Abstract: Techniques for a logic analyzer instrument that permit the acquisition of digital samples from a plurality of logic signals in a large mainframe computer, or other system under test, in a manner that the signals can be reconstructed for viewing and analysis of the relationship between them. Edges of the signals are located, during their reconstruction, with many times higher resolution than that of the sampling clock. A plurality of sample records, asynchronously timed, are taken of the logic signals from the system under test, and the samples are combined in a way that locates logic signal edges with precision.

Abstract: A technique utilizing either particular software with a microprocessor or computer or a hard wired digital or analog circuit for determining, from a few sample magnitudes acquired from an analog signal at equal time intervals, the shape of the waveform and displaying it. The analog waveform slope at each sample is calculated from the magnitude of the two samples taken from the waveform immediately preceding a given sample and the two immediately following the given sample. A slope of the analog waveform intermediate of each sample interval is then calculated from this information, leading to a final calculation of the magnitude of a selected number of points during the sample interval. The acquired sample magnitudes and the calculated intermediate magnitudes are then combined in a display of a reconstruction of the original analog waveform.

Abstract: Techniques for displaying on a cathode ray tube a plurality of logic signals either from a single electronic circuit under test wherein the signals are acquired by a single probe, or in comparison to signals from a known good electronic circuit of the same type wherein compensation is provided to eliminate differences in the logic signals that are due to differences in the timing signal frequencies of the two circuits.