Quantum Audio Travan 40 Tape Drive STT3401A - Manual (Page 97)

ATAPI Interface Chapter 5
Seagate Travan 40 Product Manual Page 89
WRITE FILEMARK (Group 0, Op. Code 10)
This command writes a specified number of Filemark blocks to the tape.
CDB for WRITE FILEMARK command
Data Bits
Byte 7 6 5 4 3 2 1 0 Hex
0 0 0 0 1 0 0 0 0 10
1 0 0 0 0 0 0 WSMK IMM 00
2
3
4 MSB
Transfer Length
LSB
XX
XX
XX
5 0 0 0 0 0 0 0 0 00
WSMK—Write Setmarks: This bit must be set to 0. Writing Setmarks is not
supported. If RSMK is set to 0 in Mode Data page 10h, Byte 8, Bit 5, Illegal Request
will result when this bit is set in the CDB. Reading Setmarks is supported and
Setmarks are treated as Filemarks, but Setmarks are counted separately.
IMM—Immediate: When IMM is set to 1, the drive returns status upon verification of
the CDB. When IMM is set to 0, the drive writes all buffered data to the tape
including the specified number of filemarks, prior to sending command Complete
with “Good” status. Filemarks written in Immediate mode do not interrupt streaming.
NOTE: The ATAPI interface does not have an IMM bit or functional equivalent. IMM
is assumed to be set (1).
Transfer Length: Specifies the number of Filemark blocks to be written. When this
value is 0 (and IMM = 0), the drive writes all data in the Data Buffer to tape and no
Filemarks are written, but an EOD frame will be written. If it is successful, the drive
issues a Good Status. If not, it issues a Check Condition (Status 02). The Sense
Information Bytes returned by the REQUEST SENSE command reflect the number
of blocks remaining in the Data Buffer.
NOTE: The STT3401A maintains the total number of filemarks written in a session.
The counter may be read by means of the REQUEST SENSE command. If
the Immediate bit is set to 0, streaming will be interrupted when the last
block is written and the data buffer is flushed.
The locations of the filemarks are recorded in the media header. If the tape
is not rewound after the last WRITE command or WRITE FILEMARK
command, the media header will not be updated and it will not be accurate. If
the Eject button is pressed, the cartridge will be rewound and the media
header will be updated. If AutoPark is enabled, the drive will rewind the
cartridge and update the media header after the drive is idle for several
minutes.
If AutoPark is not enabled and the cartridge is not ejected, the cartridge in
the drive is vulnerable to a power shutdown or a power failure causing the
drive to leave the cartridge with an old version of the media header. The
cartridge will be useable, but the lack of an accurate header will cause
substantial delays during a SPACE or LOCATE command. This problem can