View from below on the reading head of the drive model NEC1100A
We are primarily interested in small trimming resistors mounted directly on the head. These resistors regulate the current through the laser diode and by changing their value, it is possible to change the brightness of the laser radiation within certain limits. In the figure, they are circled and marked with numbers 1 and 2.
The location of these regulators for different models of drives can vary greatly. For example, this photo shows the optical head of a newer drive:
You need to take a thin screwdriver and add a little brightness to the desired laser. You can find the right regulator by experience. Let's assume that our drive reads CDs well and reads DVDs very badly. We take a marker and make notes on the resistors to remember the position of the engine, which was made at the factory when setting up the head. Then, one of the resistors, for example number 1, is unscrewed to the extreme position counterclockwise. We assemble the drive and check the reading of CDs and DVDs. To do this, it is convenient to use the program Nero CD-DVD Speed. If the reading of CDs, which were previously well read, has deteriorated sharply, then we have turned the laser regulator responsible for reading this format. We return the resistor engine to its previous position. If the quality of reading CD discs has not changed, then we guessed the DVD laser brightness control.
After we have found the desired regulator, we turn it about 5 - 10 degrees clockwise relative to the position that was set at the factory and which we marked with a marker. We assemble the drive again and check the readability of the DVD disc. If it doesn’t help, we twist the resistor again, in the end, 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 DVD+R discs are used, because DVD-R has it by default. If you want the disc to be guaranteed to be read on any even the most ancient player, you need to set the Book Type to DVD-ROM. It is recommended to set Book Type for double-layer (DVD+R9 DL) discs as well. otherwise, they may well not be read even on the most modern DVD players.
Lite-On IT DVD Drive - SOSW-833SX
Specifications of SOSW-833SX:
Interface - USB 2.0
The maximum recording speed of DVD±R discs is 8x;
The maximum recording speed of DVD±RW discs is 4x;
The maximum recording speed for DVD±R DL discs is 2.4x;
The maximum write speed for DVD-RAM discs is 5x;
The maximum recording speed of CD-RW discs is 24x;
The maximum recording speed of CD-R discs is 24x;
Buffer size - 2 MB
Slim form factor
Weight - 362 gr.
DVD burner DRW-1608P2S with support for recording on dual-layer media:
Lite-On IT releases LightScribe drive with 8X DVD+R DL recording.
Features 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
- Recording to DVD+ / - R9
- Buffer underrun protection technology SMART-BURN
- CD-DA/VCD/DVD SMART-X Speed Adjustment Technology
- Noise and vibration suppression system for writing and reading VAS
- Support for Fixed Packet, Variable Packet, TAO, SAO, DAO, Raw Mode Burning & Over-Burn recording modes
- DVD Reading: DVD Single/Dual Layer (PTP/OTP), DVD-R (3.9GB/4.7GB), DVD-R, DVD+R, DVD+R Multisession, DVD-RW and DVD+RW
- CD Reading: CD-DA, CD-ROM, CD-ROM/XA, Photo-CD, Multisession, Karaoke-CD, Video-CD, CD-I FMV, CD Extra, CD Plus, CD-R and CD-RW
- Support 80 and 120mm CD and DVD
- Communication modes: PIO mode 4, DMA mode 2 and Ultra DMA mode 4
- Lightscribe Support
ASUS CB-5216A1T: SATA DVD/CD-RW Drive
The CB-5216A1T supports ASUS FlextraLink, FlextraSpeed and DDSS II proprietary technologies.
FlextraLink technology prevents buffer underrun errors and eliminates the possibility of disc corruption, while FlextraSpeed is designed to increase accuracy and reliability when reading/writing/rewriting media of various formats. In turn, the DDSS II Dual Dynamic Suspension System is designed to minimize vibration caused by the optical drive's spindle motor and resonance between the drive and the computer case by stabilizing both vertically and horizontally.
Specifications ASUS CB-5216A1T:
- CD-R Write Speed: 52X
- CD-RW rewriting speed: 32X
- CD-ROM reading speed: 52X
- DVD reading speed: 16X
- FlextraLink Technology
- FlextraSpeed technology
- DDSS II
- AI Auto Speed Adjustment Technology
- Support for accelerated decoding of music CDs (max. speed - 52X) and Video CD
- Mt support. Rainier
- Support for DAO-RAW, TAO, DAO, SAO, Multi-Session, Packet Write and Overburn
- Support for 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
- Vertical and horizontal installation possible
- SATA interface
Hitachi GSA-4166B
Hitachi introduced the drive - GSA-4166B supports all formats, including DVD-RAM.
