Standard CD volume. Compact disc is the term for an encyclopedic collection. How to remove a disk from a faulty drive

A brief history of the creation of CDs. Parameters and properties of different optical media. Difference between BD and CD and HD DVD formats.

Today there is a wide variety of CDs, but knowing the main types, you can quite easily figure out for what specific purpose a particular optical disc is needed. They differ not only in the amount of information stored, but also in the ability to overwrite files.

CDs were the first to be developed - these CDs, in the late seventies of the last century, were created for storing and listening to music. The very first ones could hold up to 650 MB, a little later the memory capacity became larger - 700 MB.

In 1996, DVDs appeared on the CD market. They are comparable in size to CDs, but with a larger storage capacity of up to 4.7 gigabytes. There is also the possibility of saving video images, and therefore DVD technology cost much more.

In the 21st century, almost all computers are equipped with a standard DVD drive. DVD format discs are now in greater demand than CDs, but CD manufacturers haven't stopped there.

Technologies for recording and storing various files are constantly being improved. This is how double-sided and multilayer disks were created, on which the amount of information can be recorded an order of magnitude greater.

The next stage of development was the creation of the BD format; the Blu-ray disc or “blue ray” was introduced to the public at the turn of the millennium. The CD got its unusual name from the color of the recording laser.

Over the course of several years, developers perfected the technology, and in 2006 the BD version that still exists today was created. This format was in first place in terms of the volume of stored information - up to 23 gigabytes. Today in everyday life you can use a four-layer disk with a capacity of 100 gigabytes. Discs with ten recording layers and a capacity of 320 gigabytes have also been developed.

Dual Discs are not so well known to the average user; they occupy a separate position among compact discs and combine two formats - CD and DVD. So on one side music is stored, on the second, in DVD format, the following can be recorded: menus, videos, images, surround sound, subtitles.

Such CDs are characterized by the speed of writing or reading information. Thus, the designation 4x MAX stands for increasing the disk rotation speed four times faster compared to conventional CDs.

Another type of CD is HD DVD. These disks can hold up to 15 GB if they are single-layer. The capacity of double-layer ones doubles. However, today optical media in the HD DVD format are no longer available. They have been supplanted by Blu-ray technology, which is more in demand today.

They were replaced a year ago by new CDs developed on the basis of BD, but in comparison, they are cheaper, since production costs are lower than those of BD. They have not yet received their own name.

New optical media exceeds the capacity of all previous disks - terabytes of memory. Twenty-layer recording technology allows them to accommodate such a volume of information. CD manufacturers plan to increase the capacity of optical media to 15 terabytes.

Structure of CD.

DVD structure.

Rules for using CDs.

CD/DVD drive.

In the late 1970s, Sony and Philips began jointly developing a single standard for optical storage media. Philips created the laser player, and Sony developed the technology for recording on optical media. At the suggestion of the Sony Corporation, the disc size was 12 cm, since this volume made it possible to record Beethoven's entire Ninth Symphony. In 1982, a document called the Red Book published a standard for processing, recording and storing information on laser discs, as well as the physical parameters of the disc.

Note.

There is a legend that the Red Book document was named so because of the cover in which it was stored. All further CD standards were named books of different colors: Yellow Book, Orange Book, White Book, Blue Book, Green Book.

The following parameters were defined in the Red Book standard.

Physical size of the disk.

Disk structure and data organization.

Note.

All data on the disk is divided into frames. Each frame consists of 192 bits for music, 388 bits for modulation and error correction data, and one control bit. 98 frames make up one sector. Sectors are combined into a track. A maximum of 99 tracks can be recorded on a disc.

Recording data in a single stream from the center to the periphery.

Reading data with constant linear speed(Constant Linear Velocity, CLV).

Note.

During recording and reading of information, when the laser beam moves from the center to the periphery, the rotation speed of the disk decreases. This is necessary to ensure that the same amount of information can be read and written in the same amount of time. Therefore, without the use of CLV technology, when playing, for example, musical works, there would be a change in the speed of execution.

Due to the relatively small size of laser discs compared to vinyl records they came to be called compact discs, or CD (Compact Disk) for short. The first CDs were intended for recording and playing music (in fact, that's what they were created for) and could store up to 74 minutes of high-quality stereo sound. The standard for such discs was called CD-DA (Compact Disk Digital Audio).

With the development of the computer industry, a need arose for technology that allows storing not only digital sound, but also various data on CDs. Computer programs could not fit on floppy disks, and the volumes user files became more and more.

In 1984, a standard called the Yellow Book was published. Sony and Philips companies reorganized the structure of CDs and began to use new error correction codes - EDC (Error Detection and Correction) and ECC (Error Correction Code). The main unit of data placement was the sector. One sector contains: 12 bytes for synchronization, 4 bytes for headers, 2048 bytes for user data and 288 bytes for error correction.

CAV (Constant Angular Velocity) technology was developed to read computer data. CAV technology allows you to read information from a disk faster than CLV technology, since the data flow increases as the laser beam moves from the center to the periphery. Modern CD drives support both technologies.

Computer laser disks were called CD-ROM - Compact Disk ReadOnly Memory (literally, “read-only memory on CDs”). In the late 1990s, the CD drive became a standard component of any computer and the vast majority of programs began to be distributed on CDs.

The consumer market was rapidly expanding, production volumes were increasing, and the largest manufacturers began developing technology that allows the user to independently record any information on a CD. In 1988, Tajio Yuden released the world's first CD-R (Compact Disk Recordable). The biggest challenge faced by CD recorder designers is finding highly reflective materials. Tajio Yuden successfully completed the task. The gold-cyanine alloy they used to make these drives had a reflectivity of over 70 %. The same company developed a method for applying an active organic layer to the surface of a disk, as well as a technology for dividing the disk into tracks.

A Compact Disk (CD) is a disk with a diameter of 120 mm (4.75 inches) or 80 mm (3.1 inches) and a thickness of 1.2 mm. The depth of the stroke is 0.12 µm, the width is 0.6 µm. The strokes are arranged in a spiral, from the center to the periphery. The stroke length is 0.9–3.3 µm, the distance between the tracks is 1.6 µm. Compact discs are made up of three to six layers.

To accommodate five- and three-inch discs in the CD drive tray there are special recesses - 5 and 3 inches, respectively.

Note.

In oral speech, as well as in print, rounded values ​​for the diameter of the disk are most often used: instead of 4.75 inches - 5, instead of 3.1 inches - 3.

