1. A method of analyzing input signals to providing display scaling and triggering for a digital oscilloscope, comprising the steps of: (a) converting an input signal to digitized samples; (b) assembling the amplitude values of said digitized samples into an amplitude histogram determining therefrom the minimum and maximum amplitudes of said input signal; (c) establishing from said minimum and maximum amplitudes a low voltage level and a high voltage level intermediate said minimum and maximum amplitudes; (d) detecting time intervals occurring in said input signal and assembling detected time intervals in a time histogram to determine a predominant time interval, wherein each detected time interval is the time for the input signal to pass through a first amplitude level, then a second amplitude level, and then back to the first amplitude level, said first amplitude level comprising one of said low voltage level and said high voltage level, and said second amplitude level comprising the other of said low voltage level and said high voltage level; and (e) selecting at least one of said low voltage level and said high voltage level as a trigger level.