Drive cd rom dvd description. What is CD-ROM
172.3 Kbps (audio from CD-DA)
CD-ROM drives are a popular and cheapest means for distributing software, computer games, multimedia and other data. CD-ROM (and later DVD-ROM) became the main medium for transferring information between computers, displacing the floppy disk from this role (it is now giving way to more promising solid-state media).
Often the term CD-ROM mistakenly used to refer to the drives (devices) themselves for reading these disks (correctly - CD-ROM Drive, CD drive).
Technical details
A compact disc is a 1.2 mm thick polycarbonate substrate, covered with a thin layer of metal (aluminium, gold, silver, etc.) and a protective layer of varnish, on which a graphic representation of the contents of the disc is usually applied. The principle of reading through the substrate was adopted because it makes it possible to very simply and effectively protect the information structure and remove it from the outer surface of the disk. The diameter of the beam on the outer surface of the disk is about 0.7 mm, which increases the system's immunity to dust and scratches. In addition, on the outer surface there is an annular protrusion 0.2 mm high, which allows the disk, placed on a flat surface, not to touch this surface. There is a hole with a diameter of 15 mm in the center of the disk. The weight of the disc without the box is approximately 15.7 g. The weight of the disc in a regular (not “slim”) box is approximately 74 g.
CDs are 12 cm in diameter and originally held up to 650 MB of information. However, starting around 2000, 700 MB disks began to become increasingly widespread, subsequently completely replacing the 650 MB disk. There are also media with a capacity of 800 megabytes or even more, but they may not be readable on some CD drives. There are also 8-centimeter disks that can hold about 140 or 210 MB of data and CDs shaped like credit cards (so-called business card disks).
CD-ROM under an electron microscope
Information on the disk is recorded in the form of a spiral track of so-called pits (recesses) extruded into a polycarbonate base. Each pit is approximately 100 nm deep and 500 nm wide. Pit length varies from 850 nm to 3.5 µm. The spaces between pits are called lands. The pitch of the tracks in the spiral is 1.6 microns.
There are read-only disks (“aluminum”), CD-R - write-once, CD-RW - write-multiple. The last two types of discs are designed for recording on special burner drives.
CD business card
CD business card is an optical disk made in the format of a business card (repeats its size 90×50 mm).
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See what "CD-ROM" is in other dictionaries:
Rom- (Roma) ... Deutsch Wikipedia
Rom: Großmacht und Weltreich- Rom hatte vor dem Pyrrhoskrieg jahrzehntelange höchst aufreibende Kriege geführt und brauchte Ruhe. Es beschäftigte sich damit, allerlei Nachbereinigungen vorzunehmen, um die Herrschaft Schritt für Schritt zu sichern, und errichtete in aller… … Universal-Lexikon
Rom- (Roma), die merkwürdigste Stadt auf der Erde, gegenwärtig die Hauptstadt des Kirchenstaats, liegt unterm 41°53 54 nördl. Breite, 10°9 30 östl. Länge zu beiden Seiten der Tiber, 3 etc. Ml. von deren Mündung auf den bekannten 7 Hügeln (mons… … Herders Conversations-Lexikon
ROM hacking- is the process of modifying a video game ROM image to alter the game s graphics, dialogue, levels, gameplay, or other gameplay elements. This is usually done by technically inclined video game fans to breathe new life into a cherished old game,… … Wikipedia
ROM- bezeichnet: Rom, die Hauptstadt Italiens Provinz Rom, die nach der Stadt Rom benannte italienische Provinz Römisches Reich, in der Zeit vom 6. Jahrhundert v. Chr. bis zum 6. Jahrhundert n. Chr. Zweites Rom, Konstantinopel, antique Hauptstadt des… … Deutsch Wikipedia
Rom (Begriffsklärung)- Rom bezeichnet: Römisches Reich, in der Zeit vom 6. Jahrhundert v. Chr. bis zum 6. Jahrhundert n. Chr. Römische Kurie, die Zentralbehörde des Heiligen Stuhls für die römisch katholische Kirche einen männlichen Angehörigen der Roma… … Deutsch Wikipedia
Bottom view of the reading head of the drive model NEC1100A
We are primarily interested in small trimming resistors installed directly on the head. These resistors regulate the current through the laser diode and, by changing their value, you can change the brightness of the laser radiation within certain limits. In the figure they are circled and designated by numbers 1 and 2.
The location of these controls can vary greatly between different drive models. For example, this photo shows the optical head of a newer drive:
You need to take a thin screwdriver and slightly increase the brightness of the desired laser. You can find the right regulator experimentally. Let's assume that our drive reads CDs well and reads DVDs very poorly. We take a marker and make marks on the resistors to remember the position of the engine, which was made at the factory when setting up the head. Then, we twist one of the resistors, for example number 1, to its extreme position counterclockwise. We assemble the drive and check the reading of CD and DVD discs. To do this, it is convenient to use the program Nero CD-DVD Speed. If the reading of CDs, which were previously readable well, has sharply deteriorated, it means that we have turned the regulator of the laser responsible for reading this format. We return the resistor slider to its previous position. If the quality of reading CDs has not changed, then we guessed the brightness control of the DVD laser.
After we have found the desired regulator, we turn it approximately 5 - 10 degrees clockwise relative to the position that was set at the factory and which we marked with a marker. We reassemble the drive and check the readability of the DVD disc. If this does not help, we tighten the resistor further, ultimately achieving the best reading quality.
Bitsetting
The Bitsetting function allows you to change the bit responsible for the media type (ROM, -R, +R), the so-called Book Type. This bit is located in the Lead-in area of the disk and can take one of three values. But you can change it only if you use DVD+R discs, because for DVD-R it is registered by default. If you want the disc to be guaranteed to be readable on any player, even the most ancient one, you need to set the Book Type to DVD-ROM. It is recommended to set Book Type for two-layer (DVD+R9 DL) discs, because otherwise, they may well not be readable even on the most modern DVD players.
Lite-On IT DVD Drive – SOSW-833SX
SOSW-833SX Specifications:
Interface – USB 2.0
The maximum recording speed of DVD±R discs is 8x;
The maximum writing speed for DVD±RW discs is 4x;
The maximum recording speed of DVD±R DL discs is 2.4x;
The maximum writing speed of DVD-RAM discs is 5x;
The maximum writing speed for CD-RW discs is 24x;
The maximum writing speed for CD-R discs is 24x;
Buffer volume – 2 MB
Slim form factor
Weight - 362 gr.
DVD recorder DRW-1608P2S with support for recording on dual-layer media:
Lite-On IT releases a drive with LightScribe technology and 8X recording to DVD+R DL.
