Improvements in or relating to Data Stores

1,190,939. Magnetic data storage apparatus. INTERNATIONAL BUSINESS MACHINES CORP. 28 June, 1967 [30 Nov., 1966], No. 53516/66. Heading H3B. In a data store uniaxial anisotropic magnetic thin film material is supported on a non- magnetic conductive layer, e.g. of copper, coated on a magnetic, preferably ferromagnetic, substrate. The printed digit/sense lines of the store are connected at one end to the copper layer, which acts as a return conductor, and it is stated that the use of a thin layer reduces the noise induced in the sense line due to eddy currents flowing in the layer after a write operation. The ferromagnetic layer may also be thin and may in turn be carried by a conductive substrate of copper or molybdenum. The substrate in each case acts as a heat sink. It is stated that noise reduction increases with an increase in permeability and a decrease in conductivity of the material beneath the conductive layer, and that there is an optimum thickness for the copper layer of the order of 17 microns.