In the period 1994-1995, the basic configuration of personal computers ceased to include disk drives of flexible disks with a diameter of 5.25 inches, but instead of them the standard was considered to be considered the installation of the drive CD-ROM, having the same external dimensions.
Abbreviation CD-ROM. (Compact Disc Read-Only Memory) translated into Russian as a constant storage device based on a CD . The principle of operation of this device consists in reading numerical data using a laser beam, reflected from the surface of the disk. Digital recording on a CD differs from recording on magnetic disks Very high density, and standard CD can store approximately 650 MB of data.
Large data volumes are characteristic of multimedia information (graphics, music, video), so drives CD-ROM. Refer to hardware multimedia.
Today, multimedia publications conquer an increasingly strong place among other traditional types of publications. For example, there are books, albums, encyclopedias and even periodic publications (electronic logs) manufactured on the CD-ROM.
The main disadvantage of standard drives CD-ROM. It is the impossibility of writing data, but in parallel with them there are also a device of a single record CD-R. (Compact Disk Recorder), and multiple recording devices CD-RW. .
The main parameter of the drives CD-ROM. is the speed of reading data. It is measured in multiple shares. Over the unit of measurement adopted the read speed in the first serial samples, which was 150 KB / s. Thus, a double reading speed drive provides 300 KB / s performance, with a quailing speed - 600 KB / s, etc. Currently, the devices have the greatest distribution reading CD-ROM With a capacity of 48x-52x. Modern samples of single-record devices have a productivity of 16x-32x, and multiple recording devices up to 32x.
By 1995, Philips and Sony firms developed a Multimedia CD CD. Toshiba and several more companies created another CD technology and also increased capacity. Began battle for the market. Then the two largest groups, CITWG (Computer Industry Technical Working Group) and HVDAG (Hollywood Video Disc Advisory Group), combined to fight against the appearance of these incompatible standards. In 1995, the total effort was created new standard – DVD.. It was intended primarily for the film industry as a videotape substitute and therefore the abbreviation was decrypted as Digital Video Disc.. Then this format was renamed in the Digital Versatile Disc - a digital universal disk. However, in 1997, Philips and Sony came out of the consortium. Subsequently, other DVD manufacturers followed their example.
At the moment there are several DVD formats and it brings some unfortunate to the market because not all formats are compatible. There are DVDs - R, DVD - ROM, DVD - RAM, DVD - RW. DVD drives - ROM without special adjustment can not read DVD disks - RAM (with the exception of the DVD-ROM of the so-called third generation, manufactured from mid-1999). But DVD drives - RAM can read DVD - ROM, as well as CD - R and CD - RW. DVD + RW drive is compatible with DVD - ROM and with conventional CD. And the DVD + RW format is not recognized by many manufacturers. The first generation DVD-ROM devices used the CLV mode and read from the disk at a speed of 1.38 MB / s (in the traditional designation for DVDs it is 1x). The second-generation devices could read the DVD from twice the speed - 2x (2.8 MB / s). Modern DVD-ROM - third-generation devices - use the rotation control mode (CAV) with a maximum read speed of 4x-6x (5.5 - 8.3 MB / s) and more.
The main differences between the DVD standard from CD:
1) A laser with a smaller wavelength is used. If in the CD - ROM drives the wavelength is 780-nanometers, then in the DVD drives - 635 nanometers. This allows you to reduce the length of the stroke and increase the speed of reading the data.
2) due to the use of more advanced materials, the DVD is used to record data into two layers on one side of the disk or one layer, but from two sides of the disk or two layers from two sides of the disk, depending on the DVD format. Capacity of the discs varies from 2.6 GB to 17 GB.
3) A completely new sectors format is used, a more reliable error correction code, and improved channel modulation. Now let's, more detail about the layers.
Single Side / Single Layer (one-sided / single-layer)
This is the easiest structure of the DVD disk. On such a disk you can accommodate up to 4.7 GB of data. This capacity is 7 times the capacity of the usual audio CD and the CD-ROM disk.
Single Side / Dual Layer (one-sided / duct)
This type of discs has two layers of data, one of which is translucent. Both layers are read on one side and on such a disk can be placed 8.5 GB of data, i.e. 3.5 GB more than on a single-layer / one-sided disk.
Double Side / Single Layer (double-sided / single-layer)
9.4 GB of data is placed on such a disk (4.7 GB on each side). The capacity of such a disk is twice the one-sided / single-layer DVD disk. Meanwhile, due to the fact that the data is located on both sides, you will have to turn the disk or use a device that can read the data on both sides of the disk yourself.
Double Side / Double Layer (double-sided / duct)
The structure of this disk provides the ability to place up to 17 GB of data on it (8.5 GB on each side).
The thickness of the DV disk is 0.6mm, that half is less than the thickness of the standard CD disc. This makes it possible to connect two disks inverse and get a double-sided disk in thickness equal to the usual CD. For another technology, a second layer is created to place data, it allows you to increase the capacity of one side of the disk. The first layer is made translucent, thus, the laser beam can pass through it and reflects from the second layer.
Among other things, DV discs have the ability to increase the recording density. For this, manufacturers go different ways:
1. Apply a more perfect laser
2. Reduce the length of the stroke
3. Reduce the distance between the turns
4. Increase the data area without changing the total size of the disk
5. Increase ECC efficiency
6. Apply more efficient modulation
Now about rewritable disks. These include DVD - RAM format. In such disks, the material developed by TDK engineers is also called Avist. The principle of recording is practically the same as CD. The most important advantages of DVD-RAM disks are the ability to overwrite up to 100,000 times and the presence of a recording error correction mechanism. On DVD + RW drives, you can write both streaming video or sound and computer data. DVD + RW discs can be overwritten about 1000 times, but the DVD + RW format is moving only by its developers - Hewlett-Packard, Mitsubishi Chemical, Philips, Ricoh, Sony and Yamaha and not supported by the DVD forum. DVD-RW - multiple format developed by Pioneer. DVD-RW discs contain 4.7 GB to one side, are available in one-sided and double-sided modifications and can be used to store video, audio and other data. DVD-RW discs can be overwritten up to 1000 times. Unlike DVD + RW and DVD-RAM formats, DVD-RW discs can be read on the first generation DVD-ROM drives.
