Electronic organizer Electronic organizer An electronic organizer (or electric organizer) is a small calculator-sized computer, often with an in-built diary application but few other functions such as an address book and calendar. It normally has a small alphanumeric keypad and an LCD screen of one, two or three lines. Because of the advent of personal digital assistants, and later smartphones in the 2000s and 2010s respectively, both of which have a larger set of features, electronic organizers are rarely seen today. Casio digital diaries were produced by Casio in the early and mid 1990s, but have since been entirely superseded by Mobile
Mechanical calculator as tax collector in Rouen, Pascal designed the calculator to help in the large amount of tedious arithmetic required; it was called Pascal's Calculator or Pascaline. Thomas' arithmometer, the first commercially successful machine, was manufactured two hundred years later in 1851; it was the first mechanical calculator strong enough and reliable enough to be used daily in an office environment. For forty years the arithmometer was the only type of mechanical calculator available for sale. The comptometer, introduced in 1887, was the first machine to use a keyboard which consisted of columns of nine keys (from 1 to 9) for