Re: Changing the positioning of the arithmetic keys -- why? Message #5 Posted by Karl Schneider on 2 Jan 2008, 1:57 a.m., in response to message #4 by Trent Moseley
Quote:
All this leads to the question of why the telephone keypad is reversed from the calculator keypad i.e., from top to bottom? I think the Bell System had their design out first.
Trent --
I'm sure that you recall (as even I can), that the ten digits on the rotary dial were arranged sequentially counterclockwise as 1 through 9, then 0. Dialing a given digit generated a corresponding series of pulses, with "0" giving ten pulses. The successor touch-tone keypad compactly arranged the rotary-dial digits as the lines of a Western language would be written -- left-to-right, proceeding from top to bottom.
Complete telephone numbers are merely codes -- a sequence of digits. In the US (and perhaps most countries), "0" by itself also served a special purpose to reach the Operator.
Conversely, on the input to a computing device -- such as a ten-key or a calculator keypad -- the digits have quantitative values. So, it makes more sense to physically arrange the digits by magnitude in a consistent and intuitive order: increasing bottom-to-top, then left-to-right.
-- KS
Edited: 2 Jan 2008, 3:19 a.m.
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