Chapter 23: Machines that think? Electronic Computers BY: Abby Heineman Catherine Yeager General Information Electronic computers were not around until the mid twentieth century. ► In the early days, computers were large, slow, and clumsy. ► Its nickname was the dinosaur. ► The Story starts about 5,000 years ago… ► With the Oriental Abacus, a calculating device of beads and rods. ► Still in use today, in some countries. ► However, its more appropriate to trace computers, modern computers, back to the 17th century in Europe. 1630 ► Scottish Scientist, John Napier, implemented a new system of logarithms and a set of movable sticks. ► These sticks were numbered in a way that by sliding them in relation to each other, multiplication was done automatically. ► These sticks were often made of Ivory. ► These sticks became known as Napier’s Bones. Napier's Bones Early seventeenth century ► Hindu-Arabic replaced Roman Numerals as the system of choice for writing numerals in Europe. ► Also, this system made it easier for writing and doing algorithms for doing elementary arithmetic, which was fairly well developed. 1642 – 1652 ► Blaise Pascal, famous French mathematician, designed and completed a machine for adding and subtracting. ► This was called the Pascaline and it is similar to a cars odometer. ► Used the base ten principle of dials, numbered zero to nine. It was geared so one full revolution on one dial would automatically move the next dial to the next number. ► Numbers, added or subtracted, were dialed in and the machine did the rest. The Pascaline Major difficulty in making mechanical devices ► Gears, pivots, or precision devices had to be individually made by hand. ► Machines were not able to be produced in large quantities and each one was made one by one. ► Therefore, the success of the machine was held “hostage” in the metalworker, not the inventor. Gottfried Leibniz ► One inventor of Calculus that devised an improvement on the Pascaline. ► The improvement was multiplication (by repeated adding) and division (by repeated subtracting). ► Leibniz’s machine was called the Stepped Reckoner, that represented a major theoretical advancement over the Pascaline. ► This was because its computations were done in binary (base 2) arithmetic (AKA-modern computer language). ► Craftsmanship of 1694, not yet up to making reliable quantities, so its success was delayed 150 years. Stepped Reckoner Early 19th century ► Charles Babbage, a Cambridge math professor, began work on a machine for generating accurate logarithmic and astrology tables. ► This was very important for navigation. ► In 1822, British government took interest in his work. ► He created the Difference Engine, which created tables with six place accuracy. ► After many set backs, this project was set aside. 1862 Charles de Colmar of France improved a version of the Stepped Reckoner called the Arithmometer, which won a gold metal at the 1862 international exhibit in London. ► Due to mass production techniques from the industrial revolution, it was manufactured and sold in quantity well into the 20th century. ► Promoters claimed that the Arithmometer could: ► 1. Multiply 2 eight digit numbers in 18 seconds. ► 2. Divide a sixteen digit number by eight digits in 24 seconds. ► 3. Find the square root of a sixteen digit number in one minute. ► It’s slow by today’s standards, but fast compared to hand calculations, at that time. ► Mid 1800’s ► George Boole, professor of math at Queens College in Ireland, published two works in machine logic: 1. The Mathematical Analysis of Logic (1847) 2. The Laws of Thought ( 1854) ► Boole explained logic processes could be expressed by ones and zeros, now called Boolean Algebra. ► It became the theoretical key to all the circuitry of today’s computers. 1880 ► Herman Hollerith, who was a Census Employee, created a machine that used electricity to sort and tabulate data that had been recorded on punched cards. ► Reduced the sorting time from eight years to two and a half years. ► Hollerith also founded the Tabulating Machine Company, which eventually became IBM. 1937 Max Newman worked at the British code-breaking center and devised a way to break German complex code. ► However, the process was far to slow to be practical. ► His concept was then presented to Thomas Flowers – electronic engineer who worked at the British Post Office. ► In less than one year (March 1943 – January 1944), he built a machine that used 1500 vacuum tubes to run the decoding process. ► Machine was dubbed the Colosses, which could decode German messages in hours instead of weeks or months. ► The design made it twice as fast as some modern Pentium PC’s doing the same task. ► 10 machines were then built to decode messages; these machines are thought to have shortened WWII by months and saved thousands of lives. ► 1944 ► The first American, general purpose computer was designed. ► It was called the Mark I and was built by Howard Aiken and IBM engineers at Harvard. ► It used mechanical electromagnetic relays and got instructions from paper punch tape. ► Mark I was more than 50 feet long; it contained 800,000 parts and 500 miles of wire. Mark I 1946 ► ► ► ENIAC (Electronic Numerical Integrator and Calculator) was built by J. Presper Eckert and John Mauchly at the University of Pennsylvania. ENIAC intended to help war efforts by calculating naval artillery firing charts. Weighing in at 30 tons, it contained: 42 panels that measured 9 by 2 by 1 foot 18,000 vacuum tubes 1500 electrical relays Its use of vacuum tubes, instead of mechanical relays, was a major improvement compared to the Mark I (about 500 times faster). ► However, like light bulbs, vacuum tubes burn out with use. ► Programming was done manually by rearranging external wiring and by flipping switches. ► ENIAC had no data storage capacity. ► ENIAC 1950-1960 ► ► ► ► ► Vacuum tube technology, like in the ENIAC, was costly in dependability, cost, and space. However, this changed when Bell Labs invented the transistor in the mid-1950s. Computers used this “second generation” technology and became smaller, faster, more powerful, and economical. The third generation introduced integrated circuitry in the mid-1960s. Also, personal computers became more affordable and have decreased in size from minis all the way to desktops, laptops, and palmtops. Brief History of Calculators ► ► ► ► ► The discovery of calculators is given to the French Mathematician Blaise Pascal; this machine was called the Arithmetic Machine. German mathematician, Wilhelm Schickard, wrote a letter to Johannes Kepler; he wrote about a machine that “immediately computes the given numbers automatically (adds, subtracts, multiplies and divides).” No working copies of his machine were ever found, but working models have been made from his notes. Heinz Nixdorf, in 1953, built the first electronic calculator that resembles today’s models; it performed basic arithmetic calculations. After this time, our current calculator competitors emerged at various times (Texas Instruments, Casio, and Hewlett Packard). Technology was developed into today’s calculators by the rivalry between these three companies. Come on down, you’re the next contestant… Which early computer is this? Name this one too… And last, but not least… Timeline ► 1630--John Napier, implemented a new system of logarithms and a set of movable sticks. ► 1642 – 1652-- Blaise Pascal designed the Pascaline ► 1694 – Leibniz’s machine, The Stepped Reckoner ► 1822 – Babbage created the Difference Engine ► 1862 – de Colmar created the Arithmometer ► Mid-1800s – Boole/Boolean Algebra Timeline cont’d ► 1880 – Hollerith founded the Machine Tabulating Co. ► 1937– Max Newman created the Colosses ► 1944 – Aiken created Mark I ► 1946 – ENIAC created by Eckert and Mauchly References ► ► ► ► ► A History of Computers. 15 Nov. 2005 http://www.maxmon.com/history.htm. A History of Computers Part 1. 15 Nov. 2005. http://www.hitmill.com/computers/history/index.html. Aspray, William ed. Computing Before Computers. Iowa State University Press. Ames IA. 1990. Goldstein, Herman. The Computer from Pascal to von Neumann. Princeton University Press. Princeton, NJ. 1972. Hoyle, Michelle A. The History of Computing Science. 15 Nov. 2005 http://www.eingang.org/Lecture/toc.html.

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# Chapter 23: Machines that think? Electronic Computers