Originally named CD Write-Once (WO), the CD-R specification was first published in 1988[citation needed] by Philips and Sony in the Orange Book, which consists of several parts that provide details of the CD-WO, CD-MO (Magneto-Optic), and later CD-RW (ReWritable). The latest editions have abandoned the use of the term "CD-WO" in favor of "CD-R", while "CD-MO" was rarely used. Written CD-Rs and CD-RWs are, in the aspect of low-level encoding and data format, fully compatible with the audio CD (Red Book CD-DA) and data CD (Yellow Book CD-ROM) standards. The Yellow Book standard for CD-ROM only specifies a high-level data format and refers to the Red Book for all physical format and low-level code details, such as track pitch, linear bit density, and bitstream encoding. This means they use Eight-to-Fourteen Modulation, CIRC error correction, and, for CD-ROM, the third error correction layer defined in the Yellow Book. Properly written CD-R discs on blanks of less than 80 minutes in length are fully compatible with the audio CD and CD-ROM standards in all details including physical specifications. 80-minute CD-R discs marginally violate the Red Book physical format specifications, and longer discs are noncompliant. CD-RW discs have lower reflectivity than CD-R or pressed (non-writable) CDs and for this reason cannot meet the Red Book standard. Some hardware compatible with Red Book CDs may have difficulty reading CD-Rs and, because of their lower reflectivity, especially CD-RWs. To the extent that CD hardware can read extended-length discs or CD-RW discs, it is because that hardware has capability beyond the minimum required by the Red Book and Yellow Book standards (the hardware is more capable than it needs to be to bear the Compact Disc logo).[citation needed]
On July 3, 1991, the first recording of a concert directly to CD was made using a Yamaha YPDR 601. The concert was performed by Claudio Baglioni at the Stadio Flaminio in Rome, Italy. At that time, it was generally anticipated that recordable CDs would have a lifetime of no more than 10 years. However, as of July 2020 the CD from this live recording still plays back with no uncorrectable errors.[citation needed]
Why Are Cd-R More Expensive Than Dvd-R
In the United States, there is a market separation between "music" CD-Rs and "data" CD-Rs, the former being notably more expensive than the latter due to industry copyright arrangements with the RIAA.[3] Specifically, the price of every music CD-R includes a mandatory royalty disbursed to RIAA members by the disc manufacturer; this grants the disc an "application flag" indicating that the royalty has been paid. Consumer standalone music recorders refuse to burn CD-Rs that are missing this flag. Professional CD recorders are not subject to this restriction and can record music to data discs. The two types of discs are functionally and physically identical other than this, and computer CD burners can record data and/or music to either.[4] New music CD-Rs are still being manufactured as of the late 2010s, although demand for them has declined as CD-based music recorders have been supplanted by other devices incorporating the same or similar functionality.[5]
As well as degradation of the dye, failure of a CD-R can be due to the reflective surface. While silver is less expensive and more widely used, it is more prone to oxidation resulting in a non-reflecting surface. Gold on the other hand, although more expensive and no longer widely used, is an inert material, so gold-based CD-Rs do not suffer from this problem. Manufacturers have estimated the longevity of gold-based CD-Rs to be as high as 100 years.[20]
The "write-once" nature of CD-Rs also ensures that data cannot be accidentally modified or tampered with and is good for use in archiving. CD-Rs are more economical than CD-RW discs. For more information on CD-Rs, view this Understanding CD-R and CD-RW PDF.
CD-RWs are more expensive than CD-Rs. However, CD-RW disc manufacturers claim longer durability and better data safety of CD-RW discs. For more information on CD-RWs, view this Understanding CD-R and CD-RW PDF.
A DVD+R format offers more functionality if you are looking to create your own movies and audio. However, the DVD-R format is officially approved by the DVD Forum. Either disc is a good option for storing or transferring large amounts of information between computers. If you are looking for a DVD that will function like a flash drive (constantly adding and deleting content on the disc) than you must use a -RW/+RW format.
1. Use more than one backup set (no matter what media). DVDs can be ok, but you need more than set of backups in case one breaks.2. Store the backups at different places. This prevents loss from fire, robbery etc.3. Read them back occasionally, to make sure the still work.
I still keep the bast mayority of the disc I have burned since then (I am talking about more than 500 CDR and DVDRS!) and only some of them gave me CRC errors. However, I think this could be caused by how the discs were burned (some of the defective ones, I remember that they were burnt with my old laptots DVD writter, which was not very good) more than the brands itself.
