ISO/IEC 13923:1996
(Main)Information technology — 3,81 mm wide magnetic tape cartridge for information interchange — Helical scan recording — DDS-2 format using 120 m length tape
Information technology — 3,81 mm wide magnetic tape cartridge for information interchange — Helical scan recording — DDS-2 format using 120 m length tape
Specifies the physical and magnetic characteristics of a 3,81 mm wide magnetic tape cartridge to enable physical interchangeability of such cartridges between drives and specifies the quality of the recorded signals, the recording method and the recorded format.
Technologies de l'information — Cartouche de bande magnétique de 3,81 mm de large pour l'échange d'information — Enregistrement par balayage en spirale — Format DDS-2 utilisant une bande de 120 m de long
General Information
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Standards Content (Sample)
ISO/IEC
INTERNATIONAL
13923
STANDARD
First edition
1996-l 2-15
Information technology - 3,81 mm wide
magnetic tape cartridge for information
Helical scan recording -
interchange -
DDS-2 format using 120 m length tape
Cartouche de bande magn&lque de
Technologies de /‘information -
3,81 mm de large pour I’khange d’information - Enregistrement par
balayage en spirale - Format DDS-2 utilkant une bande de 120 m de long
Reference number
GO/I EC 13923: 1996(E)
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ISO/IEC 13923:1996(E)
Contents
Page
Section 1 - General
1
1 Scope
1
Conformance
2
1
Magnetic tape cartridge
2.1
1
2.2 Generating system
2
2.3 Receiving system
2
3 Normative References
2
4 Definitions
2
4.1 Absolute Frame Number (AFN)
2
4.2 a.c. erase
2
Access Point
4.3
2
4.4 Algorithm
2
4.5 Area ID
2
Automatic Track Finding (ATF)
4.6
3
4.7 Average Signal Amplitude
3
4.8 azimuth
3
back surface
4.9
3
4.10 byte
3
4.11 cartridge
3
Channel Bit
4.12
3
4.13 Codeword
3
4.14 Data Format ID
3
Early Warning Point (EWP)
4.15
3
4.16 End of Data (EOD)
3
Entity
4.17
3
4.18 Error Correcting Code (ECC)
3
4.19 flux transition position
3
flux transition spacing
4.20
3
4.21 Frame
3
4.22 Housekeeping Frame
3
4.23 Logical Beginning of Tape (LBOT)
3
4.24 magnetic tape
0 ISODEC 1996
All tights 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 the publisher.
ISO/IEC Copyright Office l Case postale 56 l CH- P 2 11 @en&e 20 l Switzerland
Printed in Switzerland
ii
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ISOAEC 13923:1996(E)
0 ISO/IEC
3
4.25 Master Standard Amplitude Calibration Tape
4
Master Standard Reference Tape
4.26
4
4.27 Optimum Recording Field
4
4.28 Partition Boundary
4
4.29 Physical Beginning of Tape (PBOT)
4
4.30 Physical End of Tape (PEOT)
4
physical recording density
4.31
4
4.32 pre-recording condition
4
4.33 processing
4
4.34 processed data
4
4.35 Processed Record
4
4.36 Processed Record Sequence
4
4.37 record
4
Reference Recording Field
4.38
4
4.39 reprocessing
4
4.40 Secondary Standard Amplitude Calibration Tape
4
4.41 Secondary Standard Reference Tape
4
Separator Mark
4.42
4
4.43 Standard Reference Amplitude
5
4.44 Tape Reference Edge
5
Test Recording Current
4.45
5
4.46 track
5
4.47 unprocessed data
5
4.48 Unprocessed Record
5
Virtual End of Tape (VEOT)
4.49
5
5 Environment and safe ty
5.1 Testing environment
5.2 Operati ng en vironment
Storage environment
5.3
Transportation
5.4
5.5 Safety
5.6 Flammability
Section 2 - Requirements for the case
7
Dimensional and mechanical characteristics of the case
6
General
61
6:2 Overall dimensions
6.3 Loading grip
6.4 Holding areas
Notches of the lid
6.5
6.6 Lid dimensions
6.7 Optical detection of the beginning and end of tape
Bottom side
68 .
