Optical disks in the storage and use

Disks. This word means a lot to a person familiar with the computer. Different types of optical discs for decades occupied a place of honor in the racks and boxes of users. Years pass, add new formats, but there is nothing fundamentally has changed. Although flash-media (popularly known as "flash") and partly pressed discs, primarily as a source of transfer information from one computer to another, but as a long-term custodian until the competitors do not have optical drives. So let's look at them closer.
The first optical discs have been developed at the turn of the 70-80s jointly by Sony and Phillips. Since then much water has flowed. Twice the technology has changed dramatically to create a disk in order to increase their capacity, the ups and downs, competition and the format war - under this sign were those three decades.
But we, first of all consumers, right? For us, it is important to understand all that variety of optical discs, which exists in the market, get acquainted with their varieties, characteristics and causes of emergence. We now turn to the case?
CD (Compact disc)
Our first guest - a compact disc (CD) which appeared in 1982. The purpose of his design was to replace the vinyl with modern, higher-quality audio carrier of information and direct distribution of music. As a result, there were disks that can accommodate 74 minutes of playing time, which was enough to record albums with the standard. This ensures high quality of music written in the form of digital data. Initially, the volume of the disc was about 650 MB.
Types of CDs:
CD-ROM - This type of CD is produced in plants by stamping and is not writable storage medium
CD-R (CD recordable) - a one-time recordable CD. Standard volume - 700 MB. Sometimes there are 800 Mbaytnye drives.
CD-RW (CD rewritable) - Rewritable (reusable) CD-ROM. Standard volume - 700 MB.
Rewritable discs (this also applies to CD-RW and DVD-RW) can not be used "forever." They also have their share. 1000 figure is usually called overwriting. However, in practice refuse to drive faster. In fact there are many reasons, but most important, perhaps, is to treat them. Most often, after a year of constant use on RW discs appear multiple scratches and as a result, problems with reading the information.
By the way, if you ever drive with a one-time use (R), it can be written only once, regardless of how much is left to the free space, but now, using multisession recording, it is possible to "append", but to erase all still impossible. At the same time MirSovetov recalls that multisession discs are not always perceived DVD-players, especially older models. They can not see either the entire disk or read only the first session (recording).
In the early 90s were designed format DDCD - CD-ROM double density (double density compact disc), which could accommodate twice more information than a regular CD. This was achieved by decreasing the size of pita. But the wheels did not spread because of the incompatibility and the high cost of production.
MiniDisk (MD)
Another type of carrier in the form of discs. Developed in 1992 by Sony as a replacement for the CD-cassettes, respectively, is mainly used as a carrier of audio, although in 2004 with the advent of the new format Hi MD can be used to store any information. Widespread MiniDisk not received. It is used primarily in the players and camcorders by Sony and Sharp. They can also be seen as a CD with drivers and utilities for computer peripherals, such as for USB-hardware (a "flash drive», Bluetooth-and WiFi-adapters, etc.)
DVD (Digital Versatile Disc)
In 1995 a group of developers (Toshiba, Matsushita, Sony, Philips, Time Warner, Pioneer, JVC, Hitachi and Mitsubishi Electric) signed an agreement on joint cooperation in developing and promoting a new type of optical disc called Digital Video Diss (DVD) - digital video drive. Later, as the DVD will decrypt the Digital Versatile Disc (digital versatile / versatile disc), because over time these disks will be used to store not only the video content.
The first DVD discs appeared in Japan in autumn 1996.
What types of DVD-ROM drive there?
DVD-5 - a one-sided single-layer (Single_sided, Single_layer) drive. Capacity - 4.7 GB.
DVD-9 - two-layer single-sided (Single_sided, Double_layer) drive. Capacity - 8.5 GB.
DVD-10 - double-sided single-layer (Double_sided, Single_layer) drive. Capacity - 9.4 GB.
DVD-14 - double-sided disc, one side has an information layer, and the second - two. Capacity - 13.2 GB.
DVD-18 - double-sided double-layer (Double_sided, Double_layer) drive. Capacity - 17 GB.
The last two are very rare and in everyday life practically not used.
Variety of DVD-ROM drive:
DVD-R (Recordable) - one-time recordable DVD discs. Capacity - 4.7 GB.
DVD-RW (ReWritable) - Rewritable (reusable) DVD discs. Capacity - 4.7 GB.
Due to the high cost of a license for DVD technology, a number of companies that are gathered under the title «DVD + RW Alliance», in the 2002 standard was developed DVD + R (W). Since DVD discs are divided on the pros and cons. Now much of a difference between them. Although some people prefer to use more pluses (using disks on the computer), for compatibility with older players is better to use a minus.
DVD + R (Recordable) - one-time recordable DVD discs. Capacity - 4.7 GB
DVD + RW (ReWritable) - Rewritable (reusable) DVD discs. Capacity - 4.7 GB
DVD-RAM (Random Access Memory) - a special rewritable random access memory, which allow you to work with them as floppy disks, that is free to write, erase data. They are more expensive than conventional drives and less common.
