Abstract: Apparatus for increasing the density of data tracks on the recording surfaces of a disc memory of the type having at least one pre-recorded servo track which is continuously read by a servo head whose output signal changes with its position relative the track and is constantly adjusted to maintain a predetermined servo head output signal condition, without increasing the number of servo tracks in the memory. The improvement comprises a servo head having a plurality of flux paths, each passing through a signal winding, and having adjacent read gaps arranged and spaced such that by successively employing one or another of the read gaps to sense a servo track, the number of data tracks can be increased by an integer multiple.

Abstract: A method for manufacturing a magnetic core for use in data transducing, characterized by having the depth of the shallower flux gap face precisely equal to a predetermined value. The method involves machining a notch in the flux gap face of one element at a precise distance from a reference surface before bonding of the two elements of the core together. The transducing surface can then be machined after assembly to an exact distance from the reference surface to automatically determine the desired flux gap depth.