10
6.8.1 Locking mechanism of the slider
10
6.8.2 Access holes
10
6.8.3 Recognition, write-inhibit and sub-datums holes
12
6.8.4 Datum holes
12
6.8.5 Access room for tape guides
12
6.8.6 Holes for accessing the hubs
13
6.8.7 Internal structure of the lower half
14
6.8.8 Light path
14
6.8.9 Support Areas
14
6.8.10 Datum Areas
14
6.8.11 Relationship between Support and Datum Areas and Reference Plane 2
..O
111
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0 ISO/IEC
ISO/IEC 13923:1996(E)
14
6.9
Hubs
15
6.10 Attachment of leader and trailer tapes
15
6.11 Interface between the hubs and the drive spindles
15
6.12 Opening of the lid
15
6.13 Release of the hub locking mechanism
16
Label areas
6.14
16
6.15 Requirement for autoloaders
Section 3 - Requirements for the unrecorded tape
28
7 Mechanical, physical and dimensional characteristics of the tape
28
7.1 Materials
28
7.2 Tape length
28
7.2.1 Length of magnetic tape
28
7.2.2 Length of leader and trailer tapes
28
Length of splicing tapes
7.2.3
28
Tape width
7.3
28
7.3.1 Width of magnetic, leader and trailer tapes
28
Width and position of splicing tape
7.3.2
28
7.4 Discontinuities
29
Tape thickness
7.5
29
7.5.1 Thickness of magnetic tape
29
7.5.2 Thickness of leader and trailer tapes
29
7.5.3 Thickness of splicing tape
29
7.6 Longitudinal curvature
29
7.7 Cupping
29
Coating adhesion
7.8
30
7.9 Layer-to-layer adhesion
30
7.10 Tensile strength
30
7.10.1 Breaking strength
30
7.10.2 Yield strength
30
7.11 Residual elongation
31
7.12 Flexural rigidity
31
Electrical resistance of coated surfaces
7.13
32
Light transmittance of the tape
7.14
32
7.15 Media Recognition System (MRS)
33
8 Magnetic recording characteristics
34
81 . Optimum Recording Field
34
82 Signal Amplitude
34
Resolution
8:3
34
Overwrite
84 .
34
750,O ftpmm and 2 999,9 ftpmm
of
8.4.1 Physical recording densities
34
000,O ftpmm
of 83,3 ftpmm and 1
8.4.2 Physical recording densities
35
85 Ease of erasure
35
8:6 Tape quality
35
8.6.1 Missing pulses
35
Missing pulse zone
8.6.2
35
Signal-to-Noise Ratio (S/N) characteristic
8.7
IV
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ISO/IEC 13923:1996(E)
0 ISO/IEC
Section 4 - Requirements for an interchanged tape
36
9 Format
36
91 . General
36
Basic Groups
92 .
