The first modern general-purpose electronic computer ENIAC was successfully developed.

Although the computer and patent application materials developed by atanasoff suffered heavy losses, the research materials he left behind had a far-reaching impact on the later development of general-purpose computers.

Atanasoff met Moakley at the annual meeting of the American Association for the Advancement of Science in February (1902- 1980).

At that time, Moakley was teaching physics at Ersnas College on the outskirts of Philadelphia. His father is a physicist, and he graduated from Johns Hopkins University. His teaching is to study the effects of cosmic rays and sunspots on the earth's weather. In order to solve the complex calculation problems in the research, an analog computer is developed for calculation. At this meeting, he read a paper on how to compare the weather with solar activity by computer calculation. At the same time, it also puts forward how to improve the computing device and improve the computing efficiency. He thinks that Bush differential analyzer, which was widely used at that time, has considerable limitations and low efficiency in dealing with a large number of calculation problems, while the response of electromechanical computers is slow (millisecond ms level), and the way to solve the problem lies in the application of electronic circuits (the response time is picosecond level, where 1ms = 1000 microseconds).

Atanasoff was very excited after hearing this report. After the meeting, he and Moakley talked about his successful electronic computer. Although Moakley mentioned the idea of making computers with electronic circuits, he just stayed in the conception stage and was shocked when he got the news. So, at the kind invitation of atanasoff, Moakley 194 1 drove to the Computer Research Institute of Iowa State University where atanasoff was located in June to visit this special electronic computer.

Atanasoff showed Moakley the calculation process of ABC computer, introduced the structure of the machine, and described how to use punched cards to input operation data, and how to use electronic circuits to control operation, arc punching technology and binary capacitor storage technology. Although he doesn't understand the advantages of using binary as data representation and operation, Moakley is fascinated by the extremely fast operation speed of this computer. He studied the principle of this computer during the day and carefully studied atanasoff's patent application materials at night. It's hard to meet a bosom friend. Atanasoff unreservedly explained to Moakley all the core technologies for manufacturing electronic computers.

Five days later, Moakley left in a hurry, because he was going to attend the postgraduate training course of Moore School of Electrical Engineering at Pennsylvania State University. Although the time was short, he knew the key technologies of ABC like the back of his hand and decided to build a more perfect computer.

Moakley met eckert (John Presper eckert, 19 19- 1995), a graduate student of Moore Institute of Electrical Engineering, in the electronic class of the national defense training class. Eckert's wealthy family let him own a garage with a workbench. He was obsessed with electronic equipment since he was a child, and made many electronic equipment in the garage, which greatly exercised his hands-on ability and accumulated rich experience in electrical appliance manufacturing. Moakley told eckert his idea of electronic computer, and eckert accepted it and thought it could be realized. From 65438 to 0942, Moakley transferred to Pennsylvania State University to teach. After teaching, he and eckert devoted themselves to the research and transformation of ABC computer. In the same year, Moakley wrote The Use of High-speed Computing Equipment, in which he expounded their plan to develop computers.

In World War II, after Japan attacked Pearl Harbor, the United States and Japan went to war. Aberdeen Ballistic Laboratory commandeered all the Bush differential analyzers of Pennsylvania State University for ballistic calculation. Nevertheless, the calculation speed of trajectory is still very slow. Goldstein's improved differential analyzer, which is responsible for calculating trajectory, reduces the calculation time of trajectory from 60 seconds to 20 minutes. However, due to the slow speed of the mechanical part of the differential analyzer and the low calculation accuracy (1%), it is still difficult to calculate six pyrometers with 900 tracks every day.

Computing equipment must be improved, but there is no relevant talent. After learning about Moakley's computer scheme, goldstein went to Moakley to describe his requirements, and suggested that Moakley write a report on computer development and submit it to the US military. After discussion, the report was approved by the US military, and the name of the computer to be manufactured was determined as "Electronic Digital Integrator and Computer", abbreviated as "Eniac" and translated into ENIAC in Chinese.

The project was officially launched in July 1943, and the US military provided150,000 dollars for research. Moore Institute of Electrical Engineering was used to build a secondary computer to complete ballistic trajectory calculation, which was used to help calculate the fire table and improve efficiency.

