Chapter 639: I will take the lead on this matter
Hey, that makes sense. If the data is fully accessed, then this protection will not be possible. Chief Engineer Gao has even considered this detail in advance.
It seems that the legend says that he is not only profound in theory, but also has extremely rich and thoughtful practical application experience. It is indeed true.
Seeing that everyone has a concept of this, Gao Zhendong said: "Let me talk about my design of the disk storage structure. First of all, the storage disk and reading mechanism of this storage device are separated from the magnetic tape. Same.”
Gao Zhendong also considered the hard disk problem, but carefully Think about it, before there were giant magnetoresistive heads, the storage density of hard disks was not very high. Even with sealed disks, rigid disks, and high-speed rotation, its core demand in this era - storage density is still the same as openness. There is no essential difference between conventional disks and the capacity can only be increased by stacking the number of platters.
In this way, the significance of the hard disk is not very prominent for the time being.
These days, computers themselves are not very fast. The main contradiction between storage devices and computer performance is capacity. With limited resources, Gao Zhendong had no choice but to focus on the main contradiction.
In addition, another major contradiction is cost. In this regard, open removable disks are much superior to closed disks. The cost of the reading mechanism is one-time. For large capacities, all you need to do is produce disks, which is very cheap, and every penny is spent on capacity expansion.
Hard disks, or external storage devices with large capacity, density and speed, Gao Zhendong is ready to put them aside for the time being.
No one has any objection to Gao Zhendong's idea. In this regard, there is no one who can think more carefully than him, and that's all in the world.
Seeing that no one had any objections, Gao Zhendong drew a schematic diagram of the disk on the blackboard.
"The basic structure of the disk, I have just said that for the disk itself, my consideration is a flexible material, that is, plastic, the diameter of the inner hole is 2.5cm, and the outer ring is left open during actual reading. There is a certain amount of redundancy. The non-data storage area of the inner and outer rings occupies a total diameter of 3cm, leaving a ring with a width of 6cm for data storage. "
Gao Zhendong said very clearly, and matched the picture on the blackboard, everything No one interrupted him because he heard clearly.
"I am going to divide these 6cm into 20 circles, that is, 20 tracks..." Gao Zhendong drew some circles in the rings on the picture.
"Each track is divided into 9 sectors..." He used line segments to divide one of the circles into many segments.
"Each sector is 512 bytes..." He enclosed one of the paragraphs in curly braces and wrote "512Byte".
Chief Engineer Chi has finished the calculation and will answer the question.
“90 kilobytes!”
Gao Zhendong nodded: “Yes, 90kB. This capacity is sufficient for most existing applications.”
Actually, this is not the theoretical limit capacity, but the formatted capacity planned by Gao Zhendong is this large. In actual operation, redundancy is required, and these will occupy physical space.
The software at this time is not that rich in functions, and there are no other messy things at all. It basically only serves the core target functions, so this capacity is completely sufficient.
Originally, it could be made double-sided, but Gao Zhendong considered minimizing the complexity of the first milestone product, increasing the success rate, and speeding up the development of equipment, so he simply put the double-sided back and made Just one side is fine.
The core of this thing is whether it exists or not. As for one-sided and double-sided, just leave it to the comrades to improve.
Single-sided is enough. Later generations of 5.25-inch single-sided low-density disks have a capacity of 180k. There is only one difference from Gao Zhendong's design - it has 40 tracks.
The two are actually about the same size, but Gao Zhendong took into account the mechanical precision issues brought about by the different times and reduced the track density.
Others can't get involved in this topic because they don't understand it at all, but Chief Engineer Chi and the others have no problem.
The comrades in the computing center simulated, calculated, and thought in their heads for a while, and they all expressed emotions similar to those of Bill Gates in later generations.
“90kB, this capacity is so large.”
“It can’t be used up, it really can’t be used up!”
“For individual users, 90kB is really too big Too big.”
"That's enough, that's enough."
"..."
Looking at them, Gao Zhendong's cheeks twitched. It's hard for him to complain about you, not to mention anything else. Maintaining a high degree of consistency with the goalkeeper.
I had to smile and say: "This capacity is enough for the time being, use it first." What they are considering is the issue of capacity, but the comrades in charge of other parts have many things to consider.
A group of old masters from the No. 3 Factory had been discussing among themselves for a while, and now they also expressed their opinions.
"General Engineer Gao, we have calculated that this is equivalent to dividing 60 mm into 20 strips, each strip is 3 mm. We don't know whether other things support it, but here, purely mechanical In terms of direction, this width is too large and a bit wasteful. ”
Having worked together for a long time, they knew that Gao Zhendong was very attentive to correct opinions and was very willing to listen to them. There was no point in his face that would prevent him from stepping down. He was very happy, so he pointed it out directly. In their opinion, there are unreasonable things in Gao Zhendong’s design.
