Cd player CD player; Cd player
Two meanings of CD:
1. CD
laser record
(a), the source of CD-R/CD-RW
1, the birth of CD
CD stands for laser disc, which is a common term used in all CD media formats. Some CD formats on the market now include audio CD, CD-ROM, CD-ROM XA, photo CD, CD-I and video CD. Among various CD formats, perhaps the most familiar is audio CD, which is a standard CD format for storing sound signal tracks such as music and songs. CD Digital Audio Signal (CDDA) is a music transmission form introduced by Sony and Philip in the period of 1980. Due to the great success of audio CD, today, the use of this medium has been extended to data storage, with the purpose of data archiving and transmission. Compared with various traditional data storage media such as floppy disks and audio tapes, optical disks are most suitable for storing a large amount of data, which may be any form or combination of computer files, audio signal data, photo image files, software applications and video data. Advantages of CD include durability, convenience and effective cost.
2. Expand the standard of CD-ROM.
From 65438 to 0989, Japan Sun Yudian Company developed an organic soda ash CD medium with a thin layer of gold on its surface. This new medium not only provides the same physical characteristics and capacity as the silver compact disc, but also has better reflection characteristics than the commercial copy disc. This medium can be recorded by a special device that can write information on the optical disc, and the written optical disc can be read by any optical drive in turn. A device that records information on a medium is called a CD- recorder, and the medium is called a CD-R (recordable CD).
The invention of CD-R technology has brought many benefits, such as:
(1) You can make your own CD on a desktop PC at a low cost.
(2) You can choose any suitable CD format to record your information;
(3) Avoid expensive training expenses and copying facilities related to business training. Because the typical CD-R medium has a lifetime of 70- 100 years, it is an ideal choice for long-term data preservation. This is a significant improvement for magnetic media with much shorter life. CD-R technology is a breakthrough, which will introduce the next revolution of data storage technology, because in this era of information explosion, the demand for large capacity is increasing.
3, the standard of optical disc
This standard allows different computers with different operating systems to access the same data format. The current success of CD-ROM should be attributed not only to the obvious advantages of the media itself, but also to the worldwide recognition and cooperation of the media through ISO9660 and other standards. All computer platforms store data on optical disks as file systems. The file system is designed to be recognized by UNIX, VAXVMS, MS-DOS and Mac and their various derivative systems. ISO9660 means compatibility with different operating systems. This compatibility is achieved by using all target systems. Therefore, the requirements of ISO9660 are as follows.
1) The directory tree cannot exceed 8 levels.
2) No long file name:
The file name including the extension must be less than 30 characters. But when used in MS-DOS, it has more restrictions: the file name is 8 characters at most and the extension is 3 characters at most.
3) There is no extension in the directory name.
4) Only capital letters are allowed.
5) Special characters such as% or @ are not allowed.
Before sending data to a CD burner for burning, CD burning software will help you create ISO9660 image files. It is easy to use and helps to eliminate recording errors at runtime, such as insufficient load in the buffer.
4. Expand ISO9660-Joliet and Romeo file system.
ISO9660 has some restrictions, such as character setting restrictions, file name length restrictions and directory tree depth restrictions. These regulations prevent users from copying data to optical disks that can be read by different computer platforms. Therefore, some operating system vendors have extended ISO9660 in various ways.
Joliet file system is one of the extended file systems proposed and implemented by Microsoft. It is based on ISO9660( 1988) standard. If the CD is created with Joliet file system, it can only be read under window 9x and window NT4.0 or higher, but not on any other platform. Under Joliet file system, the maximum number of characters allowed for long file names is 64, and the maximum number of characters allowed for long directories is 64. However, the total characters of the file name and its full path cannot exceed 120.
Romeo is only defined as the long file name of window9x, with a maximum of 128 characters.
5, the specifications of the CD
Before storing information on an optical disc, some method must be used to compress the data. In order to unify the compression method, various manufacturers have formulated many standards so that the burned discs can be used on different machines. These standards were formulated in different years and expressed in different colors of packaging. Common specifications are as follows:
1) little red book
It was made by Philips and Sony in 1980. This is a CD-DA optical disc standard for storing audio tracks. This specification contains only tracks of audio sectors. Because CD-ROM comes from audio CD, a large amount of information stored on CD can be measured by minutes, seconds and frames, among which:
1 min =60 seconds
1 sec =75 frames
1 frame =2048 bytes (2 kilobytes) mode 1 user data
Please note that the actual space occupied by a file on a CD is usually larger than its original size due to the extra consumption of sector boundaries. The disc capacity is calculated at a single speed (150KB//s). A CD can store 74 minutes of music or 650 MB of data, and the conversion method is 74 (minutes) * 60 (seconds) * 150 (KB) = 666000kb = 650MB, and the recording time of two-speed music CD is 74.
