Two isolated pulse models, the Lorentzian-like and the Mixture model, were
used to investigate the effect of GMR heads-media with different geometric
and magnetic parameters on the readback pulse shape. The matching of these
two models with ail actual pulse was compared in detail. The dependence of
the readback pulse shape of GMR head oil the head-media parameters and non-
linear distortions was discussed in this paper. When applying these models
to evaluate the performance of a recording system, it is necessary to take
into account of the difference between the linear superposition of the isol
ated pulse and the actual readback data pattern. It was suggested to linear
ize the captured isolated pulse in order to use the model correctly as a us
eful tool for evaluating the system performance.