A magnetic thin-film store of 1024 words, each of 50 bits, has been developed which repetitively read-rewrites at 2 MHz. The 2 MHz store has operated for 5000 hours without change. A similar store of 128 words cycles at 3 MHz.From the basic method of film operation, the element dimensions, flux linkage and signal outputs have been derived and measured. A brief description of the method of construction precedes some conclusions on the suitability of the design for commercial production.