CD-CompactDisk

CD（Compact Disk, Chinese name ： CD （ Because it was originally used to store audio files ）） Represents a small laser disk , Is a for all CD General terms for media formats . There are some in the market now CD Formats include audio CD,CD-ROM,CD-ROM XA, Photo CD,CD-I And video CD wait . In this diverse CD In the format , Perhaps the most familiar one is audio CD, It is a standard for storing sound signal tracks such as music and songs CD Format .

essential information

Full name ：Compact Disk（ CD , Compact disc ）

Be born

CD Represents a small laser disk , Is a for all CD General terms for media formats . There are some in the market now CD The format includes Audio CD,CD-ROM,CD-ROM XA, Photo CD,CD-I and video CD wait . In this diverse CD In the format , Perhaps the most familiar one is audio CD, It is a standard for storing sound signal tracks such as music and songs CD Format .CD Digital audio signal (CDDA) By SONY and philips stay 1980 It was introduced as a form of music communication during the year of . Because the audio CD Great success , Today, the use of such media has expanded to data storage , The purpose is to archive and transfer data . And various traditional data storage media such as floppy disk Compared with audio tape ,CD Is best suited for storing large amounts of data , It can be any form or combination of computer files 、 Audio signal data 、 Photo Image file , Software applications and video data .CD The advantages include durability 、 facilitate 、 And limited expenses .

1. standard

ISO9660 It is an internationally recognized CD Media logic level standard , It defines the CD-ROM Format of files and directories on . This standard allows different computers with different operating systems to access the same data format .CD-ROM The current success should not only be attributed to the obvious advantages of the media itself , And attributed to pass ISO9660 Such standards complete the worldwide recognition and collaboration of the media . all Computer platforms Put the data on the CD as a file system . The file system is designed to UNIX,VAXVMS,MS-DOS and Mac And their various derivative systems ,ISO9660 Means compatibility with different operating systems . This compatibility is achieved by using features common to all target systems . therefore ,ISO9660 The following restrictions are required ：

(1) The directory tree cannot exceed 8 level .

(2) No long file name ： A file name including its extension must be less than 30 Characters . however , For in MS-DOS Next use , It has more restrictions ： Maximum filenames 8 Characters , And the most extensions 3 Characters .

(3) There is no extension in the directory name .

(4) Only capital letters .

(5) Some special characters are not allowed , Such as % or @.

CD burning software will help you to officially transfer data to CD The recorder creates a before recording ISO9660 Image file . Easy to use , And help eliminate runtime logging errors . For example, the cache runs under load .

2. Color

When observing CD Surface or soap bubble , Or watching a thin layer of oil floating on the still water , You usually see rainbow patterns . These three kinds of effects are caused by the phenomena of phase interference and phase cancellation interference when the light shines on the film .

Take a thin layer of oil floating on the water . When white light hits the film , Most of the white light will pass through it , But there is also a part of it on the top and bottom of the film Reflection fall . Again , When you stand in front of the window of the house , You can see the reflection image in the window . Most of the light goes out through the window , But there is also some light reflected back to you . The light reflected at the top of the film travels a little shorter than the light reflected at the bottom .

Incident light comes in from the top left . Part of the light passes directly through the film (A); Part of the light is reflected at the top of the film (B); Another part of the light is reflected at the bottom of the film (C).

If the film thickness is in the optical wavelength sequence , There will be interference . The violet wavelength is about 4,000 Egyptian （ One millionth of a centimeter ）, The wavelength of red light is about 7,600 Egyptian , So we're talking about very thin films . From how rainbows are formed, we can know , White light is made up of all other colors .

If the film thickness is appropriate , Red light wave （ Sine wave ） The top and bottom layers will be reflected in a straight line , The generated two sine waves will be integrated , Double the brightness of the red light you see . otherwise , They may reflect out of phase , Then the red light will disappear .

because CD The surface is like a mirror , So the rainbow color will be much stronger .（ To learn about CD Description of structure , Please see the CD working principle .） Yes CD for ,CD The angle at which it is placed Determines the color you see —— Because the angle will control the travel difference .

