1. James Tam The history of computers and computing: Part I A short talk on some early computing devices and the people behind those inventions

2. James Tam The abacus Not just a child’s toy! A skilled abacus operator can be faster than the operator of a mechanical calculating machines. Origins forgotten over time

3. James Tam Abacuses from different parts of the world Chinese Seun Poon Japanese Soroban Greek (from the Darius vase) Pictures from the History of Computing Technology by Michael R. Williams

4. James Tam Gunter’s quadrant Devised by Dr. Edmund Gunter in the 16 th century Used calculation, navigation and sun dialling.

5. James Tam The Sector Developed in the 17 th century Used by artillerists to operate and fire cannons

6. James Tam Napier’s Bones Used to perform various mathematical functions (multiplication, square and cube roots) Also known as numbering rods, multiplying rulers, speaking rods Picture from the History of Computing Technology by Michael R. Williams

7. James Tam Pascal’s and his calculating machines A “self –made” philosopher and mathematician Developed almost 50 different calculating machines

8. James Tam Internal mechanisms of Pascal’s machine Picture from the History of Computing Technology by Michael R. Williams

9. James Tam Leibniz’s multiply machine He expanded the original concepts in Pascal’s calculating machine (multiplication) Leibniz’s machine Internal workings

10. James Tam Charles Babbage Often referred to as the grandfather of the computer age Another wild “self taught” mathematician Absolutely brilliant! Member of many academic organizations e.g. Member of the Extractors (Rules) 1) Every member must communicate his address to the Secretary at least once every six months. 2) If this communication was delayed beyond 12 months, it would be taken for granted that his relatives had shut him up as insane. 3)Every effort legal and illegal shall be made to get him out of the madhouse (hence the term “extractors”. 4) Every candidate for admission shall produce six certificates to be kept on file – three that he is sane and three that he is not. Quotes from the History of Computing Technology by Michael R. Williams

11. James Tam History of Babbage’s Difference Engine Designed to complete many mathematical functions His design is still a part of modern computers (input, processing, storage, output) Cost ~ $184,000 (1842 currency rates) But it was never finished

12. James Tam Woodcut of Babbage’s Difference Engine Picture from the History of Computing Technology by Michael R. Williams

13. James Tam Modern construction of the Difference Engine The ‘simplified version’ was huge and complicated: 10’ high x 6’ long with 4000 parts and weighing in at 3 tons

14. James Tam Summary (important points) What are the characteristics of some early computing devices The abacus Gunter’s quadrant The Sector Napier and his bones Pascal’s calculating machines Leibniz’s multiplying machine Babbage’s Difference Engine Who are some of the people behind these ingenious inventions and ideas Edmund Gunter John Napier Blaise Pascal Gottfried Leibniz Charles Babbage