The need to escape the hardships of human calculation All the material progress of our civilization derives, directly or indirectly, from science, and the progress of Science itself constantly depends on calculation. All the material progress of our civilization derives, directly or indirectly, from science, and the progress of Science itself constantly depends on calculation. Maurice d’Ocagne ( ) Maurice d’Ocagne ( )

 Ultra-specialized human calculating prodigies  Common mortals

Obstacles to Mechanization of Calculation  The Catholic church  Strict rules of mediaeval guilds  Lack of mechanical engineering

About 1500 Leonardo da Vinci

early 1600’s John Napier Napier’s Bones

The Slide Rule mechanical analog computer Brigg’s logarithm ( in 1617) a*b = 10^(log(a)+log(b)) and a/b = 10^(log(a)-log(b)) a*b = 10^(log(a)+log(b)) and a/b = 10^(log(a)-log(b))

 Edmund Gunter (Oxford) - single logarithmic scale- to multiply and divide with additional measuring tools  In 1630, William Oughtred (Cambridge)- a circular slide rule In 1632, two Gunter rules held together with the hands to make the modern slide William Oughtred 1575–1660 The Slide Rule

early 1600’s Wilhelm Schickard Calculating clock 1592 – 1635

The Calculating Clock  Did +, -, x,   Used cylindrical elements like Napier’s bones  Only one machine made  Destroyed in a fire (accidental?) 1623

middle 1600’s Blaise Pascal The Pascaline

late 1600’s The Step Reckoner VON Leibniz

Binary Numeral System ?  C onfusion with the Yin & Yang 4 th century BC, China 4 th century BC, China  F irst described in the Book of Changes the I Ching (Yijing) Yin = female Earth passivity receptivity the Moon Winter Yang = male Sky activity productive energy the Sun Summer 

Binary Numeral System ? Yin Yang Yin Yang ___ ___ ______  A dualistic philosophy  Not a numbering system  Chinese system strictly decimal

Leibniz was confused !  Father Joachim Bouvet ( ) sent Leibniz the 64 hexagrams __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ _____ _____ __ __ _____ __ __ _____ __ __ _____ A B C D E F A B C D E F

“Omnibus ex nihil ducendis sufficit unum” With one, everything can be drawn out of nothing Leibniz

Wrong !  Leibniz thought he saw A = = 0 B = = 1 C = = 2 D = = 3 E = = 4 F = = 5 Leibniz hoped to convert the Emperor of China to Christianity

The Jacquard Loom Joseph-Marie Jacquard – 1834

The Jacquard Loom 1.Based on punch cards 2.A moving drum 3.A swinging arm that lifted the hooks

Joseph-Marie Jacquard  Son of weavers  Went to work at age 10  Spent his inheritance  Fought in the French Revolution  Went back home to Lyons when his son was killed  Worked on loom instead of weaving 1752 – 1834

The Jacquard Loom EEEExhibited in Paris in 1801 AAAAwarded by Napoléon in 1803 WWWWeavers revolted and burned it BBBBy 1812, looms in France

Jacquard card making

Charles Babbage  English mathematician Born in Teignmoth, Devonshire, UK  analytical philosopher  proto-computer scientist

The Difference Engine N o 1 Designed to produce mathematical tables Construction funded by British government and Babbage himself Never completed Babbage lost interest in this device when he realized that its design was flawed He started working on Difference Engine No 2

The Difference Engine N o 2 design completed 1830 built 1991

The Analytical Engine Babbage formulated ideas for it between

The Analytical Engine  Store digits numbers  Mill – (CPU) added, subtracted, multiplied or divided, and returned a result to the store  Punched cards – several readers for programs and data  Printer for output making hardcopy data available to the user 

Why did Babbage not invent the computer?  Machine tools not adequate in his day  Mathematics and logic not sufficiently developed  Mechanical memory store just too slow and too limited to hold a useful program

Augusta Ada Byron Countess of Lovelace Augusta Ada Byron Countess of Lovelace  Daughter of Lord Byron famous romantic poet  Her mother did not want her to grow up to be a poet….  Competent mathematician  Member of London’s high society

Ada  Met Babbage when she was 17  Public relations for Babbage  Translated an article by Luigi Menebrea on the A.E. and added extensive notes  Some give her credit for writing the first computer program

wiki/Timeline_of_computing _750_BC-1949