An all-permalloy bubble memory with control functions based on drive-field operation

A small experimental bubble memory chip with the major-minor loop organization has been designed and tested under laboratory conditions. As distinct from the conventional current-controlled memories, the necessary functions are operated by a temporary change of rotation of the drive field. Using this method a design is possible for which in practice only one mask is needed. The transfer gates, used in the control elements, are discussed extensively as also are the generator- and annihilator-locks, which are necessary for chip selection. The specific properties of this memory are compared with those of a current-controlled memory.