Characteristics of SHW-16H5S:
- Interface: ATAPI/E-IDE
- Support DVD+R / DVD+RW / DVD-R / DVD-RW / DVD+R9 / DVD-R9 / DVD-ROM / CD-R / CD-RW / CD-ROM
- Record to DVD+ / - R9
- SMART-BURN buffer underrun protection technology
- CD-DA/VCD/DVD SMART-X reading speed adjustment technology
- Noise and vibration suppression system for recording and reading VAS
- Supports Fixed Packet, Variable Packet, TAO, SAO, DAO, Raw Mode Burning & Over-Burn recording modes
- DVD reading: DVD single/dual layer (PTP/OTP), DVD-R (3.9 GB / 4.7 GB), DVD-R, DVD+R, multi-session DVD+R, DVD-RW and DVD+RW
- CD reading: CD-DA, CD-ROM, CD-ROM/XA, Photo-CD, multi-session, Karaoke-CD, Video-CD, CD-I FMV, CD Extra, CD Plus, CD-R and CD-RW
- Supports 80 and 120 mm CD and DVD
- Data exchange modes: PIO mode 4, DMA mode 2 and Ultra DMA mode 4
- Lightscribe support
ASUS CB-5216A1T: DVD/CD-RW drive with SATA interface
The CB-5216A1T supports proprietary ASUS FlextraLink, FlextraSpeed and DDSS II technologies.
FlextraLink technology prevents errors associated with buffer underload and eliminates the possibility of disk damage, and FlextraSpeed is designed to increase accuracy and reliability when reading/writing/rewriting media of different formats. In turn, the DDSS II Dual Dynamic Suspension System is designed to minimize vibration caused by the optical drive spindle motor and resonance between the drive and the computer case by stabilizing vertically and horizontally.
Technical characteristics of ASUS CB-5216A1T:
- CD-R writing speed: 52X
- CD-RW rewriting speed: 32X
- CD-ROM reading speed: 52X
- DVD reading speed: 16X
- FlextraLink technology
- FlextraSpeed technology
- DDSS II system
- AI Auto Speed Adjustment Technology
- Supports accelerated decoding of music CDs (max. speed - 52X) and Video CDs
- Mt support Rainier
- Supports DAO-RAW, TAO, DAO, SAO, Multi-Session, Batch Write and Overburn
- Supports CD-DA, CD-ROM, CD-ROM XA, Photo CD, Mixed Mode CD-ROM, CD-I, CD-Extra, CD Text, Video CD, DVCD and Bootable CD formats
- Vertical and horizontal installation possible
- SATA interface
Hitachi GSA-4166B
Hitachi introduced the drive - GSA-4166B supports all formats, including DVD-RAM.
Main characteristics of the device:
- Super Multi Drive supporting 5x DVD-RAM and 16x DVD±R recording
- Compatible with dual-layer ±R discs
- Speed formula: 16x/6x/5x/16x/8x (DVD-R/RW/RAM/+R/+RW)
- LightScribe technology support
- Buffer volume - 2 MB
- Media loading - horizontal, automated
- Interface: IDE/ATAPI/Ultra DMA66
- Power: 12V/5V
- Supported OS: Win9X,\Win2K,XP, Media Center Edition
- DVD-R: SL 2x, 4x CLV, 8x ZCLV, 12x PCAV, 16x CAV, DL 2x, 4x CLV
- DVD-RW: 2x, 4x CLV, 6x ZCLV
- DVD-RAM: 2x, 3x, 5x CLV (Ver.2.2)
- DVD+R: SL 2.4x, 4x CLV, 8x ZCLV, 12x PCAV,16x CAV, DL 2.4x, 4x CLV, 6x ZCLV
- DVD+RW: 2.4x, 4x CLV, 8x ZCLV
- CD-R: 10x, 16x CLV, 24x ZCLV, 32x, 40x, 48x CAV
- CD-RW: 4x, 10x,16x CLV, 24x, 32x ZCLV
- DVD-R/RW/ROM: 10x/8x/16x max.
- DVD-RAM (Ver.1.0/2.1) : 2x, 3x, 5x CLV
- DVD+R/+RW: SL - 10x max., DL - 8x max./8x max.
- CD-R/RW/ROM: 48x max./32x/48x max.
Data transfer rate:
- DVD-ROM: 22.16 Mb/s.
- CD-ROM: 6 Mb/s.
Data access time:
- DVD-ROM: 145 ms
- CD-ROM: 120 ms
Supported formats (media) and recording methods:
- DVD-RAM, DVD-R/RW, DVD+R (SL, DL)/RW, CD-R/RW
- DVD-RAM/+RW: random (any) recording
- DVD-R: Disk-at-once, incremental recording
- DVD-R DL: Sequential recording
- DVD-RW: Disk-at-once, incremental recording
- DVD+R, +R DL: Sequential recording
- CD-R/RW: Disk-at-once, Session-at-once, Track-at-once, batch recording
Reading discs (formats):
- DVD-ROM, DVD-RAM, DVD-R(SL,DL), DVD-RW, DVD+R (SL,DL), DVD+RW; CD-R, CD-RW, CD-ROM, CD-ROM XA, CD-DA, CD-I, CD-Extra, CD-Text, Photo CD, Video CD
* SL - one layer (single-layer disc), DL - two-layer.
Buffalo DVSM-X516FBS and DVSM-X516IU2
Buffalo begins selling two new DVD drives.
For internal installation, it is equipped with a SATA-ATAPI adapter and supports both standards. Dimensions: 146 x 170 x 42 mm, and product weight 760 g. When connected via serial ATA, the DVSM-X516FBS model is compatible only with Win2K/XP.
The DVSM-X516IU2 external drive has IEEE 1394/USB 2.0 interface connectors. Its dimensions are 160 x 279 x 55 mm, weight 1.8 kg. Full compatibility with Win98 SE/Me/2K/XP and WinXP Media Center Edition 2005 is provided.
Both models are built on the basis of Hitachi DVD super multiple drive GSA-4167B. They provide the following data recording speeds: DVD+R DL 6x, DVD-R DL 4x, DVD±R (1-layer) 16x, DVD-RAM 5x, DVD+RW 8x and DVD-RW 6x. CD-R matrices are written at 48x, and CD-RW at 32x. Reading speeds for DVD are: DVD-ROM 16x, DVD-ROM DL 8x, DVD±R (1-layer) 10x, DVD±R DL 8x, DVD±RW 8x, and for DVD-RAM 5x. CDs are read at 48x for CD-ROM and 40x for CD-RW. The set includes a set of software "Easy Media Creator 7 Basic" and "MyDVD 6".
Cost of internal drive DVSM-X516FBS - US$130
External DVSM-X516IU2 - US$160
Plextor begins sales of external DVD±R/RW drives. This model does not have a retractable “tray” element but uses “slot loading”.
