260 K bit Flat Domain Memory Card module

Flat domain shift registers use the propagation of domains in low coercive force. channels formed in a ferromagnetlc thin film, the magnetization lying in the plane of the film. A recent design allows to store 130Kbits per substrate with reduced electronic accessing circuits. This paper describes an experimental memory card of 260 Kbit capacity, 21×17cm in size, organized in 64 blocks of 512 bytes. All the associated electronics, block selection matrix with current drivers, sense amplifiers and interface register are implemented on the card module with standard TTL signals on the connector. The format is one 8 bit character in parallel with a maximum throughput rate of 5 Mb/s. The memory is non volatile and aynchronous, the access time to the last byte of any block is 2μs and the average access time to a randomly located byte is 0.4 ms. A preliminary cost estimate indicates a manufacturing cost of 0.1 cent/bit that could be reduced to 0.05 cent/bit with further integration of the electronics.