CD and DVD device requirements?
Read access to DVD-ROM, DVD+R/RW, DVD-R/RW, CD-ROM, and CD-R/RW devices on ATAPI (IDE) connections is generally handled transparently by SYS$DQDRIVER, and SYS$DQDRIVER will transparently de-block the media-native 2048 byte disk blocks with the 512-byte blocks expected by OpenVMS and by native OpenVMS software. Read access to DVD-ROM, DVD+R/RW, DVD-R/RW, CD-ROM, and CD-R/RW devices on SCSI is handled by DKDRIVER, though SYS$DKDRIVER will not transparently de-block the native 2048-byte disk blocks into the 512-byte blocks expected by OpenVMS. The drive or external software is expected to provide this de-blocking, thus either a 512-byte block capable drive (such as all RRD-series SCSI CD-ROM drives) is required, or host software is required for a 2048-byte block drive. Third-party SCSI drives with UNIX references in their support documentation or with explicit 512-byte selectors or swiches will generally (but not always, of course) operate with OpenVMS. At least some of the Plextor PlexWr