The 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)
- Support for LightScribe technology
- Buffer size - 2 Mb
- Media loading - horizontal, automated
- Interface: IDE/ATAPI/Ultra DMA66
- Power supply: 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
Transfer rate:
- DVD-ROM: 22.16 Mbps
- CD-ROM: 6 Mb/s.
Data access time:
- DVD-ROM: 145ms
- CD-ROM: 120ms
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, Packet Write
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 - single layer (single layer disc), DL - double layer.
Buffalo DVSM-X516FBS and DVSM-X516IU2
Buffalo launches two new DVD drives.
For installation inside, it comes with a SATA-ATAPI adapter and supports both standards. Dimensions: 146 x 170 x 42 mm, and the weight of the product is 760 g. When connected via serial ATA, the DVSM-X516FBS model is only compatible with Win2K/XP.
The external drive DVSM-X516IU2 has IEEE 1394/USB 2.0 interface connectors. Its dimensions are 160 x 279 x 55 mm, weight 1.8 kg. Fully compatible with Win98 SE/Me/2K/XP and WinXP Media Center Edition 2005.
Both models are based on Hitachi DVD super multiple drive GSA-4167B. They provide the following data write speeds: DVD+R DL 6x, DVD-R DL 4x, DVD±R (1-layer) 16x, DVD-RAM 5x, DVD+RW 8x and DVD-RW 6x. Matrix CD-Rs are written at 48x, and CD-RWs 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 kit comes with 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 starts selling external DVD±R/RW drives. This model does not have a "tray" retractable element, but uses a "slot loading".
USB 2.0 and IEEE 1394 are provided for connecting to a computer. 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, while CD-RWs are written at 24x. Drive buffer size is 8Mb. The device is equipped with the "Intelligent Recording" function, which automatically selects the optimal recording speed. The products will be released in a limited edition of 500 pieces in white cases. Dimensions 167.1x253.5x53mm, weight 1.7 kg.
Other external DVD±R/RW drive .
The design of the device is similar to the PX-716UFL, but the color of the case is black, and a traditional sliding "tray" is used to receive the disk. There is also a USB 2.0 and IEEE 1394 interface, the write speed for DVD±R is 16x, DVD+RW 8x, DVD+R DL 8x, DVD-R DL 4x and for DVD-RW 6x. Matrix CD-Rs are written at 48x, and CD-RWs at 32x. Buffer size 2MB. Dimensions 167.1 x 253.5 x 53 mm, weight 1.6 kg. All drives are guaranteed to be 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 0.92kg
The drive is able to work 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 minus, but, nevertheless, all modern drives support it.
NU DDW-164 clearly needs to be improved, most of the problems are related to the fact that the manufacturer needs to improve the burning strategies for most discs and rework the list of supported discs. These problems, as a rule, can be solved in the new firmware version, so it remains to be hoped that the developers will promptly make the necessary changes, but for now the drive will suit you only if you mainly use "branded" blanks.
Q. Decided to buy a DVD-RW?
A. NEC-ND3520 Q. NEC DVD-RW ND-2500A stopped reading and writing DVDs (CD-R/RW reads)?
A. Reading and writing a DVD requires more laser power than writing a CD. That is, the most probable cause is a decrease in the radiation power. First, clean your head. If it does not help, then the laser emission is reduced, change the drive.
Q. Combo CD-RW/DVD Samsung 352F (OEM), the drive does not see the disc (it's not the disc), there is also a problem with the 7.9 GB DVD, the computer is very stressed, but it cannot read the files. Mother ECS P6S5AT. Proc Celeron 1.0 GHz, Windows XP Home system?
A. To burn a DVD, you need to install a program for burning discs. As for reading dual-layer DVDs: your drive simply does not support them or a firmware update is required (look at the drive manufacturer's website). In addition, Samsung optical drives have never been of high quality.
Q. Bought 552 TEAC. Was it worth taking instead of NEC 1100A?
A. Instead of NEC - it was not worth it, the reliability and quality of NEC drives have been noticeably higher lately.
The TT-15S1 is a perfectly smooth "milky" surface of the 28 mm thick acrylic base, a belt drive, an aluminum tonearm with an anti-roll system and, of course, no preamps.
Speed 33 x 1/3.45 rpm ±0.2%,
Signal to noise ratio - 80 dB,
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.
