ENIAC: The first electronic computer

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Chapter 3 ENIAC: The first electronic computer In 1941, a key inventor of the ENIAC machine, John Mauchly, was teaching physics in Ursinus College in Philadelphia.

1 Chapter 3 ENIAC: The first electronic computer In 1941, a key inventor of the ENIAC machine, John Mauchly, was teaching physics in Ursinus College in Philadelphia. One day, he received an invitation from the Moore Engineering School, UPenn, asking him to nominate a student for a 10 week summer program aimed at math and physics students. He decided to enroll himself in the course. 1

ABC John, very much interested in electronic computing, already got into touch with John Atanasoff, a professor in Iowa State, who had come up with a prototype of a digital computer with the help of

2 ABC John, very much interested in electronic computing, already got into touch with John Atanasoff, a professor in Iowa State, who had come up with a prototype of a digital computer with the help of Clifford Barry, one of his students. This machine was later referred to as ABC, i.e., the Atanasoff Barry Computer. This machines was declared in 1973 by a US District Court to be the first electronic digital computing device. 2

A bit more... Conceived in 1937 and successfully tested in 1942, ABC was designed only to solve systems of linear equations. Thus, it is not a general purpose machine.

3 A bit more... Conceived in 1937 and successfully tested in 1942, ABC was designed only to solve systems of linear equations. Thus, it is not a general purpose machine. Moreover, its intermediate result storage mechanism, a paper card writer/reader, was unreliable. When inventor John Vincent Atanasoff left Iowa State for World War II assignments, work on the machine was discontinued. 3

4 A bit more... On the other hand, ABC pioneered important elements of modern computing, including binary arithmetic and electronic switching elements, but its special-purpose nature and lack of a changeable, stored program distinguish it from modern computers. It was thus designated an IEEE Milestone in Let s check out how to use this machine to solve some simple equations as we did back in fifth/sixth grade. 4

5 The historic background The Pearl Harbor got hit on Dec. 7, 1941, and the War began. Many new weapons, including new guns, were developed and tested in the Army s Aberdeen Proving Ground, 80 miles away in Maryland. For each new gun to hit its target, the Army needed a new table showing the distance a shell would travel for every firing angle between five degrees and nearly vertical. By the middle of 1942, Moore School hired over a room full of women mathematicians doing vital war work, calculating ballistic tables for the military. 5

6 Track calculation Assume that the gun sends out bullet at the speed of 150 ft/sec. To plot its trajectory, assume that the gun aims at 30 degrees, we go through the following steps: 1. break the initial velocity into its vertical and horizontal components. V x V y = 150 cos(30 ) = 130 ft/sec, = 150 sin(30 ) = 75 ft/sec. 2. Choose a value for time and calculate the horizontal distance at that time. For example, after one section, the bullet travels horizontally x = V x t = = 130 ft. 6

7 3. Similarly, after one second, it travels vertically y = V y t 0.5 g t 2 = 75(1) = 58.9 ft, where g is the gravitational acceleration. 4. For each value on time, we can calculate such a point, and we can then collect all such points and draw the trajectory on a sheet of graph paper. As you can see, the concept and the calculation of trajectory is quite technical, complicated, but purely mechanical. Thus, some powerful tool was needed. 7

8 What is available? The only available tools at that time were mechanic desk calculators, and it took about 40 hours to calculate one trajectory, using such a desk calculator. Thus it took lots of time and lots of persons to complete this task. At that point, UPenn also had a differential analyzer, one of five in the whole world. It was about 20 feet long, a complicated but purely mechanical device. It took this beast about forty-five minutes to finish a trajectory calculation. Two people operated that machine eight hours a day, six days a week, no vacations, except July 4 and Christmas, during the entire war. 8

9 The big question Such a task, albeit important, is boring, labor intensive, slow, but highly mechanical, as it is just calculation based on known formulas. The question is certainly Could we do it better and faster? I bet you all know the answer now, which kicks off the computer age. History repeatedly shows us that Need is the mother of all the inventions. 9

10 ENIAC was the answer After seeing this differential analyzer in operation, John Mauchly, as early as August of 1942, wrote a note to the other professors in the Moore School, proposing to build an electronic computer that would do the work that the differential analyzer had been doing. In terms of processing speed, John estimated that, if he could get a computer to operate at 100,000 additions per second, it would take just 10 minutes or less to calculate a firing trajectory. 10

11 This is the beginning of ENIAC, namely, Electronic Numerical Integrator and Calculator. Originally, John s ideas was not well received, since people were very busy then, also thinking the war would be over quick, so why bother? But, when things got worse, more and bigger, John s idea was taken up more seriously. Thus, it is this need for a more efficient tool to support the war effort that was crucial to get the ENIAC project funded. 11

12 It is not just talking Just as John Mauchly was a mathematician and physicist, another person, Presper Eckert was an electrical engineer. It is the work of this combination that eventually made it happen. They started the design by simulating the process where it was done by hand. Essentially, they used some electronic device to store the numbers in decimal, and carry out the four basic operations, to solve the differential equations that defined the path of a shell from the gun to its target. 12

13 Sounds long, but... Although such a calculation would take millions of operations, it would not take long when the machine was to operate at the speed of 100,000 operations per second. Mauchly figured it would take about five minutes to find out one trajectory. 13

