explained in more detail below the magnetic field is generated by a current flowing in a conductor such as wire 26 whose axis runs into and out of the plane of the figure the magnetic field generated by such a conductor decreases linearly with the distance from the conductor hence basic storage cell 23 will be subjected to a smaller field than basic storage cell 21 if the current is set such that the magnetic field at basic storage cell 21 is just below the field that would switch the hard layer of cell 21 then the largest possible number of cells is that for which the magnetic field at cell 23 is just large enough to write the soft layer of that cell to implement a memory based on an array of storage cells a scheme for addressing precisely one of a group of storage cells for writing is needed the present invention utilizes one address scheme for writing a storage cell and a different address scheme for reading the storage cell as noted above data is written into a storage cell by exposing the storage cell to a magnetic field of sufficient strength to align the soft layers in a direction specified by.