Reference Guide
Chapter 4 SCSI Commands
WRITE BUFFER Command (3Bh)
DLT-S4 Interface Reference Guide 343
The drive must not contain any tape medium before starting an image
download. This is to safeguard against accidentally starting a firmware
update. If a tape cartridge is loaded when all or part of a firmware image
has been downloaded, the drive rejects another
WRITE BUFFER command
with Download Microcode mode.
An error on a
WRITE BUFFER command causes the drive to discard any
downloaded image data.The download must be restarted from the
beginning.
Download Microcode and
Save Mode (05h)
4
This mode downloads and saves the entire image at once, or downloads
the image and saves it, or starts a save operation after the image data has
been downloaded using the Download Microcode mode (04h) described
above.
This mode of the
WRITE BUFFER command causes the drive to verify the
image data and update the Flash EEPROM firmware area. During the
reprogramming of the Flash EEPROM, the Write Protect and Drive Status
LEDs on the drive’s front panel blink. Also, while it is updating the
EEPROM, the drive disconnects from the network and does not respond
until the update is complete.
When the Save operation completes successfully, the firmware restarts
itself, causing the power-on self-test (POST) to run. At that point, the
drive generates two
UNIT ATTENTION conditions: POWER UP RESET and
OPERATING CODE HAS CHANGED.
Write Data to Echo Buffer
Mode (0Ah)
4
In this mode, the drive transfers data from the application client and
stores it in an Echo Buffer. The drive ignores the Buffer ID and Buffer
Offset fields in this mode. Once a
WRITE BUFFER command completes
successfully, the data is preserved in the Echo Buffer unless there is an
intervening command to write to the Echo Buffer or unless the drive is
reset by any means.
Caution: If any type of power failure occurs during the actual
reprogramming of the FLASH EEPROM or if the
reprogramming fails before completion, the drive
subsystem becomes unusable and the drive must be
serviced.