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 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 The Bell Complex Number Calculator

15. James Tam The Harvard Mark I

16. James Tam John Atanasoff, Clifford Berry, and the ABC

17. James Tam The ENIAC

18. James Tam The Enigma

19. James Tam The first SPC

20. James Tam Early Super Computers: The Stretch

21. James Tam Summary (important points) How do perform basic mathematical operations (addition, subtraction and multiplication in different bases) Binary Octal Hexadecimal