Optical drive

Introduction

The CD-ROM drive is a CD-ROM drive, and the carrier carrying data and information is called a CD-ROM. The one that reads or writes data to or from an optical disc is called an optical drive.

The characteristics of optical discs are: large capacity, low cost, good stability, long service life, and easy to carry.

Optical drive is a product that combines optical, mechanical and electronic technologies. In terms of the combination of optics and electronics, the laser light source comes from a laser diode, which can generate a beam with a wavelength of about 0.54-0.68 microns. After processing, the beam is more concentrated and can be accurately controlled. The beam is first hit on the optical disc, and then reflected by the optical disc. , The signal is captured by the photodetector.

There are two states on an optical disc, namely pits and blanks. Their reflected signals are opposite, which can be easily identified by the photodetector.

Internal structure

(1) Laser head components: including photoelectric cells, focusing lens and other components, cooperate with mechanical components such as gear mechanism and guide rails, according to the system The signal determines, reads the disc data and transmits the data to the system through the data belt.

(2) Spindle motor: the driving force for the operation of the optical disc, which provides fast data positioning function during the high-speed operation of the optical disc reading process.

(3) Disc tray: the disc carrier in the open and closed state.

(4) Start mechanism: control the in and out of the disc tray and the start of the spindle motor. When the power is on, the start mechanism will make the servo mechanism including the spindle motor and the laser head assembly in a half-loaded state .

Working principle

The laser head is the heart of the optical drive and the most precise part. It is mainly responsible for reading data, so be careful when cleaning the inside of the optical drive.

The laser head mainly includes: laser generator (also called laser diode), semi-reflective prism, objective lens, lens and photodiode. When the laser head reads the data on the disc, the laser light emitted from the laser generator passes through the semi-reflective prism and converges on the objective lens. The objective lens focuses the laser light into an extremely small spot and hits the optical disc. At this time, the reflective material on the disc will reflect the irradiated light back, pass through the objective lens, and then irradiate the semi-reflective prism.

At this time, because the prism is a semi-reflective structure, the beam will not completely penetrate it and return to the laser generator, but will be reflected, pass through the lens, and reach the photodiode. Since the surface of the optical disc is used to record data with bumps, the reflected light will shoot in different directions. People define the signals directed in different directions as "0" or "1". The light-emitting diodes receive the data arranged in "0" and "1", and finally parse them into the data we need. In the entire process of reading data by the laser head, tracking and focusing directly affect the error correction capability and stability of the optical drive. Tracking is to keep the laser head always correctly aligned to the track on which the data is recorded.

When the laser beam coincides with the track, the tracking error signal is 0, otherwise the tracking signal may be positive or negative, and the laser head will adjust the attitude appropriately according to the tracking signal. If the tracking performance of the CD-ROM drive is very poor, there will be errors in reading data when reading the disc. The most typical phenomenon is the sound skipping when reading the audio track. The so-called focusing means that the laser head can accurately hit the beam onto the disc and receive the strongest signal.

When the laser beam is reflected from the disc, it will hit 4 photodiodes at the same time. They superimpose the signals and finally form a focus signal. Only when the focus is accurate, this signal is 0, otherwise, it will send out a signal to correct the position of the laser head. Focusing and seeking are the two most important performances when the laser head is working. What we call a good CD-ROM drive is a product with excellent performance in these two aspects.

Moreover, the focus and seek of the optical drive are largely related to the disc itself. At present, whether it is a genuine disc or a pirated disc on the market, there will be varying degrees of center point deviation and uneven distribution of optical medium density. When the disc rotates at a high speed, the disc vibrates strongly, which not only makes the disc drive produce wind noise, but also forces the laser head to repeatedly focus and track adjustment at the corresponding frequency, which seriously affects the disc reading effect and service life of the disc drive. In the 36X-44X optical drive products, the all-steel movement technology is generally adopted, and energy transfer is realized through the suspension of heavy objects.

However, in the face of high-speed products with tens of thousands of revolutions per minute, the all-steel movement technology seems a little powerless, and the market has launched an optical drive product with ABS technology as the core. ABS technology mainly uses a pair of steel ball bearings under the disc tray. When the disc vibrates, the steel ball will roll to the lighter part to fill up under the action of centrifugal force to achieve an instant balance and improve the performance of the optical drive. .

Performance indicators

Maybe many readers think that the faster the optical drive, the higher its performance. In fact, the speed of the optical drive only refers to the speed of its driving motor, and to truly measure its performance, it depends on the performance of the following indicators.

Transfer rate

The data transfer rate (Sustained Data Transfer Rate) is the most basic performance index of the CD-ROM drive, which directly determines the data transfer speed of the CD-ROM drive, usually in KB /s to calculate. The data transfer rate of the first CD-ROM was only 150KB/s. At that time, the relevant international organizations set the rate as single speed, and the speed of the optical drive that appeared later was a multiplier relationship with the single speed standard. For example, for a 2x speed optical drive, its data The transmission rate is 300KB/s, the 4x speed is 600KB/s, the 8x speed is 1200KB/s, the transmission rate at 12x speed has reached 1800KB/s, and so on. CD-ROM mainly has CLV (constant linear velocity), CAv (constant angular velocity) and P-CAV (local constant angular velocity) three types of disc reading methods.

Among them, CLv technology (Constant Linem Velocity, constant linear velocity) is a technology commonly used by optical drives below 12 times speed. CLV technology means that the track arc length read in unit time is equal in the process of moving from the inner track (inner circle) of the disc to the outer track. Since the radius of the inner ring of the CD disc is smaller than the outer ring, the rotation speed of the detection head when it is close to the inner ring is naturally faster than when it is close to the outer ring. Only in this way can the data transmission rate remain unchanged.

CAV technology (Constant Angular Velocity) is a commonly used technology for optical drives above 20 times speed. The characteristic of CAV technology is to keep the rotation speed constant, and its data transmission rate is variable. That is, when the detection optical head reads the data of the inner ring and outer ring of the disc, the data transmission rate will change accordingly. For example, a 20 times speed product may only have 10 times speed in the inner ring, and the data transmission rate gradually increases as the outer ring moves, until it can reach 20 times speed in the outer ring.