A great achievement of compatibility in DVD technology has become the unified Microudf file system adopted in 2000. The Microudf file system is an adapted version of the UDF file system in the DVD, which, in turn, is based on the International Standard ISO-13346. This file system gradually goes to replace the outdated ISO9660 created at one time to use in CDs. For the transition period (until you come out of circulation computer devices And the disks working in the ISO9660 format) will be used by the UDF Bridge file system, which is some combination of Microudf and ISO9660. Only Microudf can be used to record AUDIO / VIDEO DVDs.
To protect against illegal copying, two specifications have been developed: DVD-R (A) and DVD-R (G). Two these versions of one specification use a different laser wavelength during information recording. Thus, discs can only be recorded on their appropriate equipment specifications. Playback of discs can be performed equally successfully on any equipment that supports DVD-R format. DVD-R (A) (DVD-R for Authoring) is used in professional applications. In particular, the support of a special format (Cutting Master Format) allows you to apply these discs to record the source replica of information (pre-mastering) instead of normal use for these purposes DLT tapes.
DVD-R (G) (DVD-R for General) is designed for wider use. Disks of this format are protected from the possibility of beaten copying information from other disks. The format is supported in mass storage devices (for example, in robotic DVD libraries offered by Pioneer itself).
172.3 KB / s (audio with CD-DA)
CD-ROM drives are popular and cheapest tools for distributing software, computer games, multimedia and other data. The CD-ROM (and later and the DVD-ROM) became the main carrier to transfer information between computers, to withdraw from this role the floppy disk (now it is inferior to this role more promising solid-state carriers).
Often the term CD-ROM. Error used to designate the drives themselves (devices) to read these discs (correctly - CD-ROM DRIVE, CD drive).
Technical details
The CD is a polycarbonate substrate with a thickness of 1.2 mm, covered with the finest layer of metal (aluminum, gold, silver, etc.) and a protective layer of varnish, which is usually applied a graphical representation of the disk content. The principle of reading through the substrate was accepted, since it allows you to very simply and effectively 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 with a height of 0.2 mm, allowing the disk laying 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 disk without a box is approximately 15.7 g. The weight of the disk in the usual (not "slim") box is approximately 74.
CDs have 12 cm in diameter and initially accommodate up to 650 MB of information. However, starting from about 2000, the volume of 700 MB was becoming increasingly spread, subsequently the total displaced disk with a volume of 650 MB. There are also a carrier with a volume of 800 megabytes and even more, but they may not be read on some CD drives. There are also 8-centimeter discs on which about 140 or 210 MB of data and the CD, a form resembling credit cards (T.N. Disc-business cards).
CD-ROM under the electron microscope
Information on the disk is written in the form of a spiral path of the so-called peit (recesses), extruded in a polycarbonate basis. Each pit has about 100 nm in the depth and 500 nm in width. Pita varies from 850 nm to 3.5 μm. The gaps between the pit are called Land. The pitch of the spirals in the spiral is 1.6 microns.
There are read-only disks ("aluminum"), CD-R - for a single record, CD-RW - for repeated recording. Disks of the last two types are designed to record on special writing drives.
CD-business card
CD-business card is an optical disk performed in a business card format (repeats its size 90 × 50 mm).
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Watch what is "CD-ROM" in other dictionaries:
ROM - (Roma) ... Deutsch Wikipedia
ROM: Großmacht Und Weltreich - Rom Hatte Vor Dem Pyrrhoskrieg Jahrzehntelage Höchst Aufreibende Kriege Geführt Und Brauchte Ruhe. Es Beschäftigte Sich Damit, Allerlei Nachbereginigungen Vorzunehmen, Um Die Herrschaft Schritt Für Schritt Zu Sichern, Und Erichtete in Aller ... Universal-Lexikon
ROM - (Roma), Die Merkwürdigste Stadt Auf Der Erde, Gegenwärtig Die Hauptstadt Des Kirchenstaats, Liegt Unterm 41 ° 53 54 Nördl. Breite, 10 ° 9 30 ÖSTL. Länge Zu Beiden Seiten Der Tiber, 3 etc. Ml. VON DEREN MÜNDUNG AUF DEN BEKANNTEN 7 HÜGELN (Mons ... Herders Conversations-Lexikon
Rom Hacking - Is the Process of Modifying a Video Game Rom Image to Alter The Game S Graphics, Dialogue, Levels, Gameplay, Or Other Gameplay Elements. This Is Usually Done by Technically Inclined Video Game Fans to Breathe New Life Into A Cherished Old Game, ... ... Wikipedia
ROM - BezeichNet: Rom, Die Hauptstadt Italiens Provinz Rom, Die Nach Der Stadt Rom Benannte Italienische Provinz Römisches Reich, In Der Zeit Vom 6. Jahrhundert V. Chr. BIS ZUM 6. JAHRHUNDERT N. Chr. Zweites Rom, Konstantinopel, Antike Hauptstadt Des ... ... Deutsch Wikipedia
ROM (BegriffSklärung) - Rom BezeichNet: Römisches Reich, In Der Zeit Vom 6. Jahrhundert V. Chr. BIS ZUM 6. JAHRHUNDERT N. Chr. Römische Kurie, Die Zentralbehörde des Heiligen Stuhls Für Die Römisch Katholische Kirche Einen Männlichen Angehörigenner Der Roma ... Deutsch Wikipedia
4. CD / DVD-ROM drive
Nowadays, the CD / DVD-ROM drive is an integral part of the computer, since almost all software now applies to CDs, and separate programs Multimedia - on DVD. DVD drives support both ordinary CDs and DVDs, which makes them more versatile. In modern systems, it has long been possible to download from CD-ROM / DVD-ROM drives.
To achieve the desired effect when using CD-ROM, it is recommended to select a drive with an EIDE interface minimum 32x or 40x or a DVD-ROM at a speed of 8x.
I would recommend to acquire both CD-RW and DVD-ROM. It is not the cheapest devices yet, but by purchasing them, you immediately feel the advantages of using them: recording your own CDs, 4.7-17 GB of data on DVD and much more. Another reason for the simultaneous installation of the CD-RW and CD-ROM / DVD drive is the ability to save the contents of the optical disk without the need to copy it to the hard disk.
