ISO/IEC 22051:2002
(Main)Information technology — Data interchange on 12,7 mm, 448-track magnetic tape cartridges — SDLT1 format
Information technology — Data interchange on 12,7 mm, 448-track magnetic tape cartridges — SDLT1 format
ISO/IEC 22051:2002 specifies the physical and magnetic characteristics of magnetic tape cartridges, using magnetic tape 12,65 mm wide so as to provide physical interchange of such cartridges between drives. It also specifies the quality of the recorded signals, the recording method and the recorded format, thereby allowing data interchange between drives by means of such cartridges. The linearly recorded format, called Super Digital Linear Tape 1 (SDLT 1), has 448 tracks. It uses a combination of magnetic and optical technologies known as Laser-Guided Magnetic Recording (LGMR). The back surface of the tape presents optically detected servo marks. The format is derived from the DLT Format. It provides for a capacity of 110 Gbytes of uncompressed user data, or typically 220 Gbytes of compressed user data. Together with a standard for volume and file structure this document provides for full data interchange between data processing systems.
Technologies de l'information — Échange de données sur cartouche à bande magnétique 12,7 mm, 448 pistes — Format SDLT1
General Information
Standards Content (Sample)
INTERNATIONAL ISO/IEC
STANDARD 22051
First edition
2002-10-01
Information technology — Data interchange
on 12,7 mm, 448-track magnetic tape
cartridges — SDLT1 format
Technologies de l'information — Échange de données sur cartouche à
bande magnétique 12,7 mm, 448 pistes — Format SDLT1
Reference number
©
ISO/IEC 2002
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not
be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this
file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this
area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters
were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event
that a problem relating to it is found, please inform the Central Secretariat at the address given below.
© ISO/IEC 2002
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's member body
in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.ch
Web www.iso.ch
Printed in Switzerland
© ISO/IEC 2002 – All rights reserved
ii
Contents
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 Terms and definitions 1
4.1 back surface 1
4.2 Beginning-Of-Tape marker (BOT) 1
4.3 block 2
4.4 byte 2
4.5 cartridge 2
4.6 Cyclic Redundancy Check (CRC) character 2
4.7 Error-Detecting Code (EDC) 2
4.8 End-Of-Tape marker (EOT) 2
4.9 Entity 2
4.10 Error-Correcting Code (ECC) 2
4.11 Envelope 2
4.12 Envelope size 2
4.13 flux transition position 2
4.14 flux transition spacing 2
4.15 logical track 2
4.16 magnetic tape 2
4.17 Master Standard Reference Tape 2
4.18 object 2
4.19 page 2
4.20 recording density 2
4.21 physical track 2
4.22 Record 3
4.23 Reference Edge 3
4.24 Reference Field 3
4.25 Secondary Standard Reference Tape 3
4.26 Standard Reference Amplitude (SRA) 3
4.27 Standard Reference Current 3
4.28 Test Recording Current 3
4.29 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 4
6.1 Cartridge and tape testing environment 4
6.2 Cartridge operating environment 4
6.3 Cartridge storage environment 4
6.4 Safety 4
6.5 Flammability 4
6.6 Transportation 4
© ISO/IEC 2002 – All rights reserved
iii
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 Tape width 5
7.4 Tape thickness 5
7.5 Discontinuity 5
7.6 Longitudinal curvature 5
7.6.1 Requirements 5
7.6.2 Procedure 5
7.7 Out-of-Plane distortions 5
7.8 Cupping 5
7.9 Roughness of the coating surfaces 6
7.9.1 Roughness of the back coating surface 6
7.9.2 Roughness of the magnetic coating surface 6
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 8
7.13.1 Requirement 8
7.13.2 Procedure 8
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 Light transmittance of the tape and the leader 9
7.18 Abrasivity 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 9
7.19.3 Procedure for the measurement of the friction between the magnetic surface or the back surface and calcium
titanate ceramic 10
7.20 Servo 10
7.20.1 Servo Bands 10
7.20.2 Servo Tracks 11
7.20.3 Signal 11
7.20.4 Signal-to Noise Ratio 11
7.20.5 Missing servo mark 11
8 Magnetic recording characteristics 12
© ISO/IEC 2002 – All rights reserved
iv
8.1 Typical Field 13
8.2 Signal amplitude 13
8.3 Resolution 13
8.4 Overwrite 13
8.4.1 Requirement 13
9 Tape quality 13
9.1 Missing pulses 13
9.1.1 Requirement 13
9.2 Missing pulse zone 13
9.2.1 Requirement 13
9.3 Tape durability 13
Section 3 - Mechanical specifications of the tape cartridge 14
10 General 14
10.1 Bottom side and right side 14
10.2 Back side and left side 15
10.3 Tape reel 16
10.4 Tape leader 17
10.5 Front side 18