P-CAV technology (Partial CAV: Local Constant Angular Velocity) is a technology that combines the essence of CLV and CAV. When the detection optical head reads the inner ring data of the disc, the rotation speed remains unchanged, so that the data transmission rate can be increased; and when the detection optical head reads the outer ring data, the rotation speed is increased.

CPU occupancy time

CPU occupancy time (CPIU Loading) refers to the time that the CD-ROM drive maintains a certain speed and data transfer rate while occupying the CPU. This indicator is an important indicator to measure the performance of the optical drive. In a sense, the CPU occupancy rate can reflect the BIOS writing ability of the optical drive. Excellent products can minimize the CPU occupancy rate. This is actually a software algorithm problem for writing BIOS. Of course, this can only be reflected on better quality discs. If you encounter some very worn CDs, the CPU usage will naturally rise. If users want to save time, they must choose those CD drives that have a stronger ability to read "severely worn CDs" and lower CPu usage. It can be seen from the test data that the difference between the best and the worst scores will not exceed two percentage points when reading a disc with better quality, but the gap will increase when reading a disc with poor quality.

Cache

This indicator is usually expressed by Cache, and some manufacturers use Buffer Memory. Its capacity directly affects the operating speed of the optical drive. Its function is to provide a data buffer, which first temporarily stores the read data, and then transmits it at one time. The purpose is to solve the problem of disc drive speed mismatch.

Average Access Time

Average Access Time (Average Access Time) is the "average seek time", as a standard to measure the performance of the optical drive, refers to the detection of optical head positioning to start reading The time required for this process of disk, the unit is ms, and this parameter is related to the data transmission rate.

Fault tolerance

Although the current data reading technology of high-speed optical drives has matured, there are still some products in order to improve the fault tolerance performance by increasing the laser head emission power. To achieve the purpose of error correction, the biggest drawback of this method is to artificially cause premature aging of the laser head and reduce the service life of the product.

Stability

Stability refers to the ability of an optical drive to maintain a stable and better read capacity for a long period of time (at least one year)

Reading speed

It is worth noting that the speed of the optical drive is the nominal fastest speed. This value refers to the fastest speed of the optical drive when reading the outermost circle of the disc. The speed when reading the inner circle is lower than the nominal value, about 24X. Nowadays, many optical drive products adopt a stepwise automatic deceleration method when encountering eccentric discs and low-reflection discs, that is to say, from 48X to 32X to 24X/16X, this passive deceleration method seriously affects the service life of the spindle motor. In addition, the buffer size and addressability also play a very important role. At present, the maximum CD reading speed that can be achieved by CD-ROM is 56 times; the speed of DVD-ROM reading CD-ROM is slightly lower. There are relatively few products that reach 52 times, most of which are 48 times; COMBO products are basically Both reached 52 times the speed. The author believes that, in terms of the current software application level, the requirements for the speed of the optical drive are not very harsh, and the 48X optical drive product can fully meet the needs of use within a period of time. Because there is no software that requires CD-ROM products above 32X to be used for installation. In addition, CD-ROM as a data storage medium, the usage rate is much lower than that of hard disks. No one will install WIN98 on the CD and run it? The transmission speed of single speed CD is 150kB/s, DVD is 1350kB/s. Blu-ray disc is 36Mbps.

The speed of the CD-ROM drive is expressed by X "speed", which is relative to the first-generation CD-ROM drive. For example, the 40X optical drive is 40 times faster than the first-generation optical drive. The speed of the first-generation optical drive is approximately 150KB/S, and the speed of the 40X optical drive is approximately 6000KB/S. There are two types of optical drives in different ways to nominal speed, the most common is the "MAX" optical drive. For example, a CD-ROM drive called 40XMAX means that the CD-ROM drive can rotate at a maximum speed of 6000KB/S. However, "maximum" only refers to the outermost part of the CD, and the innermost part of the CD is usually only 12X. In general, the average speed is much lower than the nominal speed, especially when a CD is not completely written. When it is full and the outermost part is not used. Another more expensive type of optical drive is "TRUE X". This optical drive is characterized by a unique laser pickup system that can achieve the same transmission rate no matter where the information is placed on the CD. Therefore, for the same speed optical drive, "TRUE X" is much faster than "MAX". Of course, the price of "TRUE X" is also more expensive.

Fault tolerance

Compared with the speed of reading the disk, the fault tolerance of the optical drive is more important. In other words, stable disk reading performance is the prerequisite for pursuing disk reading speed. Since the optical disc is a removable storage device, and the surface of the disc is not protected, it is inevitable that there will be scratches or contamination with impurities. These small defects will affect the reading of data. In order to improve the readability of the optical drive, manufacturers offer suggestions, among which "artificial intelligence error correction (AIEC)" is a relatively mature technology. AIEC has passed the sampling test of tens of thousands of optical discs, "recorded" the reading strategy suitable for them, and saved it in the BIOS chip of the optical drive. In order to facilitate the selection of automatic disk reading strategies for eccentric disks, low-reflective disks, and scratched disks. Since the characteristics of optical discs are very different, a few optical drive products currently on the market also use rewritable BIOS technology, which enables DIYers to modify the BIOS in real-time in the current way. Therefore, the adoption of Flash BIOS technology has an impact on the overall performance of optical drives. The improvement played a huge role.

In addition, some optical drives increase the power of the laser head in order to improve fault tolerance. When the power of the optical head increases, the ability to read the disk is indeed improved, but long-term "overclocking" use will cause the optical head to age, which will seriously affect the life of the optical drive. Some CD-ROM drives showed a decline in their reading ability after only three months of use. This is likely to be the result of the aging of the bald head. This method of sacrificing lifespan in exchange for fault tolerance is undesirable. So, how to tell whether the optical drive you bought is "overclocked"? At the time of purchase, you can let the CD-ROM drive read a disc of lower quality. If the surface temperature is very high after the disc is ejected, or even hot, it may be "overclocked". However, it cannot be ruled out that it is the result of the high heat generation of the optical drive spindle motor.

