A model for threshold and timing error rate versus off-track position

A model to predict threshold and timing error rate versus position off-track is described. Missing bit and extra bit error rates are calculated separately, then combined to get the total threshold error rate. Timing error rate is calculated independent of threshold errors. The model illustrates the trade-offs in optimizing the threshold on-track versus off-track. The effect of erase width on off-track read performance is shown. The effect of thin film head undershoots on error rate is also shown. Results of the model compared favorably with experimental data.