For connection to a computer, a USB 2.0 and IEEE 1394 interface is provided. The recording speed on DVD±R matrices is 16x, DVD+RW 8x, DVD±R DL 6x, and DVD-RW 4x. Regular CD-R discs are written at 48x speed, while CD-RW discs are written at 24x speed. The drive buffer size is 8MB. The device is equipped with an “Intelligent Recording” function that automatically selects the optimal recording speed. The products will be produced in a limited edition of 500 pieces in white cases. Dimensions 167.1x253.5x53mm, weight 1.7 kg.
Another external DVD±R/RW drive.
The design of the device is similar to the PX-716UFL, but the body color is black, and a traditional retractable “tray” is used to accept the disk. There is also a USB 2.0 and IEEE 1394 interface, the recording speed for DVD±R is 16x, DVD+RW 8x, DVD+R DL 8x, DVD-R DL 4x and for DVD-RW 6x. CD-R matrices are written at 48x, and CD-RW at 32x. Buffer size 2MB. Dimensions 167.1 x 253.5 x 53 mm, weight 1.6 kg. All drives are guaranteed compatible with WinMe/2K/XP.
NU DDW-164
Specification
- Interface:IDE/ATAPI(UDMA33)
- Reading speed:
- CD-ROM: 40x Max.
- DVD-ROM: 16x Max.
- Write speeds:
- CD-RW: 24x
- CD-R: 40x
- DVD-RW: 4x
- DVD+RW: 4x
- DVD+R/DVD-R: 16x
- DVD+R DL: 4x
- Recording formats: CD Disc at Once (DAO), Session at Once (SAO) and Track at Once (TAO) recording, DVD+R Incremental Write, DVD+RW Random Write
- Data Buffer Size: 2MBytes
- Dimensions: 148mm x 42mm x 170mm
- Weight 0.92 kg
The drive is capable of working with almost all existing types of DVD media, with the exception of DVD-RAM and DVD-R DL media. Of course, the lack of support for the DVD-R DL format is not yet such a significant disadvantage, but, nevertheless, all modern drives support it.
NU DDW-164 clearly needs improvement; most of the problems are related to the fact that the manufacturer needs to refine the recording strategies for most blanks and rework the list of supported blanks. These problems, as a rule, can be solved in a new firmware version, so we can only hope that the developers will quickly make the necessary changes, but for now the drive will suit you only if you mainly use “branded” blanks.
Q. Decided to buy DVD-RW?
A. NEC-ND3520 Q. NEC DVD-RW ND-2500A stopped reading and writing DVDs (reads CD-R/RW)?
A.Reading and writing DVD requires more laser power than writing CD. That is, the most likely reason is a decrease in radiation power. First, clean the head. If it doesn’t help, it means the laser emission is reduced, change the drive.
Q. Combo CD-RW/DVD Samsung 352F (OEM), the drive does not see the disc (the problem is not the disc), there is also a problem with a 7.9 GB DVD, the computer is very strained, but cannot read the files. Mother ECS P6S5AT. Percent Celeron 1.0 GHz, Windows XP Home system?
A. To write a DVD, you need to install a disc burning program. As for reading double-layer DVDs: your drive simply does not support them or a firmware update is required (check the drive manufacturer's website). In addition, Samsung optical drives have never been of high quality.
Q. I bought 552 TEAC. Was it worth taking the NEC 1100A instead?
A. Instead of NEC - it was not worth it, the reliability and quality of NEC drives has recently been noticeably higher.
The TT-15S1 features a perfectly flat, milky 28mm thick acrylic base, a belt drive, an aluminum tonearm with an anti-skating system and, of course, no preamps.
Speed 33 x 1/3.45 rpm ±0.2%,
Signal to noise ratio - 80dB,
Frequency response - from 20Hz to 20kHz,
Impedance - 0.66 kOhm,
Power consumption - 5W
The dimensions of the TT-15S1 are typical for its class - w440 mm x t110 mm x d350 mm, weight - 8.9 kg.
Vinyl record player released in limited edition and priced at ~$2400.
Pioneer DVR-110
Model * records DL media on 8x DVD+R/-R, recording of regular DVD+R/-R discs is done on 16x. The remaining characteristics of the Pioneer DVR-110 are as follows:
Reading:
*Unfortunately, there is no mention of support for Blu-ray media.
Vinyl "blanks" CD-R
17/05/2005 The Russian company MIREX is launching CD-R MAESTRO blanks with VYNIL coating and a design stylized as vinyl records of yesteryear. MAESTRO is available in five versions, differing only in the color of the inner rings on the surface.
The disk capacity is 700MB and the maximum writing speed is 52x. According to the manufacturer, the main advantage of vinyl is double, enhanced protection of the information layer, which is especially important when the disc is frequently used and used in extreme conditions, for example, in high humidity or sudden temperature changes.
Benq with dual cooling system
Benq introduced the DVD+-R/+-RW burner drive. The model is called DW1640 and will be released with a front panel in black and white. The drive provides recording of dual-layer DVD+R DL discs at 2.4x speed. DVD-R DL support will be implemented via firmware. Other types of discs are written at 8x speed, so an 8.5GB disc is written in 16 minutes; only DVD-RW discs are written at 6x speed.
The new product is equipped with a dual cooling system Dual Cooling System (DCS) including the Air Flow Cooling System (AFCS), which enhances the heat transfer of metal parts due to constant air circulation and the Anti-Dust Cooling System (ADCS). The drive has an ATAPI interface and dimensions 146x178x42 mm.
JVC announced its development in the field of optical media with the development of dual-layer DVD-RW discs with a capacity of 8.5 GB on one side. By using highly sensitive recording layer materials and a new recording technology called N-Strategy, JVC engineers have significantly improved the rewritable disc manufacturing process and improved the quality of the latter.
The new drive allows you to store up to 8.5 GB of data or up to 11 hours of video on one side of the drive, i.e. the new product has 1.8 times more volume compared to traditional discs - single-sided and single-layer.
In addition, the method of pre-processing materials for recording layers, developed by JVC, will allow manufacturing companies to use existing equipment to produce new discs, if, of course, the proposal to standardize and adapt JVC's new DVD-RW discs receives a response in the DVD Forum, where JVC has submitted a corresponding application.
Unlike conventional dual-layer discs, JVC discs use a new material that improves both the read quality of the disc [from both layers] and improves their ability to erase and write.
In fact, physically, the disk consists of more layers [see Fig. below], but there are exactly two that are recorded - layers L1, L0, which in turn consist of reflective, protective, recordable, protective and the substrate itself.
JVC intends to continue to develop improvements to this technology with a view to future commercialization of this development.
Sony and Nichia demonstrate a prototype monolithic read/write unit
The presence of several ideologically similar formats for reading (writing) information from optical disks led to the fact that, starting from a certain moment (from the moment combo drives were released), laser heads with two separate diodes began to appear in drives (one for CD, the other for DVD), and then heads with pairs of crystals packed into a single diode housing, each of which emitted its own wavelength (such diodes, for example, are produced by Sony). The goal was quite specific: to replace a scattering of elements with a monolithic block, simplifying and reducing the cost of the design of the laser head, and simultaneously increasing its reliability.