A standard five-inch disc can contain 650–700 MB of information, 74–80 minutes of high-quality stereo sound with a sampling rate of 44.1 kHz and a digitization depth of 16 bits, or a huge amount of audio in MP3 format.

Three-inch disks hold about 180 MB of information.

Sometimes there are disks called “business cards” (Fig. 1.1). In appearance and size, they resemble a business card, but are actually three-inch disks, cut on both sides. From 10 to 80 MB is recorded on such a CD, depending on the extent to which the edges of the disc are trimmed.

Rice. 1.1. CD "business card".

The basis of a disk intended for recording information in an industrial way is transparent polycarbonate, onto which a thin layer of aluminum alloy is applied, then coated protective layer varnish and apply a printed image (Fig. 1.2).

Rice. 1.2. CD structure.

DVD, DVD-R, DVD-RW, CD, CD-R, and CD-RW discs are manufactured by various companies: AMD, Amedia, Digitex, HP, Imation, MBI, Memorex, Philips, Smartbuy, Sony, TDK, Verbatim.

When purchasing CDs, you should pay attention to the following subtleties.

The presence of varnish stains on the edges of the disk can cause additional vibration and, as a result, errors when reading and writing data.

In the absence of additional layers of paint, the disc is translucent; you should not hope for a long service life of such a product.

If the disc is translucent, pay attention to how the reflective layer is applied. When viewed under light, the CD should be free of streaks and the reflective layer should be uniform over the entire surface.

The polycarbonate base must be homogeneous, without air bubbles.

Most CDs with games, movies or programs sold in stores are made by stamping.

Industrial DVD and CD recording occurs in eight stages.

1. Prepare the data that needs to be written to a CD.

2. A photosensitive photoresist layer of a certain thickness is applied to the surface of special polished glass processed with high precision in the form of a disk. Using a computer-controlled laser beam, certain areas of the photosensitive layer are illuminated.

3. After development in special solutions, small depressions called pits and convex areas called lands remain on the glass. The matrix, or stamper, obtained in this way is called Glass Master (glass base).

4. Using special reagents or vacuum deposition, a thin layer of nickel or silver is applied to Glass Master. This way we get Metal Master (master disk).

5. Create a negative of the master disc. In place of protrusions, depressions are formed, and vice versa, in place of depressions, protrusions are formed.

6. A stamp is created from a high-strength material, in the center of which a hole is drilled.

7. The stamp is placed in a press machine and copies are made.

8. An aluminum film is applied to the copies, designed to reflect the laser beam. The film thickness is hundredths of micrometers. The disc is varnished and a printed image is applied to it.

CD-R (CD Recordable) has a more complex structure. Another layer is added to its surface, onto which recording is made. The active, or recording, layer is located between the base and the reflective layer (Fig. 1.3).

Rice. 1.3. CD-R structure.

A blank CD-R, or “blank,” has a spiral track (Pre-groove), which contains special marks and synchronization signals. During recording, preliminary marking helps the laser move along the desired path. In addition, CD burning programs themselves “read” some of the parameters of the CD-R being used, which makes it easier for the user to configure these programs. Synchronization signals are recorded at reduced amplitude and are subsequently overlapped by the recorded signal.

During recording, the laser beam moves along a spiral path and, at the moment of its activity, melts an additional layer. Under the influence of a laser, this layer changes its structure. This produces cells (pits) corresponding to the data written to the CD. After this stage, the structure of the active layer of the disk cannot be changed, and the data written to the disk cannot be deleted.

Note.

Pits are through holes in an additional layer.

The active layer is made from organic compounds: cyanine (Cyanine) and its derivative – phthalocyanine (Phtalocyanine). It is believed that phthalocyanine is more reliable and durable because it is less sensitive to sunlight. But discs with an active MetalAZO layer, developed by Mitsubishi Chemical, are even less sensitive to sunlight.

The requirements for the reflective layer of CD-Rs, compared to stamped discs, are quite high due to the presence of a recording layer. Therefore, more expensive materials are used to make the reflective layer - industrial gold and silver, as well as complex alloys.

The working surface of a CD-R, depending on the combination of substances used in the recording and reflective layers, can be of different colors. Previously, many discs had a golden working surface due to the use of gold.

Currently, silver is used to make the reflective layer, since this material is cheaper and has a higher reflectivity. Most often, the working surface is transparent, dark blue or light green. The service life of such disks, depending on the material of manufacture, ranges from 10 to 100 years.

CD-RW (Compact Disk Re-Writable - rewritable CD) (Fig. 1.4) - has, in addition to those described above, two more thermal protective layers. The presence of additional layers allows you to record on such a disc more than 1000 times.

Rice. 1.4. CD-RW structure.

During “burning” (writing a disc), the laser beam heats areas of the intermediate layer. With subsequent cooling, these areas transform from crystalline to amorphous. If information from a CD-RW needs to be erased, the laser beam heats the intermediate layer less intensely, and the amorphous areas crystallize.

In December 1995, 10 companies united in the DVD Consortium officially announced the creation of a single unified standard - DVD. The abbreviation DVD first stood for Digital Video Disc, but later its meaning was changed to Digital Versatile Disc. The disc was fully compatible with the Red Book and Yellow Book standards.

DVD is identical in appearance to CD, but allows you to record information that is 24 times larger in volume, that is, up to 17 GB. This became possible thanks to changes in the physical characteristics of the disk and the use of new technologies. The distance between the tracks was reduced to 0.74 μm, and the geometric dimensions of the pits were reduced to 0.4 μm for a single-layer disk and 0.44 μm for a double-layer disk. The data area has increased, the physical sizes of sectors have decreased. A more efficient error correction code, RSPC (Reed Solomon Product Code), was used, and more efficient bit modulation became possible.

DVD technology provides a huge number of formats and four types of designs in two sizes. A disc of this standard can be either single-sided or double-sided. There can be one or two working layers on each side. Let's look at the main characteristics DVD various types.

Disc size – 80 mm (3.1 inches).

– DVD-1 (Single-sided, single-layer) – single-sided and single-layer disc. Can contain up to 1.36 GB of information (Fig. 1.5).

– DVD-2 (Single-sided, double-layer) – single-sided double-layer disc. Contains up to 2.48 GB of information (Fig. 1.6).

– DVD-3 (Double-sided, double-layer) – a two-layer disc with one information layer on each side. Capacity – up to 2.74 GB of information (Fig. 1.7).

– DVD-4 (Double-sided, double-layer) – a disc with two information layers on each side. The capacity of such a disk is up to 4.95 GB (Fig. 1.8).

Disc size – 120 mm (4.75 inches).