Gao Zhendong is very happy. He designed 20 tracks to leave enough redundancy and reduce the difficulty of research and development. As long as it can be increased, he is happy with it.
“How much can it be increased to?”
"It's hard to say. There are strict size restrictions on this thing. The photoelectric encoder and transmission mechanism we have are a bit large. It is impossible to achieve the accuracy of some equipment, but 3 mm is definitely too big."
< br>The accuracy of some equipment naturally refers to the workpiece stage of the photolithography machine. That one is only a few microns, which is 1,000 times lower than this one!
Gao Zhendong said: "Photoelectric encoders are 1cm in size, and of course the accuracy is quite different. As for the small transmission mechanism, there are comrades from the Beijing Watch Factory here who can provide help."
< br>Mr. Long from the Beijing Watch Factory smiled and said: “The transmission we made The mechanism is small in size, but its strength is also small. It needs to be appropriately enlarged to increase the transmission dynamics. However, I estimated that the problem is not big. It is relatively simple for us to work from small to large.”
As the top in this area, Long always has their own pride.
“The only problem is that we don’t have the appropriate testing equipment to check whether the control results are in place.”
For watches, the balance spring is both a driver and a benchmark, which determines the movement status of the watch hands and how long it takes. Every time you run, no matter how much you run, it all depends on the hairspring.
But the hairspring pendulum cannot be used in this device, there is no doubt about it.
Mr. Long is not in this business, so his words are different, but everyone understands the meaning.
When the old technicians of the third factory heard this, they laughed: "Mr. Long, that photoelectric encoder that Mr. Gao just mentioned is used for this purpose. With a suitable deceleration mechanism, that thing can compare Accurately measure the movement. As long as you can fix the small transmission mechanism, leave the rest of the processing and other issues to us. ”
Mr. Long felt relieved: "That's easy to handle, that's easy to handle."
At this time, a master raised another question: "Mr. Gao, it's easy to separate lanes. But one lap is divided into at least 9*512 segments, which is almost 5,000. This requirement is a bit high. , in such a small space, there may be some difficulties, especially in the inner circle. ”
In order to reduce the control complexity, the sector division of the floppy disk is actually based on the angle, not the arc length, that is. From the inside to the outside, there are the same number of sectors, with different sector lengths, and the inner circle is the shortest.
Speaking of this, Chief Engineer Chi is not sleepy anymore.
“This is not a big problem. Master, the control of the sector is actually controlled by the switching operation of the magnetic head. It is determined by the read and write operation speed of the magnetic head and the switching speed behind it. That speed is absolutely sufficient. Yes, just leave this problem to us. There is no need to spend too much money on the mechanical part. The mechanical part only needs to ensure that the disk rotates at a constant speed.”
The old master nodded, that's no problem.
Only then did the comrades of the computing center realize the reason why Gao Zhendong divided the magnetic head control into two channels for separate control. Each performs its own duties, giving full play to the advantages of mechanics and electronics. Together, they use as simple a system as possible. Solutions solve problems.
Admire, admire!
Seeing this scene, Gao Zhendong was happier than anyone else. Comrades from different units and different positions worked together, brainstormed, divided work and cooperated, and soon considered the implementation plan for a new equipment to be very similar. This is the result he most wants to see.
He smiled and said: "Very good, it seems that this problem is not a big problem. The 3 mm track spacing is the result of me leaving enough redundancy to minimize the difficulty of research and development. During the research process, It can be adjusted according to the actual situation. In principle, it can only be reduced, not increased. Of course, you still have to consider the condition of the magnetic head. The width required for the magnetic head operation is also a decisive condition. If possible, reduce it as much as possible. Reduce, but first ensure availability and reliability.”
Everyone responded one after another, gearing up one by one, and made up their minds to do this well.
Everyone discussed the details for a long time, and finally the issues regarding the 15cm disk drive and the disk were roughly the same.
Gao Zhendong finally concluded: "I will take the lead on this matter. Mr. Chi, you have more experience in this area. I will leave the preliminary work to you."
For computer peripherals, Gao Zhendong broke from the habit of being the shopkeeper of JP-59, XS-59, and DY-60 and took charge personally. It was not because he had so many ideas about this thing that he was reluctant to give it to others.
But there are too many units involved in this matter, and later even the Audio and Video Corporation and the Haihekou Phonograph Factory will get involved due to magnetic heads and platters.
If he doesn't take the lead personally, others may not be able to control the situation, and it will be ugly then.
A wise man will not do it if a good thing turns into a bad thing.
(End of this chapter)