The train driver in the courtyard

The Beijing Institute of Mathematics is as quiet today as it was yesterday.

For researchers doing mathematical research, peace is the best working environment.

In the office located in the corner of the courtyard, Chen Ziran sat at the desk.

There were draft papers scattered on the desk, and the densely packed notes recorded his thoughts.

Chen Ziliao's brows were furrowed, as if he was silently struggling with a difficult mathematical problem.

Compared with last year, Chen Zilan looks much better.

His originally skinny cheeks had become rosy, and the Zhongshan suit he was wearing no longer had so many patches on it.

Chen Ziliao has been promoted to a full researcher with a salary level of 13, 56.5 yuan per month.

The most important thing is that he can enjoy the allowance for scientific researchers, and he will have ten more kilograms of fine grain coupons every month than ordinary workers.

Finally, after several hours of contemplation, Chen Ziran's eyes suddenly became clear, and he made the final stroke on the manuscript paper.

At this moment, there was a knock on the door outside.

Chen Ziliao hid the manuscript in the drawer and then walked over and opened the door.

"Deputy Director Zhang? What's up?"

Deputy Director Zhang of the Institute of Mathematics said with some envy: "Chen Ziyuan, I just received a call from the Beijing Railway Research Institute. They have established a new project and specifically asked you to help.

You should pack your bags and report in tomorrow."

Railway Research Institute

Chen Zilan hesitated for a moment and agreed.

By lunch time, the news that Chen Zilan was going to "aid construction" again had spread, and the researchers congratulated Chen Zilan one after another.

"Old Chen, how come you are so lucky? This is your second time going to the Railway Station, right?"

"Yes, the railway is a wealthy organization, so subsidies will be provided, and you will be praised when you return."

"You are all stubborn. Chen Xiaoshuo is studying everyone on the railway!"

Listening to the discussions, Chen Zilan took a bite of his steamed bun and began to wonder.

"What does Li Aiguo want to do this time?"

******
The early morning at Jingcheng University is both leisurely and busy.

College students carrying canvas bags passed by the dew-covered grass, hurried to the cafeteria and the classroom.

Zong Xianfeng ran downstairs to the west building in a hurry.

Yesterday, Dasha suddenly found him and said that she had lost her meal card and hoped that he could help.

Because all you need to eat is a meal card, and in order to prevent outsiders from reselling meal cards, getting a new meal card is a very troublesome thing at Capital University.

Dasha went to the logistics department to inquire, but with her poor Chinese level, it was obvious that she was unable to understand the complicated and regulated system for the time being.

Li Aiguo entrusted Dasha to Zong Xianfeng's care, so naturally he should help. He spent the whole afternoon yesterday to get the meal card ready.

Thinking that Dasha had not had breakfast yet, Zong Xianfeng rushed over.

He handed the meal sign to Dasha who had been waiting for a long time.

"Take it, and don't lose it next time."

"Thank you, Zong-san."

Dasha took the meal card, put her hands behind her back, and smiled.

"I want to go to Badaling for a stroll this weekend. Can you go with me?"

"Not on the weekends, I have to go to work at the library. I won't chat with you anymore, I have to go to class."

Zong Xianfeng saw that it was getting late, so he turned around and ran away.

Dasha looked at Zong Xianfeng's back and clenched the meal card tightly in her hand.

Zong Xianfeng ran all the way and came into the classroom.

As soon as I entered the door, I was called by the teaching assistant.

"Student Zong Xianfeng, the dean wants to see you. Please go to his office immediately."

Zong Xianfeng was a little confused, but he didn't think much about it. He ran all the way again and came to the office of the director of the Electrical Engineering Department.

"Director, are you looking for me?"

The department head said to him warmly, "You must be Zong Xianfeng, don't be nervous. This time we are looking for you because the Railway Research Institute needs technical support.

We need to transfer five comrades from our department."

"I've heard about this, but the people assigned are professors. It has nothing to do with me, right?"

“Ahem, in addition to the five professors, you have also been named by the Railway Research Institute.

Mainly responsible for communication with the Railway Research Institute, and also taking care of the professors’ lives.”

The department head couldn't figure it out either. The department had originally arranged for an officer named Huang to be in charge of miscellaneous matters to go to the Railway Research Institute to take charge of this work.

However, after the list was submitted, it was rejected by the Railway Research Institute.

They specifically asked the student Zong Xianfeng to go.

"real?!"

Zong Xianfeng was overjoyed.

