1. A system for recording and subsequent playback of the audio and graphic presentation of a classroom, teaching experience comprising; a microphone for inputing the audio text, a writing desk with a writing instrument connected to displacement transducers for inputing writing instrument coordinate position information, a writing instrument incorporating a switch means capable of signaling writing instrument contact with the writing surface, an oscillator connected to the writing instrument switch means, means for pulse width modulation encoding of the writing instrument coordinate analog signals, means for differentiation of the pulse width modulation encoded analog signals, record circuits for recording the audio, the writing instrument switched tone signals and the differentiated pulse width modulation encoded writing instrument coordinate analog signals, four record/playback head channels, four erase head channels, a tape transport, a playback circuit for the audio text, a playback circuit for the writing instrument controlled tone signal plus rectifier and integrating capacitor driving a solid state relay which controls the writing means of the plotter, means for decoding the twice differentiated pulse width modulation encoded writing instrument coordinate analog signals, a plotter for receiving the decoded writing instrument coordinate analog signals plus the electrical writing control from the solid state relay and reproducing the graphic portion of the text, an audio transducer for reproducing the audio portion of the text, switching means for controling the record and reproduction functions.
1. A system for recording and subsequent playback of the audio and graphic presentation of a classroom, teaching experience comprising; a microphone for inputing the audio text, a writing desk with a writing instrument connected to displacement transducers for inputing writing instrument coordinate position information, a writing instrument incorporating a switch means capable of signaling writing instrument contact with the writing surface, an oscillator connected to the writing instrument switch means, means for pulse width modulation encoding of the writing instrument coordinate analog signals, means for differentiation of the pulse width modulation encoded analog signals, record circuits for recording the audio, the writing instrument switched tone signals and the differentiated pulse width modulation encoded writing instrument coordinate analog signals, four record/playback head channels, four erase head channels, a tape transport, a playback circuit for the audio text, a playback circuit for the writing instrument controlled tone signal plus rectifier and integrating capacitor driving a solid state relay which controls the writing means of the plotter, means for decoding the twice differentiated pulse width modulation encoded writing instrument coordinate analog signals, a plotter for receiving the decoded writing instrument coordinate analog signals plus the electrical writing control from the solid state relay and reproducing the graphic portion of the text, an audio transducer for reproducing the audio portion of the text, switching means for controling the record and reproduction functions. 17. The system of claim 1, further comprising means for monitoring the audio as the writing is being edited.