Oi Electric "Aleph Zero"
This calculator utilized approx. 1700 unique electromagnetic devices called Parametron. These devices, invented by Dr. Eiji Goto in 1954, were much more relaible than the transistors of the early '60's, but required much higher power levels to operate. Some early Japanese electronic computers were based on the Parametron, but improvements in transistor technology soon displaced the Parametron for use in logic circuitry.
Photo Taken at Oi Electric Co., Ltd. Corporate Headquarters, Japan