11
2-5
Expansion
Cards
2-5-1 Procedure For Expansion Card Installation
1. Read the documentation for your expansion card and make any necessary
hardware or software setting for your expansion card such as jumpers.
2. Remove your computer’s cover and the bracket plate on the slot you intend to use.
3. Align the card’s connectors and press firmly.
4. Secure the card on the slot with the screen you remove above.
5. Replace the computer system’s cover.
6. Set up the BIOS if necessary.
7. Install the necessary software driver for your expansion card.
2-5-2 Assigning IRQs For Expansion Card
Some expansion cards need an IRQ to operate. Generally, an IRQ must exclusively
assign to one use. In a standard design, there are 16 IRQs available but most of
them are already in use.
Standard Interrupt Assignments
IRQ Priority
Standard
function
0 N/A
System
Timer
1 N/A
Keyboard
Controller
2 N/A
Programmable
Interrupt
3 *
8
Communications Port (COM2)
4 *
9
Communications Port (COM1)
5 *
6
Sound Card (sometimes LPT2)
6 *
11
Floppy Disk Controller
7 *
7
Printer Port (LPT1)
8
N/A
System CMOS/Real Time Clock
9 *
10
ACPI Mode when enabled
10 *
3
IRQ Holder for PCI Steering
11 *
2
IRQ Holder for PCI Steering
12 *
4
PS/2 Compatible Mouse Port
13
N/A
Numeric Data Processor
14 *
5
Primary IDE Channel
15 *
1
Secondary IDE Channel
* These IRQs are usually available for ISA or PCI devices.
NOTE!
If using PCI cards on shared slots, make sure that the drivers support “Shared
IRQ” or that the cards don’t need IRQ assignments. Conflicts will arise between the
two PCI groups that will make the system unstable or cards inoperable.