3. Extended standard

1989 year , Japan Taiyo Yuden The company has developed an organic pure base coated with a thin layer of gold CD The media . This new media not only provides and silver compression CD Same physical characteristics and capacity , And it also has more advantages than commercial replication CD Good reflection characteristics . This kind of media can be recorded through a special device that can write information on a CD , And the CD written in turn can be used by any CD-ROM Drive read . Recording information to the media equipment be called CD recorder (CD- Recorder ) and The media is called a recordable disc CD-R(CD Recordable).CD-R The invention of technology brings many benefits, such as ：

(1) Available at a low cost on a desktop PC Make your own CD-ROM Compact disc ;

(2) You can choose any suitable CD Format recorded information ;

(3) Avoid expensive training costs and replication facilities associated with business training . Because of the typical CD-R The media have 70-100 Years of life , It is ideal for long-term data preservation . For magnetic media with a much shorter lifetime , This is a significant improvement .CD-R Technology is a breakthrough , It will usher in the next revolution in data storage technology , Because in this era of information explosion, the demand for large capacity is increasing day by day .

4. Expand ISO9660

stay ISO9660 There are some limitations in , Such as character setting limit , File name length limit and directory tree depth limit . These regulations prevent users from copying data to a device that can be read by different computer platforms CD-ROM. therefore , Some operating system vendors have expanded in several ways ISO9660.

Joliet File system is one of the extended file systems , from Microsoft Propose and implement . It uses ISO9660(1988) Based on standards . If one CD Yes, it is Joliet File system creation , It can only be found in Windows 9x and Windows NT 4.0 Or the updated version , however Cannot read on any other platform . stay Joliet Under the file system , The maximum number of characters allowed for long file names is 64, The maximum number of long directories allowed is 64. however , The total number of characters of the file name plus its full path cannot exceed 120.

Romeo Only defined as Windows 9x Long filename , most 128 byte .

5. specifications

Before storing information on a CD , You must use some specific method to compress the data , In order to unify the compression method , Various manufacturers have formulated many standards , So that the recorded disc can be used on different machines . These standards were drawn up at different times , Represented by packages of various colors , Common specifications are as follows ：

（1） Red Data Book (Red Book)

It is from Philips and Sony On 1980 Made in , Is used to store audio sound tracks CD-DA CD standards , This specification only includes tracks of audio sectors . because CD-ROM From audio CD, A large amount of information stored on the CD can be recorded in minutes 、 second 、 Frame determination , among ：

1 branch =60 second ;

1 second =75 frame ;

1 frame =2048 byte (2 kilobytes ) Pattern 1 User data .

Note that due to the additional consumption of sector boundaries , The actual space occupied by files on a disc is usually larger than its original size . The capacity of the disc is in single speed （150KB/ second ） Calculated , A CD can store 74 Minutes of music or 650 MB data , The conversion method is 74（ branch ）* 60（ second ）* 150（KB）=666000KB=650MB, Two speed recording CD At 74/2=37 minute , namely 37 Minutes can be engraved 650MB data .

8cm CD-R The disc capacity is 180-220MB Between , The standard capacity is 210MB.

（2） Yellow book (Yellow Book)

It is from Philips and Sony On 1983 Made in CD-ROM Data disc standard , This specification contains only data sectors , There are two modes .

Mode 1

stay CD-ROM Added ECC(Error Checking and Correction, Error checking and correction ) check , Each field can store 2048 Byte data , Suitable for storing routine data .

Mode 2

Remove ECC check , Increased file storage space , Each field can store 2336 Byte, Suitable for storing graphics and music materials .

Define a in the yellow book 2352 The units of bytes are called blocks (Block).

（3） Green paper (Green Book)

On 1986 Made in , yes CD-I Standards for interactive discs .

（4） Yellow book +(Yellow Book Advanced)

On 1989 Made in , added CD-ROM/XA(CD－ROM eXtended Architecture) CD standards . Added Mode 2 Specifications ：

Form1： Join in ECC(Error Checking and Correction, Error checking and correction ) check , Each field can store 2048 Byte, And can be used as Mode 1 Format .

Form 2, Remove ECC check , Increased file storage space , Each field can store 2328 Byte, and Mode 2 It is also suitable for storing graphics and music materials .

The biggest use of the Yellow Book Enhanced Edition is that it can store data or audio-video in a staggered way , Avoid discontinuities in audio-visual simultaneous interpreting .

（5） Orange book (Orange Book)

It contains CD-R Standard for recordable discs ,CD The physical structure of is defined as : The sector is contained in the track , The track is contained in the data area , And the data area is contained in the CD .

