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

Li Zetian thought about giving Seagate a wake-up call and asking them to develop reluctance head technology. The benefits of magnetoresistance were discovered more than 100 years ago, but the rate of change of magnetoresistance of the material is too small to be used in practice. Now, vacuum technology has improved the purity of the material's magnetoresistive material, resulting in a higher rate of change of magnetoresistance, and the magnetoresistive effect is enough to be used in core memory, which can increase the capacity of the hard drive by more than 40%!

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

Seagate was originally a subsidiary of Apple Inc. under the leadership of Alain Shugart, the "father of disks", but the company was later split and spun off from Apple.

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

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

Alain Shugart invited Li Zetian to the office, and after the two sat down, Alain Shugart said: "Mr. Shugart · Li, what are you going to drink?"

"A glass of water will do. Li Zetian smiled.

Alan Shugart beckoned the secretary to pour a glass of water, and immediately turned his head to look at Li Zetian, "Mr. Li, you must have something very important coming this time, right?"

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

Alain Shugart shook his head.

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

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

After listening to what Li Zetian said, Alain Shugat's eyes lit up.

"Why didn't I think of using the magnetoresistive effect!!" Alan Shugart looked at Li Zetian and couldn't help but say, "Mr· Li, although you are not a hardware developer, your vision is really shocking, which is really admirable! If Seagate can develop the MR technology of the magnetoresistive barb, it will definitely be able to greatly increase the storage capacity of the hard disk and make the hard disk smaller!"

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

It's not just a big deal, it's a milestone in the field of hard drive development!!

Alain Shugart knew that if the reluctance head MR technology could be developed, Seagate would dominate the hard drive market!

"By the way, Alan Shugart, Seagate is still working on DVDs, right?"

Li Zetian asked, since the completion of the CD development, he had mentioned to Alain Shugart to develop a DVD.

"Yes, Mr. Li, Seagate is also working on a DVD, but it won't be done anytime soon. First, we must improve video coding technology, and second, we must improve hardware. ”

"In terms of video encoding, MPEG-1 has emerged, which is a customized video and audio compression format for CD media, but DVDs and CDs are in the same vein, so they can also be used for DVDs. A 70-minute CD disc has a transfer rate of about 1.4 Mbps, and MPEG-1 is optimized for a 1.2 Mbps transfer rate using block-based motion compensation, discrete cosine transform (DCT), quantization, and other techniques. ”

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

"Do you want to develop a VCD now?"

Li Zetian suddenly fell into deep thought, the resolution of the VCD is only about 352×240, and it uses a fixed bit rate, so when playing fast-action videos, due to the insufficient amount of data, the macro block cannot be fully adjusted during compression, resulting in blurry squares in the video screen. In addition, the output quality of MPEG-1 is about the same as that of traditional VCRs, which is why VCDs have not been successful in developed countries. However, developing countries, such as China, are in need. It's just that China is not very rich now, and the people who can afford to buy a TV are only a minority, let alone buy a VCD......

"Let's take a break!"

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

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

"Okay, Mr. "There are three layers of MPEG-1 audio, namely MPEG-1 Layer 1, MPEG1 Layer 2 and MPEG-1 Layer 3, and the upper layer is compatible with the lower layer, and the third layer protocol is called MPEG-1 Layer 3......"

Alain Shugart introduced the differences between these three layers and their main uses to Li Zetian in great detail.

Li Zetian's expression moved, isn't the third layer protocol of MPEG-1 MP3? After CD-alkman, MP3 can be developed to replace it. However, the current MPEG-1 technology is certainly not perfect.

"That's pretty much the case for video encoding, and for hard drives, our initial idea was to develop single-sided, double-layered, high-density multimedia CDs. ”

When Li Zetian heard this, he was slightly stunned, a single CD is not good, then the number will be made up, this is too perfunctory!

"Is this possible?" asked Li Zetian a little unconvinced.

"It should work!" said Alain Shugart, confidently.

However, Li Zetian still shook his head in his heart, feeling that Seagate still lacks foundation, especially in the field of laser technology, and Sony, Toshiba, Panasonic and other Japanese companies are a little behind.

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

Alan Shugart thought about it seriously and nodded, "Your suggestion, we will focus on it!"

"Well, that's good!"

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

After walking out of Seagate, Li Zetian thought to himself, Seagate seems to be unable to go it alone, and must work with other companies to produce DVD standards...... In the previous life, the most popular were Blu-ray discs, 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 people check which company is now at the world's top level in the laser field!!"

"Okay!"