Chapter 128 Operating System Kernel (3k)

As soon as Gao Zhendong heard it, he knew it must be a tape recorder. Lou Xiao'e was also very curious about what it was and urged Gao Zhendong to go and see it together.

There were ten tape recorders in total, along with some music tapes and a batch of blank tapes.

The tape recorder was much larger than the walkman Gao Zhendong had seen in pictures in his previous life. It was about the size of a single-card dual-speaker tape recorder. Relatively speaking, it was very portable.

Gao Zhendong borrowed flowers to offer gifts to Buddha, and immediately gave Lou Xiaoe a machine and all his music tapes to her, which made Lou Xiaoe extremely happy.

Father Lou was watching from behind, feeling very aggrieved. What happiness can you have? When you get married, you will take everything with you.

Gao Zhendong and Lou Xiao'e were trying out the tape recorder with great interest. By almost noon, the meal was ready, and Lou's mother invited them to eat.

At the dinner table, Lou's mother kept giving Gao Zhendong some black bear palms. Although time was very tight and the time for soaking and seasoning was not enough, Gao Zhendong thought the taste was really good.

However, it’s not as good as barbecue, Gao Zhendong commented.

During the meal, Gao Zhendong suggested to Lou's father: "Uncle, you can find someone who understands technology over there and integrate the radio into the tape recorder, so that the product line will be more complete."

Gao Zhendong himself is not interested in this. He has a lot of things to do. For something like this that doesn't make much sense, he can just come up with an idea and let someone else do it.

Father Lou was puzzled: "How can a radio be integrated into the body when it is so big?"

Gao Zhendong said: "That's a tube radio. Tell the technicians to use a transistor radio. It's small."

Since Gao Zhendong said this clearly, it means that this matter must be reliable. Father Lou wrote it down.

Watching Gao Zhendong teaching her father how to do things, Lou Xiao'e's eyes lit up.

Lou's mother stopped the two of them and said, "Zhendong, don't talk about work during dinner. Xiao'e said you've been very busy lately. You should get some rest."

Gao Zhendong obeyed orders and concentrated on eating.

After dinner, Gao Zhendong and Lou Xiao'e prepared to go out for a walk, and he asked Lou Xiao'e where they were going.

Lou Xiao'e smiled and said, "Let's go to your house."

Gao Zhendong was a little surprised: "Didn't you say you were going out for a walk?"

Lou Xiao'e looked at him and said, "Take the tape recorder that my brother sent back and go to your house. I know this thing will be useful to you and you must have been thinking about it. Go to your house and do whatever you want. I'll just accompany you. Business is more important."

Gao Zhendong hugged Lou Xiaoe and kissed her hard.

The two men ran downstairs and said hello to Lou's father. Gao Zhendong ran away carrying the tape recorder box, and Lou Xiao'e followed closely behind.

When the two men arrived at the courtyard, they happened to meet Liu Haizhong limping home. His first broken leg was basically healed and he could go out with a cane. Gao Zhendong greeted him with a smile.

Seeing Gao Zhendong and Lou Xiaoe carrying a large box into the house, Liu Haizhong couldn't help but think of his first broken leg, which was caused by following Gao Zhendong after listening to Yan Bugui's gossip.

Liu Haizhong felt his legs hurt even more, so he quickly walked a few steps into the middle courtyard. When he could no longer see Gao Zhendong, he spat on the ground: "Bah, damn Yan Laoxi."

Gao Zhendong entered the house, took out a tape recorder and turned it on. Lou Xiaoe took out several tapes she had brought with her and started playing music.

Gao Zhendong plans to keep this one and use it as a tape recorder.

After making arrangements with Lou Xiao'e, Gao Zhendong did not continue to unpack the tape recorder. It would be useless to do so now.

He took out a pen and paper and started drawing a circuit diagram.

In theory, using a tape recorder for storage is not complicated. It involves connecting the audio output port to the converter, converting the analog audio into digital signals, and then inputting the digital signals into the computer through the interface.

This is reading, writing is the opposite.

Of course, there are also minor issues involved here, such as the starting location of the data.

However, due to the limited frequency response range of recording tapes, the theoretical transmission rate is very low, about 9.6kbps, or 1kByte/s.

Combined with the recording length of the tape, the data capacity of a single side of a standard tape is very small, about 2M.

It may sound weak, but the above discussion about speed and capacity is based on the premise that digital technology had developed greatly in Gao Zhendong's previous life.

In fact, this speed and capacity would have been amazing in 1959!

Especially the capacity. In this era where storage capacity is generally measured in kilobytes or tens of kilobytes, less than 2M may not seem large, but in fact it is simply super space.

This comparison is actually normal. No one can predict what changes the development of technology will bring. In the IT circle, the most famous joke is Bill Gates' famous saying: "640kByte of memory is too much for an individual. A person can never use up so much memory."

However, it didn't take long for the reality to give this big man a slap in the face. As an external memory, the speed of 1kByte/s is sufficient in this era, and the capacity of about 2M has far exceeded the current needs.

Let’s take Bill Gates’ stuff as an example, because he is famous.

Before the arrival of the mature Windows era, the core part of the last generation of command line operating system Dos6.22 could be installed on a 1.44MByte 3.5-inch floppy disk, with a lot left over.

This means that Gao Zhendong can store a suitable operating system on it.

One tape contains the operating system, and one tape contains the C compiler. Perfect.

Another advantage of audio tape storage is that its information density is extremely low, so its reliability is very good. As long as a little attention is paid to maintenance, the data on it can be stored for a long time.

It’s like someone once asked, how can we reliably preserve some information for a long time, and the answer is: carve it on granite.

This is a great advantage at a time when the reliability of information equipment is not very good.

However, in order to use the tape, in addition to converting the equipment, it is also necessary to compile some supporting software. But these are not difficult for Gao Zhendong now. With his own knowledge reserves, he can make this thing without any cheats.

The only trouble is that all the logic gates used in the digital circuits have to be built one by one with transistors.

Fortunately, Gao Zhendong, who had experience with transistor computers, was familiar with this.

An entire afternoon passed slowly as Gao Zhendong was drawing and programming, while Lou Xiaoe was listening to music and cooking.

In between her busy schedules, Lou Xiao'e occasionally glanced at Gao Zhendong, who was even busier. The smile on her face and the light in her eyes never stopped.

After the two had a sweet dinner, Gao Zhendong sent Lou Xiaoe home and held the routine lottery.

See what he got today? ——《In-depth understanding of the Linux kernel》

This is a book that basically does not contain much actual code, but teaches you how to write an operating system everywhere.

It uses a large amount of space to introduce various aspects of Linux from signals, processes, memory, interrupts, time synchronization, files, and drivers. It explains the design ideas, signals, functions, function definitions, and interfaces involved in each aspect very clearly, but there is very little source code.

More importantly, this book describes these things from the perspective of the x86 architecture, which makes Gao Zhendong's 8008-based DJS-59 and even its successor models more consistent with the content of this book.

There is another point that Gao Zhendong thinks is very good, that is, all the examples involved are based on C, not C++, but C.

As for the reason for this, it has something to do with Linus, the founder of Linux. He hates C++ very much, and it is common for him to criticize C++ on the Internet and social media.

“C++ is a terrible language!” — Linus Torvalds.

The content of this book is more useful than giving Gao Zhendong the Linux source code, because when Linux appeared, it was already several decades later, and the computer environment was completely different. Many source codes would be of no use even if given to him, and are not as good as this.

I'll give you the principles and explanations, but you can figure out how to implement it on your own machine.

Of course, there are many advanced aspects of the content, but what Gao Zhendong wants now is a simple operating system architecture with development potential.
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The next day was Monday. Lao Chen informed Gao Zhendong that the research and development plan that Gao Zhendong had formulated and submitted in order to request materials for assistance from the general had been approved. The department had arranged a workshop in Jinggang that met Gao Zhendong's needs, complete with equipment and personnel.

The factory arranged for Gao Zhendong to lead the people from the first research laboratory to go directly to Jinggang to start work.

However, there is still some time before that. The factory is preparing to complete the ESR research and the results have come out. It is time, and Gao Zhendong happens to be free. By the time he starts work at Jinggang, no one knows when it will be.

Moreover, if the ESR is not completed, the work of the people in the first research laboratory will be greatly affected.

The entire First Research Laboratory was busy with this matter, but Gao Zhendong did not have much to do. He mainly signed various documents.

In addition, we arranged for people to send the first batch of high-strength steel with a large aspect ratio refined during the trial run to the Grassland Tractor Factory. Mr. He had been waiting for this product for a long time, and even the consumable electrodes used for smelting were sent by him from the Grassland Tractor Factory.

The material and process of this steel cannot be disclosed to the third steel rolling mill.

Taking advantage of this gap, Gao Zhendong called the Institute of Operations, and then asked someone to send the PCB diagram and BOM list of the tape recorder analog-to-digital converter over, asking the Institute of Operations to help with it.

This thing is made by the computing institute, which is obviously more professional than the factory.

The Computing Institute was very happy to cooperate with the work. It was obvious that Director Gao had some new thing, and it was obviously related to computers, otherwise it would not have been sent to the Computing Institute.

However, Gao Zhendong did not say what this thing was. He just told Chief Engineer Chi that this thing involved important computer peripherals.

This made Chief Engineer Chi itchy, so he personally supervised the work and tried his best to get the product done as soon as possible.

However, this thing cannot be rushed. For such small batches of boards, chemical etching is generally used to etch the circuit boards. This cannot be achieved by simply piling up people, as chemical reactions take time.

　Today there is still 4k
　
(End of this chapter)