SCSI Commands
5-108
Quantum DLT 4000 Tape Drive
MODE SENSE (6) / (10) Command (1Ah / 5Ah) (continued)
Table 5–52 Data Compression Page - Field Descriptions
Field Name
Description
PS
Parameters Savable. Not supported; must be 0.
Page Length
The value in this field indicates the number of bytes in the Control Mode
page being transferred. The value for this byte is 0Eh.
DCE
Data Compression Enable. The value returned for this bit depends on the
current WRITE density of the tape drive:
0 = Write compression is Disabled
1 = Write compression is Enabled
DCC
Data Compression Capable. The value returned for this bit indicates
whether this tape drive supports data compression:
0 = Data Compression is not supported
1 = Data Compression is supported and will process any data sent to it by
the initiator according to the setting of the DCE bit (byte 02, bit 7).
DDE
Data Decompression Enable. The value returned for this bit indicates
whether data decompression is enabled or not.
0 = Data Decompression is Disabled
1 = Data Decompression is Enabled
Note that when the tape drive reads compressed data from tape, it
automatically decompresses the data before sending it to the initiator.
The value for this bit, therefore, is always 1.
RED
Report Exception on Decompression. The tape drive does not report
exceptions on decompression (boundaries between compressed and
decompressed data). The value returned for RED is 00h.
Compression
Algorithm
The value for this field is 10h. This indicates the Lempel-Ziv high
efficiency data compression algorithm.
Decompression
Algorithm
The value for this field is 10h. This indicates the Lempel-Ziv high
efficiency data decompression algorithm. If EEPROM parameter
EnaRepDCcomp is set, a value of 0 is reported if the last block read is not
decompressed.
Summary of Contents for DLTtape DLT 4000
Page 1: ...DLT 4000 Tape Drive Product Manual November 10 2003 81 60043 04 ...
Page 5: ...USER MANUAL STATEMENTS FOR CLASS B EQUIPMENT continued ...
Page 6: ......
Page 24: ...About This Manual Quantum DLT 4000 Tape Drive xxiv ...
Page 62: ...Hardware Implementation 2 28 Quantum DLT 4000 Tape Drive ...
Page 100: ...Messages 4 12 Quantum DLT 4000 Tape Drive ...
Page 264: ...SCSI Commands 5 164 Quantum DLT 4000 Tape Drive ...
Page 274: ...Appendix B EEPROM Resident Bugcheck and Event Logs B 6 Quantum DLT 4000 Tape System ...
Page 280: ...Appendix C Updating the Firmware C 6 Quantum DLT 4000 Tape Drive ...
Page 298: ...Index Index 6 Quantum DLT4000 Tape Drive ...
Page 299: ......