Drive Letter Access (DLA) is a discontinued commercial packet writing application for the Microsoft Windows operating system that allows optical disc data storage devices to be used in a manner similar to floppy disks.
DLA is a packet writing technology for CD and DVD media that uses the UDF file system.
[6] 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.
The preferred file system is the Universal Disk Format (UDF) in versions from 1.50 onward, which is also used by DLA.
The one exception is the Dell OEM version, but instead of patching DLA it will simply install Drag-to-Disc as a replacement.