An improved simulation of pulse propagation between integrated digital circuits is presented. Two novel improvements associated with the inverse Laplace transform used are presented; 1) the introduction of two-dimensional weight factors σn,mand 2) the use of a shifting parameter a. The algorithm proposed is very fast and saves considerably on computer memory. Fast Fourier transform (FFT) techniques are also employed. The computed results agree well with the experimental observations using TTL gates. The technique deals with arbitrary input waveforms, lossy lines, aperiodic tap-off loads, and is extended to large large-scale integrated (LSI) digital systems and crosstalk prediction.