Dictabelt

The Dictabelt or Memobelt was a form of recording medium introduced by the American Dictaphone company in 1947. It used a type of "Write Once - Read Many" medium consisting of a thin, plastic belt 3.5" wide that was placed on a cylinder and rotated like a tank tread. It was inscribed with a spiral groove by the needle, which itself made a slow lateral movement across the belt. Unlike a record cutter, the audio on a Dictabelt is imprinted (pressed in) rather than cut. The recordings had better fidelity than the wax cylinders they replaced. The belts could be folded and placed in envelopes. However, if they were stored too long in a folded state, the folds would become permanent. In the 1960s, Virginia required that all of its circuit courts be outfitted with Dictabelt machines. The belts first came in red, then blue, and finally purple.