– DVD-5 (Single-sided, single-layer) – single-sided single-layer disc. Contains up to 4.7 GB of information.

Rice. 1.5. Structure of DVD-1 and DVD-5.

– DVD-9 (Single-sided, double-layer) – single-sided and double-layer disc. Capacity – up to 8.5 GB.

– DVD-10 (Double-sided, double-layer) – a two-layer disc with one information layer on each side. Contains up to 9.4 GB of information.

– DVD-18 (Double-sided, double-layer) – a two-layer disc with two information layers on each side. Capable of storing up to 17 GB of information.

Rice. 1.6. Structure of DVD-2 and DVD-9.

Rice. 1.7. Structure of DVD-3 and DVD-10.

Rice. 1.8. Structure of DVD-4 and DVD-18.

Note.

The number in the disc name—DVD-1, DVD-4, DVD-10, etc.—is a rounded capacity value.

Burning single-layer DVDs is similar to burning CDs, but burning dual-layer discs is significantly different from the process described earlier.

Double-layer discs of types DVD-2 and DVD-9 have two working layers for recording information. These layers are separated using a special translucent material. To perform its function, such a material must have mutually exclusive properties: reflect the laser beam well when reading the outer layer and at the same time be as transparent as possible when reading the inner layer. At the request of Philips and Sony corporations, 3M created a material that meets the following requirements: having a reflectivity of 40% and the necessary transparency.

When reading information from such a disk, the laser beam first passes through the translucent layer, focusing on the tracks of the inner layer. Having read all the information in the inner layer, the laser beam automatically changes its focus and reads information from the translucent layer. The presence of a buffer in the DVD drive and the ability to quickly change focus allows you to continuously feed data to the motherboard.

When making a two-layer disc, the first layer, based on polycarbonates, is first stamped. Then a translucent material is applied, which in turn is covered with a film of photopolymer material. Using ultraviolet radiation, the photopolymer is hardened, and the DVD is filled with polycarbonate, which serves as a protective layer for the disc.

DVDs are 0.6mm thick. For physical compatibility From CD to DVD, a polycarbonate backing 0.6 mm thick was additionally glued. With the aim of not only increasing DVD thickness up to 1.2 mm, but also at the same time improve its functionality by doubling the media capacity, Toshiba created a double-sided disc (types DVD-3 and DVD-10). To get a DVD-3 disc, just glue two DVD-1s together on the label side; to obtain DVD-10, two DVD-5 are connected. Thus, by gluing two 0.6 mm thick disks together, we get one disk that is equal in thickness to a CD and has the ability to record twice as much information.

To obtain DVD-4 discs, you should glue two DVD-2, for DVD-18 - respectively, two DVD-9.

The principle of writing information to DVD-R (Digital Versatile Disk Read-only - write-once DVD) and reading from it is similar to writing and reading CD-R. During DVD recording in special recorders, a high-power laser beam “burns” holes (pits) in the active layer. When reading information, a laser beam of normal power, freely passing through the resulting hole, is reflected from the metallized layer and hits the photosensor, and then the microprocessor.

To write and read information from DVD-RW (Digital Versatile Disk ReWritable - rewritable DVD), Phase Change Technology is used. The laser beam moves along a spiral path during recording. During the period of increased beam activity, the recording layer changes its structure, passing from a crystalline state to an amorphous one. When reading information, the detector recognizes from which surface the laser beam was reflected - crystalline or amorphous - and converts the data into a digital stream. Under the influence of a laser beam certain power the active (recording) layer returns to its original state, and the disk can be rewritten many times.

The material, capable of repeatedly changing its structure, was developed by TDK and was called AVIST (Advanced Versatile Information Storage Technology - a modern universal technology for storing information).

Note.

The AVIST material in the crystalline state has a 25–35% reflective ability, and upon transition to the amorphous state it darkens and does not reflect the laser beam.

For DVD-ROM, VideoDVD, AudioDVD, etc., the file format is used UDF system(Universal Disk Format- universal disk format), developed by the OSTA association (Optical Storage Technology Association - an association for supporting data storage technology on optical media). This file system is a development of the CD-ROM file system (CDFS or ISO 9660).

DVD technology was originally developed for recording and playing movies. VideoDVD must provide the following capabilities:

Playback of films with a duration of at least 133 minutes;

Various options for displaying widescreen video;

Up to 32 subtitle options in various languages;

Surround sound;

Copy protection and regional coding;

Viewing interactivity.

Navigation data;

Reproduction objects.

Playback objects are divided into video, audio and graphics.

To play digital video, a bit rate of 167 Mbps is required. Therefore, a 4.7 GB disk can hold four minutes of digitized video. To save at least 133 minutes of high-quality images, data compression is used. Video is encoded in special format MPEG-2, developed by the MPEG group (Moving Picture Experts Group).

While watching films, you probably noticed that the background against which the characters move, as a rule, remains unchanged. The fact is that approximately 95% of repeated background images can be eliminated when digitizing without noticeable loss in quality, while the volume of digital stream is significantly reduced.

Sound is encoded and compressed using various technologies: Dolby Digital, MPEG-1 and MPEG-2. AudioDVD uses LPCM (Linear Pulse Code Modulation) technology, which does not use compression. The LPCM format allows you to transmit sound waves with the highest quality and accuracy (sampling frequency - 48 or 96 kHz, digitization depth - 16, 20 or 24 bits), using from one to eight audio channels, and get dynamic range recording up to 120 dB. In this case, the digital data stream can be 6.144 Mbit/s.

Compression sound signal using Dolby Digital technology – AC-3 (Audio Cannels) – provides 5.1 sound (5 main audio channels and one low-frequency channel) with a range of 20–20,000 Hz. For audio compression, a special algorithm developed by Dolby is used, called Multichannel Perceptual Coding. The human hearing, depending on gender and age, perceives sounds in different frequency ranges with different sensitivity. In addition, there are certain frequencies and timbres that are difficult for all people to distinguish. When using Dolby Digital technology, some frequency ranges, which are difficult for the human ear to perceive, are suppressed, resulting in some data loss. However, as a result, the digital stream is significantly reduced, for example, only 348 Kbps is enough for six channels.

Audio signal compression using MPEG-1 and MPEG-2 technologies is also associated with data loss. The MPEG-1 format is intended for mono or stereo audio only. The MPEG-2 format can be multi-channel and is capable of providing 5.1 or 7.1 surround sound.

Audio signal compression using DTS (Digital Theater System - digital theater with surround sound) technology, developed in the USA, is an alternative to Dolby Digital. The sound quality is slightly higher, the perception sound effects spatially more realistic, but the data flow in this case can reach 1536 Kbps.