Development history

The first generation

Standard type

The reason why the first generation optical drive is called The standard type is because the first-generation optical drive developed many standards for optical drives, and they are still in use today. For example, the capacity of an optical disc is 640Mb (the author here refers to the traditional CD-ROM), and the data transfer rate of the optical drive is 150KB/ S, this standard also established the unique name of the optical drive of several times speed. For example, the transmission speed of a 40 times speed optical drive is 150KB/S*40=6000KB/S. The author happens to have some historical data from that time at hand, let us review it again.

In 1991, the Multimedia PC Working Group of the Software-Publishers-Association joined by 1500 software vendors around the world announced the first-generation MPC (Multimedia-Personal-Computer) specifications, which drove the development of CD-ROM publications. Popular. The capacity of an optical disc is 640MB, the data transmission rate of the optical drive is 150KB/S (as a single-speed optical drive by the International Electronics Industry Federation), and the average search time is 1 second. As the market continues to demand, hardware technology continues to improve. In 1993, the second-generation MPC specification came out, the speed of the optical drive has become double speed, the transmission rate has reached 300KB/S, and the average search time is 400ms.

With an average seek time of 400ms, a transmission rate of 300KB/S, and a capacity of 640MB, we may think that the first-generation optical drive is too slow and the capacity is too small. But you should know that when the first generation of optical drives appeared, people still used floppy disks as the main mobile copy medium. They often used more than 10 disks to copy a software or game, and then it took 2, 30 minutes to load it into the machine. If one of the disks If there is a quality problem or a wrong copy, the whole effort will be wasted. At that time, hard disks were only 200MB or so, and 400MB hard disks could only be bought at 1700 or 1800. The author also clearly remembers that when I saw his newly bought optical drive at a friend's house for the first time, I felt that it was unlimited games and software, and it was quick and easy to install. Of course, I soon had my first optical drive, the only one available in Singapore, with a speed of more than 1,000 yuan.

The feature of the first generation of optical drives is that optical drives have just appeared, and many technical standards have been formulated for optical drives. As a substitute for data exchange between floppy drives and hard drives, the capacity has been increased, the speed has been increased, and the speed has been greatly improved. Efficiency. At that time, there were very few domestic brands, and some representative brands such as SONY, Philips and some Singapore brands.

The second generation

Speed-up

The second generation divided by the author mainly refers to the development of the optical drive from 4 speed to 24 speed (32 speed) This time period. Although the speed is also increasing in the later development from 32-speed to high-speed optical drives, more technical development goals are no longer on the speed, so it is classified as the next generation.

The CD-ROM drive has been developed for a period of time. Due to its great advantages over floppy disks, it has gradually become popular and has become the standard configuration during installation. Hundreds of MB of software and games have gradually increased. It’s a little better to install the software. Once you install it, you’ll be done. When you play games, you often need to retrieve data from the CD. At this time, the CD-ROM read speed is too slow and it gradually becomes obvious. Sometimes a game goes to the next level to read the data to read 2. , 3 minutes, especially when playing RPG games like Xianjian, you often have to shuttle between levels, playing for an hour requires 20 minutes to read the disc. Who can stand this, what should I do? Speed ​​up.

At this time, speed acceleration has also become the main goal of various manufacturers' technological development, and the speed has increased from 4x, 8x, to 24x, 32x. At this time, the supported formats of optical drives also developed. In the summer of 1995, the Multimdeia PC Working Group announced the third-generation specification standards. Compatible CD formats include: CD-Audio, CD-Mode1/2, CD-ROM/XA, photo-CD, CD-R, Video-CD, CD-I, etc.

At this time, my friend of the author changed an ACER 16-speed CD-ROM drive, and it really feels fast to use. I still remember that I liked to go to him when playing fairy swords, and watched the loading data bar "唰" After a while, I feel happy. But the speed is not all good, because the disc rotates too fast, the noise becomes larger, and the heat generation becomes larger. Of course, the problem of the product still needs to be solved by the development of technology, and the optical drive has also entered the third generation-development type.

The second-generation optical drive is characterized by the gradual popularity of optical drives, but the weakness of slow speed has also emerged. Increasing speed has become the primary goal of various manufacturers in technical competition. The formats supported by optical drives have gradually increased.

The mainstream in the market is still foreign brands, such as Toshiba, NEC, etc., there have been some domestic brands, except for acer, there is still no climate.

The third generation

Development type

The speed of the optical drive is further improved, and the problem of slow transmission speed has been well solved Solved, but the problems brought about by the speed increase gradually became apparent. High-speed rotation will produce vibration, noise and heat. Vibration will also make the laser head difficult to locate, lengthen the seek time, and easily collide with the laser head, scratching the laser head; the generated heat will affect the chemical medium on the disc. Affects the accurate positioning of the laser head and prolongs the seek time; the noise caused will make people mentally uncomfortable and easy to fatigue.

In response to these problems, various manufacturers have also introduced corresponding improved technologies: NEC company installs suspension damping rubber on the four corners; Acer company uses suspension technology and rubber damping brackets; Lite-on Adopting suspension bearing technology; Asus company adopts advanced dual dynamic suspension system...

At this stage, it is worth mentioning that many domestic manufacturers have developed, and they are well received by consumers with their perfect quality and low price. Favor and become the mainstream of the market.

The feature of the third generation is that speed is no longer the main goal of various manufacturers to develop technologies. Everyone has introduced new technologies to make the CD-ROM read more stable, with lower heat generation, quieter work, and longer life. . Domestic manufacturers have developed and become the mainstream of the market.

The market share of foreign brands and Taiwanese brands has decreased to a certain extent, and many domestic brands have risen, such as Omega\Yuanxing, Jaws, Mida and so on.