The vinyl player is a limited edition priced at ~$2400.
Pioneer DVR-110
Model * burns DL media to 8x DVD+R/-R, regular DVD+R/-R discs are recorded at 16x. Other characteristics of the Pioneer DVR-110 are as follows:
Reading:
*Unfortunately no support for Blu-ray media.
Vinyl "blanks" CD-R
17/05/2005 The Russian company MIREX launches CD-R MAESTRO blanks with VYNIL type coating and design stylized as vinyl records of past years. MAESTRO is available in five versions, differing only in the color of the inner rings on the surface.
The disks have a capacity of 700MB and a maximum write speed of 52x. According to the manufacturer, the main advantage of vinyl is a double, reinforced protection of the information layer, which is especially relevant for frequent use of the disc and its operation in extreme conditions, such as high humidity or sudden changes in temperature.
Benq Dual Cooling System
Benq introduced the DVD+-R/+-RW burner. The model is called DW1640 and will be released with a black and white front panel. 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 recorded at 8x speed, so an 8.5GB disc is written in 16 minutes, only DVD-RW discs are written at 6x speed.
The novelty is equipped with a dual cooling system Dual Cooling System (DCS), which includes 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 of 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 been able to significantly improve the manufacturing process of rewritable discs and improve 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, ie. the novelty has 1.8 times more volume than traditional discs - single-sided and single-layer.
In addition, JVC's recording layer pre-treatment method will allow manufacturers to use existing equipment to produce new-style discs, if, of course, the proposal to standardize and adapt JVC's new-style DVD-RW discs receives a response in the DVD Forum, where JVC has filed a corresponding application.
Unlike conventional dual-layer discs, JVC discs use a new material that improves both the reading quality of the disc [both layers] and improves its erasability and writeability.
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 prototype monolithic read/write block
The presence of several ideologically similar formats for reading (writing) information from optical discs has led to the fact that, starting from a certain moment (since the release of combo drives), first laser heads with two separate diodes (one for CD, the other for DVD), and then heads with a pair of crystals packed in a single diode housing, each of which emitted its own wavelength (such diodes, for example, are produced by Sony). At the same time, the task pursued was quite definite: to replace the scattering of elements with a monolithic block, simplifying and reducing the cost of the design of the laser head, simultaneously increasing its reliability.
The appearance of blue-violet laser-recorded optical discs has become a real challenge for designers of pick-up heads. Indeed, now it was required to include one more diode with its own matrix and its own beam path in the reading unit. In a surge of real enthusiasm, three-in-one puzzling structures began to appear one after another: from prisms, diodes and lenses. This is clear. First you need to make a device from what is, but there were separate diodes and universal heads, and only then simplify this device.
It was about the development of a prototype of such a "brought to mind" universal laser head unit that the tandem from Sony and Nichia announced today. This pair of manufacturers, let me remind you, concluded in April of this year an unlimited cross-licensing agreement on the joint development of blue-violet laser diodes and pick-up heads based on them, which they will sell and produce, however, each separately. The created prototype will be sent to mass production by the end of 2005. By then, presumably, its versatility will only increase. Because at the moment the new laser unit is not quite universal: it emits only waves 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 unit is different: its execution is simply striking in its "conciseness":
The design principle is clear from the block diagram, and we will not dwell on it. We only note that such a prism design is as reliable as possible (all three optical sections are enclosed in a monolithic block) and easy to assemble. In addition, such a unit will need only 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 has issued an official press release announcing the release of a "Pro" version of its renowned 16-speed DVD±RW drive that 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 do it only at 2.4x speed. That is why the company did not change the drive index, limiting itself to the "Pro" suffix. Also, both drives now come with a proprietary QScan utility that allows the user to quickly check the quality of the disc and determine the optimal speed and recording parameters.
However, if we remember the specs and price of LG's anticipated super-universal GSA-4163B drive, then all of the above is no longer too important. Q. For some time now I have started having problems with DVD and CD playback. When watching a video, listening to audio by any program, "slips" periodically occur. Those. there is a movie, for example, and then immediately jumps a couple of seconds ahead. Same with MP3 when played directly from the drive. The frequency of the phenomenon is 5-20 minutes. Everything reads fine from the hard drive (SATA interface). It is copied from / to the hard drive, discs are written, discs are copied and everything else is normal and at the same speed. When playing an AudioCD, everything is also normal, but at the same time I do not use digital playback, but "analogue", i.e. The sound output does not go through the mother 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 closes 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 scratched a little, or while watching a movie or listening to music, the system wants to access some services, so there is a short-term disappearance and jumps. Maybe the laser head is dusty (clean it). When reading an Audio CD, you don't need such spin-up speeds (max - 4x) as when watching movies. Advice - rewrite films first on a screw (with a DVD, of course, it is more problematic than with a CD), otherwise you will slowly ruin your DVD / CD-Rom.
