Younger pilots may have never seen a circular "Computer" but in fact these circular slide rules with wind graphs were indeed called computers in the days when an electronic computer was something to be feared in a science fiction film. I still keep one in my bag and it does, now and then, come in handy. So, in case you've ever wondered, here is a primer on how to use either the military CPU-26 or the civilian Jeppesen CR-3.
— James Albright
Who invents this stuff? Philip Dalton - The Lost Navigator.