To control the distribution of discs and protect copyright, DVD producers divided the world into six geographical zones and developed special icons and codes for each zone. The use of such regional coding of both the discs themselves and their players made it impossible to play discs from one zone on DVD drives from another zone.

Zone 1 – USA and Canada.

Zone 2 – Western Europe, Japan, South Africa, Middle East.

Zone 3 – Southeast and East Asia, including Taiwan and Hong Kong.

Zone 4 – Latin America, South America, Caribbean Islands, Australia and New Zealand.

Zone 5 - countries of the former Soviet Union, Africa (except South Africa), India, Pakistan, Mongolia and North Korea.

Zone 6 - China.

Currently, DVD player manufacturers produce so-called "multi-zone" devices that support most formats.

A compact disc is a rather complex device that requires correct handling and care.

Do not allow the work surface to become dirty. Hold the disc by the edges and do not touch the work surface with your hands. To remove any dust or fingerprints that may accidentally fall on the disc, use a soft, clean, dry cloth made from natural fabrics that does not have abrasive properties. The movements should not be strong; you should wipe the disc from its center to the edge. Do not use solvents to clean the work surface: acetone, gasoline, kerosene, etc.

Do not damage the work surface. Do not drop, scratch or bend the disc.

Store CDs in special plastic packaging at room temperature and do not expose them to direct sunlight onto their work surface.

Do not write on the CD label with ballpoint pens, fountain pens, or hard pencils, as you may scratch the thin protective coating. Use soft pencils or felt-tip pens for this purpose, or make notes on the packaging in which the disc is stored.

To avoid shifting the center of gravity and increasing vibration when the CD rotates in the drive, do not place additional labels on the disc.

CD drives can be internal or external. They can be connected using a SCSI device, and this connection method is the most efficient, reliable and high-quality for the following reasons:

Allows you to work in background during recording;

The drive does not conflict with other devices;

Less computer resources are used;

Does not require operating system optimization.

The disadvantages of this connection are the following:

Price;

The need to purchase an additional controller, to which you can connect from seven to fifteen different devices;

More complex installation.

External drives connected via FireWire or USB buses are much slower than internal IDE drives, but they can be connected and disconnected while the computer is running without turning off the computer itself or restarting the operating system.

Note.

Passport USB ability 2.0 – 480 Mbit/s. When installing the CD drive in operating systems ah Windows XP and Windows 2000 do not require additional software. USB 2.0 allows you to connect up to 127 devices. The connected device is detected automatically. Software driver, required for each peripheral device, is turned on without user intervention.

In addition to the SCSI connector, internal models can be connected to IDE (ATAPI) connectors located on the motherboard using an 80-pin cable. The vast majority of CD burners use the IDE interface, as it is present in all modern computers. Most modern motherboards allow you to connect four IDE devices using two cables. DVD or CD drives are connected as one of hard drives, and the BIOS independently recognizes the type of connected equipment. But if for some reason the BIOS does not detect one of the drives, then this malfunction can be resolved by using BIOS utility Setup.

To access BIOS utility CMOS Setup Utility requires you to press the Delete key while your computer is booting. This should be done after BIOS boot video before loading Windows. If you have problems determining the moment of pressing Delete keys, you can start pressing and releasing it immediately after turning on the computer. If everything is done correctly, a blue screen with text in English will appear. Select Standard CMOS Features ( Standard settings) and press Enter.

Note.

To select the desired menu item, just move the red rectangle to the desired name and press the Enter key. You can move through the menu items left, up, down and right using the cursor keys: , ^ and v. To return or cancel an action, use the Esc key. If you press the Esc key several times (the number of presses depends on how deep you have gone into the BIOS), the Quit Without Saving (Y/N) dialog box will appear on the screen - this short phrase can be translated as “quit the program without saving the there are changes in it." This window provides an indispensable opportunity for a novice user to leave the program, leaving in it the parameters that were set before entering BIOS Setup.

In the menu that opens, we are interested in four parameters:

IDE Primary Master ;

IDE Primary Slave ;

IDE Secondary Master;

IDE Secondary Slave.

Note.

The names given in square brackets will correspond to the devices on your computer.

You can connect two cables to the motherboard, each of which connects two devices. For example, to the first connector of the first loop (Primary Master) you can connect one hard drive (in our case it is ), to the second connector of the first loop (Primary Slave) you can connect another hard drive or not connect anything (in this case, to this connector nothing is connected, that's why you see in square brackets ).

You can connect a CD drive to the first connector of the second cable, which is called Secondary Master (in this case it is). Another CD or DVD drive is connected to the second connector of the second cable, which is called Secondary Slave, or nothing is connected (in our case, this connector is occupied).

Sometimes, in order to save money, one cable is connected to the motherboard and a hard drive and CD drive are connected to it, but in any case, if you connect two devices to one cable, one device will be the Master and the second will be the Slave. ).

As a rule, the BIOS correctly determines the connection of devices, and you do not need to change anything in the settings yourself. If for some reason the system cannot detect a new device, you must independently indicate which connector it is connected to. This is done using the parameters Primary Master, Primary Slave, Secondary Master, Secondary Slave.

The most common mistake made by novice users is incorrect installation jumpers on the device itself. A jumper is a small metal bracket that fits into the connectors that are located on the back of the CD or DVD drive. If two devices are connected to one loop, the position of the jumper must strictly delimit their levels: one device is Master, and the other is Slave.

Select the Advanced BIOS Features option and press Enter. In the menu that opens, pay attention to four parameters that characterize the sequence of checking devices. The BIOS does not always set this sequence correctly.

First Boot Device (the device from which the operating system will boot first) – . Choice available:

FloppyHDD-1USB-ZIP;

LS120 HDD-2USB-CDROM;

HDD-0HDD-3USB-HDD;

SCSIZIP100LAN;

CDROMUSB-FDDDisabled.

Second Boot Device (the device from which the operating system will be loaded secondarily) – . The same devices are available for selection as in the First Boot Device parameter.

Third Boot Device (the device from which the operating system will be loaded thirdly) – . The same devices are available for selection as in the First Boot Device parameter.

When checking the computer before loading the operating system, the BIOS alternately queries the CD drive, hard drive, and floppy drive in the exact order in which you specify. If the Windows XP operating system is installed on your computer, then the First Boot Device parameter should be set to CDROM. If the computer defaults to booting from the hard drive, it will freeze. In this case, it will be quite difficult to “cure” the operating system using a CD. Installation of Windows operating systems is automated, and the user only needs to install BIOS settings so that the CD drive is detected before the hard drive. The BIOS will perform further actions completely independently; the user only needs to agree with all suggestions. The square brackets in the example above indicate Windows XP devices.