10.6 Operation of the cartridge 18
10.7 Tape winding 19
10.8 Moment of inertia 19
10.9 Material 19
Section 4 - Requirements for an interchanged tape 29
11 Tape format 29
11.1 Reference Edge 29
11.2 Direction of recording 29
11.3 Tape layout 29
11.3.1 Data Area 29
11.3.2 Forward Alignment and Directory Area 31
11.3.3 Reverse Alignment Area at EOT 32
12 Data format 33
12.1 Record 33
12.2 Data Bytes 33
12.3 Data Field 33
12.3.1 Pages 34
12.3.2 Pad Bytes 34
12.3.3 Page layout 34
12.3.4 MAP entries 34
12.3.5 EDC 35
12.4 Data Blocks 35
12.4.1 Control Field 1 (CF1) 36
12.4.2 Control Field 2 (CF2) 37
12.4.3 CRC 39
13 Method of recording 39
13.1 Physical recording density 40
13.2 Channel bit cell length 40
© ISO/IEC 2002 – All rights reserved
v
13.2.1 Average Channel bit cell length 40
13.2.2 Long-term average Channel bit cell length 40
13.2.3 Short-term average Channel bit cell length 40
13.3 Read signal amplitude 40
13.4 Channel skew 40
14 Block Recording Format 41
14.1 Scrambler 41
14.2 Modulation 41
14.2.1 Modulation process 41
14.2.2 Modulated Data Group 42
14.3 Precoder 42
14.4 Recording Data Block 43
14.4.1 Preamble 43
14.4.2 Sync 43
15 Types and Use of Blocks 43
15.1 Types of Blocks 43
15.2 Use of blocks 43
15.2.1 Track ID Start Blocks 43
15.2.2 End of Track Blocks (EOTR) 44
15.2.3 End of Data of Data Blocks (EOD) 44
15.2.4 ECC Blocks 44
15.2.5 Track ID End Blocks 44
16 Format of Entities 44
17 Format of Envelopes 44
18 Error handling 44
Annexes
A - Measurement of light transmittance 45
B - Procedure for the measurement of abrasivity 48
C - Generation of the Data Block CRCs 50
D - Generation of page CRCs 51
E - ECC generation 52
F - Allocation of Physical Tracks to Logical Tracks 55
G - Recommendations for transportation 56
H - Inhibitor tape 57
J - Recommendations on tape durability 58
K - Handling guidelines 59
© ISO/IEC 2002 – All rights reserved
vi
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. In the
field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
The main task of the joint technical committee is to prepare International Standards. 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 casting a 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.
ISO/IEC 22051 was prepared by ECMA (as ECMA-320) 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 to F form a normative part of this International Standard. Annexes G to K are for information only.
© ISO/IEC 2002 – All rights reserved
vii
INTERNATIONAL STANDARD ISO/IEC 22051:2002(E)
Information technology — Data interchange on 12,7 mm, 448-track
magnetic tape cartridges — SDLT1 format
Section 1 - General
1 Scope
This International Standard specifies the physical and magnetic characteristics of a 12,7 mm wide, 448-track magnetic tape
cartridge, to enable physical interchangeability of such cartridges between drives. It also specifies the quality of the recorded
signals, a format - called Super Digital Linear Tape 1 (SDLT 1) - and a recording method, thereby allowing data interchange
between drives. Together with a labelling standard, for instance ISO 1001 for Magnetic Tape Labelling, it allows full data
interchange by means of such magnetic tape cartridges.
2 Conformance
2.1 Magnetic tape cartridges
A magnetic tape cartridge shall be in conformance with this International Standard if it satisfies all mandatory requirements of
this International Standard. The tape requirements shall be satisfied throughout the extent of the tape.
2.2 Generating systems
A system generating a magnetic tape cartridge for interchange shall be in conformance with this International Standard if all
the recordings that it makes on a tape according to 2.1 meet the mandatory requirements of this International Standard.
In addition, a claim of conformance shall state
− whether or not one, or more registered algorithm(s) are implemented within the system,
− the registered identification number(s) of the implemented compression algorithm(s).
2.3 Receiving systems
A system receiving a magnetic tape cartridge for interchange shall be in conformance with this International Standard if it is
able to handle any recording made on a tape according to 2.1.
In addition, a claim of conformance shall state
− whether or not one, or more de-compression algorithm(s) are implemented within the system, and are able to be applied to
de-compress data prior to making such data available to the host,
− the registered identification number(s) of the implemented compression algorithm(s).
3 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this
International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not
apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of
applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the
normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards.
