ISO/IEC 12246:1993

Information technology — 8 mm wide magnetic tape cartridge dual azimuth format for information interchange — Helical scan recording

This International Standard specifies the physical and magnetic characteristics of an 8 mm wide magnetic tape cartridge to enable interchangeability of such cartridges. It also specifies the quality of the recorded signals, the format and the recording method, thus allowing, together with ISO 1001 for Magnetic Tape Labelling, full data interchange by means of such magnetic tape cartridges. It is based on ISO/IEC 11319, but uses Dual Azimuth Recording to allow the raw capacity to be doubled. The format supports variable length Logical Records, high speed search, and the use of a registered data compression algorithm.

Technologies de l'information — Cartouche de bande magnétique de 8 mm de large de format double azimut pour l'échange d'information — Enregistrement par balayage en spirale

La présente Norme internationale spécifie les caractéristiques physiques et magnétiques d'une cartouche à bande magnétique de 8 mm de large, dans le but de permettre l'interchangeabilité de telles cartouches. Elle spécifie également la qualité des signaux enregistrés, le format et la méthode d'enregistrement, permettant ainsi, avec l'ISO 1001 relative à l'étiquetage des bandes magnétiques, un échange total de données au moyen de telles cartouches à bande magnétique. La présente norme est basée sur l'ISO/CEI 11319, cartouche à bande magnétique de 8 mm de large pour échange d'information -- à enregistrement hélicoïdal --, mais utilisant un enregistrement «double azimut» qui permet de doubler la capacité brute. Le format autorise des enregistrements logiques à longueur variable, une recherche à haute vitesse, et l'utilisation d'un algorithme de compression de données enregistré.

General Information

• Status: Published
• Publication Date: 22-Dec-1993
• ICS: 35.220.23 - Cassettes and cartridges for magnetic tapes
• Technical Committee: ISO/IEC JTC 1/SC 23 - Digitally recorded media for information interchange and storage
• Drafting Committee: ISO/IEC JTC 1/SC 23 - Digitally recorded media for information interchange and storage
• Current Stage: 9093 - International Standard confirmed
• Completion Date: 21-Aug-2020

Standards Content (Sample)

INTERNATIONAL
ISO/IEC
STANDARD 12246
First edition
1993-12-15
Information technology - 8 mm wide
magnetic tape cartridge dual azimuth
format for information interchange -
Helical scan recording
Technologies de I’information - Cartouche de bande magnetique de
8 t~~rn de large de format double azimut pour Mchange
d’information - Enregistrement par balayage en spirale

ISO/IEC 12246: 1993 (E)
Contents
Page
Section 1 - General
1 scope
2 Conformance
3 Normative references
4 Definitions
41 . a.c. erase
42 0 algorithm
Average Signal Amplitude
43 .
. azimuth
45 . back surface
46 l bit cell
47 . byte
48 . cartridge
49 compressed data
4’10 Cyclic Redundancy Check (CRC) Character
4’11
Error Correcting Code (ECC)
4’12 flux transition Position
4’13 flux transition spacing
4’14 logical record
4’15 magnetic tape
4’16 Master Standard Reference Tape
4’17 Physical Beginning of Tape (PBOT)
4’18 Physical End of Tape (PEOT)
4’19 physical recording density
4’20 Secondary Reference Amplitude
4’21
Secondary Reference Field
4’22
. Secondary Standard Reference Tape
0 ISO/IEC 1993
All rights reserved. Unless otherwise specified, no part of this publication may be
reproduced or utilized in any form or by any means, electronie or mechanical, including