37
Entity
9.2.1
38
Group Information Table
9.2.2
40
9.2.3 Block Access Table (BAT)
43
93 . Sub-Groups
43
9.3.1 G 1 Sub-Group
44
9.3.2 G2 Sub-Group (randomizing)
44
G3 Sub-Group
9.3.3
46
9.3.4 G4 Sub-Group
50
9.3.5 Main Data Block
52
9.4 Sub-Data Area
52
9.4.1 Pack Item Number 1
53
9.4.2 Pack Item Number 2
53
Pack Item Number 3
9.4.3
55
9.4.4 Pack Item Number 4
56
9.4.5 Pack Item Number 5
57
Pack Item Number 6
9.4.6
57
9.4.7 Pack Item Number 7
58
9.4.8 Pack Item Number 8
59
9.4.9 Sub Data Block
62
10 Method of recording
62
10.1 Physical recording density
62
10.2 Long-term average bit cell length
62
Short-term average bit cell length
10.3
62
10.4 Rate of change
62
10.5 Bit shift
62
10.6 Read signal amplitude
62
10.7 Maximum recorded levels
62
11 Track geometry
62
11.1 Track configuration
63
Average track pitch
11.2
63
11.3 Variations of the track pitch
63
11.4 Track width
63
Track angle
11.5
63
11.6 Track edge linearity
63
11.7 Track length
64
Ideal tape centreline
11.8
64
11.9 Azimuth angles
64
Recording of blocks on the tape
12
64
12.1 Recorded Main Data Block
64
Recorded Sub Data Block
12.2
64
12.3 Margin Blocks, Preamble Blocks and Postamble Blocks
64
12.4 Spacer Blocks
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0 ISO/IEC
HSOIIEC 13923:1996(E)
64
Format of a track
13
64
13.1 Track capacity
65
13.2 Positioning accuracy
65
13.3 Tracking scheme
68
14 Layout of a Single Data Space tape
68
14.1 Device Area
68
14.2 Reference Area
68
14.3 Position Tolerance Band No. 1
69
System Area
14.4
69
14.4.1 System Preamble
69
System Log
14.4.2
69
14.4.3 System Postamble
69
14.4.4 Position Tolerance Band No. 2
69
14.4.5 Vendor Group Preamble
69
14.5 Data Area
69
Vendor Group
14.5.1
69
14.5.2 Recorded Data Group
70
14.5.3 ECC3
71
14.5.4 Multiple recorded instances
71
Repeated Frames
14.5.5
71
Appending and overwriting
14.5.6
73
EOD Area
14.6
73
Post-EOD Area
14.7
73
14.8 Early Warning Point - EWP
73
14.9 Initialization
73
15 Layout of partitioned tape
74
Overall magnetic tape layout
15.1
74
15.1.1 Device Area
74
Partition 1
15.1.2
75
Partition 0
15.1.3
75
15.2 Area ID
76
15.3 System Area Pack Items No. 3 and No. 4
76
15.4 Empty partitions
76
15.4.1 partition 1
Empty
76
partition 0
15.4.2
Empty
76
Initialization of partitioned tapes
15.5
76
16 Housekeeping Frames
76
16.1 Amble Frames
77
System Log Frames
16.2
77
Tape Management Frames
16.3
vi
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0 ISO/IEC ISO/IEC 13923:1996(E)
Annexes
A - Measurement of the light transmittance of the prisms
79
B - Recognition Holes 81
C - Means to open the lid 82
D - Measurement of light transmittance of tape and leaders
83
E - Measurement of Signal to Noise Ratio
86
F - Method for determinating the nominal and the maximum allowable recorded levels 87
G - Representation of g-bit bytes by lo-bit patterns 88
H - Measurement of bit shift 94
J - Recommendations for transportation
96
K - Method of measuring track edge linearity
97
L - Read-After-Write 98
M - Example of the content of a Basic Group No. 0 99
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ISOJIEC 13923:1996(E) 0 ISO/IEC
Foreword
IS0 (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the
specialized system for worldwide standardization. National Bodies that are members of IS0 or IEC participate in the
development of International Standards through technical committees established by the respective organization to deal with
particular fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with IS0
and IEC, also take part in the work.
In the field of information technology, IS0 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 casting a vote.
This International Standard was prepared by JISC (as Standard JIS X.6129-1993) with document support and contribution
from ECMA 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 IS0 and IEC.
Annexes A, D, E, F, G, H and K form an integral part of this International Standard. Annexes B, C, J, L and M are for
information only.
. . .