The introduction of laser-recorded optical discs in the blue-violet range has become a real challenge for pick-up head designers. After all, now the reading unit needed to include another diode with its own matrix and its own beam path. In a surge of real enthusiasm, puzzling “three-in-one” designs began to appear one after another: from prisms, diodes and lenses. It's clear. First you need to make a device from what you have, and there were separate diodes and universal heads, and only then simplify this device.
It was the development of a prototype of such a “polished” universal laser head unit that the tandem from Sony and Nichia announced today. Let me remind you that this pair of manufacturers entered into a time-limited cross-licensing agreement in April of this year for the joint development of blue-violet laser diodes and pick-up heads based on them, which, however, they will each sell and produce separately. The created prototype will be sent into mass production by the end of 2005. By then, one must assume, his versatility will only increase. Because at the moment the new laser unit is not entirely universal: it emits only waves with a length of 660 nm and 405 nm. In other words, it only works with DVD and Blu-ray discs. Without CD support, the value of this module drops more than noticeably. However, the real advantage of the reader block is different: its execution is simply amazing in its “laconicism”:
The design principle is clear from the block diagram, and we will not dwell on it. We only note that this prism design is as reliable as possible (all three optical sections are enclosed in a monolithic block) and is easy to assemble. In addition, such a unit will only need one focusing lens, since the source of blue and red radiation is the same diode.
BenQ is releasing a "Pro" version of its "dual-layer" DW1620 drive.
BenQ issued an official press release announcing the release of a "Pro" version of its famous 16-speed DVD±RW drive, which also supports DVD+R DL discs:
Actually, there is only one difference between the DW1620 Pro drive and the DW1620 - the new product writes double-layer DVD+R discs at 4x speed, while its predecessor could only do this at 2.4x speed. That is why the company did not change the drive index, limiting itself to the suffix “Pro”. Also, both drives now come with a proprietary QScan utility, which allows the user to quickly check the quality of the disc and determine the optimal speed and recording parameters
However, if we remember the specifications and price of the expected super-universal drive GSA-4163B from LG, then everything described above becomes not too important. Q.For some time now I have been having problems playing DVDs and CDs. When watching videos or listening to audio with any program, “slips” periodically occur. Those. a movie is playing, for example, and then immediately skips forward a couple of seconds. It's the same with MP3 when played directly from the drive. The frequency of the phenomenon is 5-20 minutes. Everything is readable from the hard drive (SATA interface). It is copied from/to the hard drive, discs are written, discs are copied, and so on, normally and at the same speed. When playing AudioCD, everything is also fine, but I’m not using digital playback, but “analog”, i.e. The sound output does not go through the motherboard via the IDE cable, but through the digital audio output of the drive directly to the sound card, where it is decoded, while the drive works like a simple CD player. It turns out that the circle is closed on the IDE interface. The drives hang on the secondary IDE: Plextor PX-712A (Master) and Plextor PlexWriter Premium (Slave). ASUS P4C800 motherboard, PC3200 512 MB Kingston RAM, P4 Presscott 3GHz processor, WinXP Prof SP1 operating system.
A. Either the discs are a little scratched, or while watching a movie or listening to music, the system wants to access some services, so short-term disappearances and jumps occur. The laser head may be dusty (clean it). When reading an Audio CD, spin-up speeds (max - 4x) are not required as when watching movies. Advice - first rewrite movies onto a hard drive (with DVD, of course, it’s more problematic than with CD), otherwise you’ll slowly ruin your DVD/CD-Rom.
DVD-RAM (Digital Versatile Disc Random Access Memory)
In July 1997, the DVD Forum approved the multi-recordable DVD format - DVD-RAM (Digital Versatile Disc Random Access Memory), which was developed by three Japanese companies: Hitachi, Matsushita and Toshiba. But DVD-RAM has not gained significant popularity in the personal computer market. Perhaps this happened because the two opposing camps, one of which promoted DVD+RW, and the other DVD-RW, were so keen on promoting their own multi-recording formats for DVD media that they simply did not get around to the third format. Although there may be another reason why manufacturers began to turn away from DVD-RAM, namely, DVD-RAM discs were supplied both in cartridges and without, which somewhat complicated the work with discs (cartridges could be collapsible or non-separable) , and dictated the need to produce drives with a tray for cartridges.
The DVD-RAM format became more popular in the corporate sector when DVD-RAM drives were included in robotic data storage libraries. Corporations chose this format because the specifications of DVD-RAM, in terms of the number of maximum possible rewrite cycles, compared favorably with DVD±RW, promising 100 thousand erases and rewrites, which is significantly more than 1 thousand for DVD±RW discs. But even the potential possibility of such a huge number of rewrites, as we see, could not help the DVD-RAM standard gain popularity among ordinary users. After all, perhaps, only non-separable cartridges could guarantee the promised number of rewrite cycles at the expense of cost and ease of storage. What the mass market was not ready to do. In the end, support for DVD-RAM recording in some drives produced today only serves to strengthen the manufacturer's reputation, but not the standard.
However, now, according to some signs, the DVD-RAM format in a “cartridge-free” version is beginning to gain momentum. The most active efforts to return DVD-RAM to the market are being taken by one of its developers - Hitachi. According to the Internet resource Clubic, LG-Hitachi currently produces 2 million laser heads per month, capable of recording DVD-RAM discs, among other formats. And, most importantly, other manufacturers are also going to explore the market of DVD-RAM media and drives! Has reaching the upper limit of the writing speed of DVD±R discs really scared manufacturers so much that they are ready to introduce something new into DVD drives by any means, expanding their functionality, even at the expense of not very popular properties? It’s like with mobile phones, which from “just a call” have turned into a kind of “Swiss knives” for, not even communications, but for entertainment or something. Be that as it may, laser heads for drives compatible with DVD-RAM are going to be produced by Sanyo , which owns from 30% to 40% of the laser head market in general. DVD Super Multi heads, according to Clubic, Sanyo will release by the end of this year or early next year. Super Multi chipsets are supplied to the market by Matsushita, Renesas and MediaTek. If for the first two the DVD-RAM format is “native”, then MediaTek is its “voluntary” supporter, which indicates an increase in interest in DVD-RAM. Taiwanese companies Lite-On and Accesstek are developing their DVD-RAM-compatible drives, preparing for the launch of new products by the second quarter of 2005. But LG Electronics regularly produces such drives. In the spring of 2004, LG announced the Super Multi drive model, which actually supported all formats, including the latest dual-layer (GSA-4120B drive).
Super Multi drive LG GSA-4160B.
Not long ago this model was updated to version GSA-4160B. The update affected only the writing speed of DVD+R discs: it increased from 12x to 16x. All other parameters remained unchanged: recording speed of DVD-R discs – 8x, DVD-RAM – 5x, DVD+RW and DVD-RW – 4x, CD-R – 40x, CD-RW – 24x; CD reading speed – 40x, DVD – 16x.