A: Those are excellent questions. Yes, it can be a confusing (and probably a frustrating) shopping experience to browse your local electronics store and decide between all the disc spindles labeled with + and - signs. Then you notice DVD+RW, DVD-RW, dual-layer, and the elusive DVD-RAM discs that are gathering dust on the shelf but are more expensive than the rest. How does one decide which format to choose without pulling out one's hair?
For example, according to its Wikipedia entry, "DVD+R utilizes what's called the ADIP (Address In Pregroove) system of tracking the speed of the recording, which is less susceptible to interference and error than the LPP (Land Pre Pit) system used by DVD-R, resulting in a more accurate recording at higher speeds." Also, the DVD+R system includes a better error-handling mechanism than DVD-R. What does this all mean for you?
Lastly, we have the odd-ball DVD-RAM format hiding in the back of the shelf. This is ironically the oldest and the least compatible of all the DVD formats. Developed in 1996, the format has had a larger presence with camcorders and set-top boxes because of the fact that data can be easily and randomly written to and erased from the disc, allowing for extensive editing. Think of DVD-RAM as similar to floppy-disc or hard disc technology; data can be randomly accessed, erased, or rewritten much more swiftly than DVD+RW. The Panasonic DMR-EZ48VK, for instance, has a feature called chasing playback that works exclusively with DVD-RAM, allowing the user to watch the beginning of a program while the unit is in the process of recording. The discs also have a longer life expectancy--as much as 30 years--and some of them come enclosed in a protective case, making the format highly reliable for backing up data. They are, however, the least compatible and most expensive DVD format out there. Amazon.com offers a single DVD-RAM disc for $19, while a 5-pack of DVD+RW discs will cost you $8.
Dual-layer discs that effectively doubled capacity to about 8.5GB were first available in the DVD+R format. Even today there is more variety and availability for double layer DVD+R discs than the DVD-R format.
Rated disc speed is more important for CD-RW than for CD-R. While most writers happily burn (or attempt to burn) any CD-R disc at the highest CD-R speed the drive supports, many writers refuse to burn CD-RW discs at anything faster than the disc's rated speed. There are four types of CD-RW media currently available:
DVD-RAM drives first shipped in 1998, beating all other writable DVD standards to market. The DVD Forum ( ) promoted DVD-RAM, initially for use primarily on PCs, although DVD-RAM later achieved some popularity for recording home video. Although it was first to market, DVD-RAM never really caught on. A combination of high drive prices, expensive media, and slow performance pretty much doomed DVD-RAM right out of the starting gate. It didn't help that the original DVD-RAM specification required discs to be enclosed in cartridges, which kept the price of DVD-RAM discs high and prevented DVD-RAM drives from being used in notebook computers. The one saving grace of DVD-RAM is that it incorporates much more robust error detection and correction than do other writable DVD formats, making DVD-RAM particularly appropriate for back ups and similar data-related tasks.
DVD-RW has relatively poor error detection and correction, and so is poorly suited for recording data. For a time, DVD-RW discs were considerably less expensive than comparable DVD+RW discs, and so were a reasonable choice for recording television programs, movies, and other noncritical uses. Nowadays, DVD-RW discs sell for the same price as DVD+RW discs, so there is no reason to use them at all unless you have an elderly drive that does not write DVD+RW discs. In that case, we recommend using Verbatim discs.
There are a few side notes that we cannot ignore here: The first being that CD-Rs and DVDs are constructed differently. The data layer in a DVD is more protected than that of a CD. However, this does not make it immune to damage.
A DVDR provides much more capacity than a CD-R and is, therefore, often the desired format for storing information. DVDRs are composed of two individual discs, which are each half the thickness of a CD-R. They are manufactured separately and then glued together. DVDRs can also have two information layers.
All recorded discs have inherent error rates, which are the number of errors per second when the disc is played. These are measured by BLER (block error rate) for CD-Rs, by PI8 (parity inner error rate averaged over eight blocks) for DVDRs and by LDC (long distance code) plus BIS (burst indication subcode) for BD-Rs. Players and readers can correct errors up to a certain point (and some are more efficient than others); however, if there are too many errors or they are too severe, the disc will not play properly. 2ff7e9595c
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