Quantum Audio STT2401A Manuel D’Utilisation

Page de 137
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 
Hex 
10 
WSMK
 
IMM 
00 


MSB 
Transfer Length 
LSB 
XX 
XX 
XX 
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