The exhibit shows the 14-A in motion. At the time, Kashio worked for the Department of Communications (now the Ministry of Internal Affairs and Communications) in charge of telephone switchboard relays. He hit on the idea of using relays to make a calculator. Although relays were unstable, Kashio devised a mechanism for ensuring the accuracy of calculations by connecting the relays in a series, making a compact all-electric calculator possible. He acquired a patent on the invention in 1956. In 1957, the 14-A fitted with 341 relays was commercialized.