DVD-DL (Double Layer) - dual-layer recordable DVD discs. Capacity - 8.5 GB. These discs are created using sophisticated technology, are at the same time several times more expensive than usual. So, if you do not want to throw good money after bad and you need to use a dual-layer disc recording, disc MirSovetov recommends choosing well-known manufacturers, but they can provide an acceptable quality (for example, Verbatim).
In fact, regular DVD discs do not have a volume of 4.7 GB and 4.38 GB. This is due to the fact that the derivation of 4.7 - consider the decimal number, ie 1 KB = 1000 bytes, while at the same time in the digital world using a binary system in which 1 KB = 1024 bytes
HD DVD & Blu-ray (BD)
A new generation of optical disc drives are HD DVD and Blu-ray (BD). Until February 2008, they co-existed in the market as competitors, but after the failure of Toshiba (the main ideologist of HD DVD) to support its product, the standard of disks for high-definition Blu-ray has become the company Sony.
Discs and players are the new generation are still quite expensive. In addition, MirSovetov would like to draw your attention to the fact that for high-definition movies require a large TV, which would support higher screen resolution. But he also is not cheap. Therefore, the majority are quite satisfied with the quality of movies on DVD and the new standard is marketed with a creak. To supplant DVD, it would take at least several years.
Blu-ray is translated as "blue ray". The word blue (cyan) was intentionally omitted the last letter, so no problems with the registration of trade marks.
Types of discs HD DVD:
HD DVD-R (High Density DVD Recordable) - a one-time recordable disc. Disk space - 15 GB. If a dual-layer drive - 30 GB.
HD DVD-RW (High Density DVD Rewritable) - Rewritable (reusable) drive. Disk space - 15 GB. If a dual-layer drive - 30 GB.

Types of Blu-ray Disc
BD-R (Blu-ray Disk Recordable) - a one-time recordable disc. The volume of the disk is 25 GB. If a dual-layer drive - 50 GB
BD-RE (Blu-ray Disc Rewritable) - a re-writable (reusable) drive. The volume of the disk is 25 GB. If a dual-layer drive - 50 GB
HVD (Holographic Versatile Disc)
For several years, developed a fundamentally new optical disc format HVD (holographic versatile disc). In contrast to the previous format, the principle of which has not been changed (changed only the width of lanes, pits, and the laser wavelength), the decision serves as the foundation technology of holography, that is, save the data in three-dimensional volume of the carrier (using two lasers). This is achieved phenomenal capacity - terabytes of information on one disk, and high speed data transmission.
Manufacturers of optical discs
If you go to the store, specializing in computer technology, you'll see a lot of different drives from different manufacturers, as is widely known and completely unknown (and sometimes without any markings). What can I recommend? It all depends on your needs.
The price difference is usually negligible. If you need something to burn the disc, without expectation of a long storage, you can use almost any product. If you are relying on long storage, and are concerned about reliability, then I would advise you to buy CDs from proven manufacturers such as Verbatim and TDK. They are a little more expensive but much safer and better. It is not advisable to buy the CDs Digitex, especially the rewritable (RW), they account for many complaints.
For all this, remember - that even the disks of the leading manufacturers are not perfect. And sometimes you can fail. There's no deetsya. In addition, the disc also depends on a lot of drive and software for recording.
On the storage and use of optical disks
What else I want to say about the optical drives? Many people think that this is a very reliable means for storing information, but it's not entirely true. Disks can be stored for a long time, but we must not forget about how storage. This should be a dry, dark place. It is desirable to store the disks in a box. Need to treat them carefully, as scratches can make it unreadable. Although the recording is allowed, so to speak, the provision for recovery of information when reading, but it is not limitless. And sometimes, after damage to the drive, it has vivify ... but that's another discussion. Do not let the dust disk to the workspace, even the most delicate part of the carrier. Be attentive to her. I've seen people like and experienced, put wheels on the part of the working table, a pile of papers, anywhere ... and then wondered - why it is difficult to read discs are?
Before you insert the disc in the drive tray, carefully inspect its inner ring on the presence of cracks. Their appearance can lead to the fact that at the crucial moment of your media information, simply smashed to pieces right in the drive.
By the way, what if the disk drive does not open? If you have not helped the standard methods of discovery, we advise to use a mechanical (do not worry, disassemble the drive it does not have to). First, take an ordinary paper clip and straighten it. Then look at the faceplate of the drive. Most of them have a small (1 mm) hole. Turn off the computer and insert a straightened paper clip into the hole. Push the disc tray and has a little bit open. We catch him by the hand and open fully. We took out the disc. This method can be used and if you turn off the computer accidentally forgotten in the middle of the drive you want.
We must also remember that even without damage discs after spending a year or two, may become unreadable. So if you have very important information, it is best to periodically peresohranyayte it.
And finally, the banal warning. Do not forget to write on the disk can only be a special marker. And only on the upper surface of the dead.
Of course, the safety of your information is influenced by other factors. For example, how driven you are using, what programs are using to burn CDs. And just as they write. But this is a topic for another discussion. And we'll talk to you about it next time.