CD rom description. CD-ROM drive parameters. What does a CD-ROM consist of?
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 regulators is different models drives can vary greatly. 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, finally achieving best quality reading.
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 ASUS specifications 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 can usually be solved by new version firmware, so we can only hope that the developers will promptly make the necessary changes, but for now the drive will only suit you 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 power laser than recording a 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 system XP Home?
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-R discs W 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 double-layer discs, JVC discs use new material, which allows you to improve both the read quality of the disk [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 on this moment The new laser unit is not entirely universal: it only emits wavelengths 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). Motherboard ASUS P4C800, RAM PC3200 512 MB Kingston, 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” of, not even communications, but 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 over 30 % up 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 functions, 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
In the period 1994-1995 in the basic configuration 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 most simple structure 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 drives downsides and get a double-sided disc 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 DVD-adapted version file system UDF (Universal Disk Format), 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. For Audio/Video recording DVD discs Only MicroUDF can be used.
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).
Design features of CD-ROM drives.
As you know, most drives are external and built-in (internal). CD drives are no exception in this sense. Most CD-ROM drives currently offered are built-in. External storage is noticeably more expensive. This is easily explained, since in this case the drive has its own housing and power supply. The form factor of a modern embedded CD-ROM drive is determined by two parameters: half-height (HH) and a horizontal size of 5.25 inches. The front panel of each drive provides access to the CD loading mechanism. One of the most common is the CD-ROM loading mechanism using a tray mechanism. The tray mechanism really looks like a tray that slides out of the drive, usually after pressing the Eject button. A CD is installed on it, after which the “tray” is pushed into the drive using a button located on the front panel of the drive. On the front panel of the drive, in addition, there is a device operation indicator (busy); there is also a hole with which you can remove the CD even in an emergency, for example, if the Eject button does not work or the power supply is suspended.
Access time.
Data access time for CD-ROM drives is determined in the same way as for hard drives. It is equal to the delay between receiving the command and the moment the first bit of data is read. Access time is measured in milliseconds and its standard rating value for 4-speed drives is approximately 200 ms. This refers to the average access time, since the actual access time depends on the location of the data on the disk. Obviously, when working on the internal tracks of the disk, the access time will be less than when reading information from the external tracks. Therefore, drive data sheets provide an average access time, defined as the average value when performing several random reads of data from the disk. Obviously, the shorter the access time, the better, especially in cases where data needs to be found and read quickly. The access time to data on a CD-ROM is constantly decreasing. Note that this parameter for CD-ROM drives is much worse than for hard drives (85-500 ms for CD-ROM and 10 ms for hard drives). Such a significant difference is explained by fundamental differences in designs: hard drives use several heads and the range of their mechanical movement is smaller. CD-ROM drives use a single laser beam and it travels along the entire disk. In addition, the data on a CD is written along a spiral, and after moving the reading head to read a given track, you still need to wait until the laser beam hits the area with the necessary data. When reading external tracks, the access time is longer than when reading internal tracks. Typically, when the data transfer rate increases, the access time decreases accordingly.
Data transfer rate (dats-transfer rate).
At standard rotation speed, the data transfer rate is about 150 kbps. In two- and higher-speed CD-ROMs, the disk rotates at a proportionally higher speed, and the transfer speed increases proportionally (for example, 1200 kb/s for an 8-speed). Due to the fact that the physical parameters of the disk (heterogeneity of mass, eccentricity, etc.) are standardized for the main rotation speed, at speeds greater than 4-6, significant fluctuations of the disk already occur, and reading reliability, especially for illegally produced disks, may get worse. Some CD-ROMs can reduce the disk rotation speed when reading errors occur, but most of them cannot return to maximum speed until the disk is changed. At speeds above 4000-5000 rpm, reliable reading becomes almost impossible, so the latest models of 10-speed or higher CD-ROMs limit the upper limit of the rotation speed. At the same time, on external tracks the transfer speed reaches the nominal one (for example, 1800 kb/s for 12-speed models, and as we approach the internal ones, it drops to 1200-1300 kb/s. To indicate the CD reading speed compared to the Audio CD standard ( CD-DA) usually use the numbers 24x, 32x, 34x, etc. However, recently the technology has changed a little.The first CD-ROM models used a constant linear reading speed (CLV), which required changing the rotation speed of the disk as the head moved. 1x devices (150kb/s) this speed was in the range of 200-530 rpm. 2x-12x high-speed devices simply increased the rotation speed. However, already increasing the speed to 12x requires a rotation speed of 2400-6360 rpm, which is very high for removable media (often also poorly centered).In addition different speed rotation for different areas of the disk increases access time, because When moving the head, it is necessary to change the speed of rotation of the disk accordingly. Further increasing the speed in this way is very problematic, so manufacturers have switched to P-CAV and CAV technologies. The first involves a transition from constant linear velocity to constant angular velocity (CAV) on the outer tracks of the disk, and the second uses constant angular velocity for the entire disk. In this regard, numbers like 32x lose their meaning a little, because usually refer to the outer side of the disk, and information on the CD is written starting from the internal tracks and on completely empty disks this speed is not achieved at all. This technology is very clearly visible in the internal and external track read speed test below.