DVD-RAM (Digital Versatile Disc Random Access Memory)
In July 1997, the DVD Forum approved the DVD-RAM format (Digital Versatile Disc Random Access Memory), which was developed by three Japanese companies: Hitachi, Matsushita and Toshiba. But in the personal computer market, DVD-RAM hasn't really caught on. 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 rewritable DVD formats that they simply did not get their hands on a third format. Although the reason why manufacturers began to turn away from DVD-RAM may be different, namely, DVD-RAM discs were supplied both in cartridges and without, which somewhat complicated the work with discs (cartridges could be collapsible or non-collapsible) , and dictated the need to produce drives with a tray for cartridges.
The DVD-RAM format turned out to be more in demand in the corporate sector, when DVD-RAM drives were introduced into robotic libraries for storing data. This format was chosen by corporations because DVD-RAM specifications, in terms of the number of maximum possible rewrite cycles, compare favorably with DVD±RW, promising 100,000 erases and rewrites, which is significantly more than 1,000 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 to gain popularity among ordinary users. After all, perhaps only non-separable cartridges could guarantee the promised number of rewriting cycles at the expense of cost and ease of storage. What the mass market was not ready to go to. In the end, support for DVD-RAM recording in some drives produced today only serves to strengthen the manufacturer's reputation, but by no means a standard.
However, now, according to some indications, the "cartridgeless" DVD-RAM format is beginning to gain momentum. One of its developers, Hitachi, is taking the most active steps to bring DVD-RAM back to the market. 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 master the market of DVD-RAM media and drives! Is it possible that the achievement of the upper limit of the speed of writing DVD±R discs has frightened manufacturers so much that they are ready to bring something new to DVD drives by any means, expanding their functionality, even at the expense of not very popular features? It's like with mobile phones, which from "just call" turned into a kind of "Swiss knives" from, not even communications, but from entertainment or something. Anyway, laser heads for drives compatible with DVD-RAM are going to be manufactured 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 the launch of new products by the second quarter of 2005. But LG Electronics releases such drives regularly. In the spring of 2004, LG announced the Super Multi drive model, which indeed supported all formats, including the latest dual-layer (GSA-4120B drive).
Super Multi drive LG GSA-4160B.
Not so long ago, this model was upgraded to version GSA-4160B. The update affected only the speed of writing DVD+R discs: it has grown from 12x to 16x. All other parameters remained unchanged: DVD-R - 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 disc?
A.Nero InCD - format your disc there, you will get the UDF format, and then you can work with it like a large floppy disk (most likely, I mean not formatted, but a blank DVD disc). If we are talking about DVD + / - RW , then when erasing in Nero, select "Complete erasing of a rewritable disc".
Q.DVD-RW drive NEC ND2510A. It turned out that he does not read discs recorded by himself. But, if you just insert a DVD disc, for example with a movie or game, then everything is OK. It seems to be reading images written to disk - that is, if there is an installer, then it will launch it. But, before it gave an error cyclic redundancy check, and now: "Incorrect Function". How do you think this is resolved?
What I tried:
A. Have you tried writing to normal Verbatim? All the NECs I saw were characterized by a frank dislike for the "left" discs. And the cheapest Noname was not even read by Pioneer after recording (although household players BBK somehow played them - albeit not for long: then the recording layer peeled off).
Q. DVD+RW NEC 2510A (new) won't write DVDs
A. DVD+R or DVD-R discs? If you give it the second type, then everything is simple - it doesn’t know how to work with them, but if the first type, go to the warranty. This device is very fastidious, it writes only those disks that it "knows" in its firmware the names of disk manufacturers are hardwired, and those that he recognizes, those he will write, and those that he does not "know", those will not. And you can't fix it by changing the firmware - it's checked!
1. Check if the ASPI driver is installed.
2. Download the new firmware from the manufacturer's website.
3. Are the discs good?
Plextor: PX-740A Dual Layer DVD Drive
Plextor has announced the PX-740A internal dual-layer IDE DVD drive. This is a normal, solid drive i.e. without any special features like the flagship PX-716A.
