ISO/IEC 12248:1993

ISO/IEC
INTERNATIONAL
STANDARD
First edition
1993-12-15
Information technology - 3,81 mm wide
magnetic tape cartridge for information
interchange - Helical scan recording -
DATA/DAT-DC format using 60 m and
90 m length tapes
- Cartouche de bande magnetique de
Technologies de I’information
3,$1 mm de /arge pour Mchange d’information - Enregistrement par
Format DATA/DAT-DC utilisant des bandes
balayage en spirale -
de 60 m et 90 m de long
Reference number
ISO/IEC 12248: 1993(E)
ISOIIEC 12248: 1993 (E)
Page
Contents
1 Scope
2 Conformance
Magnetit tape cartridge
21 .
22 . Generating System
Receiving System
23 .
3 Normative references
Definitions
4.1 Absolute Frame Number (AFN)
algorithm
42 l
43 Area ID
4:4 Automatic Track Finding (ATF)
45 . Average Signal Amplitude
azimuth
4:7 back surface
48 . byte
49 cartridge
4’10 Channel Bit
4’11 Codeword
4’12 Data Format ID
4’13 End of Data (EOD)
End of Information (EOI)
4’14
4’15 End of Partition (EOP)
4’16 enti ty
4’17 Error Correcting Code (ECC)
4’18 flux transition Position
4’19 flux transition spacing
4’20 frame
4’21
group
4’22 e Logical Beginning of Tape (LBOT)
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
photocopying and microfilm, without Permission in writing from the publisher.
ISO/IEC Copyright Office l Case postale 56 l CH-121 1 Geneve 20 l Switzerland
Printed in Switzerland
ISO/IEC 12248: 1993 (E)
4.23 Logical End of Tape (LEOT)
4.24 magnetic tape 3
master reference
4.25 3
4.26 Master Standard Amplitude Calibration Tape 3
4.27 Master Standard Reference Tape
4.28 Optimum Recording Field 3
4.29 partition 3
4.30 partition reference 3
4.31 Physical Beginning of Tape (PBOT) 3
4.32 Physical End of Tape (PEOT) 3
4.33 physical recording density 3
4.34 pre-recording condition 3
4,35 processed record 3
4.36 processed record sequence 3
4.37 processing 3
4.38 record
4.39 Reference Recording Field 3
4.40 Secondary Standard Amplitude Calibration Tape 3
4.41 Secondary Standard Reference Tape 3
4.42 Separator Mark 3
4.43 Standard Referemce Amplitude 4
4.44 tape noise amplitude
4.45 Tape Reference Edge 4
4.46 track
5 Environment and safety 4
Testing environment
51 .
52 . Operating environment
53 . Storage environment
54 . Transportation
Safety
55 .
56 . Flammability
Section 2 - Requirements for the case
6 Dimensional and mechanical characteristics of the case
.
61 General
62 . Overall dimensions
63 . Loading grip
64 . Holding areas
. Notches of the lid
66 . Lid dimensions
67 . Optical detection of the beginning and end of tape
68 . Bottom side
6.8.1 Locking mechanism of the slider
6.8.2 Access holes
6.8.3 Recognition, sub-datum and write-inhibit holes
6.8.4 Datum holes
6.8.5 Access room for tape guides
6.8.6 Holes for accessing the hubs
. . .
ISO/IEC 12248: 1993 (E)
Internal structure of the lower half
6.8.7
6.8.8 Light path
6.8.9 Support areas
6.8.10 Datum areas
6.8.11 Relationship between support and datum areas and Reference Plane Z
69 Hubs
6’10 Leader and trailer attachment
6’11 Interface between the hubs and the drive spindles
6’12 Opening of the lid
Release of the hub locking mechanism
6’13
6’14 . Label areas
Section 3 - Requirements for the unrecorded tape
7 Mechanical, physical and dimensional characteristics of the tape
71 . Materials
72 . Tape length
7.2.1 Length of magnetic tape
Length of leader and trailer tapes
7.2.2
73 . Tape width
74 . Discontinuities -
Total thickness
75 .
76 . Longitudinal curvature
77 . Cupping
78 . Coating adhesion
79 Layer-to-layer adhesion
7’10 . Tensile Strength
7.10.1 Breaking Strength
7.10.2 Yield Strength
7.11 Residual elongation
7.12 Electrical resistance of coated surfaces
Light transmittance of tape
7.13
8 Magnetit recording characteristics
81 . Optimum recording field
. Signal amplitude
83 . Resolution
Overwri te
84 .
