Davis (2000) observes the particular importance of the electromechanical relay (with its two "binary states" open and closed): It was only with the development, beginning in the 1930s, of electromechanical calculators using electrical relays, that machines were built having the scope Babbage had envisioned."
Davis (2000) mengamati pentingnya penyiaran elektromekanis (dengan "keadaan binari"-nya buka dan tutup): Hanya dengan perkembangan, dimulai sejak 1930-an, dari kalkulator elektromekanis menggunakan penggantian elektris, sehingga mesin yang dibuat memiliki ruang lingkup yang dibayangkan Babbage."