Recording time for an 8.5 GB disc on a PX-740A drive is ~15 minutes. At the same time, the drive records a single-layer disc in less than 6 minutes.
PX-740A drive features:
- Buffer size 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
- Support direct recording method DVD±VR (Video Recording)
CD-ROM devices have become so commonplace that their "breed" is less and less paid attention. Even in fidosh conferences where people who are overly concerned with computers gather, disputes about CD-ROM drives have become extremely rare. They can still argue about recorders, but the “reader” is the “reader”, what can I say.
There are serious discussions about DVD-ROM drives. In fact, it was these devices that became the heirs of the CD-ROM, and only the relatively high cost of films on DVD (and the almost complete absence of software in this format) do not allow DVD-ROMs to displace their ancestors on the gaming and home fronts, and subsequently on the vast office . Interestingly, the quality of DVD reading is rarely discussed - all the attention of the disputants is riveted to the usual CDs, and the rest is mentioned in passing. But this is not surprising: films can be watched without problems even on old models of the 1998-99 model (if, of course, they have retained their consumer properties to this day), and, honestly, you rarely have to watch them on a computer 1 . CDs, on the other hand, were and remain standard and sufficiently capacious media that can be read on any modern computer.
Therefore, when we started testing modern CD/DVD drives, even with DVD-ROM, we first of all paid attention to the speed and quality of reading CDs, and only then to DVD nuances. Indeed, today it is not so important whether the drive can read DVDs at 16x2, because movies are still watched at first speed. On the other hand, speeds of 50x and more declared by manufacturers are just beautiful numbers, and instead of “52x Max” it would be much more honest to write “35x Average” on the front panel.
We recommend that almost all owners of high-speed drives use software tools that allow you to set the speed at your discretion. Let's say that 8x is enough (and even more than enough) to watch a movie, and you can listen to mp3 in the silence provided by the 2x mode. High speeds are fraught not only with noise, but also with a high probability of "breaking" the CD. The fact is that as the media is used, microcracks form along the edges of the technological hole, and at high spindle speeds (10 thousand rpm and above), the disk sometimes does not withstand stress and shatters into small fragments with a terrible roar. The drive itself may survive after that, but you will lose the guarantee, and the drive opened by the master is not a sight for the faint of heart.
Fifteen models have passed through our hands. The following configuration was chosen as a test: Celeron 667, 256 MB RAM, Gigabyte GA-6VEML motherboard, 20 GB Fujitsu MPG3204AH hard drive. Each drive was installed by a single device on the second IDE channel in master mode. All devices, unless otherwise noted, supported UDMA/2 mode.
The drives were tested on CD-RW (Philips Highspeed 4~10x, 74 min), CD-R (Philips CD-R80, 80 min), Data-CD (682 MB licensed DivX movie and licensed mp3 collection with a total of 694 MB), Audio CD ("The Very Best of Israel"). In addition, we used a "bad" disk (intentionally scratched appendix to the "Game.EXE" magazine) and a disk with the game "Jedi Knight 2: Jedi Outcast" (to compare the application installation speed).
The DVD reading test used Once Upon a Time in America (two layers, total capacity 7.75 GB). We won't risk calling the disc licensed, but the choice was made consciously, despite the wide range of legal films. The fact is that the popularity of cheap DVDs (from 300 rubles) is very high, and if the drive copes with such an outbred creation, then there will certainly be no problems with reading a licensed disc. By the way, we tested all the DVD-ROMs on the fresh "The Doors", Special Edition (Zone 1) and were quite satisfied with the results.
Nero CD Speed 0.85e (beta), Nero DVD Speed 0.53, Nero Info Tool 1.01, CDRom Drive Analyzer 2.32 and Exact Audio Copy 0.9 (beta 4) were selected as test software. The speed of file copying was counted using Download+ 3.2, and the installation time of the game was measured by a stopwatch rounded to the nearest second. The programs ran under Windows 2000 Professional with Service Pack 2.
Not a single really bad drive could be found. Yes, sometimes there were minor (and not so) shortcomings, sometimes manufacturers overestimated the characteristics of their products, but the discs were read at the very least, and an uninitiated user most likely will not notice these nuances.
