Quantum DLT 1 Interface Manual page 96

Chapter 4: SCSI Commands
Table 4-32. Device Configuration Page — Field Descriptions (Continued)
Field Name
Active Partition
Write Buffer Full Ratio
and Read Buffer Empty
Ratio
Write Delay Time
Byte 8
Gap Size
EOD Defined
EEG
SEW and Buffer Size
At Early Warning
Select Data
Compression
Algorithm
4-54
Description
Only partition 0 is supported. The tape drive rejects any other value for this field
with a CHECK CONDITION status and the ILLEGAL REQUEST Sense Key set.
The tape drive sets these fields to 0 (unused). The tape drive uses an automatic,
adaptive mechanism to adjust its Full/Empty Buffer ratios dynamically according
to the average data rates over the SCSI bus.
This field indicates the maximum time that the tape drive waits with a partially full
buffer before forcing the data to medium (in 100 ms increments). The buffer Full/
Empty ratio, which is dynamic, can cause data to be written sooner than the Write
Delay time would indicate. The Write Delay Time defaults to 200 (C8h), causing
the buffer to be flushed in 20 seconds. The maximum value is 6500 (1964h), the
minimum value is 15 (0Fh), representing delays from almost 11 minutes down to
1.5 seconds.
Values between 0 and 15 are rounded down to 0. This causes the data to go straight
to the media without delay.
Code
DBR
BIS
RSmk
AVC
SOCF
RBO
REW
This field is not used and is 0.
End of Data Defined. This field must be 00h. The tape drive rejects any other
value.
Enable EOD Generation. This bit indicates that the tape drive generates an EOD.
The tape drive generates an EOD mark before any change of direction following a
write type operation. This bit must be 1.
Synchronize at Early Warning. This bit is 1. Buffer Size at EW is not supported
and must be 0.
Setting this field to 1 enables hardware data compression. Setting it to 0 disables
hardware data compression.
July 2004
Description
Must be 0 (Data Buffer Recovery not supported).
Must be 1 (Block Identifiers Supported in media
format).
Must be 0 (Setmarks not supported).
Must be 0.
Must be 0.
Must be 0.
Must be 0 (Do not report Early Warning EOM on
reads).
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