why keyboard is not arranged in alphabetical order

The reason dates back to the time of manual typewriters. When first invented they had keys arranged in an alphabetical order, but people typed so fast that the mechanical character arms got tangled up. So the keys were randomly positioned to actually slow down typing and prevent key jams.

Christopher Sholes designed the QWERTY layout in 1874 for the first commercial typewriter called the Remmington Number .this typewriter layout  is design in computer keyboard 

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