Vlll
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ISO/IEC 13923:1996(E)
0 ISO/IEC
Introduction
for cassettes and c -artridges containing magnetic tapes of different width and characteristics
Numerous International Standards
following rel ate to helical scan recording.
have been published. Of these, the
3,6I mm wide magnetic tape cartridge for information interchange -
ISO/IEC 10777: 1991 Information technology -
Helical Scan Recording - DDS format
ISO/IEC 11319:1993 Information technology - 8 mm wide magnetic tape cartridge for information interchange - Helical
scan recording
ISO/IEC 11321:1992 Information technology - 3,81 mm wide magnetic tape cartridge for information interchange -
Helical scan recording - DATMDAT format
ISO/IEC 11557: 1992 Information technology - 3,81 mm wide magnetic tape cartridge for information interchange -
Helical scan recording - DDS-DC format using 60 m and 90 m length tapes
ISO/IEC 12246: 1993 Information technology - 8 mm wide magnetic tape cartridge dual azimuth format for information
interchange- Helical scan recording
ISO/IEC 12247: 1993 Information technology - 3,8I mm wide magnetic tape cartridge for information interchange -
Helical scan recording - DDS format using 60 m and 90 m length tapes
ISO/IEC 12248: 1993 Information technology - 3,81 mm wide magnetic tape cartridge for information interchange -
Helical scan recording - DATMDAT-DC format using 60 m and 90 m length tapes
ISOLIEC 10777 defines a specification for data interchange using 3,81 mm wide magnetic tape cartridges, with the DDS
format.
A derivative International Standard ISO/IEC 11557 defines another data interchange specification for the same cartridges, but
with a recorded format, namely DDS-DC, which enables data to be compressed by the drive before being recorded.
This International Standard defines a specification, based on the features of both of these, which offers a further increase in
data capacity. The primary change to the recorded format is an increase in the track density by a factor of 1,5. This produces a
corresponding increase in data capacity for a cartridge of a given tape length. Such a track density, when recorded on a
cartridge tape whose tape length is 125 metres, will provide a storage capacity of 4 Gigabytes of uncompressed user data and
typically 8 to 16 Gigabytes of compressed user data.
The design philosophy is one of minimum change to the track format which is common to DDS and DDS-DC. This will aid
the development of drives that support this DDS-2 format by derivation from existing products. It will also ease the
development of drives that are able to support both previous formats as well as this format, thus providing the backwards
compatibility which the market demands. However, it is not a requirement for compliance to this International Standard that a
drive also reads and writes either the DDS format or the DDS-DC format. Nor is it a requirement for compliance to this
International Standard that a drive compresses data and writes it in entities on the tape, or that a drive decompresses data
contained within entities on the tape. All the recording on one cartridge will be at the same track density, either that of DDS
and DDS-DC, or that of DDS-2. The media coating and the track density are indicated by the combination of the states of the
Recognition Holes on the cartridge case.
This International Standard also includes the specifications of the Media Recognition System, namely a striped splicing tape.
ix
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INTERNATIONAL STANDARD 0 ISO/IEC ISO/IEC 13923: 1996(E)
Information technology - 341 mm wide magnetic tape cartridge for information
interchange - Helical scan recording - DDS-2 format using 120 m length tape
Section 1 - General
1 Scope
This International Standard specifies the physical and magnetic characteristics of a 3,81 mm wide magnetic tape cartridge to
enable physical interchangeability 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 magnetic tape
cartridges.
The recorded format, known as DDS-2, includes all the features of the DDS recorded format specified in ISO/IEC 12247 and
of the DDS-DC recorded format specified in ISO/IEC 11557. The principal difference between this recorded format and those
recorded formats is the use of a greater track density by this format.
Information interchange between systems utilising this International Standard also requires the use, as a minimum, of a
labelling specification, e.g. IS0 1001: 1986, Information processing - File structure and labelling of magnetic tapes for
information interchange, and an interchange code which shall be agreed upon by the interchange parties.
Under information interchange circumstances in which a processing algorithm is applied to the host data prior to recording on
the tape and a complementary reprocessing algorithm is applied after the data is read from the tape, agreement upon the
algorithms employed by the interchange parties is also required. It is outside the scope of this International Standard to specify
any of these.
Conformance
2
Magnetic tape cartridge
2.1
A tape cartridge shall be in conformance with this International Standard if it meets all the mandatory requirements specified
herein. The tape requirements shall be satisfied throughout the extent of the tape.
