VMS Help MOUNT, Qualifiers, /DENSITY  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /DENSITY=keyword

    Specifies the density at which a magnetic tape is to be written.
    This qualifier is valid only if you mount a tape specifying the
    /FOREIGN qualifier. If you change the density on a tape, the
    first operation on the tape must be a write operation.

    The densities supported for tapes are shown in the following
    table:

    Table 1 Keywords for Tapes

    Keyword        Meaning

    DEFAULT        Default density
    800            NRZI 800 bits per inch (BPI)
    1600           PE 1600 BPI
    6250           GRC 6250 BPI
    3480           IBM 3480 HPC 39872 BPI
    3490E          IBM 3480 compressed
    833            DLT TK50: 833 BPI
    TK50           DLT TK50: 833 BPI
    TK70           DLT TK70: 1250 BPI
    6250           RV80 6250 BPI EQUIVALENT
            NOTE: Only the symbols listed above are understood
             by TMSCP/TUDRIVER code prior to OpenVMS Version
               7.2. The remaining symbols in this table are
                 supported only on OpenVMS Alpha systems.

    TK85           DLT Tx85: 10625 BPI-Cmpt III - Alpha only
    TK86           DLT Tx86: 10626 BPI-Cmpt III - Alpha only
    TK87           DLT Tx87: 62500 BPI-Cmpt III - Alpha only
    TK88           DLT Tx88: (Quantum 4000)-Cmpt IV - Alpha only
    TK89           DLT Tx89: (Quantum 7000)-Cmpt IV - Alpha only
    QIC            All QIC drives are drive-settable only - Alpha
                   only

    TK85           DLT Tx85: 10625 BPI-Cmpt III - Alpha only
    TK86           DLT Tx86: 10626 BPI-Cmpt III - Alpha only
    TK87           DLT Tx87: 62500 BPI-Cmpt III - Alpha only
    TK88           DLT Tx88: (Quantum 4000)-Cmpt IV - Alpha only
    TK89           DLT Tx89: (Quantum 7000)-Cmpt IV - Alpha only
    QIC            All QIC drives are drive-settable only - Alpha
                   only
    8200           Exa-Byte 8200 - Alpha only
    8500           Exa-Byte 8500 - Alpha only
    DDS1           Digital Data Storage 1-2G - Alpha only
    DDS2           Digital Data Storage 2-4G - Alpha only
    DDS3           Digital Data Storage 3-8-10G - Alpha only
    DDS4           Digital Data Storage 4 - Alpha only
    AIT1           Sony Advanced Intelligent Tapes - Alpha only

    When you initialize a tape with the INITIALIZE command and do
    not specify a density, the tape is initialized at the default
    density for the media and drive you are using (usually the
    highest density available).

    The density of a tape can only be changed if the tape is at
    beginning-of-tape (BOT). To change the density of a tape that
    has previously been recorded, the first operation must be a
    write operation. If the first operation on the tape is a read
    operation, the magnetic tape is set to the density at which the
    first record on the tape was recorded, no matter what density is
    specified with the /DENSITY qualifier.

    Example

    The following command mounts a tape on the MFA0: drive /FOREIGN
    and assigns it the logical name TAPE. The /DENSITY qualifier
    specifies that the tape is to be written at TK87.

    $ MOUNT/FOREIGN/DENSITY=TK87  MFA0: TAPE