Quantum DLT 2000, Product Manual

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DLT2000 SCSI Interface
DLT2000/DLT2700 Cartridge Tape Subsystem 8-75
WP
A Write-Protected bit of zero indicates that the tape is write-enabled. A Write-Protected
bit of one indicates that the tape is write-protected.
Buffered Mode
The drive implements Immediate Reporting on WRITE commands through Buffered
mode.
If the field is zero, then the drive does not report a GOOD status on WRITE commands
until the data blocks are actually written to tape. If the Buffered Mode field is one, then
the drive reports GOOD status on WRITE commands as soon as the data block has
been transferred to the buffer. This is the default configuration for the drive. If Buffered
mode is not used, the tape drive will suffer a significant degradation in performance, but
not capacity.
Speed
The tape drive supports only one speed, the default speed.
Block Descriptor Length
This specifies the length in bytes of all the block descriptors. Since the drive only
allows one block descriptor, this value will be 8.
Density Code
This field matches the current density of the media, or zero if the density is unknown.
•
=
00h - use default density
•
=
0Ah - 6667 bpi MFM serial cart. tape X3B5/86-199 (Read only) (CompacTape)
•
=
16h - 10000 bpi MFM serial cart tape X3.193-1990 (Read only) (CompacTape
II)
•
=
17h - 42500 bpi MFM serial cart tape X3B5/91-174 - 2.6 GB (CompacTape III)
•
=
18h - (Same as 17h but with 56 track pairs vs. 24) - 6.0 GB (CompacTape III)
•
=
19h - 62500 bpi, 64 track pairs, serial cart tape - 10 GB (CompacTape III)
•
=
7Fh - No change from previous density (NOP)
•
=
80h - 62500 bpi, 64 track pairs, serial cart tape - 10 GB (CompacTape III)
(Without compression)
•
=
81h - 62500 bpi, 64 track pairs, serial cart tape -20 GB (With compression)
Number of Blocks
This field will be sent as zero, indicating that all of the remaining logical blocks on the
tape will have the medium characteristics specified by the block descriptor.