A radio or television apparatus has tuning circuitry for selecting a channel
from
an input spectrum, an output for presenting a presentation from a selected channel,
a recording apparatus having a memory with capacity for recording a fixed time
duration T of the selected presentation, and adapted to make an audio record sequentially
in a circular fashion, such that when the memory capacity is filled, the device
continues to record, overwriting the oldest recorded information, providing thereby,
at any point in time, a stored copy of time duration T immediately preceding the
point in time. This innovation provides limited rewind capability for real-time
data streams. In alternative embodiments add-on devices are provided for existing
radios and TVs.
