DLT1/VS80 SCSI Interface Guide
81-81276-01 Rev A01
July 2004
4-79
Table 4-47.
Data Compression Page — Field Descriptions
Field Name
Description
PS
Parameters Savable. The value returned for this bit is 0.
Page Code
The Page Code identifies the type of MODE SENSE data being transferred. The
value returned for this field is 0Fh (Data Compression Page).
Page Length
The Page Length indicates the number of Data Compression Page bytes that
follow this byte. The value returned for this byte is 0Eh.
DCE
Data Compression Enable. The DCE bit indicates whether data compression is
enabled. The value returned for this bit depends on the current write density of the
tape drive as follows:
0
Data compression is disabled.
1
Data compression is enabled.
DCC
Data Compression Capable. The DCC bit indicates whether the tape drive supports
data compression as follows:
0
The tape drive does not support data compression.
1
The tape drive supports data compression and
processes any data the initiator sends to it according to
the setting of the DCE bit.
The tape drive supports data compression in its native mode. The value returned
for this bit is 1.
DDE
Data Decompression Enable. The DDE bit indicates whether data decompression
is enabled or disabled as follows:
0
Data decompression is disabled.
1
Data decompression is enabled.
When the tape drive reads compressed data from tape, it automatically
decompresses the data before sending it to the initiator. The value returned for this
bit is always 1 (data decompression enabled).
RED
Report Exception on Decompression. The tape drive does not report exceptions on
decompression (boundaries between compressed and uncompressed data). The
value returned for the RED field is 00h.
Compression
Algorithm
The value returned for the Compression Algorithm field is 10h. This indicates
Lempel-Ziv (DLZ) high efficiency data compression algorithm.
Decompression
Algorithm
The value returned for the Decompression Algorithm field is 10h. This indicates
Lempel-Ziv (DLZ) high efficiency data decompression algorithm. If EEPROM
parameter EnaRepDecomp is set, a 0 value is reported if the last block read is not
decompressed.
Summary of Contents for DLT1/VS80 SCSI
Page 1: ...DLT1 VS80 SCSI Interface Guide...
Page 6: ...DLT1 VS80 SCSI Interface Guide vi July 2004 81 81276 01 Rev A01 Notes...
Page 12: ...Table of Contents xii July 2004 81 81276 01 Rev A01 Notes...
Page 16: ...List of Figures xiv July 2004 81 81276 01 Rev A01 Notes...
Page 20: ...List of Tables xviii July 2004 81 81276 01 Rev A01 Notes...
Page 24: ...Chapter 1 Introduction 1 4 July 2004 81 81276 01 Rev A01 Notes...
Page 32: ...Chapter 2 General SCSI Bus Operation 2 8 July 2004 81 81276 01 Rev A01 Notes...
Page 42: ...Chapter 3 SCSI Messages 3 10 July 2004 81 81276 01 Rev A01 Notes...
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