The fourth generation

Perfect Type

After several years of development, the technology of optical drive has become mature. Although the manufacturer's products may use slightly different technologies, the product quality is perfect, or even perfect, in terms of higher error correction rate, faster transmission speed, more stable operation, quieter, and lower heat generation. .

Maintenance

As everyone knows, the laser head is most afraid of dust. After many optical drives are used for a long time, the recognition rate decreases because there is too much dust, so do not leave the tray in normal times. Outside, don’t smoke around the computer. And when the optical drive is not used, try not to leave the optical disc in the drive, because the optical drive must maintain a "certain random access speed", so the disc will maintain a certain speed in it, which accelerates the aging of the motor (especially the plastic core The optical drive is more susceptible to damage). In addition, if the inferior disc is left close to the laser head when shutting down, the laser head will be easily scratched when the motor rotates.

The problem of heat dissipation is also very important. Be sure to pay attention to the computer’s ventilation conditions and ambient temperature. The placement of the chassis must ensure that the CD-ROM drive is kept in a horizontal position, otherwise the CD-ROM will be It is impossible to maintain the balance, it will cause fatal collision and damage to the laser head, and also fatal damage to the optical disc, so pay attention to the sound emitted when the optical drive is running. If there is a disc collision noise, please adjust the disc immediately. The location of the optical drive or chassis.

Trouble repair

Trouble phenomenon

When there is a problem with the optical drive, the indicator light of the optical drive generally flashes, cannot read the disk or reads the disk performance Down; the drive letter of the optical drive disappears. When the CD-ROM drive reads the disk, it has a blue screen of death or a prompt box such as "The CD cannot be accessed, the device is not ready" is displayed.

Improper connection

After the optical drive is installed, power-on self-test. If the optical drive cannot be detected, carefully check whether the optical drive cable is connected correctly and firmly, and whether the power supply line of the optical drive is plugged in. Good. If the screen stops when the self-checking of the optical drive is detected, check whether the jumper of the optical drive (master, slave) is correct (IDE optical drive).

Reminder: Try not to connect the optical drive and the hard drive to the same data line. (IDE CD-ROM drive)

Internal contact problems

If the CD-ROM drive is stuck and cannot be ejected, it may be that there is a problem with the contact between the internal parts of the CD-ROM drive. You can try the following methods to solve this problem. : Remove the optical drive from the chassis and use a Phillips screwdriver to disassemble, eject the optical drive tray through the emergency eject hole, so that you can remove the upper cover and front cover of the optical drive. After removing the top cover, you will see the movement of the optical drive. On the left or right side of the tray, there will be a belt with the end of the tray motor attached. You can check whether the belt is clean and whether it is misaligned, and you can also oil the belt and the end of the connected motor. In addition, there will be a row of serrations on both sides of the tray of the optical drive. This serration controls the ejection and retraction of the tray. Please oil this saw tooth and see if there is any malfunction such as misalignment. If it is oiled, wipe off the excess oil, then reinstall the CD-ROM drive, and finally try it out again.

Reminder: However, since this kind of maintenance is more professional, it is recommended that you find a professional to repair it.

CMOS problem

If the CD-ROM is found to stop or crash during the power-on self-check, it may be caused by the wrong working mode of the CD-ROM in the CMOS settings. Generally speaking, as long as all the IDE interfaces used are set to "AUTO", the working mode of the optical drive can be correctly identified. For some early motherboards or individual phenomena, settings are required.

Driver problem

In Windows system, when the motherboard driver is lost due to virus or misoperation, the IDE controller will not be correctly recognized by the system, which will cause the optical drive to malfunction. At this time, we only need to reinstall the motherboard driver.

In addition, when a CD-ROM drive has repeated driver or multiple installations and other misoperations, Windows will recognize multiple CD-ROM drives, which will cause a blue screen when Windows starts. We only need to enter the Windows safe mode (click "My Computer→Properties→CD-ROM") and delete the extra CD-ROM.

Does not support DMA

Early optical drives may not support DMA. You can turn off the DMA interface of the optical drive to avoid incompatibility. After completing the settings, press the "OK" button and restart the computer.

When the DMA interface optical drive is not compatible with the motherboard, DMA should also be turned off. If you really want to take advantage of the performance brought by the DMA of the optical drive, it is recommended to upgrade the BIOS of the motherboard or the firmware of the optical drive. In addition, after the optical drive has been used for a long time, the disc reading will become unstable. We can try to turn off DMA to reduce performance and improve stability.

Virtual CD-ROM conflict

When we install the CD-ROM, we usually install a virtual CD-ROM to use. However, after installing the virtual CD-ROM drive, it is sometimes found that the original physical CD-ROM drive is "lost". This is because there are too few available drive letters set by the hardware configuration file. Solution: Use the Notepad program that comes with Windows to open the "Config.sys" file in the root directory of the C drive, add "LASTDRIVE=Z", save and exit, and the problem can be solved after restarting.

After installing a lower version of the "virtual CD-ROM drive" with dual CD-ROM drives, in some cases, one or two physical CD-ROM drives will be "lost"! Suggestion: Change to a higher version or other virtual CD-ROM program.

Laser head aging

The cause of dust is excluded. If the optical drive cannot read the disk, it is likely that the "laser head" is aging. At this time, adjust the laser head near the optical drive. Potential regulator, increase the resistance and change the intensity of the current to increase the power of the launch tube, increase the brightness of the laser, and thus improve the disc reading ability of the optical drive.

Reminder: Everyone uses a small screwdriver to adjust clockwise (clockwise to increase the power, counterclockwise to reduce the power), adjust in 5 degree steps, adjust and try until you are satisfied. Remember not to over-adjust, otherwise the laser head may be overpowered and burnt.

Solution for trays that can’t be placed in the warehouse

Fault analysis: After comparing multiple optical drives of the same model, it is judged It should be caused by the aging of the rubber conveyor belt of the out-of-box mechanism. It is a real shot of the internal rubber conveyor belt.

