A waveform display apparatus, comprising: an interface, operable by a user, for setting a time interval of interest and for setting trigger criteria; an input terminal for receiving a signal under test; an analog-to-digital converter coupled to the input terminal, the analog-to-digital converter receiving the signal under test and producing digital data from the signal under test; an acquisition memory for storing the digital data of the signal under test as a contiguous data record having a time duration longer than the time interval of interest; a trigger unit for detecting a plurality of trigger events in the signal under test based on the trigger criteria to produce a plurality of respective trigger event information items within the data record; a trigger list memory for storing the plurality of trigger event information items as a trigger list, based on the trigger criteria; a control unit for locating the digital data in the acquisition memory based on the trigger event information items in the trigger list; and a display device for displaying a plurality of waveforms associated with the signal under test; each waveform corresponding to a respective one of the trigger event information items and within the time interval of interest, the time interval of interest being a subset of the contiguous data record; wherein the display device includes a bar that corresponds to a full data record length in the acquisition memory and that displays the locations of the trigger events based on the trigger event information items in the trigger list relative to the data record length in the acquisition memory; the waveform display apparatus being characterised in that the display device displays a composite waveform that is derived from waveforms associated with selected trigger events corresponding to the trigger event information items in the trigger list for the time interval. an interface, operable by a user, for setting a time interval of interest and for setting trigger criteria; an input terminal for receiving a signal under test; an analog-to-digital converter coupled to the input terminal, the analog-to-digital converter receiving the signal under test and producing digital data from the signal under test; an acquisition memory for storing the digital data of the signal under test as a contiguous data record having a time duration longer than the time interval of interest; a trigger unit for detecting a plurality of trigger events in the signal under test based on the trigger criteria to produce a plurality of respective trigger event information items within the data record; a trigger list memory for storing the plurality of trigger event information items as a trigger list, based on the trigger criteria; a control unit for locating the digital data in the acquisition memory based on the trigger event information items in the trigger list; and a display device for displaying a plurality of waveforms associated with the signal under test; each waveform corresponding to a respective one of the trigger event information items and within the time interval of interest, the time interval of interest being a subset of the contiguous data record; wherein the display device includes a bar that corresponds to a full data record length in the acquisition memory and that displays the locations of the trigger events based on the trigger event information items in the trigger list relative to the data record length in the acquisition memory; the waveform display apparatus being characterised in that the display device displays a composite waveform that is derived from waveforms associated with selected trigger events corresponding to the trigger event information items in the trigger list for the time interval.