Electromechanical relay units for the ETL Mark II
Image Source: museum.ipsj.or.jp

Electromechanical relay units for the ETL Mark II

Title page of the first book on an electromechanical computer made in Japan.
Image Source: www.kuenzigbooks.com
The first Japanese book published in English concerning an electromechanical digital computer built in Japan. Origins of Cyberspace 637
Detail map of 10, 6-chōme, Roppongi, Minato City, Tōkyō-to, Japan Overview map of 10, 6-chōme, Roppongi, Minato City, Tōkyō-to, Japan

A: 10, 6-chōme, Roppongi, Minato City, Tōkyō-to, Japan

The ETL Mark II, the First Full-Scale Programmable Japanese Electromechanical Computer, is Produced

11/1955
ETL Mark II operating console
Image Source: museum.ipsj.or.jp

ETL Mark II operating console

ETL Mark II, the first full-scale programmable computer built in Japan, was produced by the Electrotechnical Laboratory in Roppongi, Tokyo. It incorporated 22,253 relays, and did not store a program. The system was completed in November 1955, and was used for calculations in and outside the Electrotechnical Laboratory for about 10 years.

Timeline Themes

Computer & Calculator Industry
Data Processing / Computing
Computer & Calculator Design / Architecture