PC as 4-channel logic analyser

It is well known that a PC can be used to measure electronic quantities by making it behave as an oscilloscope through suitable software. Since a logic analyser is a variation of a digital oscilloscope, it stands to reason that a PC with its parallel inputs that can be scanned at high speed and its depth of memory to compute the measurement values is eminentIy suitable for use as a logic analyser. But where an oscilloscope displays real-time waveforms of signals, logic analysers store the signal for display in a non-real-time way.