Calculating Machines

1. Calculating Machines

2. Wilhelm Schickard(1592- 1635) • Invented the first calculating machine • Used Napier’s Bones and gears to perform multiplication through successive additions • First machine was destroyed in a fire • Letters to Johannes Kepler and a ‘bookmark’ found in a Leningrad library provided enough information to reconstruct the machine

3. The reconstruction of Schikard’s machine Schickard’s drawing of his machine, sent to Kepler

4. Blaise Pascal (1623 – 1662) • Once thought to have built the first calculating machine • His machine was vastly different from Schickard’s and it is unlikely he had ever seen or even heard of Schickard’s work • The early belief his machine was the first of it’s kind led to one of the first computer programming languages to be named after him

5. Top view of one of Pascal’s adding machines Internals of Pascal’s adding machine

6. Charles Babbage (1791 – 1871) • Held the title of Lucasian Professor of Mathematics at Cambridge, once held by Newton and later held by Stephen Hawking • Designed the Cow Catcher • Standardized the broad track rather than narrow gauge • Studied the interior of Mt. Vesuvius – while it was active

7. Became cantankerous in his old age and campaigned for the abolishment of street musicians • Ran in his riding with this forming his platform • This resulted in;“I have very frequently been disturbed … after eleven and even after twelve o’clock … a brass band played … for five hours.”

8. Though not appreciated by the lower class, his scientific reputation was known on both sides of the Atlantic • Frustrated with erroneous mathematical tables set out to publish the first error free set of tables • Rather than recalculating he used previous publications and compared them. They were then proofread 3 times.

9. Not happy with simply publishing these, he also experimented with improving readability • Tested 13 inks on 151 colours of paper to determine the best combination for reading – including black on black, yellow on yellow, and so on • This resulted in some later editions of the tables being printed on yellow paper with black ink

10. By 1822 Babbage had a working model of the Difference Engine • Differences are a method by which complex multiplications can be reduced to simpler additions • A Difference Engine can produce successive values of a function by using the differences of the function

11. Babbage asked the British government for financial aid to develop the Difference Engine and was rewarded • He discovered the tools and machinery needed though weren’t available and had to begin designing not only the full engine, but the fine tools and machinery to make it work

12. 4 years after beginning the project Babbage had nearly nothing to show for it, his mechanic having left him with nothing but the drawings • After this separation Babbage conceived the Analytical Engine • A much more complex mathematical engine would allow automated calculation of more difficult problems

13. After nine years asking for support to build the Analytical Engine the Prime Minister told him the government would no longer provide backing • He eventually drew up complete plans for the Difference Engine 2, the most complex drawings produced up to that time

14. When he presented the plans one minister joked that Babbage’s machine could be put to calculating how much money it had already cost the government • In 1991 in an homage paid to Babbage’s work in London a working version of the D.E. 2 was commissioned

16. Ada Augusta Countess of Lovelace (1815 – 1852) • While the Difference Engine was important it is the Analytical Engine that truly represents a step forward in computing machinery • Ada Augusta was a promoter of Babbage’s work and interpreted his work to make it more understandable to the lay person

17. The Analytical Engine borrowed from the Jacquard loom in that it could programmed using punch cards • It could perform loops in the program by moving backwards N steps • Contained registers to store intermediary values

18. Konrad Zuse (1910 – 1995) • Developed mechanical memory based on binary rather than the decimal memory popular in the day • Used old movie film and projector parts to create a “paper tape input” • Built Z1, Z2, and Z3 – the first true fully automatic calculator

19. Bell Labs (Lucent) • The design of telephone equipment requires the use of imaginary numbers • In the late 30s desktop mechanical calculators couldn’t handle this so Bell was looking for anything to aid in the design of equipment • George Stibitz, a mathematician, took home some relays from a scrap pile to play around with

20. Stibitz had observed the similarity between relays and binary • He built a simple circuit using the relays, scrap tin, batteries and flashlight bulbs which could add two binary numbers

21. He brought his toy to work to show his colleagues and his supervisor asked if it could be designed to handle complex numbers • Stibitz had already put some thought into the different circuits he could build and quickly drew a basic concept • This became the Complex Number Calculator

22. The CNC stayed in use for 10 years 40 – 49 • First machine with multiple terminals • First machine to be used remotely Sept. 11, 1940 • Model V • 9000 relays • 10 tons • 1000 sq feet

23. Stored numbers as floating point • Used CADET for arithmetic “Can’t Add Doesn’t Even Try”

24. Howard Aiken • Designed and built the Mark series if computers at Harvard • His designs didn’t center on any one technology, rather whatever was available • His machines therefore span the gap from mechanical to electronic

25. ABC (Atanasoff/Berry) – first North American computer to take advantage of electronic calculation • Mauchly/Eckert – Built ENIAC for the Army, then went into business and built UNIVAC • UNIVAC easily predicted the winner of the 1952 presidential election, but wasn’t announced due to fear the computer was wrong