Plain Talk About Recordable DVD.While the capacity of hard disks increased one hundred fold, CD-ROM CD-ROM: see compact disc. CD-ROM in full compact disc read-only memory Type of computer storage medium that is read optically (e.g., by a laser). has remained at 650MB capacity for more than 10 years. When the removable storage industry began to address the growing requirements of business, industry and entertainment in 1996, their objectives were to establish a family of single best DVD formats There are several competing DVD Formats: Non-recordable formats
DVD in full digital video disc or digital versatile disc Type of optical disc. The DVD represents the second generation of compact-disc (CD) technology. products across entertainment, consumer electronics, and IT industries. Hollywood wanted a storage solution that would deliver: * High picture quality, better than laser disc. * 5.1 channel high-quality sound. * 135 minutes (2+ hours) of recording. * 3-5 language capabilities plus subtitles. * Multi-aspect ratio. * Copy protection. * Parental lock features. * Low drive, media cost. The computer industry wanted a solution that would deliver: * Unified format for AV & PC. * Backward CD read compatibility. * Write-once (WORM) and rewritable compatibility. * Single file system for all content, disc types. * Random-access, high reliability. * No mandatory cartridge. * High online capacity. * High performance for both sequential, non-sequential data. * Future capacity expandability. * Low cost. Formats Like the different flavors of CDs, there are six official DVD Forum A membership organization devoted to defining DVD standards for read-only, rewritable, write-once, video and audio use. Members participate in working groups to develop new standards. variations or books: * DVD-ROM--a high-capacity data storage medium. * DVD-Video--a digital storage medium for feature-length motion pictures. * DVD-Audio--an audio-only storage format similar to CD-Audio. * DVD-R--two write-once, read-many storage formats similar to CD-R (CD-Recordable) A writable CD technology using a type of compact disc that can be recorded, but not erased (CD-Rs are "write once" discs). CD-R discs are used to master CD-ROMs, to back up data and to make copies of data for distribution. . One for professional authoring applications and one for general consumer applications. * DVD-RW--sequentially rewritable DVD for content development. * DVD-RAM--random-access rewritable DVD. A third rewritable format, DVD+RW (DVD+Read Write) A rewritable (re-recordable) DVD disc for both movies and data from the DVD+RW Alliance. DVD+RW media can be read on DVD-Video players and computer DVD-ROM drives. , has been proposed by Philips, HP, and others. All DVD media formats share common parameters for use in a wide range of personal, professional, home, and business systems and applications (Fig 1). Formats, Applications While the DVD formats have important technical differences, Figs 2, 3, 4, and 5 have been developed to help users determine which media is best for their applications. General Format Discussion DVD-R (DVD-Recordable) A write-once (read only) DVD disc for both movies and data endorsed by the DVD Forum. DVD-Rs are often called "DVD Dash Rs" or "DVD Minus Rs" to distinguish them from the competing "Plus R" format (see DVD+R). . Today, there are two DVD-R categories: authoring and general use. The first category of DVD-R--authoring--was designed to meet the needs of professional content developers and software producers. The general category DVD-R was developed for business and consumer applications--data archiving and one-time video recording. While both authoring and general media can be read by all DVD drives--DVD-ROM, DVD-Video, DVD-RW (DVD-Read Write) A rewritable (re-recordable) DVD disc for both movies and data from the DVD Forum. Also called "DVD Dash RW" and "DVD Minus RW," DVD-RW uses phase change recording. The media hold 4.7GB per side and can be rewritten 1,000 times. , DVD-RAM A rewritable DVD disc endorsed by the DVD Forum. Using phase change technology, DVD-RAMs are like removable hard disks, and the media can be rewritten 100,000 times compared to 1,000 times for DVD-RW and DVD+RW. The first DVD-RAM drives with a capacity of 2.6GB (single sided) or 5. , and DVD-Video--technical differences make it impossible to write to DVD-R authoring media using a general DVD-R system. Specification differences are outlined in Fig 6. DVD-RW. DVD-RW is officially referred to as a "rerecordable" format but is commonly called a "rewritable" format. The general-purpose media contains protection technology that prevents copying of CSS-protected discs. DVD-RW media is a sequential read/write media. Scheduled for release by mid-2001, it can also be used for home video recording and streaming computer backup applications. DVD-RW discs can be overwritten 1,000 times and have a data storage life of 30-50 years. As of December 2000, 39 firms--hardware, media, and software producers--supported the technology. Leading manufacturers include Pioneer, Sony, Mitsubishi Chemical, Sharp, Yamaha, LG Electronics, and Samsung. A number of next-generation DVD-ROM DVD-ROM: see digital versatile disc. A read-only DVD disc used to permanently store data