ISO/IEC 15896:1999

INTERNATIONAL ISO/IEC
STANDARD 15896
First edition
1999-12-15
Information technology — Data
interchange on 12,7 mm 208-track
magnetic tape cartridges — DLT 5 format
Technologies de l'information — Échange de données sur cartouches
de bande magnétique de 12,7 mm, 208 pistes — Format DLT 5
Reference number
©
ISO/IEC 1999
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ii © ISO/IEC 1999 – All rights reserved

ISO/IEC ISO/IEC 15896:1999 (E)
Contents
Section 1 - General 1
1 Scope 1
2 Conformance 1
2.1 Magnetic tape cartridges 1
2.2 Generating systems 1
2.3 Receiving systems 1
3 Normative references 1
4 Definitions 1
4.1 Average Signal Amplitude 2
4.2 azimuth 2
4.3 back surface 2
4.4 Beginning-Of-Tape marker (BOT) 2
4.5 block 2
4.6 byte 2
4.7 cartridge 2
4.8 Cyclic Redundancy Check (CRC) character 2
4.9 Early Warning (EW) 2
4.10 Error-Detecting Code (EDC) 2
4.11 End-Of-Tape marker (EOT) 2
4.12 Entity 2
4.13 Error-Correcting Code (ECC) 2
4.14 Envelope 2
4.15 Envelope size 2
4.16 flux transition position 2
4.17 flux transition spacing 2
4.18 logical track 2
4.19 magnetic tape 2
4.20 Master Standard Reference Tape 2
4.21 object 2
4.22 page 2
4.23 physical recording density 2
4.24 physical track 2
4.25 Record 2
4.26 Reference Edge 2
4.27 Reference Field 2
4.28 Secondary Standard Reference Tape 2
4.29 Standard Reference Amplitude (SRA) 3
4.30 Standard Reference Current 3
iii
4.31 Test Recording Current 3
4.32 Typical Field 3
5 Conventions and notations 3
5.1 Representation of numbers 3
5.2 Dimensions 3
5.3 Names 3
5.4 Acronyms 3
6 Environment and safety 3
6.1 Cartridge and tape testing environment 3
6.2 Cartridge operating environment 4
6.3 Cartridge storage environment 4
6.4 Safety 4
6.4.1 Safeness 4
6.4.2 Flammability 4
6.5 Transportation 4
Section 2 - Requirements for the unrecorded tape 5
7 Mechanical and electrical requirements 5
7.1 Material 5
7.2 Tape length 5
7.3 Width 5
7.4 Total thickness 5
7.5 Discontinuity 5
7.6 Longitudinal curvature 5
7.6.1 Requirement 5
7.6.2 Procedure 5
7.7 Out-of-Plane distortions 5
7.8 Cupping 5
7.9 Roughness of the coating surfaces 5
7.9.1 Roughness of the back coating surface 5
7.9.2 Roughness of the magnetic coating surface 5
7.10 Coating adhesion 6
7.11 Layer-to-layer adhesion 6
7.11.1 Requirements 6
7.11.2 Procedure 6
7.12 Modulus of elasticity 7
7.12.1 Requirement 7
7.12.2 Procedure 7
7.13 Flexural rigidity 7
7.13.1 Requirement 7
7.13.2 Procedure 7
7.14 Tensile yield force 8
7.14.1 Procedure 8
7.15 Electrical resistance 8
7.15.1 Requirement 8
7.15.2 Procedure 8
7.16 Inhibitor tape 9
7.17 Abrasivity 9
7.17.1 Requirement 9
7.17.2 Procedure 9
7.18 Light transmittance of the tape and the leader 9
7.19 Coefficient of dynamic friction 9
7.19.1 Requirements 9
7.19.2 Procedure for the measurement of the friction between the magnetic surface and the back surface 10
iv
ISO/IEC     ISO/IEC 15896:1999 (E)
7.19.3 Procedure for the measurement of the friction between the magnetic surface or the back surface and calcium
titanate ceramic 10
8 Magnetic recording characteristics 10
8.1 Typical Field 11
8.2 Signal amplitude 11
8.3 Resolution 11
8.4 Overwrite 11
8.4.1 Requirement 11
8.5 Peak shift 11
8.5.1 Requirement 11
8.5.2 Procedure 11
9 Tape quality 12
9.1 Missing pulses 12
9.1.1 Requirement 12
9.2 Missing pulse zone 12
9.2.1 Requirement 12
9.3 Tape durability 12
Section 3 - Mechanical specifications of the tape cartridge 12
10 General 12
10.1 Bottom side and right side 13
10.2 Back side and left side 14
10.3 Tape reel 14
10.4 Tape leader 15
10.5 Front side 16
10.6 Operation of the cartridge 16
10.7 Tape winding 17
10.8 Moment of inertia 17
10.9 Material 18
Section 4 - Requirements for an interchanged tape 27
11 Method of recording 27
11.1 Physical recording density 27
11.2 Channel bit cell length 27
