Digital ‘blue box’ designed by Apple founder Steve Wozniak at Bonhams New York

"If it hadn't been for the Blue Boxes, there would have been no Apple. I'm 100% sure of that." So said Steve Jobs of the electronic devices that simulate operators by generating the tones used by a telephone operator’s dialling console, and were typically used from the 1950s by so-called ‘phone phreakers’ to avail themselves of free calls.