ISO 1001:1986, Information processing — File structure and labelling of magnetic tapes for information interchange
ISO 1302:2002, Geometrical Product Specifications (GPS) — Indication of surface texture in technical product documentation
ISO/IEC 11576:1994, Information technology — Procedure for the registration of algorithms for the lossless compression of
data
4 Terms and definitions
For the purpose of this International Standard, the following terms and definitions apply.
4.1 back surface
The surface of the tape opposite the magnetic coating which is used to record data.
4.2 Beginning-Of-Tape marker (BOT)
A hole punched on the centreline of the tape towards the end nearest to the leader.
© ISO/IEC 2002 – All rights reserved
4.3 block
A set of contiguous bytes recorded on a physical track and considered as a unit.
4.4 byte
An ordered set of bits acted upon as a unit.
NOTE - In this International Standard, all bytes are 8-bit bytes.
4.5 cartridge
A case containing a single supply reel of 12,7 mm wide magnetic tape with a leader attached at the outer end.
4.6 Cyclic Redundancy Check (CRC) character
A 64-bit character, generated by a mathematical computation, used for error detection.
4.7 Error-Detecting Code (EDC)
A mathematical computation yielding check bytes used for error detection.
4.8 End-Of-Tape marker (EOT)
A hole punched on the centreline of the tape towards the end farthest from the leader.
4.9 Entity
A group of twenty blocks treated as a logical unit.
4.10 Error-Correcting Code (ECC)
A mathematical computation yielding check bytes used for the correction of errors detected by the CRC and the EDC.
4.11 Envelope
A group of Entities.
4.12 Envelope size
The number of Entities in an Envelope.
4.13 flux transition position
The point that exhibits the maximum free-space flux density normal to the tape surface.
4.14 flux transition spacing
The distance on the magnetic tape between successive flux transitions.
4.15 logical track
A group of eight physical tracks that are written or read simultaneously.
4.16 magnetic tape
A tape that accepts and retains magnetic signals intended for input, output, and storage purposes on computers and associated
equipment.
4.17 Master Standard Reference Tape
A tape selected as the standard for Reference Field, signal amplitude, resolution, and overwrite characteristics.
NOTE - The Master Standard Reference Tape has been established by the Quantum Corporation.
4.18 object
A Record or a page of type Tape Mark.
4.19 page
A logical division of a block.
4.20 recording density
The number of recorded flux transitions per unit length of track.
4.21 physical track
A longitudinal area on the tape along which a series of magnetic signals can be recorded.
© ISO/IEC 2002 – All rights reserved
4.22 Record
User data processed as described in Clause 12.
4.23 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.
4.24 Reference Field
The Typical Field of the Master Standard Reference Tape.
4.25 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/SDLT1" 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, by agreement between ECMA and Quantum Corporation, this period may be changed to take into
account the demand for such Secondary Standard Reference Tapes.
4.26 Standard Reference Amplitude (SRA)
The Average Signal Amplitude from the Master Standard Reference Tape when it is recorded with the Test Recording Current
at 2 700 ftpmm.
4.27 Standard Reference Current
The current that produces the Reference Field.
4.28 Test Recording Current
The current that is 1,1 times the Standard Reference Current.
4.29 Typical Field
In the plot of the Average Signal Amplitude against the recording field at 2 700 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 represented by strings of digits 0 and 1 shown with the most significant bit
to the left.
5.2 Dimensions
The dimensions in figures 1 to 3 are nominal dimensions. Unless otherwise stated, all dimensions in the other figures are in
millimetres with a tolerance of ± 50 mm.
5.3 Names
The names of basic elements, e.g. specific fields, are written with a capital initial letter.
5.4 Acronyms
BOT Beginning of Tape
© ISO/IEC 2002 – All rights reserved
CAF Coarse Alignment Field
CF1 Control Field 1
CF2 Control Field 2
CRC Cyclic Redundancy Check (character)
CT1 Calibration Track 1
CT2 Calibration Track 2
FAF1 Fine Alignment Field 1
FAF2 Fine Alignment Field 2
ECC Error-Correcting Code
EDC Error-Detecting Code
EOD End of Data
EOT End of Tape
EOTR End of Track
SRA Standard Reference Amplitude
6 Environment and safety
Unless otherwise stated, the conditions specified below refer to the ambient conditions in the test or computer room and not to
those within the tape drive.
6.1 Cartridge and tape testing environment
Unless otherwise stated, tests and measurements made on the cartridge and tape to check the requirements of this International
Standard shall be carried out under the following conditions:
− temperature: 23 °C ± 2 °C
− relative humidity: 40 % to 60 %
− conditioning before testing: 24 h min.
6.2 Cartridge operating environment
Cartridges used for data interchange shall be capable of operating under the following conditions:
− temperature: 10 °C to 40 °C
− relative humidity: 20 % to 80 %
− wet bulb temperature: 26 °C max.
