A Computer Simulation of the Magnetic Recording Process

Abstract

This paper describes a new method of analyzing the saturation magnetic recording process using digital computer simulation techniques. This model closely simulates the physical system and avoids the usual mathematical approximating expressions for the various recording functions. In addition, automatic consideration of nonlinear effects such as recording demagnetization and finite recording current rise time are included. The real power of such a model lies in its high computational speed such that accurate results can be obtained quickly and economically for numerous sets of operating conditions. With the use of an output plotter, the results are obtained in a visual form which is particularly easy to analyze. Of fundamental importance in simulating the system is the point or particle concept utilized by this model. The recording medium is divided longitudinally into sections and all system functions are quantized at these intervals. Writing is simulated by stepping the medium particles across the head field to obtain each particle's field history, and hence, magnetization. The convolution integral describing the read back process is then readily carried out using point by point multiplication and summation of this magnetization and the head field function. The case of an infinitely thin laminar medium is used as a basis and the results are shown to correspond to previously published work. Analysis of finitely thick media then leads to a number of significant results which include. the optimization of the system parameters, detailed effects of thickness (including the infinitely thick case) and the influence of recording demagnetization with various bit patterns. Experimental results are given which show good agreement with the computed predictions. It is concluded that this new method is an extremely valuable tool for the analysis and design of a magnetic recordings system, and some extensions of the method are outlined. © 1965, IEEE. All rights reserved.