
Tandberg Data
Track, Tape format and Encoding Specification
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Tandberg SLR Reference Manual
6-11
6.5.3. Rewrite ALRF-2 Format
The rewrite algorithm for ALRF-2 format is basically the same as for the ALRF-1 format. A
random algorithm is used to distribute the data on the two tracks available in this format.
6.6. Filemark and Setmark Blocks
Filemark Blocks are used to separate logically different sections of data. This is controlled
from the Host.
The contents of the data fields in the filemark and setmark blocks are not transferred to the
Host.
Filemarks and setmarks are numbered, verified and (if necessary) rewritten in the same way
as all the other block types.
6.7. Underrun
During write operations, situations may occur where the Host is not able to keep up
streaming. Underrun is allowed only at frame boundaries. (If necessary, the Drive will insert
filler blocks to complete the frame set).
When the buffer is empty and the Drive is not configured for “forced streaming”, the Drive will
complete the writing and verification of the last block and then write a Normal Postamble
followed by an EOD Marker (refer to the QIC-5010-DC specifications). Then the tape motion
is stopped.
MLR3 (SLR50),
QIC-5010-DC and
SLR6 (SLR24)
formats only
If the “forced streaming” option, which is used on MLR3 (SLR50), QIC-5010-DC and SLR6
(SLR24) formats only, is used, the last frame will be rewritten until new data is ready in the
buffer, or until the limit for rewrites is reached. In this case a Normal Postamble and an EOD
Marker are written, and the tape motion is halted.
The Elongated Postamble will always be recorded at the end of a Write operation.