Technical information

LS PRO OWNER'S HANDBOOK B/9
Technical Information
Appendix B
Interrupts
The interrupt request level or IRQ (the two terms are used
interchangeably) is the line over which a device sends a signal
to get the attention of, or interrupt, the processor.
Most of the computer’s interrupts are reserved for motherboard
components. Some of these interrupts are fixed, but others can
be freed by disabling the component with BIOS Setup.
The following table shows the default assignment of interrupts
in the computer and the possible choices available for the
PCMCIA interface.
IRQ Default assignment IRQ defaults and
options for PCMCIA
IRQ0 System counter
IRQ1 Keyboard controller
IRQ2 Slave interrupt controller
IRQ3 Serial port 2 (COM2/4) Option
IRQ4 Serial port 1 (COM1/3) Option
IRQ5 PCnet-32 Ethernet adapter
IRQ6 Diskette controller
IRQ7 Parallel port Option
IRQ8 Real time clock
IRQ9 PCMCIA socket Default
IRQ10 PCMCIA Card & Socket Services Preferred
IRQ11 Enhanced Business Audio
IRQ12 Mouse
IRQ13 Coprocessor
IRQ14 IDE hard disk controller Option
IRQ15 PCMCIA socket Default
Note that IRQ7 can usually be “double-booked” by the
PCMCIA interface without affecting the operation of the
parallel port. However, it is possible for software to enable
the parallel port’s use of IRQ7 (particularly in ECP/EPP modes),
which may cause problems. If you have no intention of using
the parallel port, you can disable it with the BIOS Setup utility,
thereby freeing the interrupt.