mart/ex09/explanations.txt

   1 9a1.
   2 The program just prints the number of keyboard interrupts, these are interrupts for press, release and hold.
   3
   4 9a2.
   5 It happens that within the spinning the keyboard handler prints the number of
   6 keypresses. This is because the priority is set to 257 because it's an
   7 interrupt handler.
   8
   9 9b.
  10 The program prints all interrupts, so a different for press and release.