Toshiba 4006GAH Computer Drive User Manual


 
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Toshiba Corporation Digital Media Network Company
Page 28 of 157
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9.5 Load/Unload
Be sure to issue and complete the following commands for unloading before cutting off the power
supply.
Following table shows the specification for normal load/unload cycles.
Load/unload cycle (Times) Environment
600,000 Room temperature
300,000 Operational temperature range
Unload is executed by the following commands :
Standby
Standby Immediate
Sleep
Hard reset
Load/Unload is also executed as one of the idle modes of the drive.
If power is removed from the drive while the heads are over the media an Emergency
Unload will take place. An Emergency Unload is performed by routing the back-EMF
of the spindle motor to the actuator voice coil. An Emergency Unload is mechanically
much more stressful to this drive than a controlled Unload. The minimum number of
Emergency Unloads that can be successfully performed is 20,000. Emergency Unload
should only be performed when it is not possible to perform a controlled Unload.