You should know that working at the Railway Research Institute can be regarded as an internship. Not only is there a generous salary, but your superiors will also give you priority when you graduate and are assigned a job in the future.

After realizing his gaffe, he quickly stood up and said, "Director, don't worry, I will definitely complete the work seriously."

"I've read your information. You've been working part-time since your freshman year, and your grades are pretty good. Going to the Railway Research Institute this time is a good opportunity, you should seize it."

The department head had a favorable impression of this student from the countryside, and he gave him some advice. He nodded and said, "You should report to the Railway Research Institute with a few professors tomorrow."

When Zong Xianfeng left the office, he was still immersed in excitement.

He returned to his hometown during the Chinese New Year, as his second brother was going to marry Caixia from the next village.

But Caixia's mother asked her second brother to build two new houses and buy a red quilt cover for Caixia.

Building a house in my hometown does not require any money for manpower, as my uncles and brothers can all help.

But it needs wood.

The big trees behind the mountain all belong to the commune. If you want to cut them down, you need to exchange them for work points.

Most of the children in the family went to school, and there was no labor force and not enough work points, so there was no way to build a house, and the couple's marriage was delayed.

Zong Xianfeng also wanted to help.

But he had already sent back his monthly subsidy of ten yuan, and had no money on him.

Now, with the subsidy from the Railway Research Institute, my second brother may be able to build the house.

But why did the Railway Research Institute specifically ask him to participate? Zong Xianfeng was a little confused.

Zong Xianfeng shook his head and decided not to dwell on it anymore.

After class, Zong Xianfeng told Dasha about going to the Railway Research Institute.

Dasha congratulated Zong Xianfeng, but felt a little bitter in her heart.

******
"A prosperous battle! I never thought that I, Li Aiguo, could fight such a prosperous battle in my lifetime!"

The next day, in the large conference room of the Railway Research Institute.

Li Aiguo looked at the researchers, professors, and engineers on the list and felt like he was carrying fifty RPGs to attack Ping'an County.

Looking at Li Aiguo with a smug look on his face, Liu Guozhang and Engineer Dong both felt that the freight was of great quality.

The Ministry of Railways attaches great importance to DC pulse rail circuit technology and has expressed its strong support for the project.

But it is limited to the strength of the railway family.

The Ministry of Railways has also asked for help from major universities, hoping to borrow their equipment and personnel.

Those outstanding talents are highly sought after in other companies, so who would be willing to send them to other companies as “long-term workers”?

Those equipments are even more amazing. They are all the assets that the family has worked hard to save. How can they be given to outsiders? !
But I didn’t expect that after the article was published in Renren Daily, the wind direction suddenly changed, and all ministries began to support independence.

In particular, I don’t know where the rumor came from.

Legend has it that the slogan was first proposed by Li Aiguo at a meeting of the Ministry of Railways and was related to the DC pulse rail circuit.

Within a few days, the tone of various departments and universities changed, and they all expressed their support for the Railway Research Institute.

Even the two newly separated ministries, the Second Ministry of Machine Building and the Seventh Ministry of Machine Building, expressed their willingness to provide support.

A slogan won the support of millions of people. Liu Guozhang felt that he could no longer understand this student.

Money makes things easier.

After listening to Li Aiguo's suggestion, the arrogant Railway Research Institute divided its staff into five scientific research groups.

In terms of staffing and logistical support, the same old method was adopted.

It was Zong Xianfeng’s first time at the Railway Institute. He and the professors from Jingcheng University were assigned to the signal processing group in the next room.

Zong Xianfeng discovered that in addition to several professors from the Department of Electrical Engineering of Beijing University, there were also several researchers from the Institute of Computing Technology of the Chinese Academy of Sciences, the Institute of Computing Technology of Harbin Institute of Technology, and the Beijing Radio Factory.

The Computer Institute of Harbin Institute of Technology is famous for developing my country's first analog electronic calculator in 1955, with a focus on analog electronic computing.

The Institute of Computing Technology of the Chinese Academy of Sciences and the Beijing Radio Factory began cooperating in 1955 and 1956 to jointly develop the first computer in China, and have made considerable progress.

Although electronic computing and electrical engineering both have the word "electricity" in their names, their related research directions are completely unrelated.

How did they get arranged into a group?
This made Zong Xianfeng confused.

Professor Xia Zhongsu from the Institute of Computing Technology of the Chinese Academy of Sciences also felt confused.

