Making a Call

Today, we expect to be able to make a telephone call wherever we are and whenever we want and we grumble if we can't get a signal. How soon we forget! As a child, if we wanted, or needed, to make a telephone call, we had to walk to the nearest phone box, with our coppers in our hand. How many of you are old enough to remember how to make a call from such a box and when to press buttons 'A' and 'B'?