Recording your own CDs will help save data by spending the minimum effort. CD-RW drives are used to record media as CD-RW (multiple recording) and CD-R (single entry). Please note that many old CD-ROM drives (without MULLIRAD inscription) do not support CD-RW discs, while almost all CDs for CDs are compatible with the CD-R standard.
Council. To ensure the maximum reliability of recording CD-RW discs, one of the technologies are required, thanks to which the buffer overflow can be prevented. Such technologies that eliminate the possibility of incorrect recording (and, therefore, damage) discs include Burn-Proof, Justlink or Waste-Proof.
5. Keyboard and mouse
It is obvious that the computer will need a keyboard and a cursor positioning device, such as a mouse. Selecting a specific modification of these devices directly depends on the user's personal preferences. Multiple users like different types of keyboards, so you have to try a lot of models before you find the most appropriate. One like keyboards with elastically pressing keys that can be good to "feel", others prefer "soft" keyboards that allow easy keystroke.
There are two types of keyboards connectors, so when you purchase, make sure that the keyboard connector coincides with the connector installed on the system board. Original 5-pin DIN connectors and newer 6-pin MINI-DIN connectors are electrically compatible, which allows you to adjust the keyboard connector of a type or other type to the existing keyboard. The most advanced keyboard interface is a USB bus; USB connectors got the wider distribution, not least due to computers like "Legacy-Free" containing exclusively uSB ports.
When using a USB keyboard, like any other device of this type, USB support is needed at the Basic I / O System (BIOS) level. If you want to use a USB keyboard outside the graphic user windows interfaceThe system BIOS must support technology called Legacy USB or USB Keyboard and Mouse. This feature is supported by almost all modern BIOS. At the same time, try to find a model that works with traditional keyboard ports, which will allow you to use the USB keyboard in both new and earlier systems.
The same applies to other cursor positioning devices (for example, to the mouse). Everyone can choose the most suitable option among a variety of varied modifications. Before you finally decide what exactly acquire, try multiple options. If your motherboard has a built-in mouse port, make sure that your selected connector coincides with it. The mouse with such a connector is usually called the Mouse type PS / 2, since the first port of the mouse of this type has been used in IBM PS / 2 systems. In many computers, a serial port is used to connect the mouse, but if you have the opportunity to use the mouse port embedded in the motherboard, it is better to use it. Some USB mice without any problems work with PS port "2, but mostly mouse of this type are intended only for uSB ports. I think the most acceptable option is a two-mode mouse operating in any systems. Do not forget also about the existence of wireless versions of the mouse.
Tip: Do not save on the keyboard and mouse! "Uncomfortable" keyboard and mouse can cause the disease! Personally, I recommend high-quality keyboards with capacitive sensors.
Universal sequential tire (USB) gradually displaces all other standard I / O ports. USB interface supports RPR technology and allows you to connect to one port to 127 external devices, and the data transfer rate uSB tires It is about 60 MB / s. As a rule, a USB hub is connected to the USB port, and all devices are connected directly to it. IN currently USB ports are present in almost all system boards.
The range of devices connected to USB is unusually wide. These include modems, keyboards, mice, CD-ROM drives, acoustic systems, joysticks, magnetic tape drives and drives on flexible discs, scanners, camcorders, MPZ players and many others. However, when connecting multiple devices to one low-speed USB port 1.1, certain problems may occur, to solve which you should go to the USB 2.0 interface. When buying a new system, pay special attention to the presence of USB 2.0 ports.
Batch mode, which allows without the operator intervention to perform a whole series of tests. You can create an automated diagnostic program, most effective if you need to identify possible defects or perform the same test sequence on multiple computers. These programs check all types of system memory: Basic (Base), Extended (Expanded) and ...
Different features. Such a division of the PC could be thus confused not only by ordinary users, but also technical support specialists. However, even such a classification is still better than any. Today there are five classes of computers, and mobiles are highlighted in a separate group: Requirements for such devices are very specific. The division into the category will allow ...
... (Wide Area Information Server) server; NEWS - USENET newsgroup news group; Telnet - access to Telnet resources; FTP file on the FTP server. Host. Domain - domain name on the Internet. Port is the number you want to specify if the method requires the port number. Example: http: // Support. vrn.ru/archive/index.html. The prefix http: // indicates that then the address of the Web page, / ...
N OS-6). It should be noted that the replacement of parts of the computer is unprofitable to consider as modernization. For an accountant, this is an extra work. For the amount of modernization in accounting, it is necessary to increase the initial cost of the computer. So, the costs of modernization will have to be written off immediately, but gradually, as depreciation is accrued. Therefore, in practice, the modernization of the computer can be ...
How is the CD?
A snade disk consists of a tower of layers: a polycaponate substrate, on which the disc panel, sprayed with aluminum, gold, sepper, or a disgusting alloy, and a thinner protective layer of polycapbolation or varnish, on which inscriptions and pisns are applied to which. Heotypes of the "underground" prints are very thin protective layer, or do not have it at all, which is why the submissions are fairly easy to win.
The info-motion end of the disk consists of a spa cash, which comes from the center to the neglection, along which the deposits (pit) are located. InfoMotion is encoded by cats and pits between them.
What records are used in CD-ROM?
The CD-ROM uses the same technology as in the conventional CD-DA sound system. The philips and Sony firm will be known for the philips and Sony data records on CDs are known under the names. Yellow Book ("Yellow Book"), Green Book ("Green Book"), Orange Book ("Gunning book"), White Book ("White Book") and Blue Book ("Blue Book"); All of them complement the main CD-DA Standa, described in Red Book ("Capacital Book").
Separate "sound payments" are used to record data. The said StandaPs relate not to the disk as a whole, but only to the format of individual payments, the payment on the same disk can coexist on a single disk. For their reading, a ppoigizer is needed, approaching either all the phomatics on the disk, or the pepotorous unknowns (many of the CD-ROM, and the CD-ROM bodies do not know how to prove the vehicles of unknown phirts).
Yellow Book ops up the basic files of data recording to disk: CD-ROM MODE 1 and CD-ROM MODE 2. In both types of inputs of each of each of the cash boosters, the volume of 2352 bytes, which are also called seta, 12 bytes of synchronization, 4 byte of the sectation header and 2336 bytes for data recording. Thank you by the presence of bytes of the synchronization and header, it is possible to accurately find the desired data sector, which in the usual sound disk is accurately treated.
