Hardware Data Compression; Mode Select / Mode Sense Data Compression Page Code (0Fh) - Seagate STT20000N Product Manual

SCSI Interface

Hardware data compression

Mode Select / Mode Sense Data Compression page code (0Fh)

Bit/ 7
Byte
0 PS Reserved
1
2 DCE
3 DDE
4 (MSB)
5
6
7
8 (MSB)
9
10
11
12
13
14
15
STT20000N Product Manual
Mode Select / Mode Sense Data Compression page code 0Fh has been added to
Seagate tape drives that support hardware data compression. A Seagate tape drive
that supports hardware data compression can be detected by first requesting the
available Mode Sense pages (Mode Sense page code 3Fh). Then if Mode Sense
page 0Fh (Data Compression) is present and the DCC bit is set, the drive supports
hardware data compression. A second method would be to request Mode Sense
page 0Fh (Data Compression). If the drive rejects the request or the DCC bit is not
set, then hardware data compression is not present. The Mode /Select Sense page
code 10 parameter codes for data compression are listed in the following table:
6 5
Page Length (0Eh)
DCC
RED
Compression Algorithm
Decompression Algorithm
4 3 2
Page Code (0Fh)
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Chapter 5
1 0
(LSB)
(LSB)
Page 43