A Prewired Storage Unit

A flexible and economical form of prewired semi-permanent storage with a capacity of 4096 words of 40 bits is described. A cycle time of 1 μsec can be readily achieved. The information is prepared by threading wires onto plates which are then placed over an array of ferrite rods. The sense in which a wire passes around the rod determines whether a current pulse in the wire will induce a positive or negative voltage in an output winding wound around the rod. Eight plates, each with 512 words, can be used. The plates can be removed from the store, allowing the information held in the store to be changed quickly and easily. The application of this form of storage to the design of sequential switching circuits is briefly discussed.