Part C

State chart diagram

Draw a state chart that models the operation of the tape recorder which is described below.

A single cassette tape recorder has the following seven control buttons which govern its operation.

The machine can play, fast forward and reverse, or record in either direction (right to left or left to right). We summarise its operations as follows:

• The single arrow buttons initiate replay of a tape. When the end of tape is reached, the machine will automatically continue playing in the reverse direction, i.e. play the other side of the tape.
• The double arrow buttons initiate high speed tape winding. The movement stops when the end of the tape is reached.
• The stop button stops tape movement due to play, record or fast motion.
• The record button initiates recording from an external source such as a CD player, microphone or radio. The direction of tape movement is the same direction that the tape was moving when last it was stopped. Recording stops when the end of tape is reached.
• The play, record and fast forward buttons only function when the tape is stopped --- otherwise they have no effect.
• The pause button temporarily stops operation of the tapedeck. The pause remains on until the pause is released. While the pause is on, the tape deck could be set to record, or to play or to fast forward or reverse, but no recording, playing or fast motion would actually happen while the pause is on.