11.2.1 Average Channel bit cell length 27
11.2.2 Long-term average Channel bit cell length 27
11.2.3 Short-term average Channel bit cell length 27
11.3 Flux transition spacing 27
11.4 Read signal amplitude 27
11.5 Azimuth 28
11.6 Channel skew 28
12 Tape format 28
12.1 Reference Edge 28
12.2 Direction of recording 28
12.3 Tape layout 28
12.4 Calibration and Directory Area 28
12.4.1 Scratch Area 29
12.4.2 Guard Area G1 29
12.4.3 Calibration Tracks Area 29
12.4.4 Guard Area G2 30
12.4.5 Directory Area 30
12.4.6 Guard Area G3 30
12.5 Data Area 30
12.5.1 Physical tracks 31
v
12.5.2 Logical tracks 33
13 Data format 34
13.1 Data Bytes 34
13.2 Data Blocks 34
13.3 Types of Blocks 34
13.4 Entities 34
13.5 Envelopes 34
13.6 Block format 34
13.6.1 Preamble 35
13.6.2 Sync 35
13.6.3 Data Field 35
13.6.4 EDC 36
13.6.5 Control Field 1 (CF1) 37
13.6.6 Control Field 2 (CF2) 38
13.6.7 CRC 39
13.6.8 Postamble 39
14 Use of blocks 39
14.1 Data Blocks 39
14.2 Filler Blocks 39
14.3 End of Track Blocks (EOTR) 40
14.4 End of Data Blocks (EOD) 40
14.5 ECC Blocks 40
15 Format of Entities 40
16 Format of Envelopes 40
17 Error handling 40
Annexes
A - Measurement of light transmittance 41
B - Generation of the Data Block CRCs 44
C - ECC generation 45
D - Generation of page CRCs 48
E - Format of MAP entries 49
F - Format of Control Field 1 50
G - Format of Control Field 2 51
H - Recommendations for transportation 52
J - Inhibitor tape 53
K - Recommendations on tape durability 54
L - Handling guidelines 55
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ISO/IEC    ISO/IEC 15896:1999 (E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission)
form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC
participate in the development of International Standards through technical committees established by the
respective organization to deal with particular fields of technical activity. ISO and IEC technical committees
collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in
liaison with ISO and IEC, also take part in the work.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting.
Publication as an International Standard requires approval by at least 75% of the national bodies castinga vote.
Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of
patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights.
International Standard ISO/IEC 15896 was prepared by ECMA — European association for standardizing
information and communication systems (as ECMA-259) and was adopted, under a special “fast-track procedure”,
by Joint Technical Committee ISO/IEC JTC 1, Information technology, in parallel with its approval by national
bodies of ISO and IEC.
Annexes A toG form a normative part of this International Standard. Annexes H toL are for information only.
vii
Introduction
This International Standard constitutes a further development of the magnetic tape cartridge specified in International Standard
ISO/IEC 15307. The number of tracks is raised to 208. As a result a native capacity of 35 Gbytes or, with compressed data, of
typically at least 70 Gbytes is achieved.
viii
4.1 Average Signal Amplitude: The average peak-to-peak value of the output signal from the read head at the physical
recording density of 2 254 ftpmm measured over a minimum length of track of 25,4 mm, exclusive of missing pulses.
4.2 azimuth: The angular deviation, in degrees of arc, of the mean flux transition line of the recording made on a track
from the line normal to the Reference Edge.
4.3 back surface:
The surface of the tape opposite the magnetic coating which is used to record data.
4.4 Beginning-Of-Tape marker (BOT): A hole punched on the centreline of the tape towards the end nearest to the
leader.
4.5 block: A set of contiguous bytes recorded on a physical track and considered as a unit.