After the establishment of the project, Goldstein coordinated and managed the implementation of the project as a military representative, Moakley was responsible for the overall design of ENIAC as a consultant, and eckert was the chief engineer to help Moakley complete the overall design, which solved a series of difficult and complicated technical problems in manufacturing. Moore College also convened a large number of senior engineers and other technicians to participate in the design and manufacture.

After the overall design and foundation preparation are completed, the specific manufacturing stage begins. This project is not smooth sailing. Eckert has been immersed in the laboratory, not only strictly checking the manufactured electronic components, but also deeply analyzing the difficulties encountered in the manufacturing process and looking for solutions.

1944 Summer, ENIAC entered the most critical stage of manufacturing. One evening, Captain goldstein returned to Aberdeen Railway Station, a railway station in Philadelphia. In the ballistics laboratory, he met the world-famous mathematician Dr. john von neumann (1908- 1957).

Von Neumann was born in a Jewish family in Hungary and his father was a banker. At the age of six, von Neumann learned to divide eight numbers in his mind, and at the age of eight, he learned calculus. 17-year-old von Neumann and his professor collaborated to write the first math paper. 1926 received a doctorate in mathematics from Budapest University, Hungary, and then turned to physics research. By 1930, he has become a scholar proficient in mathematical chemistry, attracting worldwide attention. He has taught at the University of Berlin and the University of Hamburg. Professor Weber, an American mathematician, recruited talented people and gave von Neumann the opportunity to teach at Princeton University. 1933, together with Einstein, von Neumann was named tenured professor of Princeton University and became one of the six founding professors of the Institute of Mathematics and a senior researcher of Princeton University. Later, due to the German Nazi policy of persecuting Jews, he became an American citizen. After World War II, von Neumann was elected as an academician of the American Academy of Sciences and a member of the Atomic Energy Commission, and became one of the senior scientific advisers of the American government. At this time, he is participating in the "Manhattan Project", that is, the atomic bomb development project.

Goldstein respectfully walked over to introduce himself, but von Neumann did not put on airs, and the two sides talked very harmoniously. When Goldstein introduced von Neumann to the computer that he participated in the development and calculated 333 multiplications per second, von Neumann was very interested and asked many questions. It turned out that the Manhattan project in which von Neumann participated encountered a similar problem to that faced by Aberdeen Ballistics Laboratory-the Manhattan project needed to calculate the nuclear fission equivalent, which was estimated to exceed the sum of known calculations in history and could not be completed by manpower. They called IBM's desktop card machine and invested a lot of manpower, but the progress was slow; Later, the electromechanical Mark -I of Harvard University was called for calculation, but the calculation speed was still unsatisfactory. The slow calculation speed seriously restricts the progress of the project. When we learned that Moore College was developing high-speed computing equipment, how could we not be moved? Because he knew that once the machine was successfully developed, it would be possible to solve the progress problem of the Manhattan project.

1In August, 944, von Neumann visited ENIAC at Moore College. The first question he raised was about the logical structure of ENIAC, which eckert secretly admired. Moakley and eckert invited von Neumann to join as a consultant and provide guidance and support.

Von Neumann's participation has played a great role in the project. On the one hand, due to his special status, the military's confidence in the project has greatly increased, and the project funds have also increased from the initial US$ 65,438+US$ 0.5 million to nearly US$ 500,000, which has greatly supported the fund demand for the project to constantly modify the plan due to problems; On the other hand, von Neumann's technical talent project has injected vitality. After he joined, he participated in the discussion and analysis of technical problems, especially storage problems. In view of the problems encountered in debugging and manufacturing, unique solutions can always be given. It has played a great role in the success of the project.

ENIAC was successfully developed and put into operation in the spring of 1945, basically meeting the design requirements. After the completion of ENIAC, it looks like a giant, covering an area of 168 square meters, occupying the whole room. It is 2.5 meters high, 0.9 14 meters wide, 30.48 meters long and weighs 30 tons. It uses 16 different types of 188000 tubes, 1500 relays, 70000 resistors and 18000 capacitors. These components are connected by 50,000 welding heads and 1 1.265km copper wire. The machine clock is 65430.

Using this computer, the calculation time of 60 seconds trajectory is shortened from 20 hours required by the differential machine to 30 seconds, which meets the time limit requirement of military firepower table calculation. Subsequently, ENIAC helped Manhattan Project solve the complex equation problem of nuclear fission smoothly, and accelerated the development of the first lesson atomic bomb.