Meet in our time a computer without CD-ROM/DVD drive almost impossible. CDs and DVDs contain a wide variety of programs, music, documents, digital photos, and more. You can purchase both discs with already recorded data (for example, a music CD or DVD with a movie), or special discs on which you can (once or several times, depending on the disc and drive) burn any information you need.
In addition to the not entirely correct name " drive”, CD/DVD readers and writers are also referred to as optical drives. Word storage device generally refers to all devices designed to store or read data. For example, HDD can be called a disk drive. The word "optical" refers to the method of reading data from discs. In CD / DVD drives, reading and writing data from discs is carried out using a special laser beam.
There are several types in total CD-ROM and DVD drives, with and without write support. Let's consider them in more detail.
- Regular disk drive CD— ROM allows only read data from disks CD, CD— R And CD— RW. You cannot write data to any discs with it. Such drives are the cheapest, but they are already outdated and are not installed in new computers.
- Drive CD— ROM with recording capability. Unlike the previous version, with the help of such a drive, you can write data to disks with a single (CD-R) or multiple (CD-RW) recording.
- Drive DVD. This drive combines the capabilities of the two previous drives, i.e. allows you to write and read data from CDs, and can also read data from DVDs.
- Drive DVD with recording capability. This is the most versatile and popular drive option and is recommended for purchase. With this drive, you can read and write any discs, including CD, CD-R, CD-RW, DVD+-R/RW.
- Also, Blu-ray disc drives are becoming more and more popular every year.
Main types of optical discs
As you already understood, the recording capabilities depend not only on the drive, but also on the discs themselves. Let's study the main types of optical discs that currently exist.
- CD, or CD. The simplest version of the optical disc. On such discs, either music (music CDs) or various programs are sold. Nothing can be written to such a disc.
- CD-R disc. Such a disk can once write down the information you need. You can't add it later. A single CD-R disc can store up to 880 MB of data, depending on the size of the disc. Such disks are most often used to store important information that will not need to be changed in the future. It can be music, video files, etc.
- CD-RW disc. This disc has the same capacity as CD-R discs, but you can write data to it many times and delete data you don't need. In total, such a disk is designed for approximately 1000 rewriting cycles, which is more than enough, for example, for periodic recording of Word documents, their subsequent deletion and recording of new files. CD-RW discs are more expensive than CD-R discs.
- Diskdvd-rom,orDVD video. DVDs are sold on these discs. Nothing can be written to such a disc. At the same time, the volume of a single-layer DVD disc is 4.7 GB, which is several times larger than the volume of CD discs.
- DiskDVD— Rand diskDVD+ R. Just like CD-R discs, DVD-R and DVD+R discs can be one write down the data you need. Unfortunately, at one time, companies - manufacturers of optical discs and drives took up arms against each other and became irreconcilable enemies, as a result of which two completely incompatible standards appeared, DVD+R and DVD-R. Fortunately, manufacturers of optical drives have solved this problem and now for most drives it does not matter at all which disc to take; Both types of drives will be supported.
- DiskDVD+ RWAndDVD— RW. Similar to CD-RW discs, DVD+RW and DVD-RW discs can be written to multiple times With a disc capacity of 4.7 GB, it is very convenient for storing and backing up a wide variety of data such as your music collection, etc. . The problem of standards incompatibility exists here as well, and it is solved in the same way - by the release of universal small format drives that support any type of disc.
- Diskblue— rey we have a huge volume that allows you to record up to 80 gigabytes of information! Agree this is a lot for an optical drive! In most cases, I record video with increased clarity on such discs, which allows you to achieve the maximum quality of the movie! The cost of such a drive can reach up to 2000 rubles!
Optical drive speed
The speed of an optical drive is usually indicated in this way 52x/24x/52x. This means that CD-R discs are recorded from 52x, recording discs CD-RW happening at a speed 24x, and reading CD-R/RW discs - also at 52x speed. In this case, the indicator 1x means a data transfer rate equal to 153 Kb / s. Now let's calculate the speed of the drive with a reading speed of 52 x. To do this, multiply 52 by 153, the result will be 7956 KB / s, i.e. almost 8 MB/s.
Compared to CD-ROM drives, rewritable DVD drives read and write data much faster. The 1x speed of a DVD-ROM drive is 1.35 MB/s, which is the same as 9x speed for a CD-ROM. Therefore, the speed of modern DVD-ROM drives with a read speed of 20x corresponds to the speed of 180x for CD-ROM drives (27 MB / s), although, of course, such a speed does not exist for CD-ROM drives.
CD-ROM drive device.