NOTE - Localised tape temperatures in excess of 49 °C may cause tape damage.
If during storage and/or transportation a cartridge has been exposed to conditions outside the above values, it shall be
conditioned before use by exposure to the operating environment for a time equal to, or greater than, the time away from the
operating environment up to a maximum of 24 h. There shall be no deposit of moisture on or in the cartridge.
6.3 Cartridge storage environment
Cartridges shall be stored under the following conditions:
− temperature: 16 °C to 32 °C
− relative humidity: 20 % to 80 %
− wet bulb temperature: 26 °C max.
The stray magnetic field at any point on the tape shall not exceed 4000 A/m. There shall be no deposit of moisture on or in the
cartridge.
6.4 Safety
The cartridge and its components shall satisfy the requirements of IEC 60950 when used in the intended manner or in any
foreseeable use in an information processing system.
6.5 Flammability
The cartridge and its components shall be made from materials which, if ignited from a match flame and when so ignited, do
not continue to burn in a still carbon dioxide atmosphere.
6.6 Transportation
This International Standard does not specify parameters for the environment in which cartridges should be transported. Annex
G gives some recommendations for transportation.
© ISO/IEC 2002 – All rights reserved
Section 2 - Requirements for the unrecorded tape
The measurements specified in Section 2 shall be performed on an unrecorded tape with servo marks
(See 7.20) on the back surface.
7 Mechanical and electrical requirements
7.1 Material
The tape shall consist of a base material (oriented polyethylene terephthalate film or its equivalent) coated on one surface with
a strong yet flexible layer of ferromagnetic material dispersed in a suitable binder. The back surface of the tape shall be coated
with a non-ferromagnetic conductive coating.
7.2 Tape length
The length of the tape from the leader splice to the hub shall be 558 m ± 1 m.
7.3 Tape width
The width of the tape shall be 12,649 mm ± 0,010 mm.
The width shall be measured across the tape from edge to edge when the tape is under a tension of less than 0,28 N.
7.4 Tape thickness
The total thickness of the magnetic tape at any point shall be between 8,20 µm and 9,30 µm.
7.5 Discontinuity
There shall be no discontinuities in the tape between the BOT and EOT such as those produced by tape splicing or
perforations.
7.6 Longitudinal curvature
The longitudinal curvature is measured as the departure of the Reference Edge of the tape from a straight line along the
longitudinal dimension of the tape in the plane of the tape surface.
7.6.1 Requirements
Any deviation of the Reference Edge from a straight line shall be continuous and shall not exceed 0,076 mm within any 229
mm length of tape.
7.6.2 Procedure
i. Measure at a tension of 1,39 N ± 0,28 N in a test fixture equipped with two guides spaced at 229 mm.
ii. Spring-load the two guides to position the Reference Edge of the tape against two edge control surfaces.
iii. Measure the maximum deviation of the Reference Edge of the tape from the line drawn between the two control surfaces.
7.7 Out-of-Plane distortions
All visual evidence of out-of-plane distortion shall be removed when the tape is subjected to a uniform tension of 0,6 N. Out-
of-plane distortions are local deformations which cause portions of the tape to deviate from the plane of the surface of the tape.
Out-of-plane distortions are most readily observed when the tape is lying on a flat surface under no tension.
7.8 Cupping
The departure across the width of the tape from a flat surface shall not exceed 2,54 mm.
Procedure
i. Cut a 1,0 m ± 0,1 m length of tape. Condition it for a minimum of 3 h in the test environment by hanging it so that both
surfaces are freely exposed to the test environment.
ii. From the centre portion of the conditioned tape cut a test piece of approximately 25 mm length. Stand the test piece on its
end in a cylinder that is at least 25 mm high with an inside diameter of 13,0 mm ± 0,2 mm.
iii. With the cylinder standing on an optical comparator measure the cupping by aligning the edges of the test piece to the
reticle and determining the distance from the aligned edges to the corresponding surface of the test piece at its centre.
© ISO/IEC 2002 – All rights reserved
7.9 Roughness of the coating surfaces
7.9.1 Roughness of the back coating surface
The back coating surface shall have an arithmetic average roughness R between 0,003 µm and 0,027 µm (ISO 1302:N 2).
ab
This measurement shall be made using a contacting stylus of radius 12,5 µm with a 20 mg load, and a 254 µm cut-off range.
7.9.2 Roughness of the magnetic coating surface
The magnetic coating surface shall have an arithmetic average roughness R between 0,003 µm and 0,008 µm (ISO 1302:
am
N 3). The set up for this measurement shall be identical with that of 7.9.1.
7.10 Coating adhesion
The force required to peel any part of the coating from the tape base material shall not be less than 0,016 N.
