A 60-ns access time plated-wire electrically alterable ROM

A high-speed easy-rewrite read-only memory has been developed utilizing 0.1-mm plated wires with multilayered NDRO thin film 4800 Å thick. Plated wires are put into grooves molded in a plastic sheet by forming wires which are slightly larger than the plated wires. The digit sheet is sandwiched between word lines formed by two turns of a pair of copper wires. Keepers are not used because of high-speed operation. Both word and digit lines are spaced at 1.0 mm center-to-center. An average output voltage of 12 mV was obtained for a word current of 400 mA with a rise time of 15 ns. IC has been used for most of the peripheral circuits. Word lines are selected by transistor matrix. An access time of 60 ns for a memory capacity of 1024 words by 144 bits was obtained.