Mechanical Calculator, ʻJIDOSOROBANʼ

This ‘JIDOSOROBAN’ is the oldest domestic mechanical calculator. It was invented by Ryoichi Yazu in 1902 and started being manufactured after being patented in a year after. The device is of a gear type, comprising one cylinder and 22 gears, and it features a unique mechanism wherein the binary system and the quinary system are employed for data entry, as is the case with an abacus. The calculator showed excellent performance, superior to foreign-made calculators at that time, including automatic shifting and automatic stopping functions.

The calculator was sold to government offices, and other entities at a price of 250 yen per unit. This first calculator manufactured in Japan is a precious machine that featured unique technologies and led the way in the use of domestic calculating machines.

On exhibition

Kitakyushu Literature Museum

Hours open:
9:30–18:00 (Entry closes at 30 mins. before closing time.) May be off exhibition for certain reasons; please be sure to call for confirmation.
Admission fee:
Permanent exhibit: 200 yen for adults, 100 yen for junior/senior high schoolers, 50 yen for elementary school children
Days closed:
Monday (the following day if falling on a holiday), year-end/New Yearʼs holidays, inventory days, etc.
4-1 Jonai, Kokurakita-ku, Kitakyushu-shi, Fukuoka 803-0813
15 mins. on foot from JR Kokura Sta., 10 mins. on foot from JR Nishi-Kokura Sta.

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