Drive Letter Access
Encyclopedia
Drive Letter Access is a commercial packet writing
Packet writing
Packet writing or IPW , is an optical disc recording technology used to allow write-once and rewritable CD and DVD media to be used in a similar manner to a floppy disk from within the operating system, i.e., it allows users to create, modify, and delete files and directories on demand without the...

 application for the Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

 operating system that allows optical disc
Optical disc
In computing and optical disc recording technologies, an optical disc is a flat, usually circular disc which encodes binary data in the form of pits and lands on a special material on one of its flat surfaces...

 data storage device
Data storage device
thumb|200px|right|A reel-to-reel tape recorder .The magnetic tape is a data storage medium. The recorder is data storage equipment using a portable medium to store the data....

s to be used in a manner similar to floppy disk
Floppy disk
A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...

s. DLA is a packet writing technology for CD and DVD
DVD
A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....

 media that uses the UDF
Universal Disk Format
Universal Disk Format is an implementation of the specification known as ISO/IEC 13346 and ECMA-167 and is an open vendor-neutral file system for computer data storage for a broad range of media. In practice, it has been most widely used for DVDs and newer optical disc formats, supplanting ISO 9660...

 file system
File system
A file system is a means to organize data expected to be retained after a program terminates by providing procedures to store, retrieve and update data, as well as manage the available space on the device which contain it. A file system organizes data in an efficient manner and is tuned to the...

.

Roxio Burn was introduced on April 30, 2009. As a replacement for DLA, it remedies compatibility issues Internet Explorer 8
Internet Explorer 8
Windows Internet Explorer 8 is a web browser developed by Microsoft in the Internet Explorer browser series. The browser was released on March 19, 2009 for Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, and Windows 7. Both 32-bit and 64-bit builds are available...

.

History

DLA was originally developed by VERITAS Software
VERITAS Software
Veritas Software Corp. was an international software company that was founded in 1983 as Tolerant Systems, renamed Veritas Software Corp. in 1989, and merged with Symantec in 2005. It was headquartered in Mountain View, California...

 and later sold to Sonic Solutions
Sonic Solutions
Sonic Solutions, acquired by Rovi Corporation in 2010, was a computer software company headquartered in Novato, California. In addition to having a number of offices in the U.S., the company also maintained offices in Europe and Asia.-History:...

 in 2002. It is very popular mainly because it was and still is shipped with a majority of CD and DVD recording drives, where DLA comes as a custom OEM
OEM
OEM means the original manufacturer of a component for a product, which may be resold by another company.OEM may also refer to:-Computing:* OEM font, or OEM-US, the original character set of the IBM PC, circa 1981...

 version for the branded drive. Most PC
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...

 systems from Dell
Dell
Dell, Inc. is an American multinational information technology corporation based in 1 Dell Way, Round Rock, Texas, United States, that develops, sells and supports computers and related products and services. Bearing the name of its founder, Michael Dell, the company is one of the largest...

, HP, IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...

, Sony
Sony
, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....

 and Toshiba
Toshiba
is a multinational electronics and electrical equipment corporation headquartered in Tokyo, Japan. It is a diversified manufacturer and marketer of electrical products, spanning information & communications equipment and systems, Internet-based solutions and services, electronic components and...

 come with DLA pre-installed or prepared for installation; also, an OEM version can often be downloaded for the specific computer system.

Technology

To use an optical medium such as a CD-R, CD-RW, DVD±R or DVD±RW just like a floppy drive it is necessary to utilize a technique called packet writing. After formatting the optical media it is then possible to write data in small packets, hence the name “packet writing.” The optical drive unit has to support the ability to write in small units, which all modern CD and DVD recording drives do. This way it is possible to save files onto optical media, as well as change, rename or delete them, or copy files separately onto the media.

Without packet writing, optical media like the above mentioned would have to be written on in one big block, like Disc At Once (DAO
Optical disc recording modes
In optical disc authoring, there are multiple modes for recording, including Disc-At-Once, Track-At-Once, and Session-At-Once.-CD Disc-At-Once:...

), Session At Once (SAO
Optical disc recording modes
In optical disc authoring, there are multiple modes for recording, including Disc-At-Once, Track-At-Once, and Session-At-Once.-CD Disc-At-Once:...

) and Track At Once (TAO
Optical disc recording modes
In optical disc authoring, there are multiple modes for recording, including Disc-At-Once, Track-At-Once, and Session-At-Once.-CD Disc-At-Once:...

