Starting prices range from $8000 to $12000. The circuit board, known as the blue box, was able to crack the phone system and get free call service. Although blue boxes appeared in the 1950s, Wozniak developed the first digital version in 1972. In his autobiography iwoz: Technology urchin woznik, apple co-founder Steve woznick once mentioned that he and Steve Jobs learned the principle of telephone switching system and blue box, and then made blue boxes to promote and sell to their college classmates. Once, he was almost caught by the police. It has also been mentioned in the biography of jobs. Global Tech