Modern drives support reading speeds for CDs up to 56x; the situation with DVD discs, speeds have also increased, and for different read/write formats there are a variety of, quite high, speeds.
Data block size.
Data block size refers to the minimum number of bytes that are transferred to the computer via the interface card. In other words, this is a unit of information that the drive controller operates with. The minimum data block size in accordance with the MPC specification is 16 KB. Since the files on a CD are usually quite large, the gaps between blocks of data are negligibly small.
Buffer size.
Many CD-ROM drives have built-in buffers, or cache memory. These buffers are memory chips installed on the drive board for recording read data, which allows large amounts of data to be transferred to the computer in one message. The typical buffer capacity is 256 KB, although models are available with both larger and smaller capacities (the larger the better!). As a rule, faster devices have a larger buffer capacity. This is done to achieve higher data transfer rates.
Modern DVD-RW drives usually have a buffer size of at least 2 MB. Drives that have a buffer have a number of advantages. Thanks to the buffer, data can be transferred to the computer at a constant speed. For example, data to be read is typically scattered across the disk, and because CD-ROM drives have relatively long access times, this can cause read data to arrive at the computer with delays. This is practically unnoticeable when working with texts, but if the drive has a long access time and there is no data buffer, when outputting images or soundtrack the resulting pauses are very nerve-wracking. In addition, if fairly complex driver programs are used to manage drives, then the table of contents of the disk can be pre-recorded into the buffer, and accessing a fragment of the requested data is much faster than when searching from scratch.
Support for playing audio CDs.
Audio CD support means you can listen to regular music CDs using your CD-ROM drive. Almost all modern drive models have this capability. Some models do not require this special programs- audio CD playback is performed at the “hardware” level. To enable this mode, there is a special button on the front panel of the drive. Any modern optical drive plays any music format.
CD-ROM/XA format support.
This implies the use of disks in the XA format, which supports storing audio and video data as a single block, which also includes information about audio synchronization. Data on audio discs and CD-ROMs is stored on tracks that hold 24-byte "frames" played back at 75 frames per second. The stored data may include audio, text, static and dynamic images. When content is in the normal format, each type should be located on a separate track, when in the XA format the data various types can be stored on one track.
Disk loading mechanism.
There are two fundamentally different types of mechanisms for loading CDs: into storage containers and into pull-out trays. Today they also produce drives in which you can load several CDs at once. These devices are similar to multi-disc players for cars.
Containers - This disk loading mechanism is used in most high-quality CD drives. The disk is installed in a special tightly closed container with a movable metal flap. It has a lid that is opened solely for the purpose of placing the disc in or removing it from the container; the rest of the time the lid remains closed. When installing the container into the drive, the metal flap is moved to the side by a special mechanism, opening the path for the laser beam to the surface of the CD. Containers are the most convenient way to load discs. If all your disks have containers, then all you have to do is select the one you need and insert it into the drive. You can safely pick up the container without fear of staining or damaging the surface of the CD. In addition to the fact that the container protects the disk from contamination and damage, with this method it is installed into the drive more accurately. This reduces reader positioning errors and ultimately reduces data access time. The only drawback of containers is their high cost. Another important advantage of drives designed for disks in containers is that they can be installed even sideways. This operation cannot be performed with drives with drawer trays.
