The Comptometer (7h 50min, nov 18, 2018 y – 20h 53min, jul 30, 2019 y)

Description:

The Comptometer was introduced in 1885, and it was the first mechanical calculator in which numbers were entered/processed by pressing keys. Making the operation of the machine easier.

Instead of having 10 keys for the numbers from 0 to 9, they had columns of 10 keys each, introducing successively . The most powerful calculators had up to 20 columns in their full keyboards.

Added to timeline:

Date: