Chapter 638 Make a small record

Yi Zhonghai can do it, but we can’t?
Therefore, all the old technicians in the Third Branch Factory are very interested in these new gadgets, and they would like to put all their strength into them.

The people from Beijing Watch Factory were a little confused. Was it really a computer thing? And it didn't sound like they wanted money, but they really needed the technology of Beijing Watch Factory?
In fact, they don’t know that the comrades of the 11th Ministry of Machine Building are very happy about this matter. They can finally participate in this matter and contribute to this cutting-edge high-tech.

There is only a difference between 11 and 12, but in this respect, the 12th Ministry of Machine Building is making great strides. As for the 11th Ministry of Machine Building, it can only do the traditional work and existing equipment for the time being. In terms of high technology, it is not as outstanding as the 12th Ministry of Machine Building in the fields of computers and electronics.

It’s not that there is no high technology in the field of the 11th Ministry of Machine Building, but there are no significant achievements for the time being, and it is not as outstanding as the 12th Ministry of Machine Building.

Now that he heard about this opportunity, he happily pulled out the Beijing Watch Factory.

So now they just listen and don't express their opinions.

It’s different for Chief Engineer Chi of the Computing Institute. For things like this, the Computing Institute should bear the brunt and take the responsibility.

"Professor Gao, what is this peripheral?"

Gao Zhendong did not say it directly, but asked a question: "Chief Engineer Chi, which one of the DJS series computer peripherals do you think you are most dissatisfied with?"

This question can only be asked to Chief Engineer Chi. The other two groups have no answer to this question and don’t even know what peripherals there are.

This question made Chief Engineer Chi ponder. The answer to this question is hard to say, as every peripheral has its unsatisfactory aspects, but to name the most unsatisfactory one, you have to think about it.

After thinking for a while, Chief Engineer Chi said decisively: "Magnetic tape storage!"

Gao Zhendong smiled. He was indeed an expert in this field. "Tell me the reason."

"The speed is slow, but that's not the most annoying thing. The most annoying thing is that the storage is sequential, not random. So when you modify a file that is not in the current tape segment, it will be very uncomfortable. The speed is very slow. Before you have your operating system, it is easy to make mistakes when programming and controlling it yourself."

Gao Zhendong nodded: "Yes, I just want to solve this problem."

Chief Engineer Chi thought for a moment and said, "High-speed tape?"

Since the speed is slow, speed it up! At the same time, the higher the speed, the faster it will take to access random data.

Gao Zhendong shook his head: "It can't solve the fundamental problem, and high-speed tapes have very high requirements for tape materials."

The way a music tape player controls the speed of the tape is actually different from what everyone imagines, that is, the two tape reels rotate synchronously in the same direction. When the tape is wound in a certain direction, only the tape reel in that direction rotates, and the other tape reel is driven. It rotates as fast as you pull.

However, it is not the take-up wheel that controls the uniform speed of the tape, because the circumference of the tape reel changes with the amount of tape wound, and the length of the tape pulled during one rotation is different. Trying to achieve uniform speed of the tape by adjusting the rotation speed in real time is too complicated for the tape drive and the cost is terribly high.

In fact, what controls the tape speed is a set of pressure rollers next to the magnetic head. The rotation speed of this thing is fixed. How much tape can be pulled by the take-up wheel is determined by its rotation speed. Only when fast-forwarding will the pressure roller be loosened and the take-up wheel will rotate at full speed to achieve fast-forwarding.

Machinery is a very interesting thing. This small set of tape advance control has many ingenious ideas.

In this case, the tape is directly subjected to tension, and the tension is applied at two places: one section from the driven wheel to the pressure roller, and another section from the pressure roller to the take-up roller.

It's OK at low speed, but it can't stand high speed and will break. There are two places where it may break! Especially from the driven wheel to the pressure pulley.

Chief Engineer Chi had not really noticed that the tape drive worked like this. After listening to Gao Zhendong's explanation, he realized that high-speed tapes would not work with this structure.

Long, the chief engineer of the Beijing Watch Factory, is familiar with this: "Then Professor Gao, how about the master and slave synchronous rotation?"

Comrades from the Beijing Watch Factory had their own advantages in small precision transmission and responded quickly.

This is the reason why Gao Zhendong chose them instead of Haihekou Record Player Factory. Although the record player is the same as the floppy disk, it also rotates, but the record player has no ability to control the position of the stylus, and the storage medium is not magnetic.

When Gao Zhendong and Lou Xiao'e first met, he knew that she liked music. In addition to the TV series, this was also the reason - Lou Xiao'e could accurately put the needle directly to the beginning of the second movement of the "New World" record~!

If I have to say, the Cultural Audio and Video Corporation, which is responsible for the production of tapes and has a division of labor with them, is more suitable than them, because after all, they still use magnetic media.

Gao Zhendong shook his head: "It's a bit technically troublesome, and it can't fundamentally solve the problem of random reading and writing."

Chief Engineer Chi thought for a moment and asked, "What should we do?"

Gao Zhendong said: "Since the magnetic tape is a one-dimensional storage method that is rolled up to form a two-dimensional storage, which means that it must be unfolded to be read, then why don't we directly use the unfolded two-dimensional surface to store data? For example, a close relative of the magnetic tape."

Whenever possible, he was used to guiding everyone to think about the problem. Everyone was lost in thought: "Two-dimensional surface, a close relative of the magnetic tape..."

After thinking for a while, Long, the chief engineer of the Beijing Watch Factory, was the first to react: "Professor Gao, are you talking about records?"

He also followed Chief Engineer Chi and called Gao Zhendong professor.

Records also rotate, watches also rotate, and they are close relatives. There is nothing wrong with him thinking of records.

After these words were spoken, everyone suddenly understood.

Yes! Isn't this thing a natural example of storing data in two dimensions?

Just replace the above with magnetic media, change the stylus into a magnetic head, add a head servo mechanism, and actively control the movement of the head, wouldn’t that be it!

Chief Engineer Chi gave a thumbs up and said, "Professor Gao's idea is very simple, but I really don't have the ability to apply it to other cases. This thing can be done!"

After saying this, he also had some doubts: "But in this case, wouldn't the advantage of tapes being portable be lost?"

Not to mention the 12-inch LP and 10-inch EP, even compared with a 7-inch single record that is larger than a fish tray, the tape is considered small and exquisite. Putting aside the huge reading device of the record, even the storage medium itself is of different size.

By the way, in later generations, small albums of a few songs released by artists were called EPs, which came from EP records. They contained more than one song, but they couldn’t hold too many.

Thinking about the situation in the future when he goes to other places to do business and a large frisbee is pulled out before he has even said a few words, Chief Engineer Chi feels a chill down his spine.

I can tolerate not having used the good ones, but once I’ve used them, there’s no going back.

His question is not completely unreasonable. In fact, the earliest floppy disk was 8 inches, which appeared in 71 and was later replaced by the 5.25 disk.

Gao Zhendong nodded: "Yes, so we don't do big things, we do small things!"

When the comrades from the Third Factory heard this, they became very excited. No wonder Chief Engineer Gao called us all over with just one phone call.

If we want to make a smaller one, we definitely need precise control over the magnetic head. As for precise control over moving parts, who among Mr. Gao’s people can compare to us?
The comrades at the Beijing Watch Factory were also full of confidence.

Originally, they were intimidated by the unfamiliar field of electronics and computers. They really didn't understand anything about it!
Now I understand clearly that what Professor Gao wants is his factory's technical expertise in small and micro transmission mechanisms. He is not bragging, there is no one in this city who can be better than him in this aspect. It is impossible, absolutely impossible.

As for the Haihe Watch Factory, isn't it the case that they are close to the water and get the moon first? Hehe.

I'm not good at electronics, and you're not good at small transmission mechanisms, which is just right.

Chief Engineer Chi looked at the people Gao Zhendong had assembled and realized that if these people cooperated and made a big move, it would be a slap in Gao Zhendong's face. He never had the habit of doing things halfway.

"Okay, Chief Engineer Gao, what do you think we need to do? What should it look like?"

Gao Zhendong started drawing on the blackboard. This is Gao Zhendong's traditional art.

"My idea is to make a disk with a diameter of 15 cm, put a plastic cover on the outside, and open the cover for reading data. The magnetic head moves over this opening."

Since we are the first to do it, let's forget about the sayings of "a few inches a few inches". We are broad-minded and use the International System of Units and its derivative units, which everyone can understand at a glance.

I won't tolerate the stupid behavior of the Citigroup guys, who not only use weird units but also divide the same unit into several types in different occasions. For example, ounces are divided into avoirdupois ounces and pharmacy (gold) troy ounces, and tons are divided into long tons and short tons. They have caused themselves a lot of trouble. In fact, at the root, this is a kind of knowledge monopoly behavior of the elite class.

A colleague from the Computing Institute asked, "Chief Engineer Gao, why don't you just control the head to access different areas of the disk? Wouldn't that save a set of rotating mechanisms?"

Before Gao Zhendong could speak, Chief Engineer Long from the Beijing Watch Factory laughed first: "Comrade, in that case, the disk rotation mechanism can be saved, but the head movement mechanism will be difficult to deal with. Mr. Gao is splitting the motion trajectory control on the two-dimensional surface into two one-dimensional motion controls, one rotation and one radial motion. Combining the two and leaving enough margin will make it much simpler."

Storage devices have been developed for decades, from floppy disks and hard disks to optical disks, and the motion control of the reading and writing mechanisms has been based on this set of principles, which is not without reason.

The exception is magnetic tape, which does not require rotation + radial movement, and even the data cannot be read. It's just that its radial movement may be replaced by parallel reading by a row of magnetic heads.

Gao Zhendong was happy. It was good to have someone to speak for him. He didn't have to explain himself. He smiled and nodded, "Boss Long is right. This way, the movement control of the magnetic head will be much simpler. Moreover, this cover can protect the disk surface very well. The disk is much more delicate than a record."

(End of this chapter)