Pull-out trays. Most simple CD drives use pull-out trays to install the disc. These are the same devices that are used in CD-DA class audio CD players. Since the discs do not need to be placed in separate containers, the loading mechanism is cheaper. True, every time you install a new disk, you need to pick it up, and this increases the risk of getting it dirty or scratched. The tray itself is a very unreliable design. It is quite easy to break, for example, by carelessly hitting it with your elbow or dropping something from the top at the moment when it is pulled out of the drive. In addition, any dirt that gets on the disk or tray is drawn into the device when the mechanism returns to its operating position. Therefore, drives with trays cannot be used in industrial or other unfavorable external conditions. In addition, the disc does not sit as securely on the tray as it does in a container. If a CD is placed on a tray at an angle, loading it may damage both the disc and the drive.
All modern standard drives have a tray mechanism for loading the disc. As the simplest (and therefore least expensive) it has supplanted almost all other types.
Reading CD-RW.
In addition to write-once devices for golden discs, which can be read on any CD-ROM device, devices for reading and writing rewritable CDs (CD-RW = CD ReWritabe) have also recently appeared. Due to their different reflectivity, reading them requires the use of special technology, it was called MultiRead. The ability of CD-ROM devices to read such discs must be taken into account (the following CD-ROMs have this ability: Hitachi CDR-8335; Samsung SCR-3230; Sony CDU-711; Teac CD-532E; NEC CDR-1900A; ASUS CD-S340 - now this can make almost all drives). For full-fledged work, support from others is also required. operating system CD-RW UDF 1.5 file system.
Dustproof.
The main enemies of a CD device are dust and dirt. Their getting into optical device or into the mechanism leads to data reading errors or, at best, to a decrease in performance. In some drives, lenses and other vertical components are located in separate sealed compartments, in others, to prevent dust from entering the drive, unique “gateways” consisting of two shutters (external and internal) are used. All these measures help extend the life of the device. Disk drives in containers are much better protected from adverse factors than models with pull-out trays. In industrial conditions, only they can be used. Nowadays, special protection against dust is practically not used, except that some manufacturers supply the lids of the retractable tray with rubber gaskets - the noise is reduced and less dust gets inside the device. Since drives now cost mere pennies, there is no point in complicating and therefore increasing the cost of the drive - it’s easier to buy a new one after some time - a year or two... By the way, these same reasons explain the general low level of quality of even expensive and prestigious drive models.
Automatic lens cleaning.
If the lenses laser device dirty, data reading is slowed down because a lot of time is spent on repeated search and read operations (in the worst case, the data may not be read at all). In such cases, it is necessary to use special cleaning discs. Some modern high-quality drive models have a built-in lens cleaner. It is very useful when the computer operates in difficult external conditions or you cannot keep your work area clean.
External and internal drives.
When choosing a CD drive model (external or internal), you need to consider how it will be used and whether you plan to upgrade your computer. Each of these types of drives has its own advantages and disadvantages. Here are some of them: external drives - these portable devices stronger and larger than built-in ones, it is recommended to purchase them only if there is not enough space inside the computer or if you need to connect the drive to one computer or another. If each of them has a SCSI adapter, then this procedure comes down to disconnecting the drive from one computer and connecting it to another. Internal drives - these devices are recommended to be purchased if the computer has a free compartment or the drive is planned to be used on only one computer. In all modern computers CD drives are installed. This question is practically meaningless today for PC owners - there is enough space and everything else in computers. A narrow contingent of consumers of such products consists of owners of old laptops (or those laptops in which the drive is broken or is not fully functional). The SCSI interface is practically not applicable in home PCs - its destiny is only sometimes, in some server systems, and even then only for hard drives.
Interfaces.
Quite often, manufacturing companies supply CD-ROM drive with a mandatory controller card, on which the so-called (own) proprietary interface is implemented. Typically this is a proprietary implementation of one of the versions of the IDE or SCSI interfaces. Often, when purchasing a CD-ROM drive as part of the Multimedia Kit, sound card the proprietary interface is located. The de facto standards for CD drive interfaces have become the Mitsumi, Panasonic and Sony specifications. One of the popular interfaces for all drives, including CD-ROM drives, is SCSI or SCSI-2. As is known, distinctive feature The IDE interface is the implementation of the controller function in the drive itself. That is why such drives are connected to a computer through a fairly simple adapter board. This interface usually supports software I/O. The drive is connected to the interface board using a flat cable, which usually differs in the number of contacts depending on the drive manufacturer (Sony - 34-pin, Panasonic - 40-pin cable). Western Digital has developed the so-called Enhanced IDE specification. This document was supported by almost all leading storage companies. This interface allows you to connect up to four hard drives simultaneously. But most importantly, the Enchanced IDE specification allows not only to increase the number of connected devices, but also to use other types of devices, such as CD-ROM drives or tape drives. In particular, Western Digital offers the ATAPI (ATA Packed Interface) protocol to support CD-ROM drives with an IDE interface. ATAPI is an extension of the ATA protocol and requires minor changes to the system BIOS. In general, a special driver is used. Recently, drives have appeared that support not only the IDE interface, but also EIDE/ATAPI.