ISO/IEC 12246: 1993 (E)
4.23 Standard Reference Current
Tape Reference Edge
4.24
Test Recording Current
4.25
4.26 track
4.27 Typical Field
uncompressed data
4.28
5 Environment and safety
51 . Testing environment
52 . Operating environment
53 . Storage environment
Transportation
54 .
Safety
55 .
56 . Flammability
Section 2 - Cartridge
6 Dimensional and mechanical characteristics of the cartridge
General
61 .
Overall dimensions
62 .
63 . Holding areas
64 . Cartridge insertion
65 . Window
Loading grips
66 *
67 . Label areas
68 . Datum areas and datum holes
69 Support areas
6’10 Recognition holes .
Write-inhibit hole
6’11
6’12 Pre-positioning sufaces
6’13 Cartridge lid
6’14 Cartridge reel leck
Ree1 access holes
6’15
6’16 Interface between the reels and the drive spindles
6’17 Light path
6’18 Position of the tape in the case
6’19 Tape path zone
6’20 Tape access cavity
6’21 . Tape access cavity clearance requirements
Section 3 - Requirements for the unrecorded tape
7 Mechanical, physical and dimensional characteristics of the tape
71 . Materials
72 . Tape length
7.2.1 Magnetit tape
Leader and trailer tapes
7.2.2
7.2.3 Splicing tape
. . .
ISOIIEC 12246: 1993 (E)
73 Width
.
74 . Discontinuities
Thickness
75 .
Thickness of magnetic tape
7.5.1
7.5.2 Thickness of leader and trailer tape
76 . LongitudinaI curvature
77 . Cupping
Coating adhesion
78 l
79 Layer-to-layer adhesion
7110 Tensile strength
7.10.1 Breaking strength
7.10.2 Yield strength
Residual elongation
7.11
7.12 Electrical resistance of the surface
7.13 Tape winding
7.14 Light transmittance of tape
8 Magnetit recording performante
Test conditions
81 .
Typical Field
82 .
83 . Signal amplitude
Resolution
84 .
Narrow-band signal-to-noise ratio
85 .
8.51 Requirement
8.5.2 Procedure
Ease of erasure
86 .
87 . Tape quality
8.7.1 Missing pulses
8.7.2 Missing pulse zone
8.8 Inhibitor tape
Section 4 - Requirements for an interchanged tape
9 Format
GeneraI
91 .
Information Matrix
92 .
9.2.1 Loading of the Information Matrix
10 Method of recording
10.1 Physical recording density

