Quantum DLTtape DLT 4000, Product Manual

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SCSI Commands
5-160 Quantum DLT 4000 Tape Drive
WRITE BUFFER Command (3Bh) (continued)
Table 5–79 WRITE BUFFER Command Data - Field Descriptions
Field Name Description
Mode The tape drive supports the following values within the field. If any other value is
set, the drive terminates the command with CHECK CONDITION status and an
ILLEGAL REQUEST sense key set.
Mode Description
000b WRITE combined header and data (Section 5.27.1)
010b WRITE data (Section 5.27.2)
100b Download Microcode (Section 5.27.3)
101b Download Microcode and Save (Section 5.27.4)
Buffer ID For all of the modes described for the Mode field, only a Buffer ID of 0 is supported.
If the Buffer ID field is a value other than 0, the command is rejected. The target
detects and rejects commands that would overrun the buffer.
Buffer Offset See Sections 5.26.1 through 5.26.4 for the appropriate settings.
5.27.1 Write Combined Header and Data Mode (000b)
The data to be transferred is preceded by a 4-byte header consisting entirely of
reserved bytes. This header is discarded (not stored within the buffer). The buffer
offset field must be 0 for this mode.
5.27.2 Write Data Mode (010b)
Similar to Header and Data Mode, except there is no header in the data passed
to the target. Any potential buffer overruns are detected and the command is
rejected. The buffer offset field must be 0 for this mode.
CAUTION
During the actual reprogramming of the FLASH EEPROM, if any type
of powerfail occurs, or if the reprogramming fails before
completion, the tape drive subsystem becomes unusable and the
tape drive must be replaced.