As you know, the SCSI interface has become one of the most important industrial standards for connecting such peripheral devices, such as hard drives, tape drives, laser printers, CD-ROM drives, etc. It should be noted that SCSI is a higher level interface than IDE. Physically, the SCSI bus is a flat cable with 50-pin connectors through which up to eight peripheral devices can be connected. SCSI standard defines two methods of signal transmission - common-mode and differential. Differential signaling versions of the SCSI bus allow for longer bus lengths. To ensure signal quality on a SCSI bus, the bus lines must be terminated on both sides (a set of termination resistors, or terminator). The SCSI-2 interface version allows you to increase throughput bus by increasing the exchange clock frequency and reducing the critical timing parameters of the bus, using the latest LSIs and high-quality cables. Thus, the “high-speed” version of SCSI-2 is implemented - Fast SCSI-2. The “Wide” (Wide SCSI-2) version of the bus provides an additional 24 data lines due to the connection of a second 68-wire cable (not used for CD-ROM drives). Typically, the data transfer speed on the SCSI(-2) bus for CD-ROM drives reaches from 1.5-2 to 3-4 MB/s. Despite the standardization of the SCSI interface, the problem of drive compatibility with SCSI adapters still remains. If you implement your own interface, connecting devices other than a CD-ROM drive is quite problematic. It should be noted here that there is an ASPI (Advanced SCSI Programming Interface) specification, which was developed by Adaptec, a leading manufacturer of SCSI adapters. ASPI defines standard software interface for the main (host) SCSI adapter. ASPI software modules fit together quite easily. The main ASPI software module is the ASPI host manager. ASPI driver programs are associated with it, for example, for devices such as CD-ROM drives, floptical and removable hard drives, scanners, etc. If the SCSI device manufacturer provides an ASPI-compatible driver, it is compatible with all host adapters or interface cards from Adaptec and most other manufacturers. Unfortunately, in some cases, CD-ROM drive manufacturers supply their controller card with its own (non-ASPI compatible) driver, calling the interface SCSI. This is something to keep in mind if you want to connect other devices to SCSI. Which interface is preferable to use on IBM PC-compatible computers for CD-ROM drives? Although theoretically the SCSI interface can provide a transfer speed slightly higher than IDE, in practice everything is somewhat more complicated. We should not forget, for example, the fact that the IDE interface mainly uses software I/O, and SCSI devices in most cases use data transfer via direct memory access. On single-user systems, software I/O is often much more efficient. This is especially true when using improved caching algorithms. The advantage of SCSI adapters is undeniable, primarily in multitasking and multi-user systems. The fact is that commands for a SCSI device can be queued, which frees up the processor to perform other operations. Also, if the CD-ROM drive is used in local network As a collective device, there is probably no alternative to SCSI yet. On the other hand, installing an IDE drive is quite simple. In most cases, the principle of “plug and play” is valid. For normal operation There is usually no need to add any additional software drivers to the system configuration files. For a SCSI adapter, the installation process is more complicated. First, you should remember about shared system resources: I/O ports, IRQs, DMA channels, areas in the upper memory UMB. Secondly, you need to correctly determine the SCSI ID for specific device, thirdly, we should not forget the parity signal (prohibit or enable), installation of terminators, etc. In addition, the configuration files must be supplemented with the appropriate software drivers for the adapter and devices. As for the cost, a SCSI adapter is usually not included in the computer and you have to buy it additionally. As mentioned above, the SCSI interface, due to its high cost and complexity, has become less widespread, especially in the optical drive sector. Nowadays you can still find old SCSI devices, but these are mainly hard drives, printers and scanners. To this day, only HDDs with this interface are produced. So all the information in this chapter of the article is really useless.
Now the actual IDE/ATA standard is being replaced by the new SATA and SATA-2. The new standard simplifies the installation of the drive to elementary primitivism! At the same time, SATA devices not only easy to install, but also more technologically advanced, etc.
