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Chapter 2 Hardware Setup
IRQJ 0J
System TimerJJ
1
IRQJJ
Function DescriptionJ
Priority
IRQJ 1J
Keyboard ControllerJ
2
IRQJ 2J
Programmable InterruptJ
N/A
IRQJ 3J
Serial Port (COM 2)J
11
IRQJ 4J
Serial Port (COM 1)J
12
IRQJ 5J
FreeJ
13
IRQJ 6J
Floppy Disk ControllerJ
14
IRQJ 7J
Parallel Port (LPT1)J
15
IRQJ 8J
Real Time Clock (RTC)J
3
IRQJ 9J
FreeJ
4
IRQJ 10J
FreeJ
5
IRQJ 11J
FreeJ
6
IRQJ 12J
PS/2 Mouse PortJ
7
IRQJ 13J
CoprocessorJ
8
IRQJ 14J
Primary IDE ChannelJ
9
IRQJ 15J
Secondary IDE ChannelJ
10
2-10 IRQ Description
• Both ISA and PCI expansion cards may require IRQs. System IRQs are
available to cards installed in the ISA expansion bus first, then any remain-
ing IRQs are available to PCI cards. Currently, there are two types of ISA
cards.
• The original ISA expansion card design, now referred to as “Legacy” ISA
card, requires you to configure the card’s jumpers manually and then install
it in any available slot on the ISA bus. To see a map of your used and free
IRQs in Windows 98, the
Control Panel
in
My Computer
, contains a
Sys-
tem
icon, which gives you a
Device Manager
tab. Double-Clicking on a
specific hardware device gives you a
Resources
tab which shows the In-
terrupt number and address. Double-Clicking
Computers
to see all the in-
terrupts and addresses for your system. Make sure that each ISA device
should be assigned to one IRQ respectively. If ISA device share IRQ with
any other device, your computer will easily get into trouble.