Tandberg Data
Product Specifications
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Tandberg SLR Reference Manual
3-11
3.6.5. Recording Specifications
Recording
method
The ALRF-1, ALRF-2 and ALRF-6 formats are encoded according to VR
2
RLL. The MLR3
(SLR50), QIC-5010-DC and SLR6 (SLR24) formats are encoded according to RLL1,7.
The QIC-2GB and QIC-4GB formats are encoded according to the 0,2 GCR rules.
Recording
density
ALRF-6:
7322 data bits per mm (186 000 data bits/inch) ALRF-
1/ALRF-2:
6000 data bits per mm (152 400 data bits/inch)
MLR3 (SLR50):
4060 data bits per mm (103 124 data bits/inch)
QIC-5010-DC:
2667 data bits per mm (67 733 data bits/inch)
SLR6 (SLR24):
2667 data bits per mm (67 733 data bits/inch)
QIC-4GB:
1952 data bits per mm (49 600 data bits/inch)
QIC-2GB:
1600 data bits per mm (40 640 data bits/inch)
Maximum flux
density
ALRF-6:
Maximum 7322 ftpmm (186 000 ftpi)
ALRF-1/ALRF-2:
Maximum 6000 ftpmm (152 400 ftpi)
MLR3 (SLR50):
Maximum 3045 ftpmm (77 343 ftpi)
QIC-5010-DC:
Maximum 2000 ftpmm (50 800 ftpi)
SLR6 (SLR24):
Maximum 2000 ftpmm (50 800 ftpi)
QIC-4GB:
Maximum 2441 ftpmm (62 000 ftpi)
QIC-2GB
Maximum 2000 ftpmm (50 800 ftpi)
Block size
ALRF-1/ALRF-2/ALRF-6/MLR3 (SLR50)/
5010-DC/SLR6 (SLR24):
512 data bytes
QIC-4GB/2GB:
1024 data bytes
Nominal overhead
per block
ALRF-1/ALRF-2/ALRF-6:
21.25 bytes (Preamble 4, Block Marker 0.25,
Seed 3, Control Field 8, CRC 6)
MLR3 (SLR50)/5010-DC/
SLR6 (SLR24):
29 bytes (Preamble 13, Block Marker 3,
Block Addr 8, CRC 4, Postamble 1)
QIC-4GB:
78 bytes (Preamble 63, Block Marker 1,
Block Addr 4, CRC 4, Postamble 1)
QIC-2GB:
59.5 bytes (Preamble 49.5, Block Marker 1,
Block Addr. 4, CRC 4 and Postamble 1
Write procedure
ALRF-1 and ALRF6 records four tracks in parallel, while ALRF-2, SLR6 (SLR24), MLR3
(SLR50) and QIC-5010-DC are recorded by writing two tracks in parallel. The tracks written
simultaneously is called a
Track-set
. The first Track-set written is 0, then Track set 1, 2 and
so on. Even numbered Track-sets are recorded in the forward direction, odd Track-sets are
recorded in the reverse direction.
Erase is not used for ALRF-1,ALRF-6, ALRF-2, MLR3 (SLR50), QIC-5010-DC or SLR6
(SLR24) recording, old data is simply overwritten by new data.
In MLR3 (SLR50), QIC-5010-DC and SLR6 (SLR24), it is possible to have up to 36 partitions,
for ALRF-1 and ALRF-6 maximum 24 and for ALRF-2 maximum 3 partitions.
For all formats other than ALRF-1, MLR3 (SLR50), QIC-5010-DC and SLR6 (SLR24), data is
recorded one track at a time, starting at Track 0. For these formats, all tracks are erased
when writing from beginning of tape on Track 0.
Read procedure
Reading starts from the beginning of Track/Track-set 0 and is performed in an evenly rising
order, i.e. 0, 1, 2, etc.