CD-ROM drive is a complex electronic-optical-mechanical device for reading information from laser discs. A typical drive consists of an electronics board (sometimes two or even three boards - a spindle control circuit and an opto-receiver amplifier separately), a spindle assembly, an optical read head with a drive for its movement, and disk loading mechanics.
On the electronics board are placed:
- circuit for amplifying and correcting the signal from the optical head;
- signal PLL circuit and ACS spindle;
- Reed-Solomon code processing processor;
- ACS circuits for beam focusing and dynamic track tracking;
- optical head movement control circuit;
- control processor (logic);
- buffer memory;
- interface with controller (IDE/SCSI/other);
- connectors for interface and audio signal output;
- block of mode switches (jumpers/jumpers).
A typical drive consists of an electronics board, a spindle motor, an optical readhead system, and a disc loading system. The electronics board contains all the control circuits of the drive, the interface with the computer controller, the interface connectors and the sound signal output. Most drives use a single electronics board, however, in some models, separate circuits are placed on auxiliary small boards.
Spindle assembly (motor and actual spindle with disc holder) is used to rotate the disc. Typically, the disk rotates at a constant linear speed, which means that the spindle changes speed depending on the radius of the track, from which the optical head is currently reading information. When moving the head from the outer radius of the disk to the inner radius, the disk must quickly increase the speed of rotation by about half, so a good dynamic response is required from the spindle motor. The motor is used for both acceleration and deceleration of the disc.
On the axis of the spindle motor (or in its own bearings) the spindle itself is fixed, to which the disk is pressed after loading. The surface of the spindle is sometimes covered with rubber or soft plastic to eliminate disc slippage, although more advanced designs rubberize only the top clamp to increase the accuracy of placing the disc on the spindle. Pressing the disk to the spindle is carried out using the upper clamp located on the other side of the disk. In some designs, the spindle and clamp contain permanent magnets whose attractive force presses the clamp through the disk against the spindle. Other designs use helical or flat springs for this.
Optical head system consists of the head itself and its movement system. The head contains a laser emitter based on an infrared laser LED, a focusing system, a photodetector and a preamplifier. Focus system represents a movable lens driven by an electromagnetic voice coil system (voice coil), made by analogy with a movable loudspeaker system. Changes in the strength of the magnetic field cause the lens to move and refocus the laser beam. Due to the low inertia, such a system effectively monitors the vertical beats of the disk even at significant rotation speeds.
Head movement system has its own drive motor that drives the carriage with an optical head using a gear or worm gear. To eliminate backlash, a connection with an initial voltage is used: with a worm gear - spring-loaded balls, with a toothed gear - pairs of gears spring-loaded in different directions. A stepper motor is usually used as a motor, and much less often a DC collector motor.
Disc loading system There are three options: using a special cassette for a disk (caddy) inserted into the receiving niche of the drive (similar to how a 3 "floppy disk is inserted into a drive), using a drawer (tray), on which the disk itself is placed, and using a retractable Tray systems usually contain a special motor that provides the tray extension, although there are designs (for example, Sony CDU31) without a special drive, pushed in by hand.Systems with a retractable mechanism are usually used in compact CD-Changers for 4-5 discs, and necessarily contain a motor for retracting and ejecting discs through a narrow charging slot.
On the front The drive usually has an Eject button for loading/unloading a disc, a drive access indicator, and a headphone jack with electronic or mechanical volume control. Some models have added a Play/Next button to start playing audio discs and switch between audio tracks.
Most drives also have a small hole on the front panel, designed for emergency ejection of a disk in cases where it is impossible to do it in the usual way - for example, if the tray drive or the entire CD-ROM fails, if the power goes out, etc. You usually need to insert a pin or a straightened paperclip into the hole and gently press - this unlocks the tray or disc case, and you can pull it out manually (although there are drives, such as Hitachi, in which you need to insert a small screwdriver into such a hole and rotate it located behind the front drive panel axis with slot).
Structural diagram of a CD-ROM
Functional diagram of a CD-ROM
A very important component of the device is an optical-electronic system for reading information. Despite its small size, this system is a very complex and precise optical device.
It consists of:
- servo control systems for disk rotation;
- servo systems for positioning the laser reader;
- autofocus servo systems; radial tracking servo system;
- reading systems;
- laser diode control circuits.
The disk rotation servo control system ensures the constancy of the linear speed of the reading track on the disk relative to the laser spot. In this case, the angular velocity of disk rotation depends both on the distance of the read head to the center of the disk and on the conditions for reading information.