In the MODE 1, used in most CD-ROM, 288 bytes are allocated from the data area of \u200b\u200bthe data area (Error Detection Code / Error Correction Code - error codes and execution of errors), thank you who are read more reliable than Sound discs are the same manufacturer's quality. The remaining 2048 bytes are discharged for data sewage.
In the mode of MODE 2, key codes are not used, and all 2336 bytes of these sectoys are discharged to record information. It is necessary that the recorded info movement is either already contributing to codes, or insensitive to minor errors that remained after the cooping of the low-level Reda Solomon code. This file is primarized mainly to record compressed sound signals and tool.
The MODE 1 file disk, which is combined with sound via and data, called Mixed Mode Disk. In this way, the data is recorded on the breakdown, and on all subsequent - sound info. Most of the sounds are not in charge of the fields of payments and databases are trying to get it to reproduce it, which can be used to win the amplifiers and acoustic systems.
MODE 2 FOPMAT V pure form It does not use it - on the basis of its CD-ROM / XA files (Extended Architecture - Paulized APhitendDed Architecture) of two Waiters (Green Book). In the transmission block of 2336 bytes, 8 bytes of the subtitle, 4 bytes of EDC and 276 bytes of ECC, leaving 2048 bytes for "MODE 1" for data, is released from the 2336 byte. In the second VPIANT, the ECC does not use and the data remains 2324 bytes. The SEKTOs of both the first and second Vaitates can be installed one way of FDPMAT XA. The advantage of this approach is the possibility of simperient reading in the portion of data and sound and / or video information, without any excess processes between the payments.
The CD-I file (CD-Interactive - Internet CD), described in Orange Book, the videos of the video pavement on the boosters of Foft Xa and the use of the Special CD-I POPO-I on the household TV Parllylly with the winding of the sound transmission. The CD-I software will not be included in the disk table of contents (TOC), so they are not visible on the apparat that does not approach this file.
For compatibility with the Standal Sound Sounds, the FPMAT CD-I Ready ("Ready-to-Lock on the CD-I POW-I") was used, in which there was a fired pause for recording to write, Ignorated with most conventional POPOs.
For compatibility with the reading of disc reads in the XA file, the CD-Bridge ("CD-Bridge" file) was supplemented, which contained the CD-I FIP MOD-I disk disk included in the overall table contents, the promotional tags of both phirts - CD-I and XA.
Orange Book also opens the files of the recordable CD-R discs (CD-Recordable), which can be recorded in several specimen (sessions), as well as have a postpone from the manufacture of the initial session (the so-called Hybrid Disk - a fifood disk). Each session is provided with an introductory entry (LEAD IN), the actual data and output entry (LEAD OUT).
White Book describes a VIDEOCD formation based on CD-Bridge and used for the xpanlation of moving tools in the Codips of AVI, MPEG and the like. Blue Book describes the CD-XTRA file, consisting of two sessions - sound and data session.
The file system on the CD-ROM is described by the ISO 9660 Standa. Upper 1 This Standa includes files of MS-DOS and HFS file systems (Apple Macintosh). MS-DOS catalog nesting can not be handing 8, and the name of the name is 8 + 3 characters. Upper 2 describes the file system with long names and ugly nesting up to 32. The ROCK Ridge extension describes the UNIX file system.
A special case of CD-R is a Kodak Photo CD format used for multi-step recording of photographic collections. Photo CD uses the CD-Bridge Foftware, which is the ISO 9660 File System. PHOTO CDs can be given to special POPOs on the household TV or read by the CD-ROM computers.
How is CD-ROM installed?
A typical PRP consists of an electronic circuit board, a spindle engine, an optical reading head system and a disk headband system.
Has Electronic Circuit Board Passed All Updating Control Schemes, Intemp FILE with the Controllet of Computers, Passions of Intepair and Output sound signal. Most of the FIPS uses one electronic card, however, in some models, individual schemes are submitted for auxiliary small fees.
The spindle engine serves to switch the disk into account with a constant or pedented linear velocity. Saving permanent linear velocity tries changes in the corner of the disk depending on the position of the optical head. Disc searching the disk can work with greater impact, rather than reading, therefore, there is a good dynamic characteristic of the spindle engine; The engine is used both for the Pazgona and for the use of the disk.
The HA axis of the spindle engine is skipped by the stand, the disk is used to which after the zadapup. The repetition of the stand is usually influencing with a meter or soft plastic for the termination of the disc-encoding of the disk. The disk to the stand is carried out with the help of the washer, located with the disk side of the opening; Stand and washer Promitted permanent magnets, the strength of which is the puck of the puck drive to the stand.
The optical head system consists of the head and the system of its proceedings. The head has a laser emitter, based on an infpacapic laser LED, a focusing system, a photographic and a focusing amplifier. The focusing system is a mobile lens, which flows the electro-magnetic system VOICE COIL (sound coil), made by analogy with the moving system of the GRUGOV. Changing the magnetic field drinking causes the lens and transfix the laser beam. Thank you with a small insidency, such a system effectively monitors the versatile discs of the disk even in significant suggestions.
The head of the head of the head has its own typewater engine, which turns into the movement with an optical head of the help of a toothed either by the Cell Peredach. To eliminate the backup, a connection with the initial flashing is used: POW COMBULAR STEPS - SUPPUED SUPPLES, POWE CUT CORMET - SUBJECTED TO PAZNOE STRONDS PAINTS PAINTS.
The disk headband system is performed in two Waitches: using special disk (Caddy) (Caddy), inserted into the PRIVER DISTRIPTION, and using a retractable tray (tray), the disc itself is mounted. In both cases, the system is assisted by the engine, the tray or footman, as well as the mechanism of the PAM, on which the entire mechanical system is screened together with the spindle engine and the optical head, in the future position when the disc falls on the spindle engine stand.
Using the usual tray of the TRANSFER cannot be installed to another position, the throat. In print positions that mounted in a specific position, the constriction of the tray includes the clocks, the fixatives that manage the disk are put forward by the tray.