（6） white paper (White Book)

It defines the VCD(Video CD, video CD) Standards for .

（7） Blue Book (Blue Book)

This standard defines additional mode discs (CD-Extra), Specify the first track as CD-DA Music segment , The second orbit is CD-ROM Data segment .

Main categories

Gold discs and silver discs

Gold CD , Also known as CD-R Compact disc , It is to wrap a thin reflective gold layer on a blank CD . Silver CD , Also known as commercial replication CD, It has a thin aluminum layer . Because of different plating methods , Physical appearance , Especially the color , In these two categories CD It's different . A blank gold disc can be used as a recordable medium , You can use one CD The recorder writes data and music signals to a gold disc , A silver CD cannot be used as a recordable medium , Because the data has been compressed into polycarbonate . The life of a silver disc is about 25 The life span of gold discs is 70--100 year . This fact points to their different uses ： The silver disc is suitable for data transmission and mass commercial reproduction , Gold discs are ideal for data archiving .

CD-R、CD-RW Disc press Surface coating The differences are divided into the following categories

（1) Green disk

from Taiyo Yuden Company R & D , The raw material is Cyanine( Cyanine ), The storage life is 75 year , This is the earliest developed standard , The most compatible , Manufacturer has Taiyo Yuden、TDK、Ricoh( Ricoh )、Mitsubishi( Mitsubishi ).

（2) Blue disk

from Verbatim Company R & D , The raw material is Azo( Azo ), Under the reflection of silver reflector , You will see the water blue surface , The storage time is 100 year , Manufacturer has Verbatim and Mitsubishi.

(3) Gold plate

from Mitsui Toatsu Company R & D , The raw material is Phthalocyanine( Phthalocyanine ), Strong light resistance , Storage time up to 100 year , Manufacturer has Mitsui Toatsu、Kodak( Kodak ).

(4) Purple plate (CD-RW)

It is made of special materials , There is only one color like purple glass .CD-RW To produce by phase change technology Crystalline and amorphous state , respectively 0 and 1, And can be written multiple times , Also known as a reproducible disc .

CD-ROM、CD-R、CD-RW

although CD-ROM、CD-R、CD-RW They are all CDs , But their essence is very different .CD-ROM Is the most common , The surface is white , Also called silver plate . It is mass produced by the optical disc processing line , As soon as it is produced, it already has content , CD writer Is unable to make CD-ROM Of .

CD-R The surface of the is coated with a reflective layer ( green 、 Blue or gold ), When it was first produced, there was no content , You can find that after burning , The color of the disc will change , At this point, the data has been stored . current CD-R/CD-RW You can use... Without formatting , It's like buying a floppy disk and using it , It's very convenient ！

CD-RW(Compact Disc-Rewritable, Re recordable disc ) There is also a reflector ( violet ), And can be used many times , The limit is 1 About a thousand times , Although it can not be used as a hard disk , But it is also good for backup .

CD-R and CD

Usually bought in a shop CD The plate is moulded out . and CD-R The disc is made by laser lithography . The appearance is also different ,CD-R There are green flakes on the plate 、 Gold sheet 、 Blue chip, etc , Unlike ordinary tablet pressing CD The plate is silver . They follow the tablet pressing CD Compared with , Can't stand extreme temperature and sunlight , And the service life is relatively short . But a lot of CD-R The disks are said to have a service life of 100 year .

Start the principle

In many commercial compact discs , You will find that the CD startup function is printed on the cover , Also is to use CD-ROM To boot the system , The problem of insufficient floppy disk capacity and slow speed can be avoided . Actually , use CD-R and CD-RW You can also start the CD , The principle is as follows ：

(1) stay BIOS Set CD startup in ;

(2)POST(Power On Self Test, Power on self test ) The rear CD-ROM drive checks whether the CD-ROM has boot function ;

(3) Read the disc first Sector 17 The main mark of the zone States ;

(4) Load according to the address stated in the master tag BCF(Boot Catalog File, Start the catalog file );

(5) Load according to the startup directory file BIF(Boot Image File, Boot image file );

(6) Run the boot program in the boot image file , Start entering the operating system .