2) Yellow Book
It is a CD-ROM data disc standard formulated by Philips and Sony in 1983. This specification contains only data sectors and is divided into two modes.
Mode 1
Error checking and correcting check is added to the CD, and each sector can store 2048 bytes of data, which is suitable for storing conventional data.
Mode 2
The removal of ECC check increases the file storage space, and each sector can store 2336 bytes, which is suitable for storing graphics and music materials.
Defining a unit of 2352 bytes in the Yellow Book is called a block.
3) Green Paper
Formulated in 1986, it is the standard of CD-I interactive CD.
4) Yellow Book+(Yellow Book Advanced)
1989, which supplements the CD-ROM/XA (optical disc expansion architecture) standard. Added specification of mode 2:
Form 1: ECC(Error Checking and Correction) check is added, and each sector can store 2048 bytes, which can be used as Mode 1 format.
Form 2 removes ECC checking and increases file storage space. Each sector can store 2328 bytes, which is as suitable for storing graphics and music materials as mode 2.
The greatest use of the enhanced yellow book is that it can alternately store data or audio and video to avoid the intermittent phenomenon when audio and video are transmitted at the same time.
5) Orange Book
It contains the standard of CD-R recordable discs. The physical structure of CD is defined as: sectors are contained in tracks, tracks are contained in data areas, and data areas are contained in optical disks.
6) White paper (writing a book)
It defines the standard of VCD (Video Disc).
7) Blue Book
The standard defines an extra mode optical disc (CD-Extra), and stipulates that the first track is a CD-DA music segment and the second track is a CD-ROM data segment.
6. The difference between a gold CD and a silver CD.
Gold CD, also known as CD-R CD, is a blank CD covered with a thin reflective gold layer. Silver CDs, also known as commercial copy CDs, have a thin layer of aluminum. Because of the different electroplating methods, the physical appearance, especially the color, of these two types of discs are different. Blank gold discs can be used as recordable media. You can use a CD burner to write data and music signals to a gold disk, but a silver disk cannot be used as a recordable medium because the data has been compressed into polycarbonate. The life of silver CD is about 25 years, while that of gold CD is 70- 100 years. This fact points out their different uses: silver discs are suitable for data transmission and large-scale commercial reproduction, while gold discs are very suitable for data archiving.
CD-R and CD-RW discs can be divided into the following types according to the different surface coatings: 1) green discs.
Developed by Sun Yudian Company, the raw material is cyanine (cyan pigment), and its storage life is 75 years. This is the earliest standard and has the best compatibility. The manufacturers are Sun Electric, TDK, Ricoh and Mitsubishi.
2) Blue disk
Developed by word for word company, the raw material is Azo (azo). Under the reflection of the silver reflective layer, you will see a water-blue disc with a storage time of 100 years. The manufacturers are word for word and Mitsubishi.
3) Gold plating
Developed by Mitsui Dongjin Company, the raw material is phthalocyanine (phthalocyanine), which has strong light resistance and the storage time is as long as 100 years. The manufacturers are mitsui Toyo and Kodak.
4) purple compact disc (CD-RW)
It is made of a special material and has only one color similar to purple glass. CD-RW uses phase change technology to produce crystalline and amorphous, representing 0 and 1 respectively, which can be written many times and is also called rewritable optical disc.
7. the difference between CD-r and CD-RW.
Although CD-R, CD-R and CD-RW are all optical disks, they are quite different in essence. CD-ROM is the most common, and its surface is white, also called silver disk. It is mass-produced by a CD processing line. As soon as it is produced, there is already content, and it is impossible for a burner to make a CD.
The surface of CD-R is coated with a reflective layer (green, blue or gold), which has no content when it is first produced. It can be found that the color of the disc will change after burning, and the data has been stored. Now CD-R/CD-RW can be used without formatting, just like a floppy disk can be used when bought, which is very convenient!