Procedure
i. Take a test piece of the tape approximately 380 mm long and scribe a line through the recording coating across the width
of the tape 125 mm from one end.
ii. Using a double-sided pressure sensitive tape, attach the full width of the test piece to a smooth metal plate, with the
magnetic coating (recording surface) facing the plate, as shown in figure 1.
iii. Fold the test piece over 180°, adjacent to, and parallel with, the scribed line. Attach the metal plate and the free end of the
test piece to the jaws of a universal testing machine and set the speed of the jaw separation to 254 mm per min.
iv. Note the force at which any part of the coating first separates from the base material. If this is less than 0,016 N, the tape
has failed the test. If the test piece peels away from the double-sided pressure sensitive tape before the force 0,010 N, an
alternative type of double-sided pressure sensitive tape shall be used.
v. Repeat i) to iv) for the back coating.
Recording surface Scribed line
125 mm Pressure-sensitive tape
93-0120-A
Figure 1 - Measurement of coating adhesion
7.11 Layer-to-layer adhesion
Layer-to-layer adhesion refers to the tendency of a layer, when held in close proximity to the adjacent layer, to bond itself to an
adjacent layer so that free and smooth separation of the layers is difficult.
7.11.1 Requirements
There shall be no evidence of delamination or other damage to the coatings.
7.11.2 Procedure
i. Fasten one end of a 914 mm length of tape, magnetic coating inwards, to a horizontally mounted stainless steel cylinder
with a low cold-flow adhesive material.
ii. The dimensions of the cylinder shall be:
- diameter: 12,7 mm
- length: 102 mm
© ISO/IEC 2002 – All rights reserved
iii. Attach a mass of 1 000 g to the opposite end of the tape.
iv. Attach, 25,4 mm above the mass, a narrow strip of double-sided adhesive tape to the magnetic coating.
v. Slowly rotate the cylinder, so that the tape winds uniformly around it into a compact and even roll. The double-sided tape
secures the end and prevents unwinding when the mass is removed.
vi. The cylinder with the tape shall then be exposed to the following temperature and humidity cycle:
Time Temperature RH
16 h to 18 h 54 °C 85 %
4 h 54 °C 10 % or less
1 h to 2 h 21 °C 45 %
vii. Open the end of the roll and remove the double-sided adhesive tape.
viii. Release the free end of the tape.
ix. The outer one or two wraps shall spring loose without adhesion.
x. Hold the free end of the tape and allow the cylinder to fall, thereby unwinding the tape.
xi. The tape shall show no coating delamination, except for the 51 mm of tape nearest to the cylinder.
12,712,7
25,425,4
stripstrip
10001000 gg
94-0085-A94-0085-A
Figure 2 - Measurement of layer-to-layer adhesion
7.12 Modulus of elasticity
The modulus of elasticity (Young's modulus) is the ratio of stress to strain in the longitudinal direction.
7.12.1 Requirement
2 2
The modulus of elasticity shall be between 5 884 N/mm and 11 768 N/mm .
7.12.2 Procedure
i. Clamp a test piece of tape at least 180 mm in length with an initial 100 mm separation between the jaws of a universal
testing machine with a nominal crosshead speed of 3 mm per minute.
ii. Calculate the modulus using the chord of the curve between the force at 0 % and 1 % elongation.
© ISO/IEC 2002 – All rights reserved
12,712,7
7.13 Flexural rigidity
Flexural rigidity is the ability of the tape to resist bending in the longitudinal direction.
7.13.1 Requirement
-7 . -7 .
The flexural rigidity of the tape in the longitudinal direction shall be between 3 x 10 N mm and 9 x 10 N mm.
7.13.2 Procedure
Calculate the flexural rigidity D from the following equation:
Et
D = ()1 − υ
where:
E = modulus of elasticity obtained from 7.12
t = measured thickness of the tape in mm
ν = Poisson's ratio, set to 0,33
7.14 Tensile yield force
The tensile yield force required to elongate the test piece by 3 % shall not be less than 9,6 N.
7.14.1 Procedure
i. Use a static-weighing-constant-rate-of-grip separation tester capable of indicating the load with an accuracy of 2 %.
ii. Clamp a test piece of tape at least 178 mm long with an initial 102 mm separation between the jaws.
iii. Elongate the test piece at a rate of 51 mm per minute until a minimum elongation of 10 % is reached.
iv. The force required to produce an elongation of 3 % is the tensile yield force.
