A logic analyzer having clock channels and data channels includes digitizer followed by a digital filter in each channel, the digital filter compensating for losses in signal fidelity in a signal under test. The resulting enhanced multi-bit samples are stored in respective waveform memories for subsequent display as analog waveforms and as logic data. The multi-bit samples from each channel are re-sampled by a regenerated sample clock to determine the logic values of the signal at precise times. For high speed serial data, each channel is divided into multiple clock channels and sampling channels, the outputs from the clock channels being phase adjusted to provide a precise sample clock to the sampling channels and the outputs from the sampling channels being combined to form a serial data output.