Table 14-12: Fixed Block Lengths - Tandberg Data SLR7-140 PROGRAMMER Manual

Number Of Blocks
Block Length
Block Length
000000h
000002h – 40000h
Tandberg Data
Note that the different drive types will not have write
compatibility on all tape formats. See table 1-1 for an
overview. See also
medium types that can be used for which tape format.
Note also that not all combinations of tape formats and
block lengths are allowed (see the description of the
Block Length field).
This field must be set to zero, it is not changeable
(the whole tape must have the same density code).
This field selects the Block Length used (on the SCSI-
bus) when reading, verifying and writing fixed length
blocks.
Description
The Drive is set into Variable Block mode. In this mode it is illegal to issue
commands that have the FIX bit set to one. Only variable block READ, VERIFY
WRITE commands are allowed.
When writing variable blocks the Drive will write all blocks as Variable Data Blocks
according to the corresponding QIC Development Standards [9] - [13].
See also the section on the READ command for further details on the difference
between Variable Block mode and Fixed Block mode.
When the value in the Block Length field is different from 000000h, the Drive is set
into Fixed Block Mode. The Block Length used when transferring fixed length
blocks on the SCSI-bus is given by the specified value.
When using an SLRtape140, SLRtape100, SLRtape75, SLRtape60, SLRtape50,
SLRtape40, SLRtape7, SLR32 or SLRtape24 medium the block length can be set
to any even value in the range 2 to 262144 (40000h).
When using an SLR5 or DC9250 medium, the only legal Fixed Block Mode block
lengths are 512 (200h) and 1024 (400h) bytes.
When writing 512 byte fixed length blocks on an SLR5 or DC9250 medium, the
Drive will pack two 512 byte logical blocks into one physical tape block according to
[9], [10].
When the block length is different from 512 and 1024 bytes, the Drive will write all
logical blocks as Variable Length Data blocks as defined in [9], [10].
Table 14-12: Fixed Block Lengths
The length of fixed length logical blocks is set by the
three bytes available in the Block Length field. The
table below indicates the legal block length values for
the different tape formats.
1
VERIFY is not supported by SLR7 and SLR140
14-9 Tandberg SLR Product Line SCSI Functional Specifications
Table 30-2 for
Mode Select
details on which
1
or