If your computer is running Windows 95 or 98, then the First Boot Device parameter should be set to Floppy (disk drive), since emergency booting in these operating systems is most often done from a floppy disk. The Second Boot Device parameter should be set to CDROM, otherwise the operating system will have to be installed using the command line, which does not always lead to the desired results. In the Third Boot Device parameter, select your hard drive.

Once you have configured the required settings, press F10. As a result, the Save & Exit Setup (Y/N) window will appear - this phrase can be translated as “exit the program, saving the settings made.” Press the Y key (Yes), and then Enter. The computer will continue to boot.

The quality of operation of a CD recording drive is significantly affected by the clock speed of the processor and the amount of RAM. It is not recommended to work in Windows 2000 or XP systems with less than 128 MB of RAM; in this case, errors will occur during recording, which will lead to damage to the workpieces. To avoid unwanted consequences, you should burn discs on low-performance computers by first disabling unused applications.

The operation of the CD reader/writer is quite simple.

1. A laser diode emits a low-power beam of light with a length of 730–780 nm, which, passing through a guide prism and a beam splitter, hits a reflecting mirror.

Note.

During recording, the power of the laser beam increases significantly, and when erasing data it decreases.

2. Obeying the commands of the microprocessor, the carriage with the reflecting mirror moves to the desired track.

3. The laser beam is reflected from the disk, hits the mirror, then the beam splitter and then onto the guide prism.

4. From the prism, the beam enters the photo sensor, the photo sensor sends signals to the microprocessor built into the CD drive, where the data is processed and transmitted via a loop to the motherboard.

CD drives are produced by various companies: Yamaha, Plextor, Hitachi, HP, Sony, Ricoh, Philips, Panasonic, TEAC, AOpen, Mitsumi, etc. The cost of CD and DVD drives depends on the quality of the model, the level of the manufacturer, and functions and technical characteristics. For example, consider specifications some CD, DVD, and combo drives and their meanings.

CD-ROM Samsung SC/H152 (OEM).

– Speed ​​formula – 52x.

– Buffer size – 128 KB.

– Data access time – 80 milliseconds.

– Supports formats: CD-ROM, Audio CD, Video CD, CD-i/FMW, CD-R, CD-RW, CD-Extra, Photo CD, Karaoke CD.

– Interface – IDE (ATAPI).

CD-ROM SONY CDU 415.

– Interface – SCSI.

– CD loading mechanism – tray.

– Supports formats: CD-DA, CD Extra, CD-ROM (Mode1), CD-ROM XA (Mode 2 Form 1 & 2), CD-I (Mode 2 Form 1 & 2), CD-I Ready, CD Bridge , Photo CD (single and multisession), Video CD.

– Buffer size – 0.25 MB.

– MTBF – 100 thousand hours.

– Dimensions – 14.6 x 4.1 x 20.3 cm.

Benq CB523B combo drive.

– Interface – E-IDE (ATAPI).

– CD loading mechanism – tray.

– CD/CD-R reading speed – up to 7800 KB/s (52x max CAV).

– DVD reading speed – up to 2100 KB/s (16x max CAV).

– Supports formats: CD-I, CD-ROM, Audio CD, Video CD, CD-R, CD-RW, Photo CD, Karaoke CD, Text CD, Enhanced CD, Bootable CD, Data CD, DVD-ROM, DVD- R, DVD-RW, DVD+R DVD+RW.

– Recording formats – TAO (Track at Once), DAO (Dick at Once), SAO (Session at Once), Multi-Session, Packet Writing, UDF.

– Data access time CD -120 milliseconds, DVD – 140 milliseconds.

– Data buffer size is 2048 KB, Seamless Link buffer underrun error prevention technology is used.

– Supported disc sizes are 8 and 12 cm in diameter.

– MTBF – 125 thousand hours.

– Dimensions – 146 x 42 x 198 cm.

Writemaster TS-H552.

– Interface – IDE (ATAPI).

– CD loading mechanism – tray.

– CD-RW reading speed – 32x max.

– DVD reading speed -16x max.

– Reading speed DVD-R, DVD+R DVD-RW, CD-RW, DVD+R DL – 16x max.

– CD-R writing speed – 40x max.

– CD-RW recording speed – 32x max.

– DVD+RW recording speed – 4x max.

– DVD-RW recording speed – 4x max

– DVD+R recording speed – 16x max.

– DVD-R recording speed – 12x max.

– DVD+R DL recording speed – 2.4x max.

– Supports CD formats – CD-ROM, CD-ROM XA, CD-DA, Video CD, Photo CD, Text CD, CD-R, CD-RW.

– Supports DVD formats – DVD-ROM (Single/dual layer), Video DVD, DVD-ROM, DVD-R, DVD-RW, DVD+R, DVD+R DL, DVD+RW.

– Data access time: CD – 110 milliseconds, DVD – 130 milliseconds.

– Supported disc sizes are 8 and 12 cm in diameter.

– Dimensions – 148.2 x 42 x 184 mm.

– Interface – IDE (ATAPI, UDMA/33).

– CD loading mechanism – tray.

– CD/CD-R reading speed – 48x max.

– DVD reading speed – 16x max.

– CD-R writing speed – 24x max.

– CD-RW writing speed – 6x max.

– DVD+RW recording speed – 8x max.

– DVD+R/DVD-R recording speed – 16x max.

– DVD+R/-R DL recording speed – 4x max.

– Supports CD formats – CD-DA, CD-ROM, CD-ROM/XA, Photo CD, Video CD, CD Extra, Text CD, Bridge CD.

– Supports DVD formats – DVD single/dual layer, DVD-R/+R, DVD-RW/+RW, DVD+R9/-R9.

– Recording formats – TAO with Zero gap, DAO (Dick at Once), SAO (Session at Once), Multi-Session, Fixed and Variable Packet.

– Data access time: CD – 120 milliseconds, DVD – 140 milliseconds.

– Data buffer size – 2 MB.

– Supported disc sizes are 8 and 12 cm in diameter.

– Dimensions – 148 x 42 x 190 mm.

ASUS CRW-5232AS-U. External CD drive.

– Interface – USB 2.0 (USB 1.1).

– CD loading mechanism – tray.

– CD-ROM reading speed – up to 7800 KB/s (52x max CAV).