14 Money first Once the design was completed, the head of the Moore School went to the Army s Ballistic Research Lab for the financial support. On April 8, 1943, they submitted a formal proposal, and a final contract was signed off on June 5, which authorized six months of research and development of a electronic numerical integrator and computer at the cost of $61,

15 It was huge When ENIAC was completed, it cost half a million, occupying a room 50 feet by 30, with 18,000 vacuum tubes, 70, 000 resistors, etc.. It also generated lots of heat and the cooling systems weighted a couple of tons. The following machine shows how the machine looked like. Let s find out more about it. 15

16 The role played by women The ENIAC was not completed when the War ended. All the real computers, i.e., the human calculators, got laid off then, except five, who were chosen to be trained as programmers, again in 10 weeks. It is important to point out that women worked side by side with men, and were primarily responsible for the daily running of ENIAC, which is so clear in the video clips. 16

17 The role played by women Female programmers also developed improvements to ENIAC, and were honored in 1997 by the Women in Technology Hall of Fame. It is thus really a pity to see so few female students are among us today in choosing CS as their majors. 17

Not impressive technically Technically speaking, ENIAC had no internal memory, so by programming, it really meant plugging in and pulling out cables to form different circuitry in a switch panel.

18 Not impressive technically Technically speaking, ENIAC had no internal memory, so by programming, it really meant plugging in and pulling out cables to form different circuitry in a switch panel. For example, to calculate a firing table for a particular gun, it would take days to rewire the machine. The following figure shows the wires and switch panels in ENIAC. Thus, at that time, programming was even more difficult than what we are doing today. 18

19 What did it do? ENIAC was finally ready in November 1945, and its first problem was to test the feasibility of the hydrogen bomb, and its first run was deemed successful. It was then introduced to the public in February, 1946, as a thinking machine. The interest for such a machine was intense and worldwide. The first order for an ENIAC came within 10 days from Moscow, which was not accepted. 19

20 What happened afterwards? Even as ENIAC was constructed, its creators, Mauchly and Eckert thought this machine was useless, being so big, and started to work on its sequel, which was based on the binary system. In such a system, every number is represented in two digits, 0 and 1, but not in 10 digits as we are used to, just as all the computers do. This transition makes the computer much more reliable and drastically cuts down the number of components that a computer contains, since we now only need two different parts, instead of ten. Although it is difficult for us to work with a binary system, it fits right in with a digital computer. 20

21 What else? Such a successor would also come with an internal memory to store the program and data, which makes programming much faster. The ENIAC creators also thought about the potential commercial use of a computer, which was very visionary at the moment. On the other hand, a dispute did come up between Mauchly and Ekcert and the Moore School as who owned the patent of ENIAC, and it got really ugly, when most of the participants of the project left the School. The machine itself was eventually moved to the basement of the Ballistic Research Lab and was switched off for the last time on October 2, It operated 80,233 hours and processed 5,000 arithmetic operations per second. 21

von Neumann architecture John von Neumann, a very accomplished mathematician and later a great computer scientist, was a part-time consultant to the ENIAC project in 1944, who thought

22 von Neumann architecture John von Neumann, a very accomplished mathematician and later a great computer scientist, was a part-time consultant to the ENIAC project in 1944, who thought out the idea of letting ENIAC test the feasibility of a hydrogen bomb. He was called the last of the great mathematicians, and made major contribution in many fields of mathematics. 22

23 John von Neumann and CS In 1944, John von Neumann published a paper First draft of a report on the EDVAC, where he laid out the basic composition of a modern computer: input, processor, output, control and memory. In particular, the memory should store both program and data. We get to point out that almost all the computers that we have built since adopt this storedprogram computer, or von Neumann architecture, idea. 23

24 What else? John is also credited as the inventor of the mergesort algorithm, which put a list of data into order. It is actually one of the fastest sortintg method. Is estimated that about 50% of what computers do fall into the category of searching and sorting. 24

25 Activities Pick a topic among the following, do some research and write a report. We will talk about it in a group setting. 1. Dig out some details of the ABC machine. How did it start? Was it completed? If not, why did Atanasoff and Barry abandon this ABC project? What is the impact of ABC on future development of computers? 2. Why did a dispute arise about the patent on the ENIAC machine between Mauchly and Ekcert and the Moore School? How did that dispute play out? 25

26 3. What project came up after ENIAC in Moore School? 4. Describe John von Neumann s contribution in developing modern computer in layman s language. What other architectures exist other than the von Neumann architecture? 5. Would von Neumann architecture continue when the Moore s law ceases to hold? What is Moore s law any way. What did Bill Gates talk about Moore s law over the passing summer? What kind of applications fit the non von Neumann machine better? 26

HISTORY OF COMPUTERS HISTORY OF COMPUTERS. Mesleki İngilizce - Technical English. Punch Card. Digital Data. II Prof. Dr. Nizamettin AYDIN.

HISTORY OF COMPUTERS HISTORY OF COMPUTERS. Mesleki İngilizce - Technical English. Punch Card. Digital Data. II Prof. Dr. Nizamettin AYDIN. Mesleki İngilizce - Technical English II Prof. Dr. Nizamettin AYDIN naydin@yildiz.edu.tr Notes: In the slides, texts enclosed by curly parenthesis, { }, are examples. texts enclosed by square parenthesis,