Quantum DLT 4000 Product Manual page 236

DLT4000 SCSI Interface
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)
16h – 10000 bpi MFM serial cart tape X3.193-1990 (read only)
17h – 42500 bpi MFM serial cart tape X3B5/91-174 - 2.6 GB
18h – (Same as 17h but with 56 track pairs vs. 24) - 6.0 GB
19h – 62500 bpi, 64 track pairs, serial cart tape - 10 GB
1Ah
80h – 62500 bpi, 64 track pairs, serial cart tape - 10/15 GB (without
compression)
81h – 62500 bpi, 64 track pairs, serial cart tape - 20/40 GB (with
compression)
82h – 81633 bpi, 64 track pairs, serial cart tape - 20 GB (without
compression)
83h – 81633 bpi, 64 track pairs, serial cart tape - 40 GB (with compression)
8-76 DLT4000/DLT4500/DLT4700 Cartridge Tape Subsystem
81633 bpi, 64 track pairs, serial cart tape - 20 GB