For each recorded Entity any algorithm used for Processing the data therein shall have been registered, and the registration
identification shall be included, when appropriate, in Byte No. 3 of the Entity Header.
A recorded tape shall be either a Single Data Space Tape or a Partitioned Tape.
2.2 Generating system
A system generating a magnetic tape cartridge for interchange shall be entitled to claim conformance with this International
Standard if all recordings on the tape meet the mandatory requirements of this International Standard, and if either or both
methods of appending and overwriting are implemented.
A claim of conformance shall state which of the following optional features are implemented and which are not
-
the performing of a Read-After-Write check and the recording of any necessary repeated frames;
-
the recording of multiple representations of the same Basic Group;
-
the generation of ECC3 Frames.
In addition a claim of conformance shall state
-
whether or not one, or more, registered algorithm(s) are implemented within the system and are able to process data
received from the host prior to collecting the data into Basic Groups, and
- the algorithm registration identification number(s) of the implemented algorithm(s).
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ISO/IEC 13923:1996(E) 0 ISO/IEC
2.3 Receiving system
A system receiving a magnetic tape cartridge for interchange shall be entitled to claim full conformance with this International
Standard if it is able to handle any recording made on the tape according to this International Standard. In particular it shall
-
Separator Marks from only one of these
be able to recognize repeated Frames and to available to the host, data and
Frames;
- be able to recognize multiple representations of the same Basic Group, and to make available to the host, data and
Separator Marks from only one of these representations;
- be able to recognize an ECC3 Frame, and ignore it if the system is not capable of using ECC3 check bytes in a process of
error correction;
-
be able to update the System Log(s) if the Write-inhibit Hole state so permits;
-
the algorithm registration
be able to recognize processed data within an Entity, identify the algorithm used, and make
number available to the host;
- be able to make processed data available to the host.
In addition a claim of conformance shall state
-
whether or not the system is capable of using ECC3 check bytes in a process of error correction;
-
whether or not one or more Reprocessing algorithm(s) are implemented within the system, and are able to be applied to
Processed Data prior to making such data available to the host;
-
algorithm is
the algorithm registration number(s) of the processing algorithm(s) for which a complementary Reprocessing
implemented.
3 Normative References
The following standards contain 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 indicated below. Members of IEC and IS0 maintain regesters of currently valid international
standards.
ISO/R 527: 1966, Plastics - Determination of tensile properties.
IS0 1302: 1992, Technical drawings - Method of indicating sueace texture.
ISO/IEC 11576: 1994, Information technology - Procedure for the registration of algorithms for the lossless
compression of data.
IEC 950 : 1991, Safety of information technology equipment including electrical business equipment.
4 Definitions
For the purposes of this International Standard, the following definitions apply.
Absolute Frame Number (AFN) : A sequence number, encoded in the Frame.
4.1
4.2 a.c. erase : A process of erasure utilising magnetic fields of decaying intensity.
4.3 Access Point : A point, at the start of a processed record sequence, at which the presentation of Codewords to a
reprocessing algorithm is required to start, regardless of whether the data of interest in a retrieval operation starts at
that point or at a subsequent point.
4.4 Algorithm : A set of rules for transforming the logical representation of data.
4.5 Area ID : An identifier defining the area of the tape and specifying the types of Frame written.
Automatic Track Finding (ATF) : The method by which tracking is achieved.
4.6
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ISO/IEC 13923: 1996(E)
0 ISO/IEC
4.7 Average Signal Amplitude : The average peak-to-peak value of the output signal from the read head at the
fundamental frequency of the specified physical recording density over a minimum of 7,8 mm of track, exclusive of
missing pulses.
4.8 azimuth : The angular deviation, in degrees, minutes and seconds of arc, made by the mean flux transition line with
the line normal to the centreline of the recorded track.
back surface : The surface of the tape opposite to the magnetic coating which is used to record data.
4.9
4.10 byte : An ordered set of bits acted upon as a unit.