Anything that happens to get in and out of the warehouse is almost all related to the rubber belt in the picture. Due to the long-term use, the rubber belt is aging and becomes a little loose. After pressing the in and out button, the in and out mechanism cannot get enough transmission force, and the metal movement cannot be fully in place, which causes the processor inside the optical drive to be misjudged as a foreign object. Stuck, so as to perform the exit action protectively.

Solution: You can change a conveyor belt of the same specification, but it takes time, labor and money, and the quality of the ordinary conveyor belt is far from comparable to the original product.

Automatically eject when the disc is read

This situation is not directly related to the operating system. This failure is mostly caused by the unstable operation of the tray access control circuit of the optical drive, or it may be caused by the unstable input power of the optical drive, or even the above two Factors are possible. In order to verify whether the input power of the optical drive is stable, I removed the malfunctioning optical drive from my friend’s computer, and then installed it on my computer for testing. After the test, I found that the Apache 50XCD-ROM drive was in the author’s computer. The automatic "spit out" failure of the warehouse door still occurs, which proves that there must be a problem with the control circuit of the optical drive tray in and out.

Common failures

The optical drive is one of the accessories with the shortest service life in computer hardware. In fact, many obsolete optical drives still have great value in use, as long as they are slightly repaired. This often does not require any advanced radio expertise, nor does it require the use of too complicated maintenance tools and materials. As long as you carefully observe the fault phenomenon and refer to the following troubleshooting methods, I believe your old CD-ROM drive can still restore its former "elegance". Common fault 1: The hard disk light always flashes when the optical drive is working. This is an illusion, but it is not the case. The hard disk light flashes because the optical drive and the hard disk are connected to the same IDE interface, and the hard disk light is also controlled when the optical disk is working. The optical drive unit can be independently connected to an IDE interface.

Common failure 2: When operating on CD-ROM in Windows environment, it displays "32 disk access failure" and then crashes.

Obviously, Windows 32-bit disk access CD-ROM has a certain impact. Most of the CD-ROM is connected to the IDE interface of the hard disk, and does not support the 32-bit disk access function of Windows, which causes Windows to crash due to an internal error. After entering Windows, double-click "Control Panel" in the "Main Group" to enter the "386 Enhanced Mode" setting, click the "Virtual Memory" button and then click "Change", and change the "32-bit Disk Access" in the lower left corner The check box is closed, after confirming, restart Windows, and then access the CD-ROM in Windows to enter without error.

Common failure 3: CD-ROM cannot read the disk normally, the screen displays: "There is no disk in drive X, insert the disk and try again", or "CDR101:NOT

READY READING DRIVE X ABORT .RETRY.FALL? "Occasionally, I read the disc several times in and out of the box, but did not read the disc after a while.

In this case, the virus should be detected first, and the whole machine should be checked and disinfected with anti-virus software. If no virus is found, use the file editing software to open the CONFIG.SYS" file in the root directory of the C drive, and check Whether the optical driver has been hung up again and whether the driver has been damaged and processed, you can also use text editing software to check whether there is "MSCDEX.EXE/D:MSCDOOO /M:20/V" in the "AUIOEXEC.BAT" file. If the problem is not found in the above two steps, the CD-ROM drive can be removed for repair.

Common failure 4: Read and write errors or no disk prompts occur when the CD-ROM drive is in use

This phenomenon is mostly due to replacement The failure caused by operating the optical drive before the disc is in place. All operations on the optical drive must wait for the optical disc indicator to show that it is in place. The time should also be adjusted when playing the video disc. Change the disc at zero hour, so as to avoid the above error.

Common fault 5: The picture is paused or broken when playing a movie VCD

Check the AUTOEXEC.BAT file Whether the "SMARTDRV" is placed after MSCDEX.EXE. If it is, you should put the SMARTDRV statement before MSCDEX.EXE; if you don’t use the CD-ROM drive, change it to SMARTDRV.EXE/U ;The fault can be eliminated.

Common fault six: When the CD-ROM drive is reading data, sometimes it cannot be read, and the time of reading the disk becomes longer.

Mainly concentrated on the laser head assembly, and can be divided into two situations: one is the use of too long and the laser tube is old

; the other is that the photoelectric tube surface is too dirty or the laser tube lens is too dirty And displacement deformation. Therefore, when adjusting the power of the laser tube, you need to clean the photoelectric tube and the laser tube lens.

The cleaning method of the photoelectric tube and focusing lens is: unplug the laser head assembly A set of flat cables, remember the direction, and disassemble the laser head assembly. At this time, you can see the sheath covering the focusing lens of the laser head. After removing the sheath, you will find that the focusing lens is connected to the focusing and tracking coils by four thin copper wires. The photoelectric tube assembly is installed in the small hole directly below the lens. Wipe it with a small amount of distilled water wrapped in cotton with fine iron wire (do not use alcohol to wipe the surface of the photoelectric tube and focusing lens), and check whether the lens is hung horizontally and directly facing the laser tube. Otherwise, it must be adjusted properly. At this point, the cleaning work is complete.

Adjust the laser head power. There is a small potentiometer like a cross screw on the side of the laser head assembly. Use color to note down its initial position, generally first Rotate clockwise by 5°～10°. If the installation and test machine cannot work, then rotate counterclockwise by 5°～10° until the disk can be read smoothly. Be careful not to rotate too much, so as not to burn the photocell due to too much power.

This may be due to the loosening of the optical drive data cable connector or the hard disk data cable loss If it is damaged or the optical drive jumper is set incorrectly, when encountering this kind of problem, we should first check whether the data cable connector of the optical drive is loose. , Insert tightly. If this still does not solve the fault, then we can find a new data line and try it. If the fault still exists at this time, we need to check the jumper settings of the CD. If there is an error, change it.