The first panel of the PRIVE panel is usually located the EJECT button for the junction / discsoring of the disk, the indicator of the procedure to print and the jack for connecting headphones with an electronic or mechanical geek. In the model of models, the PLAY / NEXT button has been added to run the ongoing sounds of sound drives and the transition between sound shoes; The EJECT button is usually used to stop the touch without dischargeing a disc. There are some of some models with a mechanical metering of a durability, made in the form of a fuzzy, the pp bypass and move are carried out by pressing the adjustment.
Most of the PPPs also have a small response on the panel, which has been applied for an emergency removal of the disk in cases where it is impossible to do this in the usual way - we will use it, you will use the output of the tray or the entire CD-ROM, and the power supply and the like. In response, you need to insert a hairpin or a snapper of the scope and carefully press - the blocking of the tray or disk bag is removed, and it can be pulled out.
What is the CD-ROM?
SCSI, IDE - CD-ROM is connected to the SCSI or IDE / ATE master (ATA) master with the use of the SCSI or Master / Slave - for IDE. IDE CD-ROM typically use ATAPI (ATA Packet Interface - ATA batch intake).
Sony, Mitsumi, Panasonic - TPI of the most press-based intepair, which are approximate by many audible capes and individual adaptines. Mitsumi and Panasonic use a 40-pin connecting cable, as for IDE, and Sony is a 34-pin, as for floppy disk drives.
There are also CD-ROMs with the so-called proprietary interface - the manufacturer's own intepair, supplied with the adaptable and connecting cable.
CD-ROM is currently available with SCSI and IDE intepair.
Why do you use a CD-ROM disk with a serious mind?
InfoMotion on the CD is recorded with a constant linear density, therefore, to achieve a constant scope of reading, the scope of proprietary changes depending on the reading head proceedings. Standard velocity of the disk - 500 rpm is reading from internal zones and 200 rpm - read with external (info-movement is recorded to be exhausted).
What does N-Square CD-ROM mean?
PRI of the standal velocity of data transfer is about 150 kb / s. In a two-time and more approximate CD-ROM, the disk is in progressively greater, and it is recommended to increase the operation (apply, 1200 Kb / s for 8-speed).
Due to the fact that the physical papames of the disk (lamination of the mass, eccentricity, etc.) Standatized for the main approach, on challenges, large 4-6, there are already significant disk oscillations, and reliable reading, especially for illegal disks, May deteriorate. Heotypes CD-ROMs are reading errors can reduce the speed of discs, but most of them cannot be exhaped to maximum speed up to the disk change.
There are more than 4000-5000 rpm. Reliable reading becomes virtually impossible, so the latest models of 10- and more attendant CD-ROMs are outpaning vertinity. In addition, on external exchanges, the emergence of perpetuals reaches nominal (apply, 1800 Kb / s for 12-speed models, and on the method of contacting internally - drops to 1200-1300 kb / s.
Why "illegal" discs are often readable worse than "firm"?
StandaPT on CDs, their physical and optical papames are described: the thickness and exhaust ability of the aluminum layer, the depth and fob of the peit (record items), the dancer between the exchanges, the priesthood of the protective layer, eccentricity, etc. Leading FIPS, PREPENING CDs, have received technologies and reliable completion, allowing you to comply with these papames; Appapapoint and technology of illegal printing agents are not perfectly provided.
Mechanics and optics of CD-ROM performing models have dial tolerances and opportunities of the underwear, because of which some models can read the discs, which are not readable by dpug models. Also, in the result of operational wear, the papames of the PRIVE with the extension deteriorates that there is a deterioration in the reading of the discs, which were fully read on the new PTP.
Is it possible to visually descend the quality of the disk?
You can. It is easy to carefully pass through the disk effect - it must be POV, and there should be no Chaniapine, inspired areas, convexities or depression, as well as "PAs" on the sublinking layer. Then look at the disc on the light (there are still an end to myself) - it can be slightly pronounced, but without explicitly fall in the existing layer. What the dispenser is the higher the exemption of its unpretentious reading.
Cheap discs (especially China's perception) usually do not have with a regular side of the protective lacquer layer - even small quiapine on this forecast can be used to the complete reading of the corresponding disk area.
What is the quality of the sound discs on the CD-ROM?
The ongoing sound disks is a side for CD-ROM function, and is usually done "by residual application" - a purest (often 12- or 14-dspeed) DAC and a simple output amplifier. Mass CD-ROM is significantly inferior to the HI-FI facilities, separate models are proclaimed to abruptly permanent pensioners. In any case, the quality of the output for headphones (perpetual panel) is worse than on a linear outlet (rear wall) - due to additional distortions.
The quality of the DAC, most CD-ROMs do not perform any digitization of the digital signal to improve the signal-to-noise ratio, nor Internet and mask - to smooth out and partial compensation for insurgent errors. The lack of integration and masks takes to noticeable distortions and clicks include erroneous reading of the disks, which is not as noticeable on the sound simulator of the reading error.
Many match CD-ROMs have an additional sound output in a digit form (S / PDIF - Sony / Philips Digital Interface Format - Sony / Philips digit intee / philips), which can be connected to a studio or household apparatus having an S / PDIF input or AES / EBU, which allows you to take the sound from the disk inactively without distortion (some distortions can be made to the CD-ROM decoder).
What is the maximum CD CD?
It is 650 MB (* 1024 * 1024 bytes) - 74 minutes of recording, data flow - 153600 bytes / c. Such an entry of the recording is described by the Standa, however, it is more dense the positions of the boards or the pit themselves on the disk can be obtained more occurring sound or amount of data. Such disks with deviations from the standard may be unstable with some of these, or not read at all.
What is CD-R and CD-E?
A single-page system (CD-Recordable is a recordable CD) and a multi-page (CD-Erasable - served CD recording). The CD-R and CD-E are denoted by both the stop for recording and the wheels themselves.
For one-page recording, the so-called "golden" discs are commonly used, the usual CD, in which the exhausting layer is made of a gold film, and a non-referenced plastic-free plastic to it - from the mother's darkening. In the printing of the record, the laser beam is imparted by plastic sections, which darkens and pepspel the light to the exhaust layer, having completed the "pp broadcasters" between the "pites" - unchanged printing areas of the plastic.
To facilitate the tracking of the info-making cash in the recording of the records, the CD-R discs are made with auxiliary poresame. Contribute to reading the tracking is known as usual, on the recorded sweep of the pit.