files. DVD-ROM discs are widely used to distribute large software applications that exceed the capacity of a CD-ROM disc. drives and DVD players will support DVD-RW media. DVD-RAM. DVD-RAM (DVD Random Access Memory) is the official DVD Forum-approved rewritable format. DVD-RAM provides 4.7GB per side storage capacity and uses phase-change technology for recording. Data on the media can be accessed in the same fashion as a hard drive and discs can be overwritten 100,000 times. Today, the technology has more than 100 supporters including Toshiba, Hitachi, Panasonic, LG Electronics, Samsung, Acer, IBM (International Business Machines Corporation, Armonk, NY, www.ibm.com) The world's largest computer company. IBM's product lines include the S/390 mainframes (zSeries), AS/400 midrange business systems (iSeries), RS/6000 workstations and servers (pSeries), Intel-based servers (xSeries) , Compaq, LaCie, and others. The 4.7GB single-sided disc is available as a bare disc or with a removable cartridge removable cartridge n. A hard disk that has a self-contained casing, can be removed from the drive, and has greater storage capacity than floppy disks. for reading by a growing number of shipping DVD-ROM readers, DVD players, and DVD-R recorders. Using DVD Forum standard lossless See lossless compression. (algorithm, compression) lossless - A term describing a data compression algorithm which retains all the information in the data, allowing it to be recovered perfectly by decompression. Unix compress and GNU gzip perform lossless compression. video editing See nonlinear video editing and video editor. technology, individual 2Kbit data blocks can be replaced with a high degree of accuracy. DVD+RW. Scheduled to be introduced in 2001, DVD+RW is an alternative rewritable product backed by HP, Philips, Ricoh, Sony, and Mitsubishi Chemical. It will have a capacity of 4.7GB per side and should be suitable for real-time video recording and random data recording. When available, the DVD+RW media will look like DVD Forum standard media. The media will not require a cartridge, but a caddy A plastic container that holds a CD or DVD disc for added protection. The bare disc is placed in the caddy, and the caddy is inserted into the drive. A caddy is not a jewel case. A jewel case protects the disc for transportation. A caddy protects the disc while reading and writing. is recommended for "extreme environments"--such as dust, dirt, or handling--that can damage data. All physical parameters comply with DVD specifications. Using Philips' unique DVD+RW video format, video will be encoded with a variable bit-rate (VBR (1) See MP3 VBR. (2) (Variable Bit Rate) Refers to a communications or computer channel that changes its transmission speed based on any number of criteria. ) and lossless linking so that individual 32Kbit data blocks can be replaced. Tim Clatterbuck is the director of optical storage marketing at Verbatim Corp. (Charlotte, NC). Fig 1 Disc Parameters * Disc Diameter : 120mm * Data Area : 48-116mm * Lead in Area : 45.2 - 48.0mm * Clamping Area : 44 - 66mm * Center Hole : 15mm * Refractive index A property of a material that changes the speed of light, computed as the ratio of the speed of light in a vacuum to the speed of light through the material. When light travels at an angle between two different materials, their refractive indices determine the angle of transmission : 1.55 * Disc Thickness : 0.6 x 2mm General Parameters * User Data per Sector : 2048 Bytes * Error Correction Code Noun 1. error correction code - (telecommunication) a coding system that incorporates extra parity bits in order to detect errors ECC telecommunication - (often plural) the branch of electrical engineering concerned with the technology of electronic : Reed-Solomon Product Code RS(208,192,17)xRS(182,172,11) * ECC (1) (Error-Correcting Code) A type of memory that corrects errors on the fly. See ECC memory. (2) (Elliptic Curve Cryptography) A public key cryptography method that provides fast decryption and digital signature processing. Constraint Length : 16 Sector(32KB Block Size) * Modulation : 8/16, RLL (Run Length Limited) An encoding method commonly used on magnetic disks, including RLL, IDE, SCSI, ESDI, SMD and IPI interfaces. The actual number of bits recorded on the disk is greater than the data bits. (2,10) * User Data Bit Rate : 11.08Mbps * Wave Length of Laser Diode A semiconductor-based laser used to generate analog signals or digital pulses for transmission through optical fibers. Both laser diodes and LEDs (light-emitting diodes) are used for this purpose, but the laser diode generates a smaller beam that is easier to couple with the smaller core : 650 / 635 nm * Numerical Aperture The measurement of the acceptance angle of an optical fiber, which is the maximum angle at which the core of the fiber will take in light that will be contained within the core. Taken from the fiber core axis (center of core), the measurement is the square root of the squared refractive of Objective Lens : 0.6 * Substrate Thickness : 0.6 x 2mm
Fig 2
DVD Formats Features
DVD-VIDEO High-quality picture & audio
Movie titles, Live video, Education
video
DVD-AUDIO High audio quality
Music titles
DVD-ROM PC digital data/games
Dictionary, etc.
