APPENDIX
B. Interrupt Request Lines (IRQ)
Peripheral devices use interrupt request lines to notify CPU for the service required. The following table shows the IRQ used by the devices on board.
| Level |
|
| Function |
|
| IRQ0 |
| System Timer Output |
| |
| IRQ1 |
|
| Keyboard |
|
| IRQ2 |
| Interrupt Cascade |
| |
| IRQ3 |
| Serial Port #2 |
| |
| IRQ4 |
| Serial Port #1 |
| |
| IRQ5 |
| Reserved |
| |
| IRQ6 |
| Floppy Disk Controller |
| |
| IRQ7 |
| Parallel Port #1 |
| |
| IRQ8 |
| Real Time Clock |
| |
| IRQ9 |
| Reserved |
| |
| IRQ10 |
| Reserved |
| |
| IRQ11 |
| Reserved |
| |
| IRQ12 |
| PS/2 Mouse |
| |
| IRQ13 |
| 80287 |
| |
| IRQ14 |
| Primary IDE |
| |
| IRQ15 |
| Secondary IDE |
| |
64 |