ISO/IEC 12246: 1993 (E)
Long-term average bit cell length
10.1.1
10.1.2 Short-term average bit cell length
10.1.3 Rate of Change
10.2 Bit shift
10.3 Read Signal amplitudes
Amplitude of data Signals
10.3.1
Amplitude of servo Signals
10.3.2
10.4 Erasure
11 Track geometry
11.1 Track positions
11.2 Track pitch
11.2.1 Adjacent track pitch
11.2.2 Average track pitch
11.3 Track width
11.4 Track angle
11.5 Straightness of track edge
Azimuth
11.6
12 Format of a track
12.1 Charme1 Bit
12.2 Information Segment
12.2.1 Bit Synchronization Field
12.2.2 Information Segment Number
12.2.3 Information Segment field
Information Block
12.3
Physical track types
12.4
12.4.1 Tl and T2 track layouts
12.5 Search Field Zones
Search Field Data Zones
12.5.1
12.5.2 Search Field Zone Sequence of recording
12.6 Servo Zone
Servo Zone 1
12.6.1
Servo Zone 2
12.6.2
Zone 3
12.6.3 Sewo
12.7 Information Tracks
ISO/IEC 12246: 1993 (E)
12.7.1 Format Track
12.7.2 Data Track
12.7.3 Long Tape Mark Track
12.7.4 Gap Track
12.7.5 End of Data Track 49
13 Tape Mark
13.1 Long Tape Mark
13.2 Short Tape Mark
14 End of Data
15 ID Information 50
15.1 Physical Block ID 50
15.2 Logical Block ID
15.3 Logical Record ID
15.4 Block type 50
15.4.1 Data Block 51
15.4.2 Gap Block
15.4.3 Format Block
15.4.4 Long/Short Tape Mark Block
15.4.5 End of Data Block
16 Rewritten Information Blocks 53
17 Physical Tape Format 54
17.1 Initial Erased Area 54
17.2 Logical Beginning of Tape Area (LBOT Area) 54
17.3 Usable area of the tape
Annexes
A - Measurement of light transmittance of tape and leaders 55
B - Measurement of bit shift 58
C - Representation of 8-bit bytes by 10.bit Patterns
D - Recommendations for transportation 64
E - Inhibitor tape 65
Vi
I!SO/IEC 12246: 1993 (E)
Foreword
ISO (the International Organization for Standardization) and IEC (the Inter-
national 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 estab-
lished by the respective organization to deal with particular fields of technical
activity. ISO and IEC technical committees collaborate in fields of mutual inter-
est. 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. Draft International Standards adopted by
the joint technical committee are circulated to national bodies for voting. Publi-
cation as an International Standard requires approval by at least 75 % of the na-
tional bodies casting a vote.
International Standard ISO/IEC 12246 was prepared by the European Computer
Manufacturers Association (ECMA) (as Standard ECMA-169) and was adopted,
by Joint Technical Committee ISO/IEC
under a special “fast-track procedure”,
JTC 1, Information technology, in parallel with its approval by national bodies
of ISO and IEC.
Annexes A, B and C form an integral part of this International Standard. Annexes
D, E and F are for information only .
Vii
ISODEC 12246:1993 (E)
Introduction
ISO/IEC have produced a series of International Standards for cassettes and cartridges containing magnetic tapes of different
width and characteristics.
The fllst International Standards (e.g. ISO 3407, ISO 4057, ISO 8063, ISO 8462, ISO/IEC 9661, ISO/IEC 11559) dealt with
media designed for the digital recording of data for storage and processing in data processing Systems. Later, other magnetic
media, originally developed for audio and Video applications, have been considered for use in data processing applications for
stomge as well as for information interchange. The recording method known as helical scan recording, together with new
types of magnetic tapes, allows to achieve capacities of more than 1 gigabyte of user data. International Standards ISO/IEC
10777, ISO/IEC 11319, ISO/IEC 11321, ISO/IEC 11557, ISO/IEC 12247 and ISO/IEC 12248 deal with such magnetic tape
cartridges.
This International Standard is based on ISO/IEC 11319 with extensions and modifications which specify the additional
features of the Dual Azimuth format. The specifications of the tape, cartridge, recorded Signal, recording method and much
of the recorded format are identical with those in ISO/IEC 113 19.
It is not intended that this International Standard replace ISO/lEC 11319. Existing drives and cartridges which conform to
ISO/IEC 11319 will continue to do so and will not conform to this International Standard. Future drives and tapes which
conform to ISO/IEC 11319 may, in addition, conform to this International Standard, but only if they support those features
herein which are not in ISO/IEC 113 19.
. . .
VW
INTERNATIONAL STANDARD ISO/IEC 12246:1993 (E)
Information technology - 8 mm wide magnetic tape cartridge dual azimuth formst for
information interchange - Helical scan recording
Section 1 - General
1 Scope
This International Standard specifies the physical and magnetic characteristics of an 8 mm wide magnetic tape cartridge to
enable interchangeability of such cartridges. It also specifies the quality of the recorded Signals, the formst and the recording
method, thus allowing, together with ISO 1001 for Magnetit Tape Labelling, full data interchange by means of such
magnetic tape cartridges. It is based on ISO/IEC 11319, but uses Dual Azimuth Recording to allow the raw capacity to be
doubled. The format supports variable length Logical Records, high speed search, and the use of a registered data
compression algorithm.
2 Conformance
A magnetic tape cartridge conforms b this International Standard if it satisfies all mandatory requirements specified herein.
The tape requirements shall be satisfied throughout the extent of the tape.
3 Normative references
The following Standards coniiun provisions which, through reference in this text, constitute provisions of this International
Standard. At the time of publication, the editions indicated were valid. All Standards are subject to revision, and Parties to
agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent
editions of the Standards listed below. Members of IEC and ISO maintain registers of currently vaIid International Standards.
ISO/R 527: 1966, Plastics - Determination of tensiie properties.
ISO 1001: 1986, Information processing - File structure and labelling of magnetic tapes for information interchange.
ISO 1302: 1992, Technical drawings - Method of indicating surface texture.
ISO/IEC 11319: 1993, Information technology - 8 mm wide magnetic tape cartridge for information interchange - Helical
scan recording.
ISO/IEC 11576: 1993, Information technology - Procedure for the registration of algorithms for the lossless compression of
data.
IEC 950: 199 1, Safety of information technology equipment, including electrical business equipment.
4 Definitions
For the purposes of this International Standard, the following definitions apply.
4.1 a.c. erase: A process of erasure utilizing altemating magnetic Felds of decaying level.
4.2 algorithm: A set of rules for transforming the logical representation of data.
43 Average Signal Amplitude: The average peak-to-peak value of the Signal output of the read head measured over a
minimum of 1,40 mm of track, exclusive of missing pulses.

