Abstract: A recorder apparatus comprises a modulator, arranged to be fed with a carrier signal of a frequency at the low end of the audio spectrum (e.g. 80 Hz), for pulse modulating said signal with serialized data corresponding to a time code. A voltage controlled amplifier is connected to the output from the modulator and controlled by an amplitude detector in a separate audio component channel. A mixer is arranged to mix the output from the voltage controlled amplifier and the second audio component channel for feeding to a record head. A play back apparatus which may be integral with the recorder apparatus comprises a low pass filter and a high pass filter arranged to be fed with signals from a read head. A decoder is connected to receive signals from the low pass filter via demodulator to provide time-code signals for a utilization device. The high pass filter is connected to a normal audio channel.

Abstract: An attachment for a data recording machine having a movable recording medium which comprises, circuitry for receiving and storing a first signal indicative of a rest position of the data recording medium and circuitry for entering a second signal indicative of a required position of the data recording medium. Further circuitry is provided arranged to compare said first and second signals to predict any required operation of fast-rewind or fast-forward controls and to cause any such actuation of said controls, in use.