7.15 Electrical resistance
7.15.1 Requirement
The electrical resistance of any square area of the magnetic coating shall
− be greater than 10 Ω
− not exceed 50 x 10 Ω
The electrical resistance of any square area of the back coating shall
− not exceed 100 x 10 Ω
7.15.2 Procedure
i. Condition a test piece of tape in the test environment for 24 h.
ii. Position the test piece over two 24-carat gold-plated, semi-circular electrodes having a radius r = 25,4 mm and a finish of
at least N4, so that the recording surface is in contact with each electrode.
iii. Place these electrodes parallel to the ground and to each other at a distance d = 12,7 mm between their centres.
iv. Apply a force F of 1,62 N to each end of the test piece.
v. Apply a d.c. voltage of 100 V ± 10 V across the electrodes and measure the resulting current flow.
vi. From this value, determine the electrical resistance.
vii. Repeat for a total of 5 positions along the test piece and average the 5 resistance readings.
viii. For the back coating repeat the procedure with the back surface in contact with the electrodes.
© ISO/IEC 2002 – All rights reserved
r r
d
F F
93-0050-B
Figure 3 - Measurement of electrical resistance
When mounting the test piece, make sure that no conducting paths exist between the electrodes except that through the coating
under test.
NOTE - Particular attention should be given to keeping the surfaces clean.
7.16 Inhibitor tape
This International Standard does not specify parameters for assessing whether or not a tape is an inhibitor tape. However,
annex H gives further information on inhibitor tapes.
7.17 Light transmittance of the tape and the leader
The light transmittance of the tape and the leader shall be less than 5 % when measured according to the method specified in
annex A.
7.18 Abrasivity
Tape abrasivity is the tendency of the magnetic coating to wear the magnetic heads. When measured according to annex B, the
depth of the wear pattern in the specified ferrite bar shall be in the range 45 µm to 65 µm.
7.19 Coefficient of dynamic friction
The coefficient of dynamic friction shall be measured between the two surfaces of the tape and between them and calcium
titanate ceramic.
7.19.1 Requirements
Between the magnetic surface and the back surface : greater than 0,15
Between the magnetic surface and calcium titanate ceramic: 0,05 to 0,35
Between the back surface and calcium titanate ceramic: 0,05 to 0,20
7.19.2 Procedure for the measurement of the friction between the magnetic surface and the back surface
i. Wrap a first piece of tape around a calcium titanate ceramic cylinder (R = 0,05 µm) of diameter 25,4 mm and wrap it with
a
a total wrap angle of more than 90° with the back surface outwards.
ii. Wrap a second test piece, with the magnetic surface inwards, around the first test piece with a total wrap angle of 90°.
iii. Exert on one end of the outer test piece a force of F = 0,64 N.
iv. Attach the other end to a force gauge mounted on a linear slide.
v. Drive the slide at a speed of 1 mm/s, measure the force F required.
vi. Calculate the coefficient of dynamic friction g from the equation
1 F
γ = ln
φ F
1
where φ is the value of the wrap angle in radians.
© ISO/IEC 2002 – All rights reserved
7.19.3 Procedure for the measurement of the friction between the magnetic surface or the back surface and calcium
titanate ceramic
i. Wrap a piece of tape around a calcium titanate ceramic cylinder (R = 0,05 µm) of diameter 25,4 mm and wrap it with a
a
total wrap angle of 90° with the magnetic surface or the back surface, as appropriate, inwards.
ii. Exert on one end of the test piece a force of F = 0,64 N.
iii. Attach the other end to a force gauge mounted on a linear slide.
iv. Drive the slide at a speed of 1 mm/s, measure the force F required.
v. Calculate the coefficient of dynamic friction g from the equation
1 F
γ = ln
φ F
1
where φ is the value of the wrap angle in radians.
7.20 Servo
There shall be four servo bands of 17 servo tracks each. In each servo band these servo tracks shall be numbered 0 to 16. Each
servo track shall consist of servo marks recorded on the back side of the tape.
7.20.1 Servo Bands
The four servo bands recorded optically are designated as Servo Bands 0, 1, 2 and 3.
The centreline of Servo Track 0 of Servo Band 0 shall be at a distance of 2,43 mm ± 0,05 mm from the Reference Edge.
All Servo Bands shall be at a distance from their adjacent band(s) of 2,794 0 mm ± 0,018 0 when measured between the
centrelines of their respective Servo Track 0.
The cumulative error over the distance between Servo band 0 and Servo band 3 shall not exceed ± 0,0018 0 mm.
Figure 4 – Servo Bands
© ISO/IEC 2002 – All rights reserved
7.20.2 Servo Tracks
Each servo mark shall have a diameter of 12,0 µm ± 0,6 µm (See figure 5). They shall be at a distance of 141,0 µm ± 2,0 µm
from each other. The servo tracks shall be at a distance of 24 µm ± 1 µm from each other. In every second servo tracks the
servo marks shall be shifted by 70,5 µm ± 2,0 µm relative to those in the adjacent servo tracks. In each servo band the
cumulative tolerance over the distance between Servo Track 0 and Servo Track 16 shall not exceed 1 µm.
