| IRQ Line |
Used/Available |
| IRQ0 |
Reserved; generated by the
system timer |
| IRQ1 |
Reserved; generated by the
keyboard controller to signal that the keyboard output
buffer is full |
| IRQ2 |
Reserved; generated
internally by the interrupt controller to enable IRQ8
through IRQ15 |
| IRQ3 |
Available for use by a PC
Card unless the built-in serial port or infrared port is
configured for COM2 (the default) or COM4 |
| IRQ4 |
Available for use by a PC
Card unless the built-in serial port is configured for
COM1 (the default) or COM3 |
| IRQ5 |
Reserved; generated by the
audio controller |
| IRQ6 |
Reserved; generated by the
diskette drive controller to indicate that the diskette
drive requires the attention of the microprocessor |
| IRQ7 |
Available for use by a PC
Card or audio controller if the built-in parallel port is
disabled |
| IRQ8 |
Reserved; generated by the
system I/O controller’s RTC |
| IRQ9 |
Reserved; generated by the
video controller |
| IRQ10 |
Available for use by a PC
Card or audio controller unless the C/Port Advanced Port
Replicator or C/Dock Expansion Station is attached |
| IRQ11 |
Generated by the USB and
PC Card controllers; available for use by a PC Card |
| IRQ12 |
Reserved; generated by the
keyboard controller to indicate that the output buffer of
the integrated touchpad or external PS/2 mouse is full |
| IRQ13 |
Reserved; generated by the
internal math coprocessor |
| IRQ14 |
Reserved; generated by the
hard-disk drive to indicate that the drive requires the
attention of the microprocessor |
| IRQ15 |
Reserved; generated by the
CD-ROM drive in the modular bay to indicate that the
drive requires the attention of the microprocessor |
