Ferrite Matrix

a component of a computer memory unit, in the form of a rectangular frame of insulating material within which are placed ferrite cores threaded by insulated wires. The wires are connected to lead-out contacts in one or two rows along the sides of the frame. The frame may consist of two parts: one for the placement of the address-decoding elements of the memory cells (transistors, pulse transformers, semiconductor diodes, and resistors) and one for the memory elements, or ferrite cores, which may number as many as several tens of thousands in a single matrix.

The arrangement of cores and wires in a ferrite matrix depends on the organization of the access (the scanning for a required cell) and the information reading and writing operations. When a ferrite matrix is designed, particular attention is given to reducing the electrical interference created in the wires by the presence of inductive and capacitive couplings. In order to reduce or compensate the interference, the writing and reading wires or windings may be grouped in sections or laid out according to a specially developed plan. Two, three, or four wires may be threaded through the cores, depending on the organization adopted for the access.

The principal requirements imposed on a ferrite matrix are minimum reactances in the access, writing, and reading windings in order to shorten the signal transmission time within the windings; maximum reliability for the contacts, soldered connections, insulation (especially where wires intersect), and cores; interchangeability; and the possibility of threading the cores automatically.