DVD-R Authoring DVD authoring (content check)
DVD-R General Streaming one time write archiving
DVD-RAM The bridge format for AV & PC
*PC data archive (high reliability)
*AV data recording(2 hours long/high
quality)
*DVD-Recorder (consumer)
*Shipping since 1998
DVD-RW AV oriented
*Consumer recorder - sequential
*Available 2001
DVD+RW *Subquential, random recording
*CLV, CAV recording
*Available 2001
DVD Formats Disc Capacity / notes
DVD-VIDEO Single-sided 4.7GB/8.5GB
Double-sided 9.4GB/17.0GB
Playback only medium
DVD-AUDIO Distrbution
DVD-ROM
DVD-R Authoring Single-sided 4.7GB
Write-Once, read many
DVD-R General Single-sided 4.7GB
Copy protection included on disc
DVD-RAM Single-sided 4.7GB
Double-sided 5.2GB/9.4GB
Comprehensive defect management
Rewritable DVD (write many, read many)
random access read, write to 100,000+
times
Rewrite down to 2kb data block
DVD-RW Single-sided 4.7GB
Rerecordable disc
no defect management
max 1,000 times - sequential read, write
DVD+RW Single-sided 4.7GB
Double-sided 9.4GB
Defect management handled by drive
Rewrite 32Kb data block
max 1,000 rerecordable cycles
Fig 3
PC data
DVD-ROM DVD-RAM DVD-RAM DVD-RW
DISC Drive Drive (2.6GB) Drive (4.7GB) Drive (4.7GB)
DVD Video [delta] [delta] [delta] [delta]
DVD-ROM [delta] [delta] [delta] [delta]
DVD-RAM (2.6GB) * O O x
DVD-RAM (4.7GB) * [delta] O x
DVD-RW * (TBD) (TBD) (TBD)
DVD-R Authoring [delta] [delta] [delta] O
DVD-R General [delta] x * *
DVD+RW [delta] x (TBD) (TBD)
AV data
DVD
DVD+RW DVD-R DVD Player Recorder
DISC Drive (4.7GB) Drive (DVD Video) (DVD-RAM)
DVD Video [delta] * [delta] [delta]
DVD-ROM [delta] * x x
DVD-RAM (2.6GB) x * x x
DVD-RAM (4.7GB) x * [delta] O
DVD-RW (TBD) * (TBD) (TBD)
DVD-R Authoring (TBD) O [delta] [delta]
DVD-R General (TBD) O [delta] *
DVD+RW * (TBD) * (TBD)
DVD
Recorder
DISC (DVD-RW) DVD-RW DVD+RW
DVD Video [delta] [delta] [delta]
DVD-ROM [delta] * [delta]
DVD-RAM (2.6GB) (TBD) * x
DVD-RAM (4.7GB) (TBD) * x
DVD-RW O * (TBD)
DVD-R Authoring [delta] [delta] (TBD)
DVD-R General * [delta] (TBD)
DVD+RW (TBD) (TBD) [delta]
(O)= Write/Read OK
([delta])= Read OK (not applicable for some models)
(*)= Read OK on some of the drives
(x) = Write/Read impossible
Fig 4
Hardware Physical Layer
DVD-R DVD-R DVD-RW DVD+RW
Authoring General
DVD Video Player O O [delta] [delta]
DVD-ROM Drive O O O O
DVD-RAM Drive O [delta] (TBD) x
DVD+RW Drive O (TBD) (TBD) O
DVD Video Recorder O O [delta] (TBD)
DVD-RW Video Recorder x O O (TBD)
DVD-R Writer O O x [delta]
Appications Layer
Hardware DVD Video VR
DVD-RAM Read Write Read
DVD Video Player [delta] O [delta] * [delta]
DVD-ROM Drive [delta] O x x
DVD-RAM Drive [delta] O O * O *
DVD+RW Drive O O O * O *
DVD Video Recorder O O O O *
DVD-RW Video Recorder x O [delta] * [delta]
DVD-R Writer [delta] O O * O *
Hardware
Write
DVD Video Player [delta]
DVD-ROM Drive x
DVD-RAM Drive x
DVD+RW Drive O *
DVD Video Recorder O *
DVD-RW Video Recorder [delta]
DVD-R Writer O *
(O)= Compatible
([delta])= Some Compatibility
(x)= Not Compatible
(*)= Software Dependent
Explanations: 1. Hardware must support physical layer, then application
layer
2. Physical compatibility refers to recording support
Fig 5
DVD Media Specifications
DVD-R DVD-R
Authoring General
Capacity 4.7GB 4.7GB
Laser Wavelength 635nm 650nm
Numerical Aperture 0.6 0.6
Recording Layer Azo Dye Azo Dye
Reflectivity 45-85% 45-85%
Track Pitch 0.74[micro]m 0.74[micro]m
Min. Pit Length 0.40[micro]m 0.40[micro]m
Channel Bit Rate 26.16Mbps 26.16Mbps
Rewritability N/A N/A
Copy Protection None CSS
Operating Environment -5 - 55[degrees]C -5 - 55[degrees]C
5 - 85%RH 5 - 85%RH
