giants of the era

Chapter 295 DVD Development
Hard drives are very important storage devices, not only used in personal computers, but also in various industries.

Li Zetian thought about planning to remind Seagate and let them develop magnetoresistive head technology.The magnetoresistance benefit was discovered more than 100 years ago, but it has not been practically applied because the magnetoresistance change rate of the material is too small.Right now, vacuum technology has improved the purity of the magnetoresistance material and obtained a higher magnetoresistance change rate. The magnetoresistance effect is enough to be used in magnetic core memory, which can increase the capacity of the hard disk by more than 40%!

After Li Zetian visited Mango Computer Company, he couldn't wait to go straight to Seagate Company.

Seagate was originally a subsidiary of Apple, headed by "Father of Disk" Alan Shugart, but later the company split up and became independent from Apple.

For Li Zetian's arrival, Alan Shugart was very surprised, because Li Zetian rarely came to Seagate.

A few years ago, when Seagate was developing CD technology, Li Zetian came once.

Alan Shugart invited Li Zetian to the office. After the two sat down, Alan Shugart said, "Mr. Li, what do you want to drink?"

"A glass of water is enough." Li Zetian smiled.

Alan Shugart called the secretary to pour a glass of water, and then turned to look at Li Zetian, "Mr. Li, you must have something important to do here this time, right?"

"That's right!" Li Zetian nodded and said, "Alan Shugart, I want to know, is Seagate researching magnetoresistive head technology?"

Alan Shugart shook his head.

Li Zetian thought to himself, sure enough, Seagate in the previous life also had the "father of disks" in charge, but the early hard disk leader was always IBM.

"Then you might as well study the MR technology of the magnetoresistive head! As we all know, based on the magnetoresistance effect, its resistance changes with the change of the magnetic field. If the magnetoresistive element is connected to a very sensitive amplifier, the tiny resistance can be measured Change, and the data on the disc can be read by using the resistance value to change with the magnetic field, so that higher storage density can be achieved!"

After hearing what Li Zetian said, Alan Shugart's eyes lit up.

"Why didn't I think of using the magnetoresistance effect!!!" Alan Shugart looked at Li Zetian and couldn't help but said, "Mr. Li, although you are not a hardware developer, your vision is really shocking. People admire it! If Seagate can develop the magneto-resistive thorn head MR technology, it will greatly increase the storage capacity of the hard disk and make the hard disk smaller!"

Li Zetian smiled faintly, and said: "I read a scientific literature on the magnetoresistance effect a few days ago, and suddenly thought that if the magnetoresistance effect is applied to the hard disk, it should be very promising!"

Not only is it promising, it is simply a milestone in the field of hard disk development! ! !
Alan Shugart knows very well that if the MR technology of magnetoresistive heads can be developed, Seagate will dominate the hard disk market!
"By the way, Alan Shugart, Seagate is still developing DVDs, isn't it?"

Li Zetian asked, since the development of CD was completed, he had mentioned to Alan Shugart to develop DVD.

"Yes, Mr. Li, Seagate is also developing DVD, but it can't be completed in a short time. First, we need to improve video encoding technology, and second, we need to improve hardware."

"In terms of video coding technology, MPEG-1 has emerged, which is a video and audio compression format customized for CD disc media. However, DVD and CD are in the same line, and can naturally be applied to DVD. The transmission rate of a 70-minute CD disc is about 1.4 Mbps, MPEG-1 adopts block-based motion compensation, discrete cosine transform (DCT), quantization and other technologies to optimize the transmission rate of 1.4Mbps."

Li Zetian nodded, knowing that MPEG-1 was adopted as the core technology of Video CD, that is, the core technology of VCD.With the current technical conditions, it is completely possible to make VCD.

"Do you want to develop VCD now?"

Li Zetian suddenly fell into contemplation. The resolution of VCD is only about 352×240, and it uses a fixed bit rate. Therefore, when playing fast-moving videos, due to insufficient data, the macroblocks cannot be fully adjusted during compression. Blurred squares appear.In addition, the output quality of MPEG-1 is about the same as that of a traditional video recorder VCR, which is why VCD has not been successful in developed countries.However, developing countries, such as China, are in great need.It's just that China is not very rich now, and there are only a few people who can afford a TV, let alone a VCD...

"Let's take it easy!"

Li Zetian shook his head secretly, then looked up at Alan Shugart, and said, "Alan Shugart, please continue."

Just now, Alan Shugart stopped when he saw Li Zetian lost in thought.

"Okay, Mr. Li," Alan Shugart continued, "MPEG-1 audio is divided into three layers, namely MPEG-1 Layer1, MPEG1 Layer2 and MPEG-1 Layer3, and the high layer is compatible with the low layer. The layer protocol is called MPEG-1 Layer3..."

Alan Shugart introduced the differences and main uses of these three layers to Li Zetian in great detail.

Li Zetian's expression changed, isn't the third layer protocol of MPEG-1 just MP3? After CD-Walkman, MP3 can be developed to replace it.However, MPEG-1 technology is definitely not perfect at the moment.

"Video encoding is almost like this. In terms of hardware, our initial idea is to develop a single-sided, double-layer high-density multimedia CD."

Li Zetian was slightly taken aback when he heard the words, a single CD is not enough, so the quantity should be combined, this is too perfunctory!
"Is this feasible?" Li Zetian asked a little uncertainly.

"It should work!" Alan Shugart replied confidently.

However, Li Zetian still has no idea. He feels that Seagate still lacks foundation, especially in the field of laser technology, which is a bit behind Sony, Toshiba, Panasonic and other RB companies.

"Alan Shugart, I think it may be more promising to use laser technology to accommodate more capacity in the same recording area!" Li Zetian suggested.

Alan Shugart thought about it seriously, then nodded, "We will seriously consider your suggestion!"

"Ah That's good!"

Li Zetian took a sip of water, then stood up and said goodbye to Alan Shugart.

After leaving Seagate, Li Zetian thought to himself, Seagate seems to be unable to fight alone, and must cooperate with other companies to produce DVD standards. What kind of single-sided double-layer high-density multimedia CD sounds very worrying... Blu-ray discs were the most popular in the previous life, this is the direction of DVD development!
After getting into the car, Li Zetian said to Dongfang Yuqin who was sitting on the side: "Let me find out which company is currently the world's top level in the laser field!!"

"Ok!"

(End of this chapter)