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 Casio digital diaries were produced by Casio in the early and mid 1990s, but have since been entirely superseded by Mobile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 James White (1822). The mechanical calculator industry started in 1851 Thomas de Colmar released his simplified Arithmomètre which was the first machine that could be used daily in an office environment. For 40 years, the arithmometer was the only mechanical calculator available for sale and was sold all over the world. By then, in 1890, about 2,500 arithmometers had been sold plus a few hundreds more from two licensed arithmometer clone makers (Burkhardt, Germany, 1878 and Layton, UK, 1883). Felt and Tarrant, the only other competitor in true commercial production, had sold 100 comptometers in three years. The 19th century