Q.How to format a DVD?
A.Nero InCD - format your disc there, you will get a UDF format, and then you can work with it like a large floppy disk (most likely, this means not a formatted, but a blank DVD disc). If we are talking about DVD +/-RW , then when erasing in Nero, select “Full erase of a rewritable disc.”
Q.DVD-RW drive NEC ND2510A. It turned out that he does not read the blanks he himself wrote down. But, if you just insert a DVD disc, for example with a movie or game, then everything is OK. It seems to read the images written to the disk - that is, if there is an installer, it will launch it. But, before it gave a cyclic redundancy check error, but now: “Incorrect Function”. How do you think this can be solved?
What I tried:
A.Have you tried writing to normal Verbatim? All the NECs I have seen were characterized by an outright dislike for “left-handed” discs. And the cheapest Noname couldn’t even be read by Pioneer after recording (although household players BBKs somehow played them - albeit not for long: then the recording layer peeled off).
Q. DVD+RW NEC 2510A (new) does not write DVDs
A. DVD+R or DVD-R discs? If you give him the second type, then everything is simple - he doesn’t know how to work with them, but if the first type - go to the warranty. This device is very picky, it writes only those disks that it “knows” are in its firmware The names of the disk manufacturers are hardcoded, and those that he recognizes, he will write, and those that he does not “know,” he will not. And changing the firmware will not fix this - checked!
1. Check if the ASPI driver is installed.
2. Download new firmware from the manufacturer’s website.
3. Are the wheels good?
Plextor: PX-740A Dual Layer DVD Drive
Plextor has announced the PX-740A internal dual-layer IDE DVD drive. This is an ordinary, high-quality drive, i.e. without any special features, like the flagship PX-716A.
The recording time for an 8.5 GB disc on the PX-740A drive is ~15 minutes. In this case, the drive writes a single-layer disc in less than 6 minutes.
PX-740A Drive Specifications:
- Buffer capacity 2 MB
- Buffer Underrun Proof technology
- 16 x DVD±R recording
- 8x DVD+R DL recording
- 4x DVD-R DL recording
- 8x DVD+RW recording
- 6x DVD-RW recording
- 16x DVD-ROM reading
- 48x CD-R recording
- 32x CD-RW dubbing
- 48x CD-ROM reading
- Supports DVD±VR (Video Recording) direct recording method
CD drives
To solve a wide range of information technology problems, the following optical information storage devices are used:
CD-ROM (Compact Disk Read-Only Memory) - storage devices only for reading information from them;
CD-WORM (Write Once Read Many) - storage devices for reading and writing information once;
CD-R (CD-Recordable) - storage devices for reading and repeatedly writing information;
MO are magneto-optical storage devices that can be written to multiple times.
The operating principle of all optical storage devices is based on laser technology. The laser beam is used both to write to an information carrier and to read previously recorded data, and is, in fact, a kind of information carrier.
CD-ROM drives
CD-ROM is a compact disc (CD) designed to digitally store information previously recorded on it and read it using a special device called a CD-ROM driver - a drive for reading CDs.
The tasks for which the CD-ROM device is intended include: installing and updating software; searching for information in databases; launching and working with gaming and educational programs; watching videos; listening to music CDs.
The history of the creation of CD-ROMs begins in 1980, when Sony and Philips joined forces to create technology for recording and producing CDs using lasers. Since 1994, CD-ROM drives have become an integral part of the standard PC configuration. The information carrier on a CD is a relief substrate on which a thin layer of light-reflecting material, usually aluminum, is applied. Recording information on a CD is a process of forming a relief on a substrate by “burning” miniature pits with a laser beam. Information is read by registering a laser beam reflected from the substrate relief. The reflective area of the disk surface gives a “zero” signal, and the signal from the stroke gives a “one”.
Data storage on CDs, like on magnetic disks, is organized in binary form.
Compared to hard drives, CDs are much more reliable in transportation. The volume of data located on a CD reaches 700 - 800 MB, and if the operating rules are followed, the CD practically does not wear out.
The CD manufacturing process includes several stages. At the first stage, an information file is created for subsequent recording on the medium. At the second stage, using a laser beam, information is recorded onto a medium, which is a fiberglass disk coated with a photoresist material. Information is recorded in the form of a sequence of indentations (strokes) located in a spiral, as shown in Fig. 3.7. The depth of each pit stroke (pit) is 0.12 µm, the width (in the direction perpendicular to the plane of the drawing) is 0.8 - 3.0 µm. They are arranged along a helical track with a spacing of 1.6 µm between adjacent turns, corresponding to a density of 16,000 TPI (625 TPI). The length of the streaks along the recording track ranges from 0.83 to 3.1 µm.
At the next stage, the photoresistor layer is developed and the disk is metallized. A disc made using this technology is called a master disc. To replicate CDs, several working copies are made from the master disc using electroplating. Working copies are coated with a more durable metal layer (for example, nickel) than the master disk, and can be used as matrices for duplicating CDs up to 10 thousand pieces. from each matrix. Replication is carried out by hot stamping, after which the information side of the disc base, made of polycarbonate, is vacuum metallized with a layer of aluminum and the disc is coated with a layer of varnish. Disks made by hot stamping, in accordance with the passport data, provide up to 10,000 cycles of error-free data reading. The thickness of the CD is 1.2 mm, diameter - 120 mm.
CD-ROM drive contains the following main functional units:
Boot device;
Optical-mechanical unit;
Drive control and automatic control systems;
Universal decoder and interface unit.
In Fig. 3.8 shows the design of the optical-mechanical CD-ROM drive unit, which operates as follows. An electromechanical drive rotates a disk placed in the loading device. The optical-mechanical unit ensures that the optical-mechanical reading head moves along the radius of the disk and reads information. A semiconductor laser generates a low-power infrared beam (typical wavelength 780 nm, radiation power 0.2 - 5.0 mW), which hits a separation prism, is reflected from a mirror and focused by a lens on the surface of the disk. The servo motor, following commands from the built-in microprocessor, moves a movable carriage with a reflective mirror to the desired track on the CD. The beam reflected from the disk is focused by a lens located under the disk, reflected from the mirror and hits a separation prism, which directs the beam to a second focusing lens. Next, the beam hits a photosensor, which converts light energy into electrical impulses. Signals from the photosensor are sent to a universal decoder
Automatic tracking systems for the disk surface and data recording tracks ensure high accuracy of information reading. The signal from the photosensor in the form of a sequence of pulses enters the amplifier of the automatic control system, where tracking error signals are isolated. These signals enter automatic control systems: focus, radial feed, laser radiation power, linear speed of disk rotation.
