Reference Guide

Chapter 4 SCSI Commands
MODE SENSE (6) / (10) Command (1Ah / 5Ah)
DLT-S4 Interface Reference Guide 174
Table 98 Data Compression
MODE SENSE Page — Field
Descriptions
4 — 7
(MSB)
Compression Algorithm (10h)
(LSB)
8 — 11
(MSB)
Decompression Algorithm
(LSB)
12 — 15 Reserved
Field Description
PS Parameters Savable. Always set to 0.
SPF SubPage Format. Always set to 0. Indicates that this page uses the page_0 page
format.
Page Code Identifies the type of
MODE SENSE page being transferred. A value of 0Fh
identifies this as the Data Compression page.
Page Length Indicates the number of bytes in the page, excluding bytes 0 and 1.
DCE Data Compression Enable. The value the drive returns depends on the current
WRITE density of the drive.
DCC Data Compression Capable. The value the drive returns indicates whether the
drive supports data compression. Always set to 1 indicating the drive is capable or
data compression.
DDE Data Decompression Enable. The value the drive returns indicates whether data
decompression is enabled or not.
Always set to 1. When the drive reads compressed data from tape, it automatically
decompresses the data before sending it to the host.
Bit
Byte
7 6 5 4 3 2 1 0