Electronic organizer Phones and PDAs. 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
Mechanical calculator of a number in one movement of the hands on a Comptometer quicker than was possible serially with a 10-key electronic calculator. In fact, it was quicker to enter larger digits in two strokes using only the lower-numbered keys; for instance, a 9 would be entered as 4 followed by 5. Some key-driven calculators had keys for every column, but only 1 through 5; they were correspondingly compact. The spread of the computer rather than the simple electronic calculator put an end to the Comptometer. Also, by the end of the 1970s, the slide rule had become obsolete. Mechanical calculator