Abstract: An oscilloscope having a displayed trigger indicator is provided in which triggering level, slope, and source information on displayed directly on the viewing screen adjacent corresponding waveforms. In a preferred embodiment, a vertical bar represents the triggering level range, and a marker or dot is superimposed thereon to indicate the trigger level. Slope polarity is also indicated, as is triggering source. These indicators permit the triggering point to be quickly selected and set while viewing them in relationship to corresponding waveforms, and are always on screen for convenient reference and waveform photography.

Abstract: A data compression circuit has a compression mode of operation where it determines and stores minimum and maximum values of successive sequences of applied data words and provides an output comprising a pair of data words representing the stored minimum and maximum for each sequence, offset by a selected amount. The circuit also has a transparent mode of operation where output data sequences match input data sequences.