Quantum DLT 4000 Product Manual page 219

DDE (Data Decompression Enable)
When the DLT4000 drive reads compressed data from tape, it automatically
decompresses the data before sending it to the initiator. Data compression is always
enabled, so this bit must be set to 1 (enable data decompression).
RED (Report Exception on Decompression)
The DLT4000 drive does not report exceptions on decompression (boundaries between
compressed and uncompressed data). The RED field must be 00h.
Compression Algorithm
The Compression Algorithm field indicates which compression algorithm the
DLT4000 drive will use to process data from the initiator when the DCE bit (byte 02,
bit 7) is 1. The only value currently supported for this field is 10h.
_________________________ NOTE ____________________________
Specifying a value other than 10h for this field causes the DLT4000 drive
to return Check Condition status with the sense key set to Illegal Request
(5h). However, if EEROM parameter EnaRepDecomp is set, the
parameter in this field is ignored and not Check Condition status is
returned.
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Decompression Algorithm
The Decompression Algorithm field indicates which decompression algorithm the
DLT4000 drive will use when decompressing data encountered on the tape. The only
value currently supported for this field is 10h.
_________________________ NOTE ____________________________
Specifying a value other than 10h for this field causes the DLT4000 drive
to return Check Condition status with the sense key set to Illegal Request
(5h).
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DLT4000/DLT4500/DLT4700 Cartridge Tape Subsystem 8-59
DLT4000 SCSI Interface