He looked at Engineer Chen from the Beijing Radio Factory who was sitting next to him and asked, "Old Chen, what is the Railway Research Institute going to do?"

"Who knows? I came here for a cleanup mission or a vacation."

"Me too." Professor Xia Zhongsu smiled bitterly.

The development of their Type 103 computer has reached the critical stage.

If it weren't for the task assigned by the department, there is no way they would have come to the railway station for a "vacation".

That’s right, the original words of the Second Ministry of Machine Building’s leader were: “You have worked hard in recent years, and it’s time to take a few days off. There is a project in the Railway Institute, you can go and take a look. If you can help, then help. If you can’t, then just treat it as a vacation.

It is said that the canteen of the Railway Research Institute serves large pieces of meat and the tea served is also large leaves.

The door opened.

A group of leaders from the Railway Research Institute entered the room.

When Zong Xianfeng saw Li Aiguo in the crowd, he immediately understood why a student like him could participate in this project.

Liu Guozhang looked around and introduced Li Aiguo's identity to the professors and researchers.

After learning that Li Aiguo was just a worker, the professors and researchers did not show any contempt.

After all, who would dare to look down on a person who can get comments from the higher-ups on internal reference materials?
Liu Guozhang was going to arrange other tasks, so he handed the work to Li Aiguo and left.

After the door closes.

Li Aiguo looked at the researchers and professors below and felt a sigh in his heart.

These people are the country's top talents, and many of them have their names in textbooks.

It is only in this era that they can all be brought together to work on joint research projects.

Li Aiguo looked around and said, "You are all experts in electrical engineering, computer science, and electronic computing. I am very grateful that you can help our Railway Research Institute with its research."

His humble attitude won him a lot of goodwill.

A professor raised his hand and reminded: "Comrade Patriot, we are all very busy." "Well, now I will briefly explain the tasks of our signal processing team."

Li Aiguo asked Engineer Dong to get a piece of wood and hang it on the wall. He took out some chalk and wrote on it: "Uninsulated track circuit pulse signal!"

Several professors frowned and said, "Pulse signals are a subject of electrical engineering and have nothing to do with our computer science."

Professor Xia Zhongsu coughed twice and said, "Old Chen, Old Wang, don't worry. Since the Railway Institute invited us here, there must be a reason."

Li Aiguo looked at Professor Xia Zhongsu and continued to explain slowly: "This pulse signal can detect whether there is a train (vehicle) occupying the track.

Able to send information about whether the track is free and complete, acting as a message transmitter

To realize this pulse signal, hardware and software support is required.”

"Software?" Professor Xia Zhongsu frowned.

Well, there was no such thing as software back then. Li Aiguo explained: "It can be understood as a combination of pulse signal transmission codes.

Coding converts a signal from its original domain to a representation in the frequency domain or vice versa.

The frequency and internal logic structure of the code determine the stability and anti-interference ability of the pulse signal."

Li Aiguo explained his idea.

You should know that the ZPW-2000A non-insulated track signal is a relatively mature technology of later generations, and it is particularly advanced in this era.

Even though Li Aiguo cut off most of the functions, he only retained the function of detecting train occupancy.

However, because the original design used knowledge of signal science and computer science, the design ideas are exactly the same as later computer programming, so it is very difficult to explain.

"The coding combination of machine language is a machine language." Professor Xia Zhongsu nodded.

In the 103 computer project, his job was to design the computer's underlying machine language, and he was well aware of the difficulty of designing underlying languages.

It seems that the Railway Research Institute has big ambitions. Are they so confident?
Li Aiguo continued: "Pulse coding can be divided into three steps.

Sampling. That is, taking out the instantaneous value of the original analog signal at regular intervals to form a series of pulse signals with varying amplitudes;

Quantization. Use the standard amplitude to measure the amplitude of each pulse, and round it off to make the sample value an integer to obtain a quantized signal;

Encoding. Represent the quantized signal value in binary.
Thus, we can achieve a sampling rate of 8KHz, with each sample value encoded with 8 bits, that is, a total of 28=256 quantized values.

Therefore, the standard digital rate of each voice channel after PCM encoding is a pulse signal of 64kb/s.

It took a full two hours, and the wooden board was covered with dense symbols. Li Aiguo finally stopped and picked up the enamel mug to drink some tea.

"What do you guys think?"

There was silence in the meeting room at this time.

For the first time, Zong Xianfeng felt as if he had returned to elementary school.