7.20.3 Signal
When the optical beam from an optical pickup is focussed on the back side of the moving tape, a series of pulses due to the
servo marks will be detected by the detector in the pickup. The modulation amplitude of the envelope divided by 2√2 is called
the signal. Measurements shall be performed with the incident beam from the spectrometer being perpendicular to the sample
surface within 10°. The wavelength of the light beam shall be in the range 250 nm to 1 100 nm.
7.20.4 Signal-to Noise Ratio
When the focussed beam traverses the tape over the non-marked zone, the reflected beam, as seen by the detector contains
noise. This noise signal shall be low-pass filtered at a cutoff of 4 kHz at the 3 dB point. The resultant RMS value is called
noise. The Signal-to-Noise Ratio shall be 24,5 dB ± 1,5 dB.
7.20.5 Missing servo mark
If the requirement for the Signal-to-Noise Ratio of 7.20.4 is not satisfied by three consecutive servo marks, this is considered to
be a missing servo mark. Over 100 consecutive servo marks there shall not be more than one missing servo mark. In the
consecutive 100 servo marks following such a missing servo mark, there shall not be any servo mark missing the requirement
of 7.20.4. If the tape presents 4 consecutive missing servo marks, it shall be rejected.
© ISO/IEC 2002 – All rights reserved
Figure 5 – Servo Tracks
8 Magnetic recording characteristics
The magnetic recording characteristics shall be defined by testing the requirements given below.
When performing the tests, the output or resultant signal shall be measured on the same relative pass for both a tape calibrated
to the Master Standard Reference Tape and the tape under test (read-while-write, or on equipment without read-while-write
capability, on the first forward-read-pass) on the same equipment.
The following conditions shall apply to the testing of all magnetic recording characteristics, unless otherwise noted.
− Tape condition: a.c. erased to 2 % or less of the Average Signal Amplitude
− Tape speed: 2,946 m/s ± 0,029 m/s
− Read track: within the written track
− Gap alignment: the read gap and the write gap to be parallel within 2,54 µm
− Write gap length: 1,00 µm ± 0,10 µm
− Write gap width: 23 µm ± 1 µm
− Read gap length: 0,376 3 µm ± 0,037 6 µm
© ISO/IEC 2002 – All rights reserved
− Read gap width: 14 µm ± 1 µm
− Tape tension: 0,83 N ± 0,01 N
− Recording current: Test Recording Current
− Physical recording
density 5 400 ftpmm ± 100 ftpmm
− Bandwidth of the read
amplifier 25,0 MHz
8.1 Typical Field
The Typical Field shall be between 85 % and 125 % of the Reference Field.
Traceability to the Reference Field is provided by the calibration factors supplied with each Secondary Standard Reference
Tape.
8.2 Signal amplitude
The Average Signal Amplitude shall be between 85 % and 115 % of the SRA.
Traceability to the SRA is provided by the calibration factors supplied with each Secondary Standard Reference Tape.
8.3 Resolution
The ratio of the Average Signal Amplitude at 2 700 ftpmm to that at 1 350 ftpmm shall be between 85 % and 125 % of the
same ratio for the Master Standard Reference Tape.
Traceability to the resolution of the Master Standard Reference Tape is provided by the calibration factors supplied with each
Secondary Standard Reference Tape.
8.4 Overwrite
Overwrite is the ratio of the residual signal of the Average Signal Amplitude recorded at 675 ftpmm after being overwritten at
5 400 ftpmm to the average signal amplitude of the 675 ftpmm signal.
8.4.1 Requirement
The overwrite for the tape shall be less than 110 % of the overwrite for the Master Standard Reference Tape.
Traceability to the overwrite of the Master Standard Reference Tape is provided by the calibration factors supplied with each
Secondary Standard Reference Tape.
9 Tape quality
9.1 Missing pulses
A missing pulse is a loss of read signal amplitude. When a base-to-peak read signal amplitude is less than 40% of half the
Average Signal Amplitude (See 8.2) for the preceding 25,4 mm of track, then these 25,4 mm constitute a missing pulse. This
measurement shall be carried out in steps of 25,4 mm of track.
9.1.1 Requirement
The average missing pulse rate shall be less than 20 missing pulses for any recorded length of track of 100 m.
9.2 Missing pulse zone
A missing pulse zone is a sequence of missing pulses exceeding 100 mm.
9.2.1 Requirement
Missing pulse zones shall not occur.
9.3 Tape durability
This International Standard does not specify parameters for assessing tape durability. However, a recommended procedure is
described in annex J.
