Mode Select; Figure 4-31. Mode Select Pages - Data Format; Table 4-29. Mode Select Pages - Field Descriptions - Quantum DLT 1 Interface Manual

Chapter 4: SCSI Commands
4.9.2 MODE SELECT Pages
Following the Command Block Descriptor are the MODE SELECT pages, which set the tape drive
parameters. Each page has a 2-byte header that identifies the page code and indicates the number of
bytes in that page.
Bit
Byte
0
1
Figure 4-31. MODE SELECT Pages — Data Format
Table 4-29. MODE SELECT Pages — Field Descriptions
Field Name
PS
Page Code
Additional Page Length
4-48
7 6
PS (0) 0
Description
Parameters Savable. For the MODE SELECT command, this bit is reserved. For
the MODE SENSE command, a PS bit of 1 indicates that the tape drive can save
the page in nonvolatile memory. If the PS bit is 0, it cannot save the supported
parameters. The tape drive does not support Savable pages. Byte 0, bit 6 must be 0.
These six bits identify the page that follows.
Page Code
01h
02h
0Ah
0Fh
11h
1Ch
3Eh
This bit indicates the number of bytes in that page. However, the value does not
include bytes 0 and 1. The tape drive returns the length on MODE SENSE; the
initiator must subsequently set it to the same value when performing a MODE
SELECT command. If the page length does not match the length the tape drive
expects, the tape drive returns a CHECK CONDITION status with the Sense Key
set to ILLEGAL REQUEST.
The tape drive returns a CHECK CONDITION status with an ILLEGAL
REQUEST Sense Key if it receives an unsupported Page Code or any Page field
with values not supported or changeable. In this case, the command changes no
parameters.
5 4
Additional Page Length
Description
Read / Write Error Recovery
Disconnect / Reconnect
Control Mode
Data Compression
Medium Partition
TapeAlert (Page
EEPROM Vendor Specific
July 2004
3 2
Page Code
(Page 4-49)
(Page 4-51)
(Page 4-51)
(Page 4-56)
(Page 4-58)
4-60)
(Page 4-61)
81-81276-01 Rev A01
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