Casio (1s, 10s, 100s, etc ... ) had nine keys. Another distinguishing innovation was the use of a single display window instead of the three display windows (one for each argument and one for the answer) used in other calculators. Casio Computer Co., Ltd. was formed in June 1957. That year, Casio released the Model 14-A, sold for 485,000 yen, the world's first all-electric compact calculator, which was based on relay technology. In the 1980s, its budget electronic instruments and its line of affordable home electronic musical keyboard instruments became popular. The company also became well known for the wide variety
Mechanical calculator is vertical, on its right side. Later on, some of these mechanisms were operated by electric motors and reduction gearing that operated a crank and connecting rod to convert rotary motion to reciprocating. The latter, type, rotary, had at least one main shaft that made one [or more] continuous revolution[s], one addition or subtraction per turn. Numerous designs, notably European calculators, had handcranks, and locks to ensure that the cranks were returned to exact positions once a turn was complete. The first half of the 20th century saw the gradual development of the mechanical calculator mechanism. The Dalton adding-listing machine