Table of Contents
Advertisement
occurs, terminator power to the bus is interrupted. After the short is removed, a
fuse in the drive is automatically reset, restoring terminator power.
Data compression
The internal tape drive provides two switches for controlling data compression.
Switch 1 determines whether hardware data compression is enable or disabled. By
default, switch 1 is set to ON, enabling hardware data compression. To disable
hardware data compression, set switch 1 to the OFF position.
Switch 2 controls whether SCSI commands are recognized for enabling or disabling
hardware data compression. By default, switch 2 is set to ON, allowing SCSI
commands to be used to enable or disable hardware data compression. To prevent
SCSI commands from enabling or disabling hardware data compression, set switch
2 to the OFF position.
When data compression is enabled, the drive compresses all data written to tape
and decompresses all compressed data read from tape. The degree of compression
varies due to the type of data being processed.
v Data with a high degree of redundancy, such as structured database files or
v Data with little redundancy, such as executable programs, are compressed the
Power-on self test
Switch 4 enables or disables the Power-On Self-Test diagnostics that the drive
performs when powered on. By default, the drive responds to SCSI commands
only after it successfully completes the Power-On Self-Test (about 5 seconds). To
prevent the drive from performing the Power-On Self-Test when powered-up, set
switch 4 to the OFF position.
Host operating system
6
DDS Gen 5 Tape Drive: User's Guide
Settings:
graphics files, are compressed most efficiently, often at a ratio of 2:1 or more.
least.
Settings:
Switches:
Default Settings:
Switch 1 ON = Enable hardware data
compression (default)
Switch 1 OFF = Disable hardware data
compression
Switch 2 OFF = Recognize SCSI data
compression commands (default)
Switch 2 ON = Ignore SCSI data
compression commands
Switch 4 ON = Drive performs Power-On
Self Test (default)
Switch 4 OFF = Drive does not perform
Power-On Self Test
5,6,7,8
Microsoft Windows
Advertisement
Table of Contents