4.11 cartridge : A case containing magnetic tape stored on twin hubs.
4.12 Channel bit : A bit after 8-10 transformation.
4.13 Codeword : A word which is generated by a processing algorithm. The number of bits in a Codeword is variable, and
is not defined by this International Standard.
4.14 Data Format ID : An identifier specifying which data format is being used on the tape.
Early Warning Point (EWP) : A point along the length of the tape at which warning is given of the approach, in the
4.15
forward direction of tape motion, of the partition boundary or of the Physical End of Tape.
4.16 End of Data (EOD) : The point on the tape at the end of the group which contains the last user data.
4.17 Entity : A unit of recorded data, comprising a Processed Record Sequence preceded by housekeeping information.
4.18 Error Correcting Code (ECC) : A mathematical computation yielding check bytes used for the detection and cor-
rection of errors.
4.19 flux transition position : That point which exhibits maximum free-space flux density normal to the tape surface.
4.20 flux transition spacing : The distance along a track between successive flux transitions.
4.21 Frame : A pair of adjacent tracks with azimuths of opposite polarity, in which the track with the positive azimuth
precedes that with the negative azimuth.
4.22 Housekeeping Frame : A Frame which contains no user data and which is identified as such by the values in the data
fields therein.
4.23 Logical Beginning of Tape (LBOT) : The point along the length of the tape where a recording of data for
interchange commences.
4.24 magnetic tape : A tape which will accept and retain the magnetic signals intended for input, output and storage
purposes on computers and associated equipment
4.25 Master Standard Amplitude Calibration Tape : A pre-recorded tape on which the standard signal amplitudes have
been recorded in the tracks of positive azimuth, 21 pm wide, recorded at a track pitch of 27,2 m, on an a.c. erased
tape.
Note 1 - The tape includes recordings made at 83,3 ftpmm, 333,3 ftpmm, 500 ftpmm, 1 000,O ftpmm and 1 499,9 ftpmm.
Note 2 - The Master Standard Amplitude Calibration Tape has been established by Reliability Centre for JZlectronic Components of
Japan (RCJ).
3
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0 ISO/IEC
ISO/IEC 13923:1996(E)
4.26 Master Standard Reference Tape : A tape selected as the standard for Reference Recording Field, Signal Ampli-
tude, Resolution, Overwrite and Signal-to-Noise Ratio.
Note 3 - The Master Standard Reference Tape has been established by RCJ.
: In the plot of Average Signal Amplitude against the recording field at the physical
4.27 Optimum Recording Field
recording density of 2 999,9 ftpmm, the field that causes the maximum Average Signal Amplitude.
: The point along the length of a magnetic tape at which partition 1 ends and partition 0
4.28 Partition Boundary
commences.
4.29 Physical Beginning of Tape (PBOT) : The point where the leader tape is joined to the magnetic tape.
Physical End of Tape (PEOT) : The point where the trailer tape is joined to the magnetic tape.
4.30
physical recording density : The number of recorded flux transitions per unit length of track, expressed in flux
4.31
transitions per millimetre (ftpmm).
4.32 pre-recording condition (see annex F) : The recording levels above which a tape intended for interchange shall not
previously have been recorded.
4.33 processing : The use of an algorithm to transform host data into Codewords.
4.34 processed data : A sequence of Codewords which results from the application of processing to data.
4.35 Processed Record : A sequence of Codewords which results from the application of processing to an Unprocessed
Record.
: A sequence of one or more Processed Records which starts on an &bit boundary and
4.36 Processed Record Sequence
ends on a subsequent &bit boundary.
record : Related data treated as a unit of information.
4.37
Reference Recording Field : The Optimum Recording Field of the Master Standard Reference Tape.
4.38
reprocessing : The use of an algorithm to transform Codewords into data as required by the host.
4.39
4.40 Secondary Standard Amplitude Calibration Tape : A tape pre-recorded as defined for the Master Standard
Amplitude Calibration Tape; the outputs are known and stated in relation to those of the Master Standard Amplitude
Calibration Tape.