CD-RW (erasable optical disc) also has a reflective layer (purple), which can be used many times, and the limit is about 1 0,000 times. Although it can't be used as a hard disk, the backup is also good.
The earliest CD burner manufacturers were Yamaha and Sony. The first generation of CD recorders produced were single-speed (150Kbps) drives, also known as 1X drives. Since then, a large number of CD burners produced by different manufacturers have appeared in the market. Later, the speed of several generations of recorders increased to twice, that is, double speed (300Kbps), and four times, that is, quadruple speed (600Kbps). A CD burner can be an external or internal device. The external driver can be separated from the computer body, and the internal driver must be installed in the computer. With the rapid development of CD-R technology, the recording speed of CD recorders has been continuously improved, and their sizes have become more compact.
In use, compared with the floppy disk or hard disk drive that you are familiar with, a characteristic of CD burner is that it requires a stable data stream during writing operation. All CD burners have a buffer memory called cache. Dure that writing operation to the optical disc, the cache area contain a certain amount of data written to the optical disc. During the whole write operation, the cache area will never run out. There must be a steady data stream that is neither too fast nor too slow, and it constantly flows from PC (RAM or hard disk) into the buffer area of the burner. Driving this stable data stream may require a high-performance PC and its dedicated resources.
Usually, CD burners are mixed with SCSI cards. SCSI stands for "Small Computer System Interface" and is an interface standard for high-speed data transmission between computers and their external devices. A SCSI interface usually allows up to eight different devices to be connected to a controller. Because most CD recorders use SCSI interface, you must install SCSI controller on your computer. The data transmission speed of SCSI card is an important factor. It must be fast enough to provide a stable data stream for the CD burner. In the past, only SCSI, a high-end device, had CD recorders, but technology always promoted the pace of human progress, and IDE interface products began to appear slowly. The current IDE CD burner is designed for CD recording and reading, just like an ordinary CD-ROM drive. In addition to the usual tray-type CD-ROM drive, there is also a cassette recorder, which puts the CD in the box first and then inserts the CD-ROM drive, but this kind of equipment is rare.
8. Precautions for burning CDs
I often hear that someone has damaged the CD. In fact, as long as you pay attention to the following points, there is no problem. At least I have carved 200 CDs and never tried to break them.
1) Turn off the power management function in BIOS and Windows.
2) Cancel the screen saver
3) Don't load any resident programs at first, and don't multitask other software.
4) Turn off AutoRun, and the CD will automatically insert the notification.
5) Before burning, run disk defragmentation.
6) Use two-speed recording instead of four-speed or higher.
7) Use the CD mirroring function, and don't burn directly.
8) Buy high-quality CDs, and only 10 yuan for better ones. You know, CDs are used to store data, and data is much more valuable than CDs. Don't you get it?
9, CD-ROM startup principle
In many commercial CDs, we will find that the CD boot function is printed on the cover, that is, using the CD boot system can avoid the problems of insufficient floppy disk capacity and slow speed. In fact, CD-R and CD-RW can also be used to start CDs. The principle is as follows:
1) Set the CD boot in the BIOS.
2) After 2)POST, the optical drive checks whether the CD has the boot function.
3) First, read the main mark description of the sector 17 area of the optical disc.
4) Load BCF (Boot Directory File) according to the address described in the main label.
5) Load BIF (boot image file) according to the boot directory file.
6) Run the boot program in the boot image file and start to enter the operating system.
According to the Yellow Book standard, an ordinary CD has 333,000 sectors, with 0~ 16 as the reserved value and 17 as the main symbol description, which stores the startup information of the CD and the location of the startup directory file. The boot directory file includes the operating system of the CD and the location of the boot mode BIF. BIF stores the startup program, which can be Windows 9x or DOS system.
There are three kinds of information in the description of the main tag: 1)CD00 1, the standard opening character of the yellow book.
2)E 1 Torito, start the recognition character of the CD specification.
3) The location of the startup directory file points to the logical part of BCF.
The boot directory file contains seven kinds of information.
1) The first digit is 0 1, starting with the CD ID number, and its value is set to 0 1.
2) The second digit is 00 for X86 system, 0 1 for PowerPC system and 02 for Macintosh system.
3)ID string, which can be manually input as CD identification information.
4)55 AA, end mark
5)88 (after 55 AA): CD can be started, but it cannot be started if it is 00.