The servo system for positioning the head of information reading ensures a smooth lead of the head to a given recording track with an error not exceeding half the width of the track in the modes of searching for the required piece of information and normal playback. The movement of the reading head, and with it the laser beam, across the disk field is carried out by the head motor. The operation of the motor is controlled by forward and reverse motion signals from the control processor, as well as signals generated by the radial error processor.
The radial tracking servo system ensures that the laser beam is kept on the track and optimal conditions for reading information. The operation of the system is based on the method of three light spots. The essence of the method is to divide the main laser beam using a diffraction grating into three separate beams with a slight difference. The central light spot is used to read information and to operate the autofocus system. Two side beams are located in front and behind the main beam with a slight offset to the right and left. The misalignment signal of these beams from the positioning sensors affects the tracking drive, causing, if necessary, correction of the position of the central beam.
The operability of the radial tracking system can be monitored by changing the error signal supplied to the tracking drive.
Control and management of the vertical movement of the focusing lens is carried out under the influence of servo focus. This system ensures accurate focusing of the laser beam during operation on the working surface of the disc. After the CD is loaded and started, focus adjustment begins according to the maximum level of the output signal of the photodetector matrix and the minimum level of the error signal of the fine focus detectors and the passage of focus zero. At the start of the disk, the CD-ROM control processor generates correction signals that provide multiple (two or three) movement of the focal lens necessary for accurate focusing of the beam on the disk track. When the focus is found, a signal is generated that allows the reading of information. If after two or three attempts this signal does not appear, the control processor turns off all systems and the disk stops. Thus, the operability of the focusing system can be judged both by the characteristic movements of the focal lens at the moment the disk starts, and by the signal for starting the disk acceleration mode when the laser beam is in focus.
The information reading system contains a photodetector matrix and differential signal amplifiers. The normal operation of this system can be judged by the presence of high-frequency signals at its output when the disk rotates.
The laser diode control system provides the nominal excitation current of the diode in the modes of starting the disk and reading information. A sign of normal operation of the system is the presence of an RF signal with an amplitude of about 1 V at the output of the reading system.
Systems for writing, reading and post-processing information determine the overall functional diagram of the CD-ROM, presented in the functional diagram. In addition to the systems discussed above, it includes a clock generator that provides clock signals to all nodes of the CD-ROM, and an EFM demodulator that converts 14-bit code packets from the disk into an 8-bit serial code. Further, the information enters the digital data processor, which, together with the system control processor, is the heart of the entire device. This is where data deinterleaving and error correction takes place. The task of data interleaving when recording information is to "stretch" each byte of information into several recording frames. In this case, if even a few frames of information are lost as a result of mechanical damage to the disk surface, the result of data deinterleaving will be the presence of small errors in individual bytes. Such errors are corrected by an error correction circuit.
172.3 kb/s (audio from CD-DA)
CD-ROMs are the most popular and cheapest medium 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 (now it is 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 CD is a 1.2 mm thick polycarbonate substrate covered with a thin layer of metal (aluminum, 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 wafer was adopted because it makes it very easy and efficient to protect the information structure and remove it from the outer surface of the disk. The beam diameter on the outer surface of the disk is about 0.7 mm, which increases the noise immunity of the system 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. In the center of the disk there is a hole with a diameter of 15 mm. The weight of the disc without the box is approximately 15.7 g. The weight of the disc in a regular (non-slim) box is approximately 74 g.
CDs are 12 cm in diameter and originally contained up to 650 MB of information. However, starting around 2000, 700 MB disks became more and more common, 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 read on some CD drives. There are also 8-centimeter discs, which hold about 140 or 210 MB of data, and CDs shaped like credit cards (the so-called business card discs).
CD-ROM under an electron microscope
The information on the disc is recorded in the form of a spiral track of the so-called pits (recesses) extruded into the polycarbonate base. Each pit is approximately 100 nm deep and 500 nm wide. The pit length varies from 850 nm to 3.5 µm. The gaps between the pits are called the land. The pitch of the tracks in the helix is 1.6 µm.
There are read-only discs ("aluminum"), CD-R - for writing once, CD-RW - for multiple recording. The last two types of discs are designed for recording on special recorders.
CD business card
CD business card - an optical disc made in the format of a business card (it repeats its size 90 × 50 mm).
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See what "CD-ROM" is in other dictionaries:
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