Installation method

The installation of the CD drive is It's relatively simple. It is very similar to the hard disk installation. For SATA optical drives, just connect the data cable and power cable. For IDE optical drives, one of the main problems is to set the main and secondary disks. Generally, jumpers are marked on the optical drive. MA means main disk and SL means secondary disk. Under normal circumstances, we set the CD-ROM drive as a secondary disk and connect it to the same data line as the hard disk; when the CD-ROM drive is set as the main disk, you can connect it with a data cable separately and connect it to the motherboard On the deputy IDE mouth. When connecting the data cable, pay attention to the direction of the interface. Another problem is the connection of the CD audio cable. The CD audio interface of the optical drive generally has 4 pins, which are the left and right channels and two ground wires. R represents the right channel, L represents the left channel, and G Represents the ground wire. There is a similar socket on the sound card, which receives the CD audio signal from the optical drive and amplifies it to the "Speaker" hole. The CD audio cable has 3 cores or 4 cores, and the 4 cores are just an extra ground wire. When connecting the audio cable, make sure that the left and right channels of the optical drive and the sound card correspond to the ground wire, otherwise there may be problems, such as only one speaker when playing a CD.

Set the method of booting from the CD-ROM drive

1) After the machine boots, first press the Del key to enter the BIOS

2) Use the keyboard Use the arrow keys to select Advanced BIOS Features

3) Press Enter to enter the BIOS setup interface

4) Use the arrow keys to select First Boot Device or (1st Boot Device) and press Enter

5）用上下方向键选中CDROM

6）按ESC返回BIOS设置界面。按F10

7）按 ‘Y’键后回车，重启电脑

8）重启电脑， 放入光盘，在读光盘的时候按回车键（就是出现黑屏上有一排英文press anykey to boot from CDROM 时，立即回车）

需要注意的是，由于BIOS的不同，进入BIOS后设置按键也有可能不同。如果是AMI bios，进入bios之后按右方向键，第四项，然后选择同样的类似first boot device 的选项，然后保存更改退出。如果是笔记本，可以按F2进入BIOS，后面的设置大同小异。

分类

光驱是台式机里比较常见的一个配件。随着多媒体的应用越来越广泛，使得光驱在台式机诸多配件中的已经成标准配置。目前，光驱可分为CD-ROM驱动器、DVD光驱(DVD-ROM)、康宝(COMBO)和刻录机等。

CD-ROM光驱：又称为致密盘只读存储器，是一种只读的光存储介质。它是利用原本用于音频CD的CD-DA(Digital Audio)格式发展起来的。

DVD光驱：是一种可以读取DVD碟片的光驱，除了兼容DVD-ROM，DVD-VIDEO，DVD-R，CD-ROM等常见的格式外，对于CD-R/RW，CD-I，VIDEO-CD，CD-G等都要能很好的支持。

COMBO光驱：“康宝”光驱是人们对COMBO光驱的俗称。而COMBO光驱是一种集合了CD刻录、CD-ROM和DVD-ROM为一体的多功能光存储产品。而蓝光combo光驱指的是能读取蓝光光盘，并且能刻录dvd的光驱

蓝光光驱：蓝光光驱，即能读取蓝光光盘的光驱，向下兼容DVD、VCD、CD等格式。

刻录光驱：包括了CD-R、CD-RW和DVD刻录机以及蓝光刻录机等，其中DVD刻录机又分DVD+R、DVD-R、DVD+RW、DVD-RW(W代表可反复擦写)和DVD-RAM。刻录机的外观和普通光驱差不多，只是其前置面板上通常都清楚地标识着写入、复写和读取三种速度。

选购

光驱的选购技巧成为了众多消费者所关注的问题。其实只要在选购DVD光驱时重视以下五点，我们完全可以非常轻松地在纷繁复杂的市场中去粗取精，挑选到满意的DVD光驱。

一、纠错能力

一直以来DVD光驱纠错能力都是众人所议论的焦点，甚至有人因此怀疑DVD光驱能否真正替代CD－ROM。其实“纠错能力一般”只是早期DVD产品的一个弊病，随着技术的成熟，现在的DVD光驱通常情况下已经拥有令人满意的纠错能力。

但要真正做到“超强纠错”也不是一件容易的事情了，这就要看各大光驱生产厂商是否拥有自己的特色技术。在“产品同质化”现象严重的今天，比纠错其实就是比特色技术。据笔者所知，明基BenQ在这方面做得不错，其热销机种1650S拥有“Smart-Film 完美放影”影片播放解决方案，包含了第二代自排挡、BVO数字视频优化处理等专有技术，纠错能力得到良好保障。

二、稳定性

我们往往会遇到这样的情况，一款光驱买回来时，怎么用都好，任何盘片都能通吃。可一旦用了一段时间后（通常3个月以上），却发现读盘能力迅速下降，这也就是大家常说的“蜜月效应”。

为避免购买到这类产品，我们应该尽量选购采用全钢机芯的DVD光驱，这样即便在高温、高湿的情况下长时间工作，DVD光驱的性能也能恒久如一，这也给 DVD影片的完美播放提供了最为有力的保障，必定是牙好胃口才好，芯好光驱才能长时间地稳定如新。另外采用全钢机芯的光驱通常情况下要比采用普通塑料机芯的整体上的使用寿命长很多。

三、速度

速度是衡量一台光驱快慢的标准，目前市面上主流的DVD光驱基本上都是16X，那为何选购DVD光驱还需要注意速度呢？因为DVD光驱具有向下兼容性，除了读取DVD光盘之外，DVD光驱还肩负着读取普通CD数据碟片的重担，因此我们还需关注CD读取速度。主流的CD-ROM的读取速度普遍是 50X至52X。

而目前市面上的很大一部分16X DVD光驱，其CD盘的最大读取速度仅为40X。知名品牌中，BenQ的1650S DVD的CD盘读取速度已经达到50X，是目前市面上同倍速DVD光驱中的最高标准。

