other by having the same IRQ. With
cards, on the other hand,
are assigned automatically from the ones
available in the system. In the case of
add-on cards, the
automatically
assigns an IRQ card to the
slot the card is installed in.
6