High-density magnetic recording

By improving the mechanical properties of magnetic recording heads and recording media, it has been possible to demonstrate consistent recordings at information densities up to 40,000 cycles per inch. No fundamental magnetic limit to the maximum recording density has been detected. The major mechanical limitation appears to be the effective head-tape separation due to mechanical surface roughness of the medium. Tape noise arises from both body and surface effects, but their relative importance is not clear. High-frequency recording in the region of several megacycles introduces no special problems with heads of suitable design, such as the outside coil head. Based on present experimental results, a maximum recording density of the order of 100,000 cycles per inch is predicted.