Heotypes of transmittance (apply, CDR Publisher) allow you to record discharged discs. For a junction with such disks, the BIOS computer should approach this feature (the latest versions of Award and Phoenix BIOS).
Why are there a pure WAV record on CD-R appear interference?
Perhaps it is that some kind of sound studies (apply, Cool Edit and Sound Forge) are placed at the end of the WAV file of their service informatization, which is an additional recording in full compliance with the RIFF format. However, the simplicine support of some CD-R Ignizes a field of the sound fond length, translating the entire balance of the file after the header, as a single audio french, follows that the service information enters the disk in the number of digital audio and is presented as noise or clicks at the end of the transma. To complete this phenomenon, it is necessary to either be able to save the soundtaches in the WAV file information information in the WAV file, or to remove it with the help of dpugs.
These are multi-session recording of individual sounds at the beginning and end of each session, the introductory and output zone are familiar to the opening zone, hitting the occurrence of a random signal. Sound disks are remembered to record one session, it becomes Full Full sound file.If the CD-R software does not allow you to combine the files in the recording progress.
Expanded, interference on recorded sound disks may occur due to the instability of the data stream in CD-R (the internal bouquet of the stream or the flow of the flow), deviations from the napma parameters of the recorded signal, the laser view of the lase or the speed of the disk, factory disk defects, as well as the fault of the POPOs, unable to read the conquer Disc instances. In the case of poor records of discs with data with data, the provision is inappropriate to save large amounts of codes of codes, which are included in the CD-ROM phirts.
Is it possible to use with IDE CD-ROM DPEVEP from a dish model?
In most cases, yes, if the CD-ROM will use ATAPI in Standa. However, some dpipes may not be easy to use CD-ROM strange models.
For reading video recordings, it is necessary to apply from the end of the drive itself and its work, as well as the videos videosphoam. Weight combinations from the contact, the contact, dpayvep and the onaspeckers are incompatible with a dpug. You can take to change to change the dpayp or the PAsPacks. There are also cases when you install a CD-ROM to one channel with an HDD video video will be renewed much slower.
You can - for this, you need a CD-ROM, which approaches the Read Long command and capable of finding sound sectors in the reflash access (apply, many of the drives with SCSI-Internet, most of the Panasonic models), and a special programmam - grabber - to read full sound sectors, We will apply, Cdgrab, CDDA, CDT, etc. Often, such a programmamms are given a list of CD-ROM models that approach the long reading command. Due to small dresses in Internet, some of these drives do not work with one of these vias, but can be used with dpugs.
One of the main challenges should read the audio disks - errors synchronization between sects. They occur when the reading disk of the probe does not have time to issue a reading sector's reading command before the internal Buffal CD-ROM buffer starts and the data from the start of the sector will be sweat. In this case, the CD-ROM is forced to perform positioning, and the submissions of the audio discs does not make it possible to start reading exactly from the right place. As a result of such failures in the file, the file has false or the appearance of several excess signal samples. For bugs with synchronization errors, some progresses have a way, in which the adjoining sectors in which the adjacent sectors are in contact. Using the use of CD-ROM with a large volume of the bouquency, the error is reduced.
There are often erroneously called "Jitter" in the results of synchronicization. In fact, the Timin Jitter simultaneizes the dealer of the digital signal phase due to fast fluctuations in the flow of the flow, resolved by changing the speed of discs and its versatile beating. In some kind of synchronicization, the phase errors are higher than the phase error, however, the Jitter is not exactly coPpec.
What are the Bad SAMSUNG-631 CD-ROM SAMSUNG-631 POPs?
In addition to the low quality of the mechanism itself and the reading system, there are insufficient disks to the spindle in these prints, which is why the discs are pusing and for use. The ongoing weak application is a large zexing between the spindle magnet and the metal disk, which is performed by a magnet. Michael Svechkov (2: 460 / [Email Protected]It is recommended to pink to the magnet of a steel washer with a thickness of 1-2 mm, appropriate it so that the gap between the magnet and the metal disk is minimal, however, they should not be easily connected with each other, otherwise the tray spreading system will be available.
Any hardware or software part of the computer uses the processor. The processor loads call the time that the processor spends on the execution of a specific task. Low processor load when executing the task says that the rest of the devices and programs will quickly receive access to it. In relation to CD / DVD-ROM drives, three factors affect the processor load: drive speed CAV., Buffer size and interface type.
Direct memory access
Currently, in almost all computers the controller is installed Bus Master IDEwhich allows you to place data directly into RAM, bypassing the processor. When using such controllers, the processor loading the CD / DVD-ROM (regardless of the interface type) is reduced to 11%.
Almost all modern CD-ROM drives (12x and above) and system boards support data transmission directly to memory. To determine if your system has supported direct memory access, click on the icon System (System) in the window Control Panel (Control Panel). In the tab Device Manager Click on the "+" sign near the device group. Controllers hard disks (Hard Disk Controllers). If there is a device in the list Bus MasterSo, your system supports direct memory access. To install direct memory access not enough to have a controller Bus Master IDE, More devices are needed (hard drives and CD-ROM drives) that will support this mode. Find out the type of drives installed on your system and consult manufacturers about supported properties. Hard drives and CD-ROM drives that support modes Multiword DMA Mode 2 (16,6 MB / s), Ultradma Mode 2 (33 MB / s), Ultradma Mode 4 (66 MB / s) Or faster, can use direct memory access.
In order to activate direct access to hard memory CD-ROM drive or drive, double-click on it in the tab Devices dialog box Properties: System and in the properties window that appears this device In the tab Settings) Check the box DMA.
Interface
Under interface CD-ROM drive is understood as the physical connection of the drive from the extension bus. Since the interface is a channel, with which the data is transmitted from the drive to a computer, its value is extremely large. To connect the CD-ROM drive, the following types of interfaces are used to the computer:
- SCSI / ASPI (Small Computer System Interface / Advanced SCSI Programming Interface) ;
- IDE / API (Integrated Device Electronics / Attachment Packet Interface) ;
- parallel port;
- uSB port;
- Fire Wire (IEEE-1394).
Loading mechanism
There are three fundamentally different types of booting CDs: in the drive containers, in retractable trays and startup mechanisms.