What the teacher says on the blackboard seems very simple, but I can’t understand it, I really can’t understand it!
The expressions of several electrical engineering professors have become serious.

They felt that Li Aiguo's uninsulated track signal had already involved the cutting-edge technology of electrical research.

Experts from the School of Computational Mathematics, represented by Professor Xia Zhongsu, stared at the blackboard.

They felt that the code written casually on the blackboard seemed particularly beautiful and familiar.

However, when you look closely, it seems very strange and obscure.

Professor Xia Zhongsu couldn't help but raise his hand and asked, "Comrade Aiguo, is this combination of pulse codes the same principle as the program running in the computer?"

Li Aiguo nodded in admiration: "Professor Xia, you are indeed the leading computer expert in our country.

That’s right, to generate coding combinations and run computer programs, you need to use machine language to generate regular signals.

The only difference is that the pulse coded combination requires a pulsed electrical signal.

The principle of the computer is based on the technology of vacuum tubes, which uses the electric field to inject electronic modulation signals into the control grid in a vacuum, and obtain different parameter signal data after signal amplification or feedback oscillation at the anode.

In principle, they are exactly the same.”

[At that time, all computers at home and abroad were vacuum tube computers, which were very different from the transistor computers of later generations. ]

Li Aiguo paused for a moment and finally stated his purpose.

“We want to develop a program that can run on a vacuum tube computer to control the pulse signal encoding and thus realize the automation of railway signals.”

boom!
As soon as these words were spoken, the meeting room suddenly became lively.

The computer experts felt the task was impossible.

Take the Model 103 general-purpose digital tube computer they are researching for example. It is simply unable to complete such complex signal control tasks.

Professor Xia Zhongsu also felt that Li Aiguo’s ambitions were too big.

"Patriotic comrade, our current 103 vacuum tube computer cannot handle such a complex calculation task!"

Li Aiguo said slowly: "What if we upgrade the 103 electronic tube computer?"

"upgrade?"

Professor Xia Zhongsu was stunned at first, but when he understood Li Aiguo's intention, he felt excited.

The 103 vacuum tube computer was copied from the old Russian M-3 small vacuum tube computer.

The M-3 small vacuum tube computer itself is the product of the Russians' "political achievement" project.

Although it was equipped with a vacuum tube computer, its computing speed was only 30 times per second.

This calculation speed is not even as fast as an abacus.
In other words, the 103 vacuum tube computer is not practical at all.

Professor Xia Zhongsu realized this at the beginning of the project.

I have proposed to the Second Ministry of Machine Building and the Academy of Sciences several times that we should actually develop a practical electronic tube computer for use in calculations of major projects.

However, the funds provided by the Chinese Academy of Sciences, the Third Department of the General Staff, and the Second Ministry of Machine Building were limited.

So his letters sank into the sea.

Li Aiguo said: "I have learned from the comrades of the Academy of Sciences that there is no problem with the structure and architecture of the 103 vacuum tube computer. The reason why the performance is so poor is that there are too few vacuum tubes and diodes."

At this point, Li Aiguo nodded to Professor Xia Zhongsu and said, "Professor Xia, in the improvement of the 103 vacuum tube computer, even though you knew that there was a lack of vacuum tubes, you still adopted a new architecture and did so much extra work. This is really admirable."

"I just did what I should do. I always feel that vacuum tube computers will become an important tool for our scientific research and even production."

Professor Xia Zhongsu pondered for a moment and said, "Deputy Team Leader Li, if you, the railway company, are willing to provide financial support, we are confident that we can upgrade the 103 electronic tube computer."

This is exactly what Li Aiguo was waiting for.

After the 103 computer was developed in the previous life, the department realized that it had been a little timid.

In particular, we encountered many difficulties in the process of marrying Miss Qiu, and we continued to use electronic tubes and computers to assist.

Then they wasted another two years and spent a lot of money to build a 104-vacuum tube computer, which did not delay Miss Qiu's marriage.

What Li Aiguo needs to do now is to use the project in his hands to help the domestic electronic tube computer industry avoid some detours.

In addition, if Li Aiguo wants to bring out the technology in the system in the future, he will also need the help of vacuum tube computers.

It can not only help improve the level of the domestic computer industry, but also complete the project, and use the vacuum tube computer to help with calculations.

Triple win.

Li Aiguo won three times.

When Mr. Teng from the Ministry of Railways learned that Li Aiguo had requested a sum of money from a brother unit to carry out computer research, he was somewhat amused.

