KBD Interrupt

The Int 0Ah Keyboard interrupt is invoked by the hardware after keydown is detected on a keyboard that was in the Reset state. This means that

All Output key lines are active.

No other keys are held down.

Generally, interrupts on key-break are not provided by the hardware. Instead, it is up to the TIMER1 service to detect keyboard changes and perform appropriate processing. See Int 09h on page 3-31 for additional detail.