1670 AD 
In the 1670s, a German Baron called Gottfried von Leibniz
(sometimes von Leibnitz) took mechanical calculation a step beyond his predecessors. Leibniz, who entered university at fifteen years of age and received his bachelor's degree at seventeen, once said: "It is unworthy of excellent men to lose hours like slaves in the labor of calculation, which could be safely relegated to anyone else if machines were used." 


a 

Leibniz developed Pascal's ideas and, in 1671, introduced the Step Reckoner, a device which, as well as performing additions and subtractions, could multiply, divide, and evaluate square roots by series of stepped additions.  
a 
Leibniz also strongly advocated the use of the binary number system, which is fundamental to the operation of modern computers.  Pascal's and Leibniz's devices were the forebears of today's desktop computers, and derivations of these machines continued to be produced until their electronic equivalents finally became readily available and affordable in the early 1970s.  
a 
See also:  
Leonardo da Vinci's mechanical calculator John Napier and Napier's Bones 
a  
These notes are abstracted from the book Bebop BYTES Back 