– CD-R recording speed – up to 7800 KB/s (52x max P-CAV).

– CD-RW recording speed – up to 4800 KB/s (32x max P-CAV).

– Audio track digitization speed – 52x max.

– Supports formats: Audio CD, CD-ROM, CD-ROM/XA, Photo CD, CD Extra, Video CD, Text CD, Karaoke CD, I-Trax.

– Data buffer size – 2 MB.

– Supported disc sizes are 8 and 12 cm in diameter.

– Installation method – vertical and horizontal.

– Dimensions – 156 x 50 x 226 mm.

Let's look at the parameters that affect the quality of the CD drive.

Speed ​​formula for CD. CDs were originally developed for recording and storing music, and the data read speed was 153,600 bytes/s. With the advent of CD drives designed for computer data, the speed increased, but still remained a multiple of 153,600 bytes/s. Subsequently, the speed of reading information from disks increased, but at the same time remained a multiple of this initial value. Based on this, you can calculate the speeds inherent in modern drives: if your drive has a read speed of 52x, then multiplying 52 by 153,600 bytes/s, we get 7,987,200 bytes/s. If the write speed of your drive is 24x, then this is 24 x 52 = 3,686,400 bytes/s.

Note.

Often, for ease of calculation, the speed of the first CD drive is assumed to be 150 KB/s, rather than 153,600 bytes/s.

In a similar way, let's try to calculate the data reading speed for DVD drives. For the first speed in this case, you should take nine CD speeds. Therefore, 153,600 x 9 = 1,382,400 bytes/s, or, in round numbers, 1385 KB/s. Accordingly, the data reading speed for DVD 16x is 16x1382,400 = 22,118,400 bytes/s. With these simple mathematical calculations you can calculate the data flow at any speed.

The CD loading mechanism can be of several types.

– Tray – tray. Pull-out CD loading mechanism.

– Caddy is an assistant. First, the disc is inserted into a special box, and then this box is inserted into the drive receiving device. This mechanism for loading CDs is more reliable, but less convenient.

– Slot-in – can be roughly translated as “entrance slot”. The disc is directly inserted into the drive slot. Loading a CD this way is similar to loading a regular floppy disk.

Buffer size.

During recording, data of all types must be continuously fed to the recording device; if this process is interrupted, the workpiece will be damaged. To ensure error-free operation, all modern drives have special set microcircuits where information intended for recording is placed in advance. This is the buffer. There are three types of buffers.

– Static buffer – stores in memory all information entering the CD drive.

– Dynamic buffer – increases the transfer speed of fragmented data and small files.

– Read-ahead buffer – data is buffered in advance and transferred to the recording device as needed. The computer seems to predict which file will be needed for recording.

How larger size buffer, the better and more reliable the CD drive.

Data access time. This is the delay between receiving a command to read data and actually reading the data. This option significantly affects the recording of highly fragmented files, as well as a large number of small data located on different parts of the hard drive.

The drive data sheet indicates the average data access time. On internal tracks the delay will be greater, and on external tracks it will be less than specified in the characteristics. The faster the data access time, the faster the CD drive is.

CD drives can support the following CD formats.

– Audio CD, or CD-DA. Red Book is a format developed for recording music CDs. After recording, such a disc can be listened to on a household CD player.

– CD-ROM. Yellow Book is a format designed for recording and storing computer data. Such CDs are produced using special equipment using the stamping method.

– Video CD – format for recording and storing video data.

– CD-R – the CD drive can play and burn one-time discs.

– CD-RW – the drive plays and writes discs for reusable use.

– CD Extra – the CD drive allows you to create discs that can contain both audio data and computer data.

– Photo CD is a format developed by Kodak. Used to record collections of photographs.

The DVD formats that CD drives can handle are as follows.

– DVD-ROM – a disc recorded industrially using the stamping method.

– DVD-R – DVD-Recordable – a recordable disc that differs from a factory DVD-ROM by the presence of a special pigment layer between the transparent substrate and the reflective surface. Holes (pits) in such a layer are not stamped, but burned out with a high-power laser beam.

– DVD+R – similar to DVD-R format. The DVD+R and DVD-R formats are similar to each other, their technical characteristics are the same. The only difference between these formats is that different organic substances are used as dyes. The presence of such similar formats is caused by competition among manufacturing companies.

– DVD-RW – rewritable discs. The format was developed by Pioneer.

– DVD+RW – analogue of the DVD-RW format. Developed by Sony and Philips.

MTBF. This is the period during which your CD drive must operate smoothly according to the MTBF standard. After this time, the drive parts will exhaust their service life, and the manufacturer cannot guarantee that the product will continue to work correctly and efficiently. The more time a CD drive can operate, the better; it cannot operate indefinitely.

The main enemies of high-quality drive operation are vibration and heat. After stamping, the disk profile is usually a curved line with two characteristic bends, and only the central part corresponds to the norm. Even very expensive discs are not without this drawback. To extend the life of your CD drive, you must use it properly.

– Try not to create a large number of copies of CDs in a row. Household recording drives become very hot during recording, which can lead to premature wear of the mechanism. It is recommended to make a maximum of two or three copies in a row, then let the drive rest for half an hour, after which you can make two or three more copies, etc. During the break, it is better to disconnect the computer from the network.

– Do not use CDs that are severely warped or scratched. Remember: the cost of a CD drive is significantly more than the cost of a disc.

– If the CD drive is very dirty, the drive itself may scratch the discs. In this case, the scratches are located around the circumference.

To prevent severe contamination of drives, it is necessary to use the PMC Clean program.

Buy a drive cleaning CD from the store. On the working side of such a disk there is a small brush. Apply one drop of the special liquid included in the kit to the brush, insert the CD into the drive. Select Start > My Computer. Double-click on the drive icon to open the contents of the cleaning disc. Find the PMC Clean launcher icon and double-click to launch it. Select the language in which commands will be displayed. In the window that appears, press the START button, after which the music will play and cleaning the drive will begin (Fig. 1.9). Upon completion of cleaning, press the TEST button to start the test program. After reviewing the results, you can exit the drive cleaning program by pressing the END button.

The second way to work with PMC Clean is to install the program on your hard drive and launch it using a shortcut that can be placed on the Desktop. As you understand, the cleaning disk will still have to be inserted into the drive. After installing the program, you can configure it automatic start. In this case, for example, a week after cleaning the drive, a window will appear on your computer screen after loading the operating system reminding you of the need to carry out maintenance work.

Rice. 1.9. Cleaning the CD drive.

Attention!

