High Linear Density Recording Study

Abstract

A series of tests were conducted in an attempt to study the recording behavior of Enhanced Nonreturn to Zero (ENRZ) code at high linear recording densities. Using the "eye" pattern as a criteria in the first phase, the tests clearly demonstrate the sensitivity of a tape recorder to the DM (Delayed Modulation) coding technique as compared to ENRZ. For the same linear density, ENRZ has a considerably wider margin than the DM code. In the second phase of that study, a series of tests were conducted using high energy tape and magnetic heads with reproduce gaps in the order of 12 μin, referred to as "double bandwidth heads." Using present day technology, it was possible to demonstrate linear packing density never before achieved on magnetic recording tape.