1946 February 10, after a year of trial operation, ENIAC meets the world. The US Army Ordnance Department and Moore Institute of Electrical Engineering jointly held a press conference to announce that the world's first electronic computer was successfully developed by Moore Institute of Electrical Engineering.

The successful development and operation of ENIAC marks that mankind has entered a new computing era and opened the door to the information age. After visiting the operation of ENIAC, a reporter from Time magazine wrote: "Its electronic wisdom has opened a new world".

After the ENIAC computer was put into operation, it was transported to the military Aberdeen test base in Maryland. In addition to ballistic calculation, it is also used for data processing and calculation of many scientific research projects, the most famous of which are wind tunnel tests such as weather forecast and aircraft design, nuclear energy calculation, cosmic ray calculation, pi calculation and so on. The first general-purpose electronic computer in human history was not retired until1June 2, 955, and the actual running time was as long as 80223 hours.

Careful observation of ENIAC's logical structure and design shows that its design ideas are all copies of ABC computers. Unfortunately, however, Mocquery did not explain it to the world.

1967 Honeywell Company and sperry Rand Company, which purchased the ENIAC computer patent, filed a lawsuit against the ENIAC patent. Finally, after six years of evidence collection and court hearing in 135, the court finally ruled that sperry Land Company lost the case in 1973, and the ENIAC patent was invalid. The verdict reads: "Moakley and eckert did not invent the automatic electronic computer first, but obtained relevant materials from Dr. atanasoff's invention."

Although Moakley refused to admit that he had obtained valuable information from atanasoff during the whole trial and after the verdict, people realized the truth from the verdict. Atanasoff is regarded as the real father of electronic computers.

Compared with previous computers, ENIAC computers have great advantages:

1) has fast calculation speed;

2) Have memory storage capability;

3) Have the ability of logical judgment;

4) The calculation result has high accuracy and credibility;

Of course, there are also many shortcomings:

1) adopts decimal instead of binary, which leads to complicated design of the arithmetic unit;

2) No program storage capacity;

3) small storage capacity;

4) High failure rate;

5) High power consumption;

In the process of manufacturing and debugging, the shortcomings of ENIAC were found. Von Neumann put forward the disadvantage of adding decimal, and the complexity of operators led to the final multiplication speed of only 50 times per second, which did not reach the expected goal of 333 times per second. However, the early design of the project has been completed and only proper maintenance and repair can be carried out.

Aware of the influence of the improved design on the performance of the machine, Von Neumann discussed and studied with Moakley, Eckert and other project team members, and worked out the improvement scheme.

1in June, 945, von Neumann drafted a new computer design report-"Draft on Discrete Variable Automatic Electronic Computer", which was submitted to the Army Ordnance Department and allowed to be used to develop new computers. In this report on 10 1 page, von Neumann named this new type of computer as "discrete variable automatic electronic computer", abbreviated as "EDVAC", which was transliterated as "Adafak" in Chinese.

EDVAC's design scheme fundamentally solves the shortcomings of ENIAC in two aspects:

1) Replace decimal with binary. Binary state, it is easier to express 0,1with electronic circuit open and closed; On the other hand, the operation is simplified. There are only four states of unit addition: 0+0, 0+ 1, 1, 1+ 1. Addition, subtraction, multiplication and division can be realized by adder, which simplifies the complexity and speed of operation components.

2) Put forward the concept of storing programs in computer memory. The memory of EDVAC machine uses mercury delay line to store instructions, which is designed as 1024 bytes. Program instructions and data are input through punched cards. After reading this information into the storage unit, the machine can automatically perform specific calculation tasks. If you want to change the calculation task, you can automatically complete different calculation tasks by reading punched cards representing different meanings, which realizes universality, avoids manual intervention and improves the operation speed.

After these two improvements, the composition of EDVAC machine can be divided into five parts:

1) operator

Used for arithmetic and logical operations, such as addition, subtraction, multiplication and division.

2) Logic controller

Used to automatically control the automatic execution of machine instructions and coordination programs.

3) Memory

Used to store instructions and data of programs.

4) Input device

Read in program instructions and data and send them to memory.

5) Output devices

Send out the results of computer operation and the data needed by people.

The design scheme of EDVAC machine laid the structural framework of modern computer, which is still in use today. This system structure is called "von Neumann machine".