6)02 (after 88), analog 1.44MB floppy disk is started, 0 1 means analog 1.2MB floppy disk, 03 means analog 2.88M floppy disk, and 04 means analog hard disk.
7) Start the image file location and point to the logical part of BIF.
The content of the boot image file is to mirror the boot file of the 1.44M floppy disk. Do you feel very troublesome after reading the above principle? Don't worry, almost all the software on the market can make a bootable CD, and it only takes a few mouse clicks, and everything is done by the program itself. It should be noted that after the CD-ROM drive is started, the image file of the CD-ROM drive becomes drive A, the first floppy drive becomes drive B, and the second floppy drive cannot be used.
Conference on Disarmament
The artist is also called CorleDRAW CD, and photoshop is called PS for short.
CorleDRAW is a professional and powerful drawing program based on vector drawing.
Compatible number
Cheat anti-terrorism and anti-cheating software
Christian Dior is a world-renowned women's clothing brand owned by christian dior.
The important attributes in the cool blizzard game StarCraft determine the attack speed of the object.
In network language, "CD" means "slow". If someone calls you a CD in a post, it's because your reflection is not smart enough. Corresponding to this is "VCD", which means "very CD", which means that you are "very slow"
Element symbol:
English name of Cd: cadmium Chinese name: cadmium
Relative atomic mass: 1 12.4 1 common valence: +2 electronegativity: 1.69.
Peripheral electron configuration: 4d 10 5s2 Extranuclear electron configuration: 2,8, 18,18,2.
Isotope and radiation: CD-106cd-108cd-109 [462d] CD-10cd-11cd-/
Electron affinity and energy:-26 kj mol-1.
The first ionization energy is 867.8kJ mol-1,the second ionization energy is1631.4kJ mol-1,and the third ionization energy is 3610kJ mol-/kloc-0.
Element density: 8.65g/cm3 Element melting point: 320.9℃ Element boiling point: 765.0℃
Atomic radius: 1.7 1 angstrom ion radius: 0.95(+2) angstrom valence radius: 1.48 angstrom.
Common compounds: cdbr2cd (oh) 2ccdo3cdo.
Discovered by: Strohmeier Time: 18 17 Location: Germany.
Name source:
Greek: kadmeia{ the ancient name of allotrope (zinc oxide)}.
Element description:
A soft and malleable blue-white metal.
Element source:
By-products of zinc refining.
Element usage:
Used for electroplating steel and manufacturing nickel-cadmium batteries. The compound is used for preparing oil painting pigments. Boiling cadmium metal will produce strange yellow toxic vapor.
Second, the international brand CD brand file
Founder: christian dior
Place of registration: Paris, France (1946)
Designer:
1946-1957, christian dior
1957 - 1960，YvesSaintLaurent。
1960-1989, Mark Bohan (Mark Bohan)
1989-1996, gianfranco ferre (gianfranco ferre)
After 1996, John galliano (John galliano)
Brand line: ChristianDior christian dior: high-end women's wear, high-end ready-to-wear
Category: high-end women's wear, high-end garments, knitted garments, underwear, perfume, cosmetics, jewelry, accessories, etc.
Brand recognition:
Dior clothing is different from other famous brands. It never sticks any obvious signs such as "CD" or "Dior" on clothes, and the word ChristianDiorParis on the clothes label is its only way of identification.
1.CD: This abbreviation often appears on Dior accessories, such as belts, buckles of wallets, or the side of glasses frames.
2. DIOR: The key ring with the word Dior strung on the bracelet is the most obvious symbol of the "LadyDior" wallet, and later it almost became another obvious symbol of Dior.
3. Diamond Plaid: This kind of diamond cut lattice specially designed for Dior rarely appears on clothes, but only on Dior's leather goods.
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In addition, CD is the abbreviation of CROSS DRESSER.
Chinese translation is "cross-dressing", which is often called cross-dressing. The CD mentioned here is not casual clothes worn by people who have fun on a whim, nor is it an actor who plays the role of the opposite sex, but a man who has a strong desire to dress up as a woman for a long time. This desire is almost unstoppable and unchangeable. Only through cross-dressing, can we feel self-release, unspeakable relaxation and pleasure, and even sexual pleasure. They think that CD is the best way to switch between the sexes freely and combine yin and yang. However, transvestites don't want to be real women, remain heterosexual and don't want to have their sexual organs removed. Therefore, they are different from homosexuals.