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Cdb fields: write specific status, Residue information – HP C737990900 User Manual

Page 155

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Commands 155

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CDB Fields:

Write Specific Status:

See also the

“Additional Sense Codes” on page 136

for a variety of possible

hard errors.
An attempt to write to a write-protected cartridge will produce a

CHECK

CONDITION

with a sense key of

DATA PROTECT

and additional sense of 2700h

(write-protected).
An attempt to write to a cartridge whose Cartridge Memory has failed will

produce a

CHECK CONDITION

with a sense key of

MEDIUM ERROR

and

additional sense of 3004h (cannot write medium). If, however, the tape is not

positioned at BOT, the drive will respond with sense data as if the tape is write-

protected. The WP flag in the Mode Parameter Header will also be set.
If EOM (end of medium) is encountered during a write,

CHECK CONDITION

status is reported. The EOM flag will be set. The sense key will be set to

VOLUME OVERFLOW

with additional sense of 0002h (EOT). Residue

information will be as below. The logical position will be EOD.
Subsequent Request Sense commands will, however, give tape position as

EOP/M (end of partition/media). It may still be possible to write a smaller

quantity of information at this point (such as filemarks or a smaller block). This

is because logical position after failure to write a block returns to the start of

the unwritten block.
Early Warning EOM information is reported only if a write operation is

successful. This is done by reporting

CHECK CONDITION

status with a sense

key of

NO SENSE

and additional sense of 0002h (EOT). Residue information is

valid and indicates zero blocks/bytes.

Residue Information:

Residue information depends on two variables:

Fixed or Variable block mode.

Fixed

0

The Transfer Length field specifies the length of the transfer in bytes.

1

The Transfer Length field specifies the length of the transfer in blocks. The size of each

block (in bytes) is determined by the current Block Length given in the Mode Select

Parameter block descriptor.

Transfer Length

0

No data is transferred. The current logical position will be unchanged.

>0 The amount of data to be transferred, in bytes or blocks as determined by the Fixed field.