A universal decoder is a processor for processing signals read from a CD. It consists of two decoders, a random access memory device and a decoder control controller. The use of double decoding makes it possible to recover lost information up to 500 bytes. The random access memory serves as a buffer memory, and the controller controls the error correction modes.
The interface unit consists of a digital-to-analog converter, a low-pass filter and an interface for communication with a computer. When playing audio information, the DAC converts the encoded information into an analog signal, which is sent to an amplifier with an active low-pass filter and then to a sound card that is connected to headphones or speakers.
The following are performance characteristics that you should consider when selecting a CD-ROM for your specific application.
Data Transfer Rate (DTR) is the maximum speed at which data is transferred from the storage medium to the computer's RAM. This is the most important characteristic of a CD-ROM drive and is almost always mentioned along with the model name. The disk rotation speed is directly related to the data transfer speed. The first CD-ROM drives transferred data at 150 KB/s, as did Audio CD players. The data transfer speed of the next generations of devices is usually a multiple of this number (150 KB/s). Such drives are called drives with two-, three-, four-fold speed, etc. For example, a 60-speed CD-ROM drive provides information reading at a speed of 9000 KB/s.
The high data transfer speed of a CD-ROM drive is necessary primarily for synchronizing picture and sound. If the transmission speed is insufficient, video frames may be dropped and audio may be distorted.
However, further increasing the reading speed of CD-ROM drives by more than 72 times is impractical, since with a further increase in the CD rotation speed the required level of reading quality is not ensured. And, in addition, a more promising technology has appeared - DVD.
Reading quality is characterized by the error rate (Eror Rate) and represents the probability of receiving a distorted information bit when reading it. This parameter reflects the ability of the CD-ROM device to correct read/write errors. The passport values of this coefficient are 10~11-10~12. When data is read from a dirty or scratched area of a disk, groups of erroneous bits are recorded. If the error cannot be corrected using the anti-jamming code (used when reading/writing), the data reading speed is reduced and the reading is repeated many times.
Average access time(Access Time - AT) is the time (in milliseconds) that the drive requires to find the necessary data on the media. Obviously, when working on internal areas of the disk, the access time will be less than when reading information from external areas. Therefore, the drive data sheet provides the average access time, defined as the average value when performing several data reads from different parts of the disk. As CD-ROM drives improve, the average access time decreases, but nevertheless this parameter differs significantly from that for hard disk drives (100 - 200 ms for CD-ROMs and 7 - 9 ms for hard disks). This is explained by fundamental differences in designs: hard disk drives use several magnetic heads and the range of their mechanical movement is less than the range of movement of the optical head of a CD-ROM drive.
Buffer memory capacity is the amount of random access memory on a CD-ROM drive used to increase the speed of access to data recorded on the media. Buffer memory (cache memory) is a memory chip installed on the drive board for storing read data. Thanks to buffer memory, data located in different areas of the disk can be transferred to the computer at a constant speed. The buffer memory capacity of individual CD-ROM drive models is 512 KB.
Mean time between failures- average time in hours characterizing the failure-free operation of the CD-ROM drive. The average time between failures of various models of CD-ROM drives is 50-125 thousand hours, or 6-14.5 years of round-the-clock operation, which significantly exceeds the obsolescence of the drive.
In the process of development of optical disk drives, a number of basic formats for recording information on CDs have been developed.
CD-DA (Digital Audio) format - digital audio compact disc with a playing time of 74 minutes.
The ISO 9660 format is the most common standard for the logical organization of data.
The High Sierra (HSG) format was introduced in 1995 and allows data recorded on disk in ISO 9660 format to be read by all types of drives, which has led to the widespread replication of programs on CD and contributed to the creation of CDs aimed at various operating systems systems.
The Photo-CD format was developed in 1990-1992. and is intended for recording on CD, storing and playing static video information in the form of high-quality photographic images. A Photo-CD format disc holds from 100 to 800 photographic images of the corresponding resolutions - 2048x3072 and 256^384, and also stores audio information.
Any CD-ROM disc containing text and graphic data, audio or video information is classified as multimedia. Multimedia CDs exist in various formats for various operating systems: DOS, Windows, OS/2, UNIX, Macintosh.
The CD-I (Intractive) format was developed for a wide range of users as a standard multimedia disc containing various text, graphic, audio and video information. A CD-I format disc allows you to store a video image with sound (stereo) and a playback duration of up to 20 minutes.
The CD-DV (Digital Video) format provides recording and storage. high-quality video with stereo sound for 74 minutes. During storage, compression is provided using the MPEG-1 (Motion Picture Expert Group) method.
Reading the disc is possible using a hardware or software MPEG decoder.
The 3DO format was developed for game consoles.
CD-ROM drives can operate with either a standard IDE (E-IDE) interface or a high-speed SCSI interface.
The most popular CD-ROM drives in Russia are products with the brands Panasonic, Craetive, Samsung, Pioneer, Hitachi, Teac, LG.
In the period 1994-1995, the basic configuration of personal computers no longer included floppy drives with a diameter of 5.25 inches, but instead the installation of a floppy drive became standard CD-ROM having the same external dimensions.
Abbreviation CD-ROM (Compact Disc Read-Only Memory) translated into Russian as CD-ROM-based read-only storage device . The operating principle of this device is to read numerical data using a laser beam reflected from the surface of the disk. Digital recording on a CD differs from recording on magnetic disks in its very high density, and a standard CD can store approximately 650 MB of data.
Large volumes of data are typical for multimedia information(graphics, music, video), so disk drives CD-ROM classified as multimedia hardware.
Today, multimedia publications are gaining an increasingly stronger place among other traditional types of publications. For example, there are books, albums, encyclopedias and even periodicals (electronic magazines) published on CD-ROM.
The main disadvantage of standard disk drives CD-ROM is the impossibility of recording data, but in parallel with them there are also write-once devices CD-R (Compact Disk Recorder) and rewritable devices CD-RW .
The main parameter of disk drives CD-ROM is the data reading speed. It is measured in multiples. The reading speed in the first production samples was taken as the unit of measurement, which was 150 KB/s. Thus, a drive with double the read speed provides performance of 300 KB/s, with quadruple speed - 600 KB/s, etc. Currently, the most common devices are CD-ROM reading with a productivity of 48x-52x. Modern examples of write-once devices have a performance of 16x-32x, and write-multiple devices - up to 32x.
By 1995, Philips and Sony developed a high-capacity compact disc, Multimedia CD. Toshiba and several other companies have created a different CD technology and also with increased capacity. The battle for the market has begun. Then the two largest groups, CITWG (Computer Industry Technical Working Group) and HVDAG (Hollywood Video Disc Advisory Group), came together to fight against the emergence of these incompatible standards. In 1995, through joint efforts, a new standard was created - DVD. It was intended primarily for the film industry, as a substitute for video cassettes, and therefore the abbreviation stood for Digital Video Disc. Then this format was renamed Digital Versatile Disc - digital versatile disk. However, in 1997, Philips and Sony left the consortium. Subsequently, other DVD manufacturers followed suit.