To meet in our time a computer without CD-ROM/DVD drive almost impossible. A wide variety of programs, music, documents, digital photographs, etc. are recorded on CDs and DVDs. You can purchase both discs with already recorded data (for example, a music CD or DVD with a movie), and special discs on which you can (one or more times, depending on the disc and drive) record any information you need.
Apart from the not entirely correct name “ drive", devices for reading and writing CD/DVD discs are also called 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 disks. In CD/DVD drives, data is read and written from disks using a special laser beam.
There are several types CD-ROM and DVD drives, with and without recording support. Let's take a closer look at them.
- Regular drive CD— ROM allows only reading data from disks CD, CD— R And CD— RW. You cannot write data to any discs using it. Such drives are the cheapest, but are already outdated and cannot be installed in new computers.
- Drive CD— ROM with recording capability. Unlike the previous option, using this drive you can write data to write-once (CD-R) or write-once-repeat (CD-RW) discs.
- 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 that is recommended for purchase. With this drive you can read and write any disc, including CD, CD-R, CD-RW, DVD+-R/RW.
- Also, drives with support for reading Blu-rey discs are becoming more and more popular every year.
Basic Types of Optical Discs
As you already understand, recording capabilities depend not only on the drive, but also on the discs themselves. Let's study the main types of optical disks that currently exist.
- CD, or CD. The simplest version of an optical disk. Such discs sell either music (music CDs) or various programs. You cannot write anything to such a disc.
- CD-R disc. On such a disk you can once write down the information you need. You can’t add it later. One CD-R disc can store up to 880 MB of data, depending on the disc capacity. These disks are most often used for storing important information, which will not need to be changed in the future. This could 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 rewrite cycles, which is more than enough, for example, for periodic recording Word documents, their subsequent deletion and recording of new files. CD-RW discs are more expensive than CD-R discs.
- DiskDVD-ROMorDVD Video. It is on these discs that DVD films are sold. You cannot write anything to such a disk. At the same time, the volume of a single-layer DVD disc is 4.7 GB, which is several times more than the volume of CD discs.
- DiskDVD— Rand diskDVD+ R. Just like CD-R discs, DVD-R and DVD+R discs can be one once write down the data you need. Unfortunately, at one time the companies producing optical discs and drives turned against each other and became irreconcilable enemies, as a result of which two standards that were completely incompatible with each other, DVD+R and DVD-R, appeared. Fortunately, optical drive manufacturers have solved this problem and now, for most drives, it doesn't matter which drive you use; Both types of disks will be supported.
- DiskDVD+ RWAndDVD— RW. Similar to CD-RW discs, DVD+RW and DVD-RW discs can be used to record data multiple times. Given the disc capacity of 4.7 GB, this is very convenient for storing and Reserve copy a variety of data, for example your music collection, etc. The problem of incompatible standards exists here too, and it was solved in the same way - by releasing universal small format drives that support any type of disk.
- Diskblue— rey We have a huge capacity 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 me to achieve maximum film quality! The cost of such a drive can reach up to 2000 rubles!
Optical drive speed
The speed of an optical drive is usually indicated this way 52x/24x/52x. This means that CD-R discs are written from 52x, disc recording CD-RW happens at speed 24x, and reading CD-R/RW discs is also at a speed of 52x. In this case, the 1x indicator means a data transfer speed of 153 KB/s. Now let's calculate the speed of a disk drive with a read 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 speed of a 1x DVD-ROM drive is 1.35 MB/s, which is similar to the speed of a 9x 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 speed does not exist for CD-ROM drives.
4. CD/DVD-ROM drive
Nowadays, a CD/DVD-ROM drive is an integral part of a computer, since almost everything software is now distributed on CD, and individual programs multimedia - on DVD. DVD drives Support both regular CDs and DVDs, making them more versatile. IN modern systems It has long been possible to boot from CD-ROM/DVD-ROM drives.
To achieve the desired effect when using a CD-ROM, it is recommended to choose a drive with an EIDE interface of at least 32x or 40x or a DVD-ROM with a speed of 8x.
I would recommend purchasing both CD-RW and DVD-ROM. These aren't the cheapest devices yet, but once you buy them, you'll immediately experience the benefits of using them: burning your own CDs, 4.7-17 GB of data on DVDs, and much more. Another reason to install a CD-RW drive and a CD-ROM/DVD drive at the same time is that you can save the contents of an optical disc without having to copy it to your hard drive.