Run the CD drive cleaning program only when necessary. Excessive zeal in this case can only cause harm.

Another way to extend the life of your CD drive is to install programs that allow you to create virtual CD drives and virtual CDs.

The era of CDs is slowly but surely becoming a thing of the past. Now most modern users don’t even know how they differ from standard R and ROM. In order to understand the difference, you need to remember the history of their creation. Only then will it be possible to determine their main difference from classic CDs.

History of the development of optical CD media

The first compact disc was developed by Philips. They are considered pioneers in this field. At first optical discs had quite a bit of space to accommodate data. The initial volume of such a “blank” was 640 megabytes. But over time it increased to 700. The first optical discs in the compact format were called CD-R. This meant that data could only be written to them once. For a long time they were the ones who were used as carriers. However, time passed, technology developed, and very soon manufacturers introduced a rewritable compact CD-R disc W. This abbreviation (RW) comes from the English word Rewritable (with the possibility of rewriting). Such optical media have become incredibly popular among users. The very idea of ​​reusable recording to disk seemed incredible. But there was one minus. The recording speed on such media was very low. If the standard R disc was written at x53 speed, then RW Classic discs needed to be written at x6 speed. But this did not last long, as standard CDs soon went out of fashion.

The advent of DVD

The decline of classic "compacts" is directly related to the emergence of a new format - DVD-R. These optical drives were distinguished by their gigantic volume (compared to CDs). They could fit 4.5 gigabytes of information. It was a breakthrough. As expected, some time after the successful launch of classic DVDs, DVD-RW discs appeared that allow you to record on one or another medium several times. And this solution has become incredibly popular.

DVD discs were used almost everywhere: programs, operating systems, films and other information were recorded on them. Even music in formats without loss of quality was written on DVD discs. And in this regard, DVD-RW discs looked like the most universal solution. And soon double-layer DVDs appeared that could hold almost 10 gigabytes of information. This was truly a breakthrough. For a long time, DVDs were used everywhere. Special players were also released. They could also read RW, so users recorded several movies on them at once. And when they got tired of them, they re-recorded them. This went on for quite some time. But the DVD era has come to an end.

Blu-Ray era

Classic and double-layer DVDs have been replaced by Blu-Ray media. They were distinguished by increased capacity. One such disk held about 25 gigabytes of information. That's a lot. Around the same time, HD video formats also appeared. Films in this format fit perfectly on BD. This determined the area of ​​application of such optical media - the film industry.

Indeed, keeping the library on BD was somehow wrong. Moreover, at the same time, the Internet developed rapidly and large-capacity USB drives appeared. Nobody needed disks anymore; only BDs were still afloat. And that’s only thanks to those who like to watch movies in maximum quality in their home theater. Over time (as expected), dual-layer BD and BD-RW discs appeared. The latter allowed information to be overwritten. But given the volume of Blu-Ray media and the low recording speed on RW, this option has not gained popularity. To this day, BD-RW remains just an interesting technology. But nothing more.

The relevance of Blu-Ray technology is also being rethought. New video resolutions have appeared - 2K and 4K. But they require much more space and will never fit on a classic BD “blank”. The era of Blu-Ray will probably soon end successfully. But that's a completely different story.

Conclusion

So, we talked about the features of RW disks and looked at the history of the development of optical media. Classic CDs are already used exclusively in the music industry. No one has heard of DVD for a long time. Nowadays Blu-Ray technology rules the roost. But judging by latest trends In the world of multimedia entertainment, the days of the above technology are numbered. Perhaps manufacturers are now developing new type optical media. But we’ll tell you about what happens next next time...

QUESTIONS AND ANSWERS: What you need to know about burning CD-R and CD-RW discs.

1. What do you need to have to burn CDs?

You need a computer with a device installed in it called a CD-writer. This device connects to the computer in several possible ways. Most drives for recording discs have an IDE interface and are connected in the same way as regular CD-ROMs or hard drives and have an internal design. However, there are other versions, both external and internal - with a SCSI interface, connected to a parallel port or to the USB bus.
The second necessary part for burning discs is software. Its choice is very large - from the most popular commercial packages from Adaptec (Easy CD Creator, Easy CD Deluxe, Easy CD Pro) to shareware programs such as Nero or CDRWin.
And finally, you need a blank CD-R or CD-RW disc

2. What can be burned onto CD-R or CD-RW discs?

Traditionally, discs can store both sound and data. Data is stored on CDs in the same format as it is stored on a hard drive. It should also be noted that it is possible to create mixed discs, combining sound with data.

3. What's the difference? CD-R discs and CD-RW?

CD-R stands for CD-recordable, that is, “recordable.” This means that information recorded on such a disk cannot be deleted from there. The main difference CD-RW discs(CD-rewritable) is that information from them can be deleted and recorded again. As a result, CD-RW discs, which are more flexible in use, are slightly more expensive than conventional write-once discs.

4. How much information can be recorded on a CD-R disc?

5. Why is the standard duration 74 minutes?

The general consensus is that this length was chosen because the CD developers wanted a format that would accommodate Beethoven's Ninth Symphony. They determined which diameter to use, and the length of some performances decided this issue.

Recorded discs can be used on the following devices:

Home CD Player Given that home CD players predate CD-R burners, there is no guarantee that all recorded music CDs will play in audio players. However, to achieve best result It is recommended to use CD-R discs, since their specifications are much closer to traditional ones music discs, rather than CD-RW. DVD-ROM drive or DVD player The vast majority of DVD players and all DVD-ROM drives(with the exception of the first samples of these devices) is able to read information from CD-R and CD-RW discs. CD-ROM drives

All modern CD-ROM drives Excellent readability of both write-once discs and CD-RW discs. Nuances exist only with old drives, which in some cases do not read CD-R discs, or read these discs, but do not read CD-RW discs. If your old drive is marked as having a Multiread function, then this means that you can use it to cope with this task. A good indication that a drive is capable of handling recordable discs is how fast the drive reads data. If the speed is 24 or higher, then, as a rule, such a drive is quite suitable for working with CD-R and CD-RW discs.

