2 From the output, we can see that the keyboard press will trigger the interupt and the counter will increase every keyboard press.
5 The dummy task has a higher priority than the task which handle the interupt. But when the interupt is trigged, it will run the interupt first as the urgency and it become priority 257.
8 Firstly, we need to enable the interupt from the parallel port. Every key press in the parallel port, it will increase the counter.