4.6 byte: An ordered set of bits acted upon as a unit.
Note - In this International Standard, all bytes are 8-bit bytes.
4.7 cartridge: A case containing a single supply reel of 12,7 mm wide magnetic tape with a leader attached at the outer
end.
4.8 Cyclic Redundancy Check (CRC) character: A 64-bit character, generated by a mathematical computation,
used for error detection.
4.9 Early Warning (EW): A signal generated by the drive indicating the approaching end of the recording area.
4.10 Error-Detecting Code (EDC): A mathematical computation yielding check bytes used for error detection.
4.11 End-Of-Tape marker (EOT): A hole punched on the centreline of the tape towards the end farthest from the
leader.
4.12 Entity: A group of twenty blocks treated as a logical unit and recorded on a logical track, except Filler Blocks ,if any.
4.13 Error-Correcting Code (ECC): A mathematical computation yielding check bytes used for the correction of
errors detected by the CRC and the EDC.
4.14 Envelope: A group of Entities.
4.15 Envelope size:
The number of Entities in an Envelope.
4.16 flux transition position: The point which exhibits the maximum free-space flux density normal to the tape surface.
4.17 flux transition spacing: The distance on the magnetic tape between successive flux transitions.
4.18 logical track: A group of four physical tracks that are written or read simultaneously.
4.19 magnetic tape: A tape that accepts and retains magnetic signals intended for input, output, and storage purposes on
computers and associated equipment.
4.20 Master Standard Reference Tape: A tape selected as the standard for Reference Field, signal amplitude,
resolution, peak shift, and overwrite characteristics.
Note - The Master Standard Reference Tape has been established by the Quantum Corporation.
4.21 object: A Record or a page of type Tape Mark.
4.22 page:
A logical division of a block.
4.23 physical recording density: The number of recorded flux transitions per unit length of track, expressed in flux
transitions per millimetre (ftpmm).
4.24 physical track: A longitudinal area on the tape along which a series of magnetic signals can be recorded.
4.25 Record: A collection of User Bytes, the number of which is determined by the host.
4.26 Reference Edge:
The bottom edge of the tape when viewing the magnetic coating of the tape with the BOT to the
left and the EOT to the right of the observer.
4.27 Reference Field: The Typical Field of the Master Standard Reference Tape.
4.28 Secondary Standard Reference Tape: A tape the characteristics of which are known and stated in relation to
those of the Master Standard Reference Tape.
Note - Secondary Standard Reference Tapes can be ordered under Reference "SSRT/DLT4"from Quantum Corporation, 333 South Street, Shrewsbury, Mass.
01545-4195, USA. It is intended that these be used for calibrating tertiary reference tapes for routine calibration.
In principle, these Secondary Standard Reference Tapes will be available for a period of 10 years from the publication of the first version of this International
Standard. However, this period may be changed to take into account the demand for such Secondary Standard Reference Tapes.
ISO/IEC  ISO/IEC 15896:1999 (E)
4.29 Standard Reference Amplitude (SRA): The Average Signal Amplitude from the Master Standard Reference
Tape when it is recorded with the Test Recording Current at 2 254 ftpmm.
4.30 Standard Reference Current: The current that produces the Reference Field.
4.31 Test Recording Current: The current that is 1,1 times the Standard Reference Current.
4.32 Typical Field: In the plot of the Average Signal Amplitude against the recording field at the physical recording
density of 2 254 ftpmm, the minimum field that causes an Average Signal Amplitude equal to 95 % of the maximum
Average Signal Amplitude.
5 Conventions and notations
5.1 Representation of numbers
The following conventions and notations apply in this International Standard, unless otherwise stated.
− A measured value is rounded off to the least significant digit of the corresponding specified value. It implies that a specified
value of 1,26 with a positive tolerance +0,01, and a negative tolerance -0,02 allows a range of measured values from 1,235
to 1,275.
− In each block and in each field the bytes shall be arranged with Byte 1, the least significant, first. Within each byte the bits
shall be arranged with Bit 1, the least significant, first and Bit 8, the most significant bit, last. This order applies to the data,
and to the input and output of the error-detecting and error-correcting codes, and to the cyclic redundancy characters.
− Letters and digits in parentheses represent numbers in hexadecimal notation.
− The setting of bits is denoted by ZERO or ONE.
− Numbers in binary notation and bit patterns are re
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