Retractable trays
Most simple drives on CDs for installing a disk are used. retractable trays. In order to replace the disk, you must push the tray from the drive, remove the disk, put it into a transparent plastic box, remove a new disk from the other same box, put in the tray and plug it back.
Containers
Once this disc loading mechanism was used in most high-quality drives on CDs, as well as in CD-R drives and DVD-RAM. The disc is installed in a special, tightly closed container with a movable metal flap. He has a cap, which is thrown out exclusively in order to put the disk into the container or remove it; The rest of the time the lid remains closed. When installing the container in the drive metal flap with a special mechanism shifts to the side, opening the path to the surface of the CD.
Startup mechanism
In some models of drives, a mechanism of autoloading is used, i.e. You put the CD in the slot on the front panel, and the starting service mechanism itself "sues" it inside. However, this mechanism does not allow the use of 80 mm diameter discs, as well as other discs with modified physical formats or forms.
Other features of the CDs on CDs
Of course, the advantages of devices are primarily determined by their technical characteristicsBut there are other important factors.
In addition to the quality of the design and reliability, when choosing a drive, it is necessary to take into account its properties:
- dust protection;
- automatic cleaning of lenses;
- type of drive (external or internal).
Automatic cleaning lenses
If the laser device lenses are dirty, the data reading slows down, because a lot of time goes to repeated search and read operations (in the worst case, data can not be considered at all). In such a situation, use special cleaning discs. Some modern high-quality storage models have a built-in lenses cleaning device.
Record drives on CDs
There are two main types of recorded CDs and drives: written CD-R (Recordable) and overwritten CD-RW (Rewritable).
Most CD-ROM recording drives are devices. Worm (WRITE ONCE, READ MANY is a single recording, multiple read) intended for long-term storage. The actual standard of this type of device storage devices CD-Rs are ideal for backing up the system and similar operations. However, with a frequent backup copying or archiving, despite the low cost of the carrier, it becomes unprofitable to use CD-R devices in this case should pay attention to the multiple recording devices CD-RW..
CD-R drives
CD-R discs that are already recorded by any data can be played or read by almost any standard CD-ROM drive. Disks of this type are very convenient for storing archival data and creating master discs that can be replicated and spread among employees of small companies.
CD-R discs work according to the same principles as standard CD-ROM, reflecting a laser beam from the surface of the disk and tracking changes in the reflectivity when the "Wpadina-Platform" or "platform field" appears. On ordinary CDs, the spiral track is extruded or stamped in polycarbonate mass. In turn, CD-R discs contain a drawing of a depression, scorched on a raised spiral track. Thus, the depressions are dark (scorched) areas reflecting a smaller amount of light. In general, the reflective ability of the depression and platforms remains the same as on the stamped discs, so the conventional CD-ROM drives and players of music CDs are read both stamped discs and CD-R.
The CD-R recording starts even before you insert the disk into the drive. The process of manufacturing CD-R media and standard CDs is almost the same. In the other case, the molten polycarbonate mass is pressed using the forming matrix. But instead of stamping, the wpadin and platforms matrix formulates a spiral groove (which is called groove Groove)). If you look from the side of the read (and recording) laser, located under the disk, this groove is a spiral ledge, not a deepening.
The boundaries of the spiral protrusion (initial groove) have certain deviations from the longitudinal axis (the so-called oscillations). The amplitude of oscillations in relation to the distance between the tips of the track is quite small. The distance between the turns is 1.6 microns, and the magnitude of the transverse deflection of the protrusion reaches only 0.03 microns. CD-R groove fluctuations modulate some additional informationwhich is read by the drive. The synchronization signal defined by the vibrations of the track is modulated together with the time code, and the name is called absolute time of the original track ( Absolute Time In Pre - Groove - Atip). The time code is expressed in the format "Minutes: Seconds: Frame" and introduced into Q -Codes of frames recorded on the disk. The ATIP signal allows the drive to distribute the necessary areas on the disk before the actual recording of frames. Technically positioning signal is a frequency care and is determined by the carrier frequency of 22.05 kHz and a deviation of 1 kHz. To transmit information, changes in the frequency of oscillations are used.
The process of manufacturing CD-R is completed with the help of the centrifugation method of the uniform layer of an organic dye. Then creates a gold reflective layer. After that, the surface of the disk is covered with acrylic varnish, solidifying in ultraviolet rays, which is used to protect the previously created gold and painted disk layers. Studies have shown that aluminum used with an organic dye is subject to strong oxidation. Therefore, the CD-R discs use a gold coating with high corrosion resistance and having the highest possible reflectivity. On the surface of the disk, covered with a layer of varnish, the screen printing layer used to identify and additional disk protection is applied by the screen printing. The laser beam used when reading and writing a disc first passes through a transparent polycarbonate layer, a layer of an organic dye and, reflected from the gold layer, passes through a layer of dye and polycarbonate mass, after which the optical sensor sensor is traversed.
The reflecting layer and layer of organic dye have the same optical properties as unsupported CD. In other words, the track of an unappointed (pure) CD-R disk is perceived by the reading device of the CD as one long platform. The CD-R laser beam beam has the same wavelength (780 nm), but the power of the laser used to perform the record, in particular for the heating of the painted layer, is 10 times higher. A laser operating in pulse mode heats the layer of organic dye to a temperature of 482-572 ° F (250-300 ° C). At this temperature, the dye layer literally burns out and becomes opaque. As a result, the laser beam does not reach the gold layer and is not reflected backwards, which is achieved as the same effect that is reached as the reflected laser signal occurring when reading the stamped CDs.
During the reading of the disk, the drive reads non-existent depressions, which are low-reflective areas. These areas appear when heating an organic dye, so often the disk recording process is called burning. The scorched sections of the dye change their optical properties and become not reflecting. The change in these properties is possible only once, so CD-R is called media with a single record.
Drives CD-RW. References are compatible with CD-R devices and allow you to read or write data to CD-R media.
For CD-RW is characteristic of the following:
- they can overwrite;
- have a higher cost;
- differ in less recording speed;
- have a lower reflectivity.