According to the Yellow Book Standard , Ordinary CD-ROM Yes 333,000 Sectors ,0~16 For reserved value , The first 17 The first sector is the master tag narration , The location where the CD boot information and the boot directory file are stored . The boot directory file includes the operating system of the CD 、 Starting mode BIF The location of .BIF The startup program is stored in , It can be Windows 9x or DOS System .

There are three types of information in the main tag narration

(1)CD001, The standard opening character of the yellow book ;

(2)E1 Torito, The identification character of the boot disc specification ;

(3) Startup catalog file location , Point to BCF Logical section of .

The startup directory file contains 7 Kind of information

(1) first place 01, Boot CD ID Number , Its value is set as 01;

(2) Second 00, This disc is for X86 System ,01 be used for PowerPC System ,02 be used for Macintosh System ;

(3)ID String , Manually input disc identification information ;

(4)55 AA, End mark ;

(5)88( be located 55 AA after )： Bootable disc , If it is 00 Cannot start ;

(6)02( be located 88 after ), simulation 1.44MB Floppy disk boot ,01 It means simulation 1.2MB floppy disk ,03 Indicates simulation 2.88M floppy disk ,04 Indicates an analog hard disk ;

(7) Boot image file location , Point to BIF Logical section of .

The contents of the boot image file are 1.44M Floppy disk boot file caused image, Read the above principle , Does it feel very troublesome , Don't worry , Almost all software on the market can make startup discs , Just a few clicks of the mouse , Everything is done by the program itself . It should be noted that , After the disc starts , The CD-ROM image file becomes A disc , The first floppy drive becomes B disc , And the second floppy drive won't work .

CD CD writer

The first one CD The recorder manufacturer is Yamaha and Sony. First generation of production CD The recorder is a single speed (150Kbps) Driver , Also known as 1X Driver . From then on , A large number of products manufactured by different manufacturers CD Recorders appear on the market . The speed of later generations of recorders has been increased to 2X, Double speed (300Kbps), and 4X, Four times the speed (600Kbps).CD The recorder can be an external or internal device . External drives can be connected to PC The fuselage is separated , And an internal drive must be installed in PC Inside . With CD-R Technology is developing rapidly ,CD The recording speed of the recorders continues to increase and their size becomes more compact .

On use , With your familiar floppy disk or Hard drive comparison ,CD One of the recorder's features is that it requires a steady stream of data during write operations . all CD The logger has a cache memory called a cache . During a write operation to the disc , The cache contains a certain amount of data written to the disc . During the entire write operation , The cache should never be exhausted . There must be a steady stream of data that is neither too fast nor too slow , Constantly from PC machine (RAM Or hard disk ) Into the recorder's cache , Driving this steady data stream may require a high performance PC The machine and its dedicated resources .

Usually CD Writers Is and SCSI Mixed cards ,SCSI representative “ Small computer system interface ”, It is a standard for high-speed data transmission interface between computer and its external equipment . One SCSI Interface Typically, up to eight different devices are allowed to be connected to a single controller . Because most CD- The recorder uses SCSI Interface , You must install one in your computer SCSI controller , and SCSI Card data transmission speed is an important factor . It must be fast enough to provide a stable data flow to CD Recorder . There used to be only SCSI Only this high-end device has a CD burner , However, science and technology always drive the pace of human progress ,IDE Interface products are also slowly emerging . Current IDE CD- The recorder is designed for CD Record and CD Read , Like an ordinary CD-ROM Driver . In addition to the usual tray drive , There is also a cassette recorder , Put the disc in the box first , Then insert the CD-ROM drive , However, such devices are rare .

Read write conversion

Every time 1X=150KB/S（56X is 8400KB/S）

Design dimensions

3 Inch plate ：

5 Inch plate legend

Outside diameter 80mm, Inner ring round hole 15mm

Print size ： Outside diameter 78mm; The inner diameter 38mm, There are also printing to 20mm or 36mm Of .

Groove ring diameter ：33.6mm（ There are slight differences between different discs , There are also no grooves ）.

5 Inch plate ：

Outside diameter 120mm, Inner ring round hole 15mm

Print size ： Outside diameter 118mm or 116mm; The inner diameter 38mm, There are also printing to 20mm or 36mm Of .

Groove ring diameter ：33.6mm（ There are slight differences between different discs , There are also no grooves ）.

As a new type of printing, CD-ROM packaging has occupied a certain position in the market .