四、接口类型

一般情况下，DVD光驱的传输模式与CD-ROM一样，都是采ATA33模式，从理论上说这种接口已经能够满足目前主流DVD光驱数据的传输要求了，毕竟16X DVD光驱最大传输速率也就只有20MB/sec左右。然而这种传输模式存在较大的弊端，在光驱读盘时CPU的占用率非常之高，一旦遇上一些质量不好的碟片，CPU的使用率一下子就提升到了100%左右。

这样一来即便再强劲的CPU，在播放DVD或者运行其他软件时也不能应付自如，严重时甚至会引起死机。所以在选购DVD光驱时，我们一定要特别注意光驱的接口模式，在价格相差不大或者根本没有价格差异的情况下，尽量选用ATA66甚至ATA100接口的产品。

五、品牌

一个信得过的品牌是选购一款好DVD光驱的关键之一，做好了这一步将大大减轻我们DVD光驱选购的难度。

刻录技术

随着发展刻录机的刻录速度越来越快，刻录机对缓存容量的需求也越来越大，但受成本的限制缓存容量的增加幅度远远跟不上刻录速度的发展。大家知道，在刻录一盘空白的盘片的时候，不管以何种方式或格式刻录数据，刻录机都会预先读入数据到缓存（Buffer）中，当刻录机的缓存存满的时候，刻录机就会开始执行刻录数据的动作，缓存中必须要有足够的数据供给刻录机才能保证刻录的顺利完成。但是数据传输给刻录机缓存时，由于各种各样的原因容易造成输入的速度跟不上刻录机的写入速度，如果缓存中数据被耗尽，此时就会发生Buffer UnderRun（缓存欠载）错误，这样就会刻录失败，盘片报废。为了避免缓存欠载错误的发生，光储厂商相继开发了一些防刻死技术，以期望在数据短时间断流的状况下，把刻录的影响降到最低。

防刻死技术都是在激光头定位精度和Fireware软件上作了改进，当发生数据传输断流时，刻录机会自动记录下断点，并停止刻录动作，当缓存内数据符合要求时，再自动寻找到断点继续刻录。这样就避免了缓存欠载错误的发生，但防刻死技术也有它自己固有的缺点，首先使用防刻死技术会浪费时间和光盘的空间，在使用防刻死技术的时候，光头要从写状态变成读状态，而且要记录下断点，然后等待缓存中的数据满了再从断点处写入，一般来说，每使用一次防刻死技术需要大约30秒钟的时间。同时对于一些光头精度不高的刻录机来说，可能因为断点定位不准确而导致下次光驱读取不畅。有些防刻死技术还会出现使刻录的CD产生爆音等副作用。虽然有如上瑕疵，防刻死技术仍旧是降低刻坏盘几率的最佳方法之一。

各厂商开发的防刻死技术各不相同，主要采用的有一下几种：

Burn-Proof

Just Link

Seamless Link

Power-Burn

Exaclink

SAFEBURN

SMART Clone

WriteProof

SuperLink

此外还有一种常见技术叫做光雕刻录技术。其实光雕刻录和上边的刻录技术并不是一个意思，光雕技术是惠普与威宝公司共同开发的一项允许用户在光盘背面刻写个性化图案的技术，需要刻录机和光盘同时支持。光雕技术用激光雕刻涂在光盘上的一层特殊材料，使其颜色发生变化，从而实现雕刻的效果。物理结构上光雕刻录机比一般的DVD刻录机产品多了一个光头，专门用来定位的“光学定位器”，用来保证雕刻图案时的准确定位。通常支持光雕的光盘比普通光盘略贵一点。

Burn-Proof

Burn-Proof是 Buffer Under Run-Proof的缩写，意思就是缓存欠载保护。该技术由日本Sanyo（三洋）公司开发，也是最早投入商业应用并获得成功的缓存欠载保护技术之一。

Burn-Proof技术是在刻录机内部增加了一组特制的芯片，三洋公司为UltraSCSI接口和IDE接口的刻录机分别开发了相应的控制芯片LC898023和LC898093KM。在刻录开始后，该芯片组会持续监控刻录机缓存的状态，当缓存内的数据发生短缺，且数据量小于所设定的存量底限时，该芯片就会暂停刻录机的刻录动作。直到缓存中的数据充满后，先对比刻录的数据与缓存中的数据，在将每一笔数据同步后，会搜寻上一个成功刻录的磁道位置，搜寻到磁道位置后便计算和同步，同时准确定位下一个写入磁区的位置，从而接上暂停前的情况继续刻录。

虽说防刻死技术可以搜索到刻录停止的位置，但要做到后续刻录与停止前刻录数据无缝隙的连接那是根本不能达到的，只能把二者之间的间歇控制在一个不影响数据读取的范围内。在桔皮书规范中规定，CD刻录中数据之间的间隙不能超过100微米，而中间的细小间隔通过ECC校验码来修正。 Burn-Proof技术能保证从其停止位置到后续刻录之间的间隔不超过40微米，完全符合桔皮书标准，不会造成刻录产品的读取困难问题，还有效避免的缓存欠载错误的发生。

Just Link

Just Link是由理光（Ricoh）公司开发的，也是通过内加控制芯片的方法使刻录机具有防刻死功能，是理光为了对抗三洋的Burn-Proof而开发的。

JustLink的原理是：在烧录时，监视缓存中已存取的数据量，当缓存中的数据量降低到易发生缓存欠载的水准时，停止写入的动作并保持当时的状态，同时继续存取数据于缓存之中。待存储到一定量后，在停止的位置后再度开始写入，如此重复直至烧录完结，工作原理和Burn-Proof基本一致，但是间隙控制精度要高得多，可以控制在2μm以内，这对光盘的影响已不太容易察觉到了；Just Link还提供了控制使用次数的支持，可由自己来决定使用与否或使用次数。