In addition to high cost and ability to overwrite data, media CD-RW. They also differ lower (two or more times) recording speed. This is due to the fact that when recording for processing each area of \u200b\u200bthe disk area, the laser requires more time. Disks CD-RW. Also have a lower reflectivity, which limits their readability. Carriers CD-RW., for example, not read by many standard CD-ROM and CD-R drives therefore, to record music discs or compatibility with drives of different types, it is better to use CD-R discs. It should be noted that MultiRead technology supported by almost all drives with a speed of 24x and above allows you to read discs. CD-RW. Without any problems. The presence of this possibility is determined by the MultiRead logo, applied to the CD-ROM drive case.
To create a similarity of a depression on the disk surface, in the drives and CD-RW media, the process of changing the state phase is used. Discs are created on a polycarbonate substrate containing a preformed spiral groove of a wavy form, whose oscillations determine positioning information. The upper part of the base is covered by a special dielectric layer (insulation), after which the recording layer is applied, another layer of dielectric and aluminum reflective layer. Then the disc surface is covered with acrylic varnishes, solidified in ultraviolet rays, which is used to protect the previously created disk layers. The dielectric layers located above and below the recording layer are designed to shield the polycarbonate substrate and the reflective metal layer from the intensive heating used during the recording process with the change phase change.
CD-R disc recording is carried out by heating of certain parts of an organic dye (i.e., the recording layer). In turn, recording layer CD-RW. It is a fusion of silver, indium, antimony and television (AG-IN-SB-TE), which has the possibility of phase transformations. As a reflecting part of the recording layer, an aluminum alloy is used, which is no different from the usual stamped discs. During the readout or data recording operation laser device Located from the bottom of the disk. If you look from the laser side, the spiral groove will look like a protrusion, and the recording layer of the disk will be located on its upper plane.
AG-IN-SB-TE alloy used as a recording layer has a polycrystalline structure with a reflectivity of 20%. During recording data on disk CD-RW. The laser can work in two modes that are called P-Record and R-Strape. In P-record mode, the laser beam heats the material of the recording layer to a temperature of 500-700 ° C (932-1229 ° F), which leads to its melting. In the liquid state, the alloy molecule is beginning to move freely, as a result of which the material loses its crystal structure and goes into amorphous (chaotic) condition. The reflectivity of the material frozen in amorphous state is reduced to 5%. When reading the area of \u200b\u200bthe area with different optical properties, perceived the same way as the conventional CD-ROM stamped disk.
In the erase mode, the active material layer is heated to about 200 ° C (392 ° F), which is significantly lower than the melting point, but sufficient for softening the material. When the active layer is heated to the specified temperature, followed by slow cooling, the material structure in the molecular level is converted, i.e. Transition from amorphous to crystalline state. In this case, the reflectivity of the material increases to 20%. Areas having a higher reflectivity perform the same function as the zones of the stamped CD.
Although such a mode of operation of the laser and is called P-erasing, direct erasing of the data does not occur. Instead, technology is applied direct overwriting datawhen using sections CD-RW.having a lower reflectivity, do not erase, but simply overwritten. In other words, during data recording, the laser is constantly included and generates pulses of different power, thereby creating an amorphous and polycrystalline structure with various optical properties.
Storage Compatibility: MultiRead Specifications
To specify the compatibility of a drive, the OSTA Assocation (Optical Storage Technology Association) has developed an industrial standard, a testing system and a logo that must guarantee certain levels of compatibility. All this is called MultiRead specifications. Currently, there are the following levels of the specification:
- MultiRead for CD-ROM drives;
- MultiRead2 for DVD-ROM drives.
In addition, a similar Multiplay standard has been developed, which is designed for device owners. DVD-Video. and CD-DA.
| Carrier | MultiRead. | MultiRead2. |
|---|---|---|
| CD-DA (Digital Audio) | x. | x. |
| CD-ROM. | x. | x. |
| CD-R. | x. | x. |
| CD-RW. | x. | x. |
| DVD-ROM. | - | x. |
| DVD-Video. | - | x. |
| DVD-Audio. | - | x. |
| DVD-RAM | - | x. |
x - the drive will read from this carrier.
The presence of one of these logos guarantees the corresponding level of compatibility. If you acquire a CD-ROM or DVD drive and want to read overwritten or recorded discs, make sure that the MultiRead logo is on the drive. For DVD drives, MultiRead version will be much more expensive due to the additional cost of mechanisms working with two lasers. Almost everyone dVD-ROM drives used by computer systems, have a dual reading mechanism, which allows you to read data from CD-R discs and CD-RW..
Shape CD (curly CD) - optical media of digital information type CD-ROM, but not strictly round shape, but with an outline of an external contour in the form of a variety of objects, such as silhouettes, machines, airplanes, hearts, stars, ovals, in-form credit cards, etc.
Usually applied in show business as a carrier of audio and video information. A record was patented by the producer of Mario Cosos in Germany (1995). Typically, discs with a form different from the round, are not recommended to be used in CD-ROM computer drives, since at high speeds of rotation, the disk can burst, which can lead to complete output of the drive.
Standards of rewritable devices and dVD disks
| Drives | CD-ROM. | CD-R. | CD-RW. | DVD-Video. | DVD-ROM. | DVD-R. | DVD-RAM | DVD-RW. | DVD + RW. | DVD + R. |
|---|---|---|---|---|---|---|---|---|---|---|
| DVD-Video Player | R. | ? | ? | R. | - | R. | ? | R. | R. | R. |
| DVD-ROM drive | R. | R. | R. | R. | R. | R. | ? | R. | R. | R. |
| DVD-R drive | R. | R / W. | R / W. | R. | R. | R / W. | - | R. | R. | |
| DVD-RAM drive | R. | R. | R. | R. | R. | R. | R / W. | R. | R. | R. |
| DVD-RW drive | R. | R / W. | R / W. | R. | R. | R / W. | - | R / W. | R. | R. |
| dVD + R / RW drive | R. | R / W. | R / W. | R. | R. | R. | R. | R. | R / W. | R / W. |
| dVD-MULTI drive | R. | R / W. | R / W. | R. | R. | R. | R / W. | R / W. | R. | R. |
| DVD +/- R / RW drive | R. | R / W. | R / W. | R. | R. | R / W. | R. | R / W. | R / W. | R / W. |
The history of rewritable devices and DVD began in April 1997, when companies included in the DVD Forum group submitted specifications for DVD rewritable disks,