DVD-RW DVD-RAM
2.6/5.2GB
Capacity 4.7GB 2.6GB/side
Laser Wavelength 650nm 650nm
Numerical Aperture 0.6 0.6
Recording Layer Phase-Change Phase-Change
Reflectivity 18-30% 18-30%
Track Pitch 0.74[micro]m 0.74[micro]m
Min. Pit Length 0.40[micro]m 0.41[micro]m
Channel Bit Rate 26.16Mbps 11Mbps
Rewritability 1000 100,000
Copy Protection CSS,CPSR N/A
Operating Environment -5 - 55[degrees]C -5 - 60[degrees]C
5 - 85%RH 3 - 85%RH
DVD-RAM
4.7/9.4GB
Capacity 4.7GB/side
Laser Wavelength 650nm
Numerical Aperture 0.6
Recording Layer Phase-Change
Reflectivity 18-30%
Track Pitch 0.615[micro]m
Min. Pit Length 0.29[micro]m
Channel Bit Rate 26.16Mbps
Rewritability 100,000
Copy Protection CSS,CPSR
Operating Environment -5 - 60[degrees]C
3 - 85%RH
Fig 6
Physical Characteristics Authoring General
Writing Wavelength 635nm 650nm
Pre-pit Addressing the Increment Decrement
start user data area 003000h FFCFFFh
Wobble frequency 140KHz 140KHz
Pre-recording None Mandatory
(Content Scrambling System)
Key Protect
Serialization None Recommended
(Content Protection for
Recordable Media
ASK THE SCSI SCSI in full Small Computer System Interface Once common standard for connecting peripheral devices (disks, modems, printers, etc.) to small and medium-sized computers. SCSI has given way to faster standards, such as Firewire and USB. EXPERT Visit the SCSI Trade Association's web site (www.scsita.org) to ask the SCSI Expert a question. Q: What is the difference between a hard drive that is labeled "U2W U2W Ultra 2 Wide " and one that is "U2W SCM (1) (Software Configuration Management, Source Code Management) See configuration management. (2) See supply chain management. ?" A: The hard drive that is referred to as "U2W SCA (Single Connector Attachment) An 80-pin plug and socket used to connect peripherals. With a SCSI drive, it rolls three cables (power, data channel and ID configuration) into one connector for fast installation and removal. " has the SCA (Single Connector Attachment Single Connector Attachment - Single Connection Attach ) connector. It is an 80 pin connector that is designed for drives that plug into a SCSI backplane. The 80 pins include the usual 68 SCSI pins. In addition, there are pinouts The description and purpose of each pin in a multiline connector. for assigning the SCSI ID (hardware) SCSI ID - The unique address of a SCSI device. SCSI IDs range from 0 to 7 for 8-bit SCSI systems, 0 to 15 for 16-bit and 0 to 31 for 32-bit systems. The SCSI adaptor is usually assigned ID 7. A device's SCSI ID is often set by switches on the device. , powering the drive, and some control pins. In order to use a drive with the SCA connector in a cabled SCSI system, you will need an adapter that brings out the 68 SCSI pins as well as makes provision to assign the ID and power the drive. These adapters increase the stub A small software routine placed into a program that provides a common function. Stubs are used for a variety of purposes. For example, a stub might be installed in a client machine, and a counterpart installed in a server, where both are required to resolve some protocol, remote procedure length with the additional connectors and etch doubling the drive loading and can cause problems if you use more than one or two on a given SCSI bus segment. Unless you are using a SCSI backplane, I would avoid the drives with the SCA connector. Q: We manufacture high-speed digital printing equipment. We frequently cannot get data fast enough to the print controller. We are looking for Looking for In the context of general equities, this describing a buy interest in which a