Burning your own CDs will help you save your data with minimal effort. CD-RW drives are used for recording both CD-RW (write many times) and CD-R (write once) media. Please note that many older CD-ROM drives (not labeled MulliRead) do not support CD-RW discs, while almost all CD drives are compatible with the CD-R standard.
Advice. To ensure maximum recording reliability on CD-RW discs, one technology is needed to prevent buffer overflows. Such technologies that eliminate the possibility of incorrect recording (and, therefore, damage) of discs include BURN-proof, JustLink or Waste-Proof.
5. Keyboard and mouse
Obviously, a computer will need a keyboard and a cursor positioning device, such as a mouse. The choice of a specific modification of these devices directly depends on the personal preferences of the user. Different users like different types of keyboards, so you'll have to try a lot of models before you find the one that suits you best. Some people like keyboards with springy keys that you can “feel” well, while others prefer “soft” keyboards that allow the keys to be pressed lightly.
There are two types of keyboard connectors, so when purchasing, make sure the keyboard connector matches the connector installed on the motherboard. The original 5-pin DIN connectors and the newer 6-pin mini-DIN connectors are electrically compatible, allowing you to adapt one type of keyboard connector to your existing keyboard. The most modern keyboard interface is the USB bus; USB connectors have become very widespread, not least thanks to "legacy-free" computers containing exclusively USB ports.
When using a USB keyboard, like any other device of this type, USB support is required at the Basic Input Output System (BIOS) level. If you want to use USB keyboard beyond graphic user interface Windows, the system BIOS must support a technology called Legacy USB or USB Keyboard and Mouse. This feature is supported by almost all modern BIOSes. At the same time, try to find a model that works with traditional keyboard ports, allowing you to use a USB keyboard in both newer and older systems.
The same applies to other cursor positioning devices (such as a mouse). Everyone can choose the most suitable option among many different modifications. Before you finally decide what to buy, try several options. If your motherboard has a built-in mouse port, make sure the connector you select matches it. A mouse with this connector is commonly called a PS/2 mouse because this type of mouse port was first used on IBM PS/2 systems. Many computers use a serial port to connect a mouse, but if you have the option of using a mouse port built into the motherboard, it's better to use that. Some USB mice work without any problems with the PS"2 port, but mostly mice of this type are designed only for the USB port. I think the most acceptable option is a dual-mode mouse that works on any system. Do not forget also about the existence of wireless versions of the mouse.
Tip: Don't skimp on your keyboard and mouse! An “uncomfortable” keyboard and mouse can cause illness! Personally, I recommend high quality keyboards with capacitive sensors.
Universal serial bus(USB) is gradually replacing all other standard I/O ports. The USB interface supports PPR technology and allows you to connect up to 127 devices into one port. external devices, and the data transfer rate USB bus is about 60 MB/s. As a rule, a USB hub is connected to the USB port integrated into the motherboard, and all devices are connected directly to it. Currently, USB ports are present in almost all motherboards.
The range of devices connected to USB is unusually wide. These include modems, keyboards, mice, CD-ROM drives, Acustic systems, joysticks, tape drives and floppy drives, scanners, video cameras, MP3 players and many others. However, when connecting multiple devices to one low-speed USB port 1.1, certain problems may arise, for which you should switch to the USB 2.0 interface. At the time of buying new system Pay special attention to the presence of USB 2.0 ports.
Batch mode, which allows you to perform a whole series of tests without operator intervention. You can create an automated diagnostic program that is most effective if you need to identify possible defects or perform the same sequence of tests on several computers. These programs check all types of system memory: basic (base), extended (expanded) and...
Different possibilities. Such a division of the PC could thoroughly confuse not only ordinary users, but also technical support specialists. However, even such a classification is still better than none. Today, there are five classes of computers, with mobile ones included in a separate group: the requirements for such devices are very specific. Dividing into categories will allow...
... (Wide Area Information Server) server; news - Usenet newsgroup; telnet - access to Telnet network resources; ftp - file on an FTP server. host. domain- Domain name on the Internet. port - a number that must be specified if the method requires a port number. Example: http://support. vrn.ru/archive/index.html. The http:// prefix indicates that what follows is the address of the Web page, / ...
N OS-6). It should be noted that replacing computer parts is not profitable to consider as an upgrade. For an accountant, this is extra work. By the amount of modernization in accounting, you need to increase the initial cost of the computer. This means that modernization costs will not have to be written off immediately, but gradually, as depreciation is calculated. Therefore, in practice, upgrading a computer if possible...