At the moment there are several DVD formats and this brings some confusion to the market because not all formats are compatible. There are DVD-R, DVD-ROM, DVD-RAM, DVD-RW. DVD-ROM drives without special modification cannot read DVD-RAM discs (with the exception of DVD-ROMs of the so-called third generation, produced since mid-1999). But DVD–RAM drives can read DVD–ROM, as well as CD–R and CD–RW. The DVD+RW drive is only compatible with DVD-ROMs and regular CDs. And the DVD + RW format is not recognized by many manufacturers at all. First-generation DVD-ROM devices used CLV mode and read from the disc at a speed of 1.38 MB/s (in traditional DVD notation this is 1x). Second-generation devices could read DVDs at twice the speed - 2x (2.8 MB/s). Modern DVD-ROMs - third-generation devices - use rotation control mode (CAV) with a maximum reading speed of 4x-6x (5.5 - 8.3 MB/s) or more.
The main differences between the DVD standard and CD:
1) a laser with a shorter wavelength is used. If in CD-ROM drives the wavelength is 780 nanometers, then in DVD drives it is 635 nanometers. This allows you to reduce the stroke length and increase the speed of data reading.
2) due to the use of more advanced materials, DVD is used to record data in two layers on one side of the disc or one layer on both sides of the disc or two layers on both sides of the disc, depending on the DVD format. Disk capacity varies from 2.6 Gb to 17 Gb.
3) a completely new sector format, a more reliable error correction code, and improved channel modulation are used. Now let's talk about layers in more detail.
Single Side/Single Layer
This is the simplest structure of a DVD disc. This disk can accommodate up to 4.7 GB of data. This capacity is 7 times greater than the capacity of a conventional audio CD and CD-ROM disc.
Single Side/Dual Layer
This type of disk has two layers of data, one of which is translucent. Both layers are read from one side and such a disk can accommodate 8.5 GB of data, i.e. 3.5 GB more than a single-layer/single-sided disc.
Double Side/Single Layer
This disk holds 9.4 GB of data (4.7 GB on each side). The capacity of such a disc is twice that of a single-sided/single-layer DVD disc. However, because the data is on both sides, you will have to flip the disk over or use a device that can read the data on both sides of the disk on its own.
Double Side/Double Layer
The structure of this disk allows you to store up to 17 GB of data on it (8.5 GB on each side).
The thickness of a DV disc is 0.6mm, which is half the thickness of a standard CD disc. This makes it possible to connect two disks with opposite sides and get a double-sided disk equal in thickness to a regular CD. Another technology creates a second layer to house data, which allows you to increase the capacity of one side of the disk. The first layer is made translucent, so the laser beam can pass through it and be reflected from the second layer.
Among other things, DV discs have the ability to increase recording density. To achieve this, manufacturers take different paths:
1. a more advanced laser is used
2. reduce stroke length
3. reduce the distance between turns
4. increase the data area without changing the overall disk size
5. Increase ECC efficiency
6. apply more efficient modulation
Now about rewritable discs. These include the DVD – RAM format. These discs use a material developed by TDK engineers and it is called AVIST. The recording principle is almost the same as that of a CD. The most important advantages of DVD-RAM format discs are the ability to be rewritten up to 100,000 times and the presence of a recording error correction mechanism. DVD+RW discs can record streaming video or audio, as well as computer data. DVD+RW format discs can be rewritten about 1000 times, but the DVD+RW format is promoted only by its developers - Hewlett-Packard, Mitsubishi Chemical, Philips, Ricoh, Sony and Yamaha and is not supported by the DVD forum. DVD-RW is a rewritable format developed by Pioneer. DVD-RW format discs hold 4.7 GB per side, are available in single-sided and double-sided versions and can be used to store video, audio and other data. DVD-RW discs can be rewritten up to 1000 times. Unlike DVD+RW and DVD-RAM formats, DVD-RW discs can be read on first-generation DVD-ROM drives.
A major achievement in ensuring compatibility in DVD technology was the unified file system MicroUDF, adopted in 2000. The MicroUDF file system is a version of the UDF (Universal Disk Format) file system adapted for use in DVDs, which, in turn, is based on the international standard ISO-13346. This file system is gradually replacing the outdated ISO9660, which was created at one time for use in CDs. For the transition period (until computer devices and disks operating in the ISO9660 format go out of circulation), the UDF Bridge file system will be used, which is some combination of MicroUDF and ISO9660. Only MicroUDF can be used to burn Audio/Video DVD discs.
To protect against illegal copying, two specifications have been developed: DVD-R(A) and DVD-R(G). These two versions of the same specification use different laser wavelengths when recording information. Thus, discs can only be written on equipment that meets their specifications. Disc playback can be performed equally successfully on any equipment that supports the DVD-R format. DVD-R(A) (DVD-R for Authoring) is used in professional applications. In particular, support for a special format (Cutting Master Format) allows you to use these discs to record the original replica of information (pre-mastering) instead of the usual use of DLT tapes for these purposes.
DVD-R(G) (DVD-R for General) is intended for wider use. Disks of this format are protected from the possibility of bit-by-bit copying of information onto them from other disks. The format is supported in mass storage devices (for example, in robotic DVD libraries offered by Pioneer itself).
What is the difference between Cross flash firmware for an optical drive and “regular” one? Cross flash is usually marked in all catalogs with an asterisk - “*”. It can be used to reflash the drive, regardless of what firmware is currently installed in it. “Regular” can be installed correctly only on the previous version (Iron magazine).
Does flashing an optical drive void the warranty on it or not? It all depends on the specific seller from whom the product is purchased. If the warranty (and all its annexes) does not say anything about replacing the built-in software, then it will be very difficult for a store not to repair or replace a non-functioning optical drive under warranty. To be completely sure, you can call and find out everything from the technical support service, while demanding links to the official documents of this store (because it is easier for employees to say that there will be no warranty than to repair and waste time).
August 17, 1982 is considered the birthday of the compact disc, one of the most common types of storage media today.
The development of CDs was carried out by Philips and Sony. CDs are made of 1.2 mm thick polycarbonate covered with a thin layer of aluminum with a protective varnish coating. Initially, CDs were positioned for digital storage of audio information.
The external size of a CD is determined by a special standard and is 120 mm. This is the usual size that everyone is used to. There is also a more compact version - 80 mm. If you look closely at your drive, you will see that the slide-out tray has a small indentation for these disks. Standard discs originally held 650 MB of data (or 74 minutes of audio). There are several assumptions that explain this choice of the diameter and capacity of optical media. According to one of them, the volume of the disk was calculated in such a way that Beethoven’s ninth symphony, which lasts 74 minutes, would fit entirely on it. It was this work that was most popular in Japan in the late seventies of the last century. According to another version, the diameter of the CD corresponds to the size of Dutch beer coasters.