), because these media types normally do not support sectors. After formatting with packet writing the media is sectored in blocks that can be written to individually. The preferred file system is the Universal Disk Format
Universal Disk Format
Universal Disk Format is an implementation of the specification known as ISO/IEC 13346 and ECMA-167 and is an open vendor-neutral file system for computer data storage for a broad range of media. In practice, it has been most widely used for DVDs and newer optical disc formats, supplanting ISO 9660...

 (UDF) in versions from 1.50 onward, which is also used by DLA.

Packet writing is not required for writing DVD-RAM
DVD-RAM
DVD-RAM is a disc specification presented in 1996 by the DVD Forum, which specifies rewritable DVD-RAM media and the appropriate DVD writers. DVD-RAM media have been used in computers as well as camcorders and personal video recorders since 1998.-Design:DVD-RAM is one of three competing...

. DVD-RAM media are already sectored (which can be seen when looking at the surface of an empty DVD-RAM disc) and the hardware logic of DVD-RAM capable drives supports sectored read/write operations as required by the DVD-RAM standard. However, for Windows up to 2000 DLA will also add support for DVD-RAM together with the UDF file system, for Windows XP DLA will only add the UDF support.

DLA also supports the Mount Rainier
Mount Rainier (packet writing)
Mount Rainier is a format for writable optical discs which provides the packet writing and defect management. Its goal is the replacement of the floppy disk...

 standard with MRW capable drives. For Windows up to XP DLA will provide this functionality as well as the UDF support.

Windows XP is the first Windows operating system to support DVD-RAM. Windows Vista is the first Windows operating system to support full UDF functionality (UDF up to version 2.50, full support meaning read and write operations) and Mount Rainier.

Versions

DLA is available only for Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

 operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

s and only in the English language
English language
English is a West Germanic language that arose in the Anglo-Saxon kingdoms of England and spread into what was to become south-east Scotland under the influence of the Anglian medieval kingdom of Northumbria...

.
  • Version 4.95 runs on Windows 98SE, Me, NT 4.0, 2000 and XP.
  • Version 5.21 is the most recent version for Windows 98SE, Me, 2000 and XP.

Note: Currently, most OEM versions officially support only Windows 2000 and XP; however, DLA itself also runs on older versions of Windows, like Windows 98 Second Edition and Windows Me, as well as Windows NT 4.0.

Windows Vista is not supported.

Known problems

  • DLA is not compatible with Internet Explorer 8.
  • DLA can cause stop errors (BSOD
    BSoD
    BSoD is an initialism. It may stand for:* Blue Screen of Death* Black Screen of Death...

    ) on the Windows Server 2003 operating system.
  • DLA can lock up a Windows XP system when a rewritable (RW) disc is inserted.
  • DLA may prevent ejection of media from an optical drive. When this occurs, a solution is to restart the operating system.
  • DLA may prevent installation of a program distributed on a rewritable CD or DVD. A solution is to deactivate DLA as follows:
  1. Launch Windows Explorer
    Windows Explorer
    This article is about the Windows file system browser. For the similarly named web browser, see Internet ExplorerWindows Explorer is a file manager application that is included with releases of the Microsoft Windows operating system from Windows 95 onwards. It provides a graphical user interface...

     or open its My Computer component.
  2. Select the RW drive.
  3. Right click on the drive.
  4. Click "Properties"
  5. Click the "Hardware" tab
  6. Deselect (uncheck) Use with DLA

See also

Techniques used by DLA:
  • Mount Rainier (packet writing)
    Mount Rainier (packet writing)
    Mount Rainier is a format for writable optical discs which provides the packet writing and defect management. Its goal is the replacement of the floppy disk...

  • Universal Disk Format
    Universal Disk Format
    Universal Disk Format is an implementation of the specification known as ISO/IEC 13346 and ECMA-167 and is an open vendor-neutral file system for computer data storage for a broad range of media. In practice, it has been most widely used for DVDs and newer optical disc formats, supplanting ISO 9660...



Competing applications:
  • Nero InCD
    InCD
    InCD is a packet writing software developed by Nero AG for Microsoft Windows.InCD allows optical discs to be used in a similar manner to a floppy disk...

  • Roxio Drag-to-Disc (formerly Adaptec DirectCD)

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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