Packaging legend

The main cover is on the left ： Width is 126mm On the left there is 3mm The bleeding of , Gao Shi 121mm, Up and down 3mm The bleeding of . Secondary seal （ The picture on the right of the main cover ）： The dimensions of width and height are the same as those on the left , But the bleeding is on the right .

Size of backing paper （ Not including two folded edges ）： wide 138mm No bleeding , high 118mm, Up and down 3mm Hemorrhage .

The size of the two folds of the backing paper ： The effective size is... Wide 7mm+3mm Hemorrhage （ Notice one on the left and one on the right ）, High for 118mm, Up and down 3mm The bleeding of .

notes ： The red area is bleeding .

Other information

CD-R  It is generally used to record disks to customers or back up files , It cannot be deleted after engraving

CD-DA CD Music disc

CD-G  A disc that supports images , Generally do not use

CD-ROM  A CD-ROM for games or software commonly used on a computer

CD-RW  And CD-R identical , But it can be erased and rewritten repeatedly

CD The history of

stay 1982 year 10 month 1 Japan , Sony released the world's first commercial CD player in Japan CDP-101, Opened the prelude to the digital audio revolution . It shows a new audio medium “ The dawn ”, This medium promises to deliver a crystal clear music experience to a generation of consumers who are used to the hissing sound of vinyl records .

In the first ten years after listing , For many consumers, CD-ROM represents a kind of touchable 、 The link between reality and the future . It combines laser and digital computer, two cutting-edge technologies at that time , It has become a relatively inexpensive consumer product , Its function was unimaginable only ten years ago .

then , The disc appears , This product stores audio in tiny pits , Then the player reads it with the reflected laser . Although there have been optical discs before , but CD It has really become a major breakthrough in the application of laser in the mass market . In terms of the stunning success of this audio format ,CD It represents the “ The final defense ”—— Whether as an invention , Or as a commercial product .

stay 1972 year , Philips showed the press a new type of home audio media , Optical disc . This technology is called by Philips “Video Long Play”（VLP）, It was developed by Philips after years of research , The goal is to use it as a way to bring home video to the mass market .VLP The video disc looks like a larger CD, But you need to store audio and video content on a much larger disc , And it uses a simulation format （ This technique was later called “ Laser disc ”）.

stay 1979 year 3 month 8 Japan , Philips held a press conference in the Netherlands . At this conference , Journalists experienced digital music for the first time . This new product of Philips received a warm response , But the company can feel that Asian electronics giants are eyeing . A few years ago , Several Japanese electronics companies have already demonstrated their digital audio disc prototypes

For the next two years , The entire audio electronics industry is scrambling to research new technologies , The aim is to develop smaller CD player , Make its size conform to hi-fi Requirements for chassis . Sony happened to be the first to release its own CD player ; At the time , In a short period of six months 10 Each species has its own CD player .

The electronics industry soon discovered CD The potential of , Understand that this product can not only be used as a carrying tool for music . Electronics companies began using it for still video images （CD+G）、 Analog video / Digital audio mix （CD Video）、 Pure digital video （Video CD）、 Interactive elements （CD-i）、 Photo storage （Photo CD） And so on .

When audio discs first came out , Consumer media naturally view this invention from a practical point of view , That is, it can be used as a very small 、 Robust, noiseless audio media . Computer engineers are also paying attention to this technology , Notice a 4.7 Inch （ About us 12 centimeter ） CD-ROM can store amazing 63 Billion bytes of information .

Six computer media companies started a competition almost immediately , The aim is to redefine CD Use of , Use it as a medium for computer software . Created by these six computer media companies and closely connected with consumers CD The CD-ROM prototype was first built in 1983 By the end of the year , This trend continues until 1984 year . Sony and Philips realized , A possible subformat “ War ” Brewing , So the two companies decided to create an official standard , They call this standard CD-ROM（CompactDisc Read-Only Memory Abbreviation , namely CD ROMs Driver ）.

as time goes on ,CD-ROM The status of has been DVD-ROM And other optical technologies , His bearing has gradually declined . however , real “ Kill ”CD-ROM The invention of the most popular software delivery method is not DVD-ROM Or other technology , It's the Internet . Here's the irony , Now it is gradually “ Kill ” Audio CD It is also the Internet .

from ：CD（ Small laser disk ）_ Baidu Encyclopedia