CD formats
The very first CDs were intended solely for listening to music in music players. But then manufacturers saw that CDs could be used not only to record music tracks, but also to record data. And in a short time, many different formats were created, designed for different purposes. Currently the following standards exist
- CD-Audio (CD-DA)
- CD-ROM (mode 1 and mode 2)
- CD-ROM-XA (mode 2, form 1 and form 2)
- CD-i, VideoCD
- CD-Extra
- PhotoCD
- KaraokeCD
- CD-RW
Many of these formats are not widely used. But the emergence of all kinds of formats created a problem - it was necessary to have many players for each format. Fortunately, manufacturers have managed to create universal players that can read all formats presented on the disc, or can skip tracks recorded in an unfamiliar format.
CD-ROM is the name of a digital storage medium. In terms of its physical structure, it is absolutely identical to a CD-DA audio disc. The only difference is in the logical structure of the tracks. The disc consists of three layers: a polycarbonate plastic substrate on which tracks are stamped using a press, a sprayed reflective aluminum coating and a protective layer. It is on the protective layer that the design is applied.
CD Standards
The production of any type of CD must comply with certain standards, which are known as the Red Book, Yellow Book, Green Book and so on.
- The Red Book is a standard that describes a method for storing audio digital information that was created by Philips experts. All music audio CDs comply with this standard. This book later served as the basis for other standards. This format assumes the ability to record two-channel audio with 16-bit pulse code modulation (PCM) and a sampling frequency of 44.1 kHz. An error correction system based on the Reed-Solomon code allows you to easily read discs with minor scratches on the surface.
- Yellow Book - This standard expands the Red Book by adding a specification for CD-ROM multimedia devices. Regular computer games and software are recorded in accordance with the Yellow Book.
- Green Book - this standard involves a combination of the Red and Yellow Books, when the disk can contain both music tracks and programs.
- Orange Book - This standard covers the technology of recordable and rewritable CD-R and CD-RW discs.
- White Book is a standard for video CDs.
CD-R and CD-RW
Conventional CD-ROM discs were written on expensive equipment in enterprises. They had one drawback - Data was written once and could only be read. Recordable discs are more complex than standard CD-ROM discs. They have a layer of special plastic burned through a laser. Information on the disk is recorded in the form of a spiral track running from the center to the edge of the disk. The track can be continuous or consist of several parts (sessions).
A maximum of 99 sessions can be recorded on one CD.
There are two types of recordable discs: CD-R (recordable, write once) and CD-RW (rewritable, rewritable disc). How many times can a CD-RW disc be rewritten? A normal disk allows you to do this about 1000 times. The difference between disposable and rewritable discs lies in the use of different coatings on the discs - if for CD-R discs dyes are used, the change of which when burned with a laser is irreversible, then for rewritable discs materials are used, the change in the reflective properties of which is not reversible.
UDF file system
Recordable CD-R, CD-RW and DVD discs use a special file system called UDF (Universal Disk Format), which was originally developed to work with flexible magnetic media. A special feature of this system is the ability not to close the session when recording, that is, to work with a CD as with a floppy disk. Before recording, the disc to be recorded must be specially formatted in order to subsequently use it as a regular external storage device. The UDF format is used by almost all file systems and is supported by all new operating systems.
Data Capacity
A standard CD holds 650 megabytes of data, or 74 minutes of digital music. This standard has remained unchanged for a long time. But then manufacturers found a way to increase the amount of recorded information. Thanks to the increase in recording density, the overall capacity of discs has been increased - now most recordable discs sold have a capacity of 700 megabytes.
Burning discs
When burning discs using various programs such as Nero, the user sometimes does not quite correctly understand the process of “burning” the disc and makes mistakes that can be avoided. Here are a few concepts used in the disc recording process:
- A session is a special area on a disk. A CD can have sessions and tracks. Each session has one or more tracks. Each session can include a maximum of one data track, and there can be multiple audio and video tracks
- multisession (MultiSession) - a recording mode that allows you to record a CD, that is, add new information to previously recorded information. Each session will contain an initial record (lead-in), then the data itself and the final information about the session (lead-out). This mode has a certain drawback - when separating one session from another, about 15 MB are lost each time. Additionally, some older CD-ROM models cannot read discs written in this mode, and others have a limit on the number of sessions they can see.
- initial record (Lead-In) - service area on the disk. This area marks the beginning of the session recording and contains the table of contents (TOC, Table of Contents) of the session, which includes information about the tracks of this very session. It is recorded along with the Lead-Out of this session. Each Lead-nI zone occupies approximately 9 MB;
- final recording (Lead-Out) - a service area on the disk, similar to Lead-In, which indicates the end of the recording session. Always recorded with Lead-In. The first Lead-Out of the disk takes up about 13 MB, all the following take up about 4 MB;
- table of contents (TOC, Table of Contents) - contains information about the type and number of tracks, their location on the disk and the length (volume) of the entire disk. Physically, the TOC table is located in the Lead-In area. In multi-session discs, each session has its own Lead-In area and, accordingly? its own table of contents - the most “correct” at the time of recording, since it contains the latest changes.
Thus, when recording a multi-session CD, a new session is recorded each time, which consists of a Lead-In region, a data track and a Lead-Out region. The Lead-In and Lead-Out areas require approximately 15 MB per session and do not contain any useful data. Therefore, it is not recommended to write data in small portions, as you will simply waste a large amount of recording space. It's better to prepare a collection of files sufficient to fill the disk and record everything in one session.
- If possible, do not run other programs when writing to a disk, since writing a disk is a fairly resource-intensive operation, and any interference in this process can lead to a writing error and damage to the disk;
- even if you have two CD-ROM drives and you want to copy data from one drive to another, it is still advisable to copy the source files to your hard drive. The performance of hard drives is an order of magnitude higher than the fastest drives;
- If you constantly have errors when recording at high speeds, then use a lower speed. It's better to wait a little and get a working disk than to throw away damaged disks;
- SCSI CD-R drives are more reliable than IDE drives. If you work quite often and professionally with recording to disks, then choose the SCSI bus.
The speed designations 1x for CD-ROM and 1x for DVD-ROM are not the same thing. For CD-ROM, “x” corresponds to the transfer speed of the first standardized CD-ROM, which was subsequently adopted as 1x, that is, 150 Kb/s, and for DVD-ROM, 1x, accordingly, was accepted as the transfer speed of the first DVD-ROM, that is - 1350 KB per second.
Writing to a CD-RW that has been fully formatted is different from writing to a disc that has been erased by a so-called quick format. With quick formatting, the data is not physically erased, but a mark is placed at the beginning of the disk indicating that the disk is empty. When fully formatted, the disk is filled with zeros. Full formatting is more resistant to reading and writing. Quick formatting may cause glitches (