7. Why are the reflective sides of the discs different colors?

Different CD companies have patents on the various chemistries they use to produce the discs. Some companies produce disks themselves, others simply license their technology to them. As a result, the reflective side of CDs turns out to be different colors. CD-Rs are available in the following composition combinations: gold/gold, green/gold, silver/blue, and silver/silver, and their many shades. The visible color is determined by the color of the reflective layer (gold or silver) and the color of the dye (blue, dark blue or clear). For example, green/gold discs consist of a gold reflective layer and a blue dye, so the disc is gold on the label side and green on the recording side. Many have come to the conclusion that "silver" discs are made of silver and, based on this assumption, have tried to speculate about the reflectivity and durability of the media. Until a manufacturer's representative comes forward with a statement about the actual composition of the disc, it is unwise to assume anything specific. Some CDs have an additional coating (such as Kodak's "Infoguard") that makes the CD more scratch-resistant but does not affect the way the information is stored. The top (label) side of the disc is the most important area to worry about because this is where the data lives and is the area that is most easily damaged on a CD-R. You can protect the disc from scratches by sticking a round CD sticker over its entire area. CD-RW discs have a completely different structure. The data side (as opposed to the label side) is a silvery dark gray color that is hard to describe. You can also give a short list of which companies produce which discs:

Taiyo Yuden produced the first "green" CDs. They are now also made by TDK, Ricoh, Kodak, and probably a few other companies.

Mitsui Toatsu Chemicals (MTC) produced the first "golden" CDs. They are now also made by Kodak and possibly others.

Verbatim produced the first "silver/blue" CDs.

Many brands of CD-R (such as Yamaha and Sony) are OEM versions of one of the major manufacturers. By by and large, it is difficult to determine who produces what because new factories have been built and sellers may change suppliers.

8. What do the speed numbers (for example, 6x4x32) mean in the parameters of CD burners?

Conventional audio players play music CDs in 74 minutes. This speed is taken as the basis when measuring the speeds of playing and recording CDs and is called a single speed (1-x). Single speed corresponds to a transfer of 150 Kilobytes per second. A CD-ROM drive with two times the speed (2x) transfers data at a speed of 300 Kilobytes per second.

Three numbers in the parameters of CD-writers indicate the speed at which this device can write CD-R discs, CD-RW discs and, accordingly, read these discs.
For example, 6x4x32 means that this device writes CD-R discs at a speed of 6x (900 KB/sec), writes CD-RW discs at a speed of 4x (600KB/sec) and reads any type of CD at a speed of 32 (4800 KB/sec)

9. What formats exist when burning CD-R discs?

This is the most difficult question to answer, given that many different CD formats have emerged over the past few years, while there are still historical formats that have been around for a long time and are used in specialized applications. Below is an overview of the main formats:

Music discs (Audi o CD) or CD-DA or "Red Book"

To burn regular music CDs, you need the disc you burn to conform to the CD-DA standard. When recording, standard WAV files (or AIFF - Apple Audio Interchange File Format) are used as a source.

ISO9660 Data CD

This standard defines the form in which conventional data is written to CD-R discs. This standard has many restrictions, namely, the maximum number of subdirectories cannot exceed 8, file names cannot be longer than 8 characters, and 3 characters are allocated for the file name extension. However, this standard is compatible with a large number of computers and operating systems.

The format proposed by Microsoft simultaneously with the advent of the operating system Windows systems"95. The file name length is limited to 64 characters in this standard, and this format is now supported, as in Windows environment, and on MacOS and Linux. Joliet is based on the ISO9660 standard and discs written in this format can be read on almost any computer. However, filenames will be truncated to 8+3.

This format strictly applies to Macintosh computers. HFS CDs can only be read on this type of computer.

UDForPocket Writing

UDF (Universal Disk Format) is a radical extension of the ISO9660 standard, somewhat reminiscent of Joliet. Adaptec DirectCD software (included with Easy CD Creator Deluxe, or sold separately for the Mac platform) and, for example, CeQuadrat PacketCD software allow you to burn discs in this format. UDF differs from other formats in that you can treat a CD like a large floppy disk, copying files to it using standard Windows or MacOS tools. However, this format is not suitable for transferring discs to other people, because in order to read discs in this format, they will need to install special software to read such discs.

ISO 9660 Rock Ridge

An extension of the ISO9660 standard, used exclusively in Linux and UNIX operating environments.

ISO Level 2

A slightly modernized ISO9660 format, simplified in terms of restrictions. For example, the file name length in it is limited to 31 characters. However low level compatibility of this standard does not allow it to be used as widely as, for example, the Joliet format is used.

VideoCD or VCD or "White Book"

The VideoCD format was developed in the mid-90s and was intended for use in devices such as the Philips CD-I player. VideoCD discs contain video image and audio compressed using the MPEG1 standard. Despite the fact that the Philips CD-I player has not been produced for a long time, these discs can be used on the vast majority of DVD players if they support reading CD-R or CD-RW discs.

8. What format should I use if I want….

…. exchange data with friends who use an operating system similar to mine?

Everything is simple here. Windows operating system users should use the Joliet format, Mac users should use the HFS format.

…. share data with people who use different operating environments and platforms?

For maximum compatibility ISO9660 format is recommended. However, if you need to save long names files on disk, then you should try using the Juliet format. Modern Macs and most operating systems now have the ability to read discs written in this format.

…. listen to music on a regular audio player?

Then you should burn the disc in CD-DA format, which will provide the highest level of compatibility with your audio player.

10. How to burn discs with mixed content?

There are two options for burning such discs:

Mode I- when using this format, data is recorded at the beginning of the disc (in any known format), then the recorded audio tracks follow. If you need to combine audio and data, then using this mode will provide the necessary level of compatibility with various devices and operating environments.
CD-XA (Mode II)- this mode differs from the previous one in that data and sound can be recorded in random order. However, this flexibility has a negative impact on the compatibility of the recorded discs.

11. What is a multisession CD?

This technology allows you to add data or sound to a disc that already has something written on it until the disc is closed. This was very relevant in the early 90s, when the cost of a blank CD-R disc reached $12, CD-RW discs did not exist, and hard drives had a small capacity.

Discs recorded using this technology have some compatibility issues, and therefore it is not recommended to use it without compelling reasons. The UDF format makes this technology unnecessary; With Direct CD and similar software, you can burn data without worrying about compatibility. If you need to give the disc to other people, then just burn it at once in Joliet format

12. What is "closing" a disk?

"Closing" a disc means that after this procedure is completed, nothing can be done on that CD-R disc. If you never use the "multisession" feature, then there is no point in thinking about it, because the disk will close automatically after the end of writing information to the disk. Many older CD-ROM drives and audio players have problems reading unsealed discs, so it makes sense to "seal" the disc for greater compatibility.

If you want to write something to "closed" CD-RW disc just perform the "erase" function and you can write data to this disk again. If you use the UDF format, then there is no concept of “closing” the disk in the traditional sense of the word - just copy and delete files from such a disk, as from a simple floppy disk.