JustLink技术与Burn-Proof技术相比有三个较大的不同。一个是BURN-Proof是在出现缓存欠载后才暂停刻录，直到缓存内数据被充满才恢复刻录；而JustLink则是一直监视缓存中的数据量，当数据量减少到一定值（不是到零）时就会暂停刻录。第二当恢复刻录时，ustLink允许当缓存内的数据达到一定量就可以重新开始刻录；而BURN-Proof技术则要等到缓存被注满数据后才继续进行刻录。第三就是JustLink技术最大优点，中断点和续刻点之间的间隙非常小。在12倍速刻录时只有2微米的间隙，而在12倍速下BURN-Proof技术产生的间隙有40微米。而中断点和续刻点之间的间隙随着刻录速度的增加也会增大，这样在刻录速度增大时，BURN-Proof技术生成的间隙就比较大了。

Seamless Link

Seamless Link技术由菲利浦（Philips）公司所开发，该技术是以理光的Just Link技术为基础。推出的时间较前两种晚，因此在程序控制和技术完善程度都要高于前两种技术。

SeamlessLink的原理是：在进行烧录的同时，随时监控缓存中的数据量，当数据量下降到一定比例时，关闭激光刻录头，同时记录确切的中断点（ExactlyRecEndPoint），并使激光刻录头保持在暂停时的状态。当缓存中的数据量上升后，激光刻录头根据刚才记下的中断点数据搜寻到中断点后重新开始烧录工作，直至烧录进程完毕。

SeamlessLink技术除了具备JustLink技术的优点以外，还可以在刻录过程中实时显示缓存中的数据量。此外，由于BURN-Proof和JustLink技术需要额外的控制芯片才能实现防止缓存欠载的功能，不但增加了刻录机的生产成本，而且需要刻录软件必须改进和支持。而SeamlessLink技术的实现不需要额外的控制芯片，其指令被集成在刻录机的FirmWare（固件）上，因此不但降低了生产成本，而且对刻录软件没有提出额外的要求，提高了采用该技术的刻录机的适用性

Exaclink

是目前较新的防刻死技术，由美国Oak Technology公司研制开发。 Exaclink技术所形成的"空隙"不超过1微米，再配合8M的超大容量缓存，其优秀的表现可见一斑！当前代表的产品有LG系列刻录机。

SAFEBURN

Yamaha公司采用了SafeBurn技术的刻录机，还辅之以8MB的大容量缓存和刻录速度控制功能，以将刻录的稳定性提升得更高。该技术最大的特点是所有的缓存欠载应付措施都在缓存中直接进行，无需外界干预。即使刻录中欠载保护启动，恢复正常刻录时也不会产生接缝。这是首个无空白区域的链接技术。目前这种技术只应用在雅马哈刻录机上。通常雅马哈的刻录机价格比较贵，主要面向高端用户。

SMART Clone

SMART Clone包括了BURNProof防刻死技术和一项与JustSpeed类似的技术，可以通过检测盘片质量来决定刻盘时的电机转速和激光头功率的大小。通过检测使用的盘片，并与刻录机上Firmware里面的数据库进行对照，找出这张盘片所支持的最佳写入方法和速度，然后进行刻录；如果在数据库上并没有列出盘片的资料，刻录机将采用一个默认的方法，记录下这种盘片的特征以及环境参数，通过这些测试得出一个最佳写入方法和速度，然后对激光头的功率进行调整，刻录盘片，避免因盘片质量和激光功率过大而导致烧录失败。

如果你使用的盘片质量很差，刻录机将对质量较好的区域采用一个较快的速度，而在质量不好的区域将降速刻录，最终顺利完成刻录工作。 Smart-Clone技术的实用性很强，当我们在拷贝CD音轨的时候，通常从光驱提取音轨数据的速度快于将音轨数据写入磁盘的速度，Smart-Clone可以将读写速度调节一致，使之均衡，增加光驱的读盘稳定性。以避免因盘片质量和激光头功率过大导致的烧盘问题，双重保障刻录成功率。就SMART-Clone技术特点而言，它已经不仅仅单纯是解决缓存欠载的技术，它还溶入了其它优化刻录技术。

Power Burn

PowerBurn技术由Sony公司开发，工作原理和SANYO(三洋)的Burn-Proof基本相同。同其它防刻死技术一样，它也能及时控制及准确地连接数据刻录的中断及恢复点，并且其还能通过为记忆媒体设定最佳的刻录条件，自动调整主机传送数据的延误，以避免将数据写入时发生缓存欠载错误。 Power-Burn除了能自动为刻录机选择最佳的刻录条件（如刻录速度）之外，还会通过查找存储于Firmware内的光盘资料数据，如建议的刻录速度及光盘刻录面的条件等，对光盘的性能进行分析，进而做出最佳的刻录行为。工作原理与Burn Proof基本相同，二者在间隙控制方面也相差无几，PowerBurn也是在40微米左右。

WriteProof

WriteProof是Teac公司推出的一种技术。该技术的特点是：在刻录过程中，检索模块不停地检查缓存中的数据量，当少于10%的时候挂起刻录，但检查工作并未停止，直到缓存中的数据量恢复至10%时继续刻录；反之，则继续挂起。由于缓存中的数据量是不停被检查的，因此提高了刻录的成功率。当然，这样付出的代价是对CPU资源的占用率加大

SuperLink技术

SuperLink防刻录死技术是一种全新的刻录保护技术。其工作原理是在刻录时监测内置缓存的数据量，当缓存数据为空时，芯片控制刻录光头停止工作，等待缓存载满数据后，会自动搜索刻录终止点，以不大于10微米的点距进行继续刻录。可以最大限度的减少刻录CD光盘播放时暴音的出现。根据刻录机的规定，磁区间的最大间隙不能超过100微米，SuperLink技术达到的10微米间距已经远低于这项标准。

SuperLink技术基于硬件实现，无须软件支持兼容性更高，在WINXP这种内置刻录功能的操作系统中刻录CD-R/RW可以像使用软盘一样方便并且很安全。同时可以保证在完美刻录的同时可以进行上网、听音乐等任务，减少了等待的时间

光驱厂商

先锋、索尼、三星、飞利浦、建兴、华硕、

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