Select a new value for A with the switches - Press Btn1 in order to set A -  Press Btn0 for the next selection

Select a new value for B with the switches - Press Btn1 in order to set B -  Press Btn0 for the next selection

Press Btn3 or Btn2 to select the next/previous F selection -  Press Btn0 for the next selection

Press Btn3 or Btn2 to select the next/previous F selection -  Use the switches for the B -value
Press Btn0 to start all over.