Ultra-high density recording with new heads and tapes

The joint optimization of head and tape parameters as a sub-system has permitted improved recording density to 4700 bits/mm (120,000 bits/in.) both with and without bias. Overwrite without bias exceeds 30 dB at that density, 1F/2F or 2F/1F and data rates of 1.8 M bits/sec at 38.1 cm/sec (15 ips) and 30 dB SNR were obtained. The optimum head/tape combination proved to be a 0.25μm (10μ") record head and a new 800 oersted unoriented tape which supports both horizontal and vertical magnetization.