ISO/IEC 12246: 1993 (E)
4.4 azimuth: The angu1a.r deviation, in degrees of arc, of the recorded flux transitions on a track from the line normal to the
track centreline.
4.5 back surface: The surface of the tape opposite to the magnetic coating used to record data.
4.6 bit cell: A distance along the track allocated for the recording of a Channel Bit.
4.7 byte: An ordered set of bits acted upon as a unit.
4.8 cartridge: A case containing magnetic tape stored on twin reels.
4.9 compressed data: The representation of host-transmitted data after transformation by a data compression algorithm.
4.10 Cyclic Redundancy Check (CRC) Character: A Character used for error detection.
4.11 Error Correcting Code (ECC): A mathematical procedure yielding bytes used for the detection and correction of
errors.
4.12 flux transition positioo: That point which exhibits the maximum free-space flux density normal to the tape surface.
4.13 flux transition spacing: The distance along a track between successive flux transitions.
4.14 logical record: Related data, from the host, treated as a unit of information.
4.15 magnetic tape: A tape that accepts and retains magnetic Signals intended for input, output, and storage of data for
information processing.
4.16 Master Standard Reference Tape: A tape selected as the Standard for amplitude, Typical Field and Resolution.
NOTE - The Master Standard Reference Tape has txxn established by the SONY Corporation.
4.17 Physical Beginning of Tape (PBOT): The transition from the tape leader to the opaque area of the splice by which the
translucent leader tape is joined to the magnetic tape.
4.18 Physical End of Tape (PEOT): The transition from the opaque area of the splice to the translucent trailer tape.
4.19 physical recording density: The number of recorded flux transitions per unit length of track, expressed in flux
transitions per millimetre (ftpmm).
4.20 Secondary Reference Amplitude: The Average Signal Amplitude from the Secondary Standard Reference Tape when
it is recorded with the Test Recording Current at 2 236 ftpmm.
4.21 Secondary Reference Field: The Typical Field of the Secondary Standard Reference Tape.
4.22 Secondary Standard Reference Tape: A tape the Performance of which is known and stated in relation to that of the
Master Standard Reference Tape.
NOTE - Secondary Standani Refemce Tapes tan tx ordeml under the Part Number RSE-5001, until the year 2001, from the Sony Corporation, Magnetit Pmduct
Group, Data Media Sales Division, 6-7-35 Kitashinagawa, Shinagawa-ku, TOKYO 141, Japan. It is intended that these be used for calibrating Tertiw Refemce
Tapes for use in routine calibration.
4.23 Standard Reference Current: The current that produces the Secondary Reference Field.
4.24 Tape Reference Edge: The lower edge of the tape when the magnetic coati ng is facing the observer and the
SUPPlY
right.
reel i s to the observer’s
4.25 Test Recording Current: The current that is 1,5 times th
...