© ISO/IEC 2002 – All rights reserved
Section 3 - Mechanical specifications of the tape cartridge
10 General
The tape cartridge shall consist of the following elements
− a case
− a reel for the magnetic tape
− a locking mechanism for the reel
− a magnetic tape wound on the hub of the reel
− a write-inhibit mechanism
− a tape leader
Dimensional characteristics are specified for those parameters deemed mandatory for interchange and compatible use of the
cartridge. Where there is freedom of design, only the functional characteristics of the elements described are indicated.
Where they are purely descriptive the dimensions are referred to three reference planes A, B, and C forming a geometrical
trihedral. Where the dimensions are related to the position of the cartridge in the drive, they may be referenced to another
surface of the cartridge.
In the enclosed drawings a typical implementation is represented.
Figure 6 shows a general view of the cartridge.
Figure 7 shows the reference planes A, B, C.
Figure 8 shows the bottom side of the cartridge.
Figure 9 shows the right side of the cartridge.
Figure 10 shows the back side of the cartridge with the door closed.
Figure 11 shows the left side of the cartridge.
Figure 12 shows a partial cross-section of the cartridge in locked position.
Figure 13 shows a partial cross-section of the cartridge in operating position.
Figure 14 shows the leader-to-tape connection.
Figure 15 shows the splice of the leader-to-tape connection.
Figure 16 shows a partial top view at a larger scale of the buckle of the leader.
Figure 17 shows a perspective view of the relative position of the leader buckle and the take up part before contact.
Figure 18 shows a partial, enlarged view of figure 17.
Figure 19 shows a perspective view of the relative position of the leader buckle and the take up part after contact.
Figure 20 shows the front side of the cartridge.
Figure 21 shows the position of the door lock on the back side of the cartridge.
Figure 22 shows the back side of the cartridge with the door open.
Figure 6 shows a general view of the cartridge. When it is not in the operating position, the reel of magnetic tape is locked and
cannot rotate. When loaded into the drive, the back side is introduced first and the front side remains visible during operation.
During the loading process the tape reel is unlocked and the position of the cartridge within the drive is fixed by elements of
the drive engaging with corresponding elements of the case.
The position of the case relative to the reference planes A, B and C is shown in figure 7. The top side lies in reference plane A,
the right side lies in reference plane B and the back side lies in reference plane C.
10.1 Bottom side and right side (Figures 8 and 9)
The overall dimensions of the cartridge shall be
l = 105,79 mm ± 0,20 mm
l = 105,41 mm ± 0,20 mm
l = 25,40 mm ± 0,25 mm
The bottom side shall have a window the dimensions and the position of which shall be defined by
l = 4,85 mm ± 0,05 mm
l = 6,25 mm ± 0,10 mm
l = 83,61 mm ±0,20 mm
l = 3,81 mm ± 0,05 mm
© ISO/IEC 2002 – All rights reserved
This window allows one of the fingers of the drive to penetrate into the case for partially unlocking the reel of tape (See 10.6).
A positioning hole on the bottom side and a guiding notch, followed by a positioning notch in the right side determine the
position of the cartridge in the drive.
The dimensions and the position of the positioning hole shall be defined by
l = 21,59 mm ± 0,10 mm
+ 0,13 mm
l = 4,45 mm
- 0,00 mm
l = 2,79 mm ± 0,05 mm
l = 44,58 mm ± 0,20 mm
The dimensions and the position of the positioning notch shall be defined by
l = 5,56 mm ± 0,10 mm
l = 33,60 mm ± 0,20 mm
l = 5,08 mm ± 0,10 mm
h = 9,02 mm ± 0,10 mm
a = 14° ± 30'
The dimensions and the position of the guiding notch shall be defined by
l = 8,59 mm ± 0,10 mm
l = 24,64 mm ± 0,10 mm
l = 1,50 mm ± 0,05 mm
a = 45° ± 30'
a = 17° ± 30'
The right side shall have an indicator connected to the manually operable write-inhibit switch described in 10.5. The
dimensions and the position of this indicator shall be defined by
l = 8,64 mm ± 0,10 mm
l = 5,08 mm ±0,10 mm
l = 86,11 mm ± 0,20 mm
l = 10,16 mm ± 0,10 mm
Writing is enabled when the surface of the indicator is substantially flush with the cartridge wall. When this surface is recessed
by at least 5,1 mm writing is inhibited. When a force of up to 1,0 N is exerted perpendicularly on the centre of the surface of
the indicator, it shall not recede by more than 0,5 mm from reference plane B.
10.2 Back side and left side (Figures 8 and 10 and 11)
The back side shall have a window the dimensions and position of which shall be
l = 8,76 mm ± 0,10 mm
l = 4,25 mm ± 0,10 mm
l = 4,45 mm ± 0,10 mm
l = 8,89 mm ± 0,10 mm
© ISO/IEC 2002 – All rights reserved
--
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.
Loading comments...