dealer is asked to offer stock, often involving a capital commitment. Antithesis of in touch with. solutions to write data from a host system and then pick it up from the print controller. Distance is not a problem in this configuration as both controllers (host and print) reside in the same cabinet. A: There are high-speed printers that use the SCSI bus. Ultra160 SCSI (LVD See LVDS. LVD - Low Voltage Differential SCSI), the current generation, will transfer data at a rate of 160MB/sec. For point to point connections, the distance can be as far as 25 meters. Two controllers can be used to ship data to the printer faster. Ultra320 SCSI devices are just coming onto the market that will double the transfer rate to 320MB/sec. Q: Is there a minimum or maximum stub length required for Y cables? Where can I find out more about stub lengths? A: It is important to realize that Y cables are not desirable for SCSI. Do not build any into your system. The maximum stub length (including the PCB PCB: see polychlorinated biphenyl. PCB in full polychlorinated biphenyl Any of a class of highly stable organic compounds prepared by the reaction of chlorine with biphenyl, a two-ring compound. paths, if any) is 0.1 meter for single ended (hardware) single ended - An electrical connection where one wire carries the signal and another wire or shield is connected to electrical ground. This is in contrast to a differential connection where the second wire carries an inverted signal. or LVD SCSI or 0.2 meter for HVD (1) (High Voltage Differential) See SCSI and differential signaling. (2) (Holographic Versatile Disc) A high-capacity optical disc from the HVD Forum (www.hvd-forum. SCSI. This is a concession to the fact that it is necessary to have a stub from the SCSI connector There have been a large variety of SCSI connectors in use at one time or another in the computer industry. Probably no computer interconnect (with the possible exception of RS-232 serial) has caused as much confusion. to the electronics on the PCB. The ultimate source for all information on SCSI is the SCSI specification. You can find all the latest on the SCSI Committee website. Start at http://www.t10.org/scsi-3.htm and look at the SPI-3 document for LVD. HVD and SE SCSI will be found in SPI-2. Q: I have an UltraSCSI controller (20MB/sec), with UltraSCSI disks (20MB/sec) and Fast SCSI A SCSI interface that transfers at 10 Mbytes/sec rather than 5 Mbytes/sec. The maximum cable length is 9.8 feet. See SCSI. (hardware) Fast SCSI - A variant on the SCSI-2 bus. It uses the same 8-bit bus as the original SCSI-1 but runs at up to 10MB/s - double the speed of SCSI-1. disks (10MB/sec). Which is the real hard disk throughput: 10MB/sec, 20MB/sec, or both, depending the hard drive that has been accessed? A: When your SCSI bus initializes, the controller "asks" each peripheral what kind of SCSI it is--data throughput, wide or narrow, synchronous or asynchronous Refers to events that are not synchronized, or coordinated, in time. The following are considered asynchronous operations. The interval between transmitting A and B is not the same as between B and C. The ability to initiate a transmission at either end. , etc. All the devices on the bus then have that information and when any two devices exchange data they know how to "talk" to each other. Therefore, when your UltraSCSI controller exchanges data with your UltraSCSI disk, it will do so at UltraSCSI throughput. When it exchanges data with your Fast SCSI disk, it will do so at Fast SCSI throughput. |
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