Quantum Instruments DLT 7000 - Manual (Page 118)

SCSI Commands
5-14 Quantum DLT 7000 Tape System
5.3 ERASE COMMAND (19h)
The ERASE command causes data on the tape medium to be erased. Any WRITE
data currently held in buffer memory and not yet written to tape is written to
tape before the ERASE command is executed. ERASE command must be issued
while at BOT.
Note that the time for a complete erase of a DLTtape IV tape cartridge can be
well over one hour.
Bit
Byte
7 6 5 4 3 2 1 0
0 Operation Code (19h)
1 Logical Unit Number Reserved Immed Long (1)
2 - 4 Reserved
5 Unused Reserved Flag Link
Figure 5–3 ERASE Command Descriptor Block - Data Format
Table 5–6 ERASE Command Descriptor Block - Field Descriptions
Field Description
Immed Immediate. If the Immediate bit = 0, the target does not return status until the
selected operation has completed.
If set to 1, status is returned as soon as the operation has been initiated.
Long Must be set to 1. The Long bit controls the distance of tape to be erased. Filler
and End of Data (EOD) blocks are written if needed, then the entire rest of the
tape is erased.
NOTE: The ERASE command results in no operation for the tape drive unless
the Long bit is set to 1. Issuing the ERASE command away from Beginning of
Tape (BOT) is an ILLEGAL REQUEST.