"We were originally fleecing others, but now we are being fleeced instead?"

"Imagine that one day all our train dispatching is controlled by computers"

Li Aiguo also wants to paint a rosy picture for Leader Teng.

Leader Teng waved his hand to interrupt him: "Do you think I'm a rough guy? I don't know what a computer is?"

"No, absolutely not!" Li Aiguo then realized his negligence.

Although the leader in front of him, Mr. Teng, is a military man, he loves to learn and keep up with the times.

In later times, in 738, when other departments still didn't know what computers were, the Ministry of Railways, at the suggestion of leader Teng, purchased vacuum tube computers produced by Factory for railway freight processing.

Leader Teng saw that Li Aiguo was startled, handed him a cigarette, and laughed: "But you reminded me that train dispatching can also be done by computer. In that case, human errors can be avoided."

Li Aiguo: "."

He felt that Leader Teng lacked martial ethics and used military tactics to treat his subordinates.

The two chatted for more than two hours, and Leader Teng said that he could specially approve a batch of materials to help develop the 103 electron tube computer.

However, the developed vacuum tube computers need to be sold to the Ministry of Railways first.

Professor Xia Zhongsu went to the Second Ministry of Machine Building that afternoon and reported the Ministry of Railways’ proposal to the leaders of the Second Ministry of Machine Building who were responsible for Project 103.

After the leaders of the Second Ministry of Machine Building held a meeting, they invited the professor to their office.

"I originally wanted you to go on vacation, Old Xia, but now it seems like you have to be busy again."

Professor Xia Zhongsu was delighted: "Did the department agree?"

"Only by relying on one's own efforts can one be independent, Lao Xia. This slogan also applies to us computer researchers."

The leader of the Second Ministry of Machine Building nodded and said, "We are poor and cannot afford such a big business, so we have to imitate. Now that the railway big brother is willing to help, if we don't take advantage of it, wouldn't we be fools?!"

With the support of the Second Ministry of Machine Building, Professor Xia Zhongsu's plan to upgrade the 103 vacuum tube computer was quickly approved with the intention of taking advantage of the railway big brother.

The Institute of Computing Science of the Second Ministry of Machine Building, the 706th Institute of the Fourth Ministry of Machine Building, the 56th Institute of the Seventh Ministry of Machine Building, the 738th Institute of the General Staff, and the Beijing Radio Factory transferred scientific research personnel to the state-owned Factory .

The project is also known as the "738" plan.

The upgraded 103 vacuum tube computer has 22 cabinets, with the main unit and motor unit each occupying 200 square meters.

The entire machine uses 4200 vacuum tubes, 4000 crystal diodes, has a word length of 39 bits, a capacity of 4K, can perform 1 operations per second, has 2048 full-word-length magnetic cores in memory, and two 2 full-word-length horizontal magnetic drums.

The speed reaches 1 operations per second.

These are all things for later.

After mastering the vacuum tube computer, Li Aiguo and the members of the signal processing team began to study pulse signal coding.

Although this is a technology that is ahead of its time, Li Aiguo has fully mastered the relevant technology with the help of the system. He only needs to "take it out" according to the characteristics of the times.

So the project is progressing particularly smoothly.

Zong Xianfeng also quickly adapted to the job of "odd job".

I can learn knowledge from Li Aiguo and those professors while getting a salary. My life is very comfortable.

The only downside is that I can’t see Dasha as often.

Ahem, Zong Xianfeng just thought that since a foreign girl had come all the way to the capital, he, as her "master", should take better care of her and not think of anything wrong.

Time has unknowingly come to April.

After a busy day, Li Aiguo rode his bicycle back home from the Railway Research Institute.

As soon as they got home, Chen Xueru whispered, "Aiguo, have you forgotten something?"

"what?"

Seeing Li Aiguo's bewildered look, Chen Xueru said angrily, "Tomorrow is the day when your beloved disciple will take the test. Didn't the Education Office inform you a while ago?"

Bang! Li Aiguo slapped his forehead fiercely.

Huang Jing has been an apprentice driver for almost a year. When Li Aiguo was away a while ago, she also drove a train as an assistant driver.

Her level had already reached that of a formal train driver, so Li Aiguo signed her up for the train driver assessment.

"Oh, I've been so busy lately that I almost forgot about it."

Li Aiguo and Liu Guozhang asked for a day off and decided to go to the assessment site tomorrow to cheer for their apprentice.

(End of this chapter)