Note 4 - Secondary Standard Amplitude Calibration Tapes can be ordered from RCJ, l-l- 12 Hachiman-cho, Higashikurume,
Tokyo 203, Japan, under Part Number JCM 6129 until the year 2005. It is intended that these be used for calibrating tertiary
reference tapes for use in routine calibration.
Secondary Standard Reference Tape : A tape the performance of which is known and stated in relation to that of the
4.41
Master Standard Reference Tape.
Note 5 - Secondary Standard Reference Tapes can be ordered from RCJ, 1- 1- 12 Hachiman-cho, Higashikurume, Toyko 203, Japan,
under Part Number JRM 6129 until the year 2005. It is intended that these be used for calibrating tertiary reference tapes for use in
routine calibration.
,
4e42 Separator Mark : A record containing no user data, which is used to separate data.
4.43 Standard Reference Amplitude : The Average Signal Amplitude from the tracks of positive azimuth of the Master
Standard Amplitude Calibration Tape at a specified physical recording density.
4
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ISO/IEC 13923: 1996(E)
0 ISO/IEC
4.44 Tape Reference Edge : The bottom edge of the tape when viewing the recording side of the tape, with the PEOT to
the observer’s right.
4.45 Test Recording Current : The current that produces the Reference Recording Field.
4.46 track : A diagonally positioned area on the tape along which a series of magnetic signals may be recorded.
4.47 unprocessed data : Data which has not been subjected to processing.
4.48 Unprocessed Record : A record of unprocessed data, comprising an integral number of bytes.
4.49 Virtual End of Tape (VEOT) : The point along the length of the magnetic tape within partition 1 which defines the
end of the part of partition 1 which is usable for recording data for interchange.
5 Environment and safety
Unless otherwise stated, the conditions specified below refer to the ambient conditions of the air immediately surrounding the
cartridge.
5.1 Testing environment
Unless otherwise stated tests and measurements made on the tape cartridge to check the requirements of this International
Standard shall be carried out under the following conditions:
temperature : 23 “C t 2 “C
relative humidity : 40 % to 60 %
conditioning period before testing : 24 h
5.2 Operating environment
Cartridges used for data interchange shall be capable of operating under the following conditions:
: 5 “C to 45 “C
temperature
relative humidity : 20 % to 80 %
: 26 “C max.
wet bulb temperature
There shall be no deposit of moisture on or in the cartridge.
Conditioning before operating:
If a cartridge has been exposed during storage and/or transportation to a condition outside the above values, before use the
cartridge shall be conditioned in the operating environment for a time at least equal to the period during which it has been out
of the operating environment, up to a maximum of 24 h.
Note 6 - Rapid variations of temperature should be avoided.
5.3 Storage environment
For long-term or archival storage of cartridges the following conditions shall be observed:
temperature : 5 “C to 32 “C
relative humidity : 20 % to 60 %
wet bulb temperature : 26 “C max.
The stray magnetic field at any point on the tape shall not exceed 4 000 A/m. There shall be no deposit of moisture on or in the
cartridge.
5.4 Transportation
Recommended limits for the environment to which a cartridge may be subjected during transportation, and the precautions to
be taken to minimize the possibility of damage, are provided in annex J.
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0 ISO/IEC
ISO/IEC 13923:1996(E)
5.5 Safety
The cartridge and its components shall satisfy the requirements of IEC 950.
56 . Flammability
The cartridge and its components shall be made from materials, which if ignited from a match flame, do not continue to burn
in a still carbon dioxide atmosphere.
6
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0 ISO/IEC ISO/IEC 13923:1996(E)
Section 2 - Requirements for the case
Dimensional and mechanical characteristics of the case
6
. General
61
The case of the cartridge shall comprise
-
an upper half,
-
a lower half,
-
a slider movably mounted on the lower half,
-
a lid pivotally mounted on the upper half.
In the drawings, using third angle projection, an embodiment of the cartridge is shown a
...
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