Chapter 765

When Lisa came the day before yesterday, she helped Qiu Xiaojun to complete the work of making the computer sound. At the same time, she also completed the background music supporting the startup. Therefore, Ni Gong still respected Lisa and discussed with Lisa patiently and calmly. Without their hard disk, our computer is a waste. It can't give full play to its powerful performance. If it is equipped with the hard disk of commercial machine, the cost and volume can't be accepted.

"We set up our own hard drive R & D department, and we began to develop hard drives ourselves. We must not be controlled by others," Lisa said.

Lisa is a capable female entrepreneur. She immediately proposed to develop such a company by herself. Such a company can't cooperate in the future, but to crush it!

Others don't know. Lisa knows. Relying on the system in Qin Guan's brain, in this world, only other companies look at his face. It's absolutely impossible to tell him what to do and pinch his neck at any time.

There's no way to break through the hard disk. Let's just build our own hard disk!

"It's not easy," said Ni Gong. "Even if we immediately organize the R & D team, because we don't have any technical reserves, I'm afraid it will take a long time to break through, and our computers can't wait that long."

Delaying delivery as soon as it is listed will cause a lot of negative effects, especially if it sells at such a high price. If it can't enjoy satisfactory service, its own brand will be ruined.

Han did not have any hard disk technology reserves. Even Qin Guan exchanged production equipment, and there were no skilled operators. It must take time.

Lisa smiled. "During this time, we started the emergency plan and found a substitute for their hard disk."

succedaneum? What else can replace it? Even Ni Gong is very puzzled.

"Mr. Qin, please tell us." at this time, Lisa saw Qin Guan coming in and immediately gave up her voice to Qin Guan.

Others may not think of it, but Qin Guan can think of it.

"Our alternative is to use CDs," Qin said.

Lisa, who can get in touch with her brain at any time, will naturally know her alternative. Yes, it's a CD!

In later generations, optical discs have been popular for a long time until the rise of solid-state storage technology, that is, SSD hard disk. When the large-capacity USB flash disk has exceeded the capacity of optical discs, optical discs gradually decline and become history like tape.

Compared with the tape can only be pulled out to play, the CD can at least be used as a mirror and block the license plate, which is slightly more useful than the tape.

But now, CD-ROM is definitely a rising sun.

The emergence of CD, just like the invention of paper, has greatly promoted the progress of human civilization. It records the development history of human civilization and created a number of emerging industries.

From the perspective of information storage, optical disc can be regarded as a new type of paper. A small plastic disc, with a diameter of 12 cm and a weight of 20 grams, has a storage capacity of more than 600 megabytes.

Yes, it's more than 600 megabytes. Compared with the current hard disk with only a few megabytes of capacity, the capacity of optical disk is quite huge. The hard disk reads the contents on the disk through the magnetic head, while the optical disk is similar to it, except that the writing and reading of information are realized by laser.

After the laser is focused, a beam with a diameter of about 1 micron can be obtained. Just as the stylus of a compact disc is placed on the disc, this laser beam is the stylus. Therefore, the first application field of a compact disc is sound.

Philips researchers were the first to use laser beams to record and replay information. By 1972, their research was successful and put on the market in 1978.

This is the laser vision disc (LD) system. Also known as LD laser disc, this disc has a large diameter of 12 inches and can record information on both sides. In fact, it is a replica of the record. Moreover, the signal it records is an analog signal.

Analog signals are continuous signals, while computers use digital signals, which are represented by 0 and 1.

This product of Philip company has come out and achieved success, but it is a pity that there is no unified standard, which makes its development and production fall into expensive capital investment from the beginning.

After all, when this device comes out, there must be a record. The record distribution companies think it's too troublesome for anyone to use.

Until 1982, Philips and Sony developed the Red Book Standard of CD-DA compact disc. It first digitizes the analog audio signal by PCM (pulse code modulation), and then records it on the disc after EFM coding.

This realizes the digitization and realizes the rapid development of this kind of record.

At the same time, this digital recording also realizes the data storage needs of the basic computer.

"Now, Philips has developed a laser video disc, but this system is expensive and can hardly be sold. Therefore, we can buy their product patents and carry out digital transformation ourselves. In less than a month, we should be able to complete the transfer, save our system on the CD, and install an optical drive on our computer, Enable CD startup. "

A boot disk can start the computer and integrate all kinds of software. Just like the installers in the computer city of later generations, a CD goes all over the world.

This is completely a digital revolution.

Of course, there are still many problems to be solved.

This kind of disk can only be read and cannot be written, so as long as it is equipped with a floppy drive. The required data is installed on the floppy disk, which is the same as the later USB flash disk. At the same time, this kind of optical disk also needs digital transformation.

"There are two important problems. One is to establish a data structure of a disk suitable for computer reading and writing; the second is to reduce the bit error rate."

Qin Guan only knew what was inside, but Lisa took Qin Guan's words and continued: "I think we can express 0 and 1 by the depression of the disc. At the same time, the data on the disc is organized in the form of data blocks, and each block must have an address. After doing so, the data on the disc can be quickly found from the storage space of hundreds of megabytes. In order to reduce the bit error rate, an error detection and error correction scheme is added. The error detection adopts cyclic redundancy Residual detection code, the so-called CRC. "

What Lisa said was more professional, and Ni Gong's eyes slowly lit up.

There is no way for the other party to stick his neck on the hard disk. Once this system is available, the hard disk will become a chicken rib. Unless the hard disk can reach a capacity of hundreds of megabytes, it can't be compared with the optical disk at all!

This new Lisa is so capable!