002 ftpmm
recording densities of 750,6 and 3
8.4.1 Physical
1 001 ftpmm
densities of 83,4 ftpmm and
8.4.2 Physical recording
85 . Ease of erasure
. Tape quality
8.6.1 Missing pulses
Missing pulse zone
8.6.2
87 . Signal-to-noise ratio (S/N) characteristic
iv
ISOIIEC 12248: 1993 (E)
Section 4 - Format
DATA/DAT-DC format
General
91 .
92 . Basic Groups
9.2.1 Basic Groups for Group Format 0
Basic Groups for Group Format 1
9.2.2
93 . Sub-groups
GI Sub-group
9.3.1
9.3.2 G2 Sub-group
G3 Sub-group
9.3.3
9.3.4 G4 Sub-group
Main Data Block
9.3.5
94 . Sub-Data area
9.4.1 Pack Item No. 1
Pack Item No. 2
9.4.2
9.4.3 Pack Item No. 3
Pack Item No. 4
9.4.4
9.4.5 Pack Item No. 5
9.4.6 Pack Item No. 6
Pack Item No. 7
9.4.7
9.4.8 Sub Data Block
Basic Group structure
95 l
9.51 User Data
System Data
9.5.2
9.5.3 Record ID list
Heuristic Recovery Data Area
9.5.4
10 Method of recording
Physical recording density
10.1
10.2 Long-Term average bit cell length
Short-Term average bit cell length
10.3
10.4 Rate of Change
10.5 Bit shift
Read Signal amplitude
10.6
10.7 Maximum recorded Levels
Track geometry
11.1 Track configuration
11.2 Average track pitch
11.3 Variations of the track pitch
Track width
11.4
11.5 Track angle
Track edge linearity
11.6
11.7 Track length
11.8 Ideal tape centreline
11.9 Azimuth angies
V
ISO/IEC 12248: 1993 (E)
12 Recording of blocks on the tape
12.1 Recorded Main Data Block
12.2 Recorded Sub Data Block
Margin Blocks, Preamble Blocks and Postamble Blocks
12.3
12.4 Spacer Blocks
Format of a track
13.1 Track capacity
Positioning accuracy
13.2
13.3 Tracking scheme
14 Group Formats
14.1 Group Format 0
14.2 Group Format 1
Extended Gap Frames
14.3
14.3.1 Extended Leading Gap Frames
Extended Trailing Gap Frames
14.3.2
14.4 Types of Groups
14.4.1 Normal Groups
14.4.2 Spare Groups _
14.4.3 Amble Groups
Header Groups
14.4.4
15 Magnetit tape layout
15.1 Load/Unload Area
15.2 Lead-in Area
15.2.1 Preamble
152.2 Header
15.2.3 Format Parameter Set
15.2.4 Master Reference
15.25 Postamble
15.3 Parti tion
15.3.1 Partition Preamble
Partition Reference
153.2
15.3.3 Partition Postamble
15.3.4 Partition Data
15.3.5 End of Partition (EOP)
15.3.6 Unused Area
15.4 EO1
Repeated Groups
15.5
15.6 Repeated Frames within a Normal Group
Relocation of Defec tive Groups
15.7
15.8 Appending
15.8.1 Seamless appending
15.8.2 Non-seamless appending
15.9 Overwrite
vi
ISO/IEC 12248: 1993 (E)
15.9.1 Overlapped track width 102
15.9.2 Non-overlapped track width
15.9.3 Rules for overwrite 102
Annexes
A - Measurement of the light transmittance of the prisms
B - Recognition holes
C - Means for opening the lid
D - Measurement of light transmittance of tape and leaders
E - Measurement of Signal-to-Noise Ratio 110
F - Method for determining the nominal and the maximum allowable recorded levels
G - Representation of g-bit bytes by 100bit Pattern
H - Measurement of bit shift
J - Recommendations for transportation
K - Method of measuring track edge linearity
L - Read-After-Write
M - Data allocation and C3 parity
vii
ISO/IEC 12248: 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 12248 was prepared by the European Computer
Manufacturers Association (ECMA) (as Standard ECMA- 171) and was adopted,
under a special “fast-track procedure”, by Joint Technical Committee ISO/IEC
JTC 1, Infomtation technology, in parallel with its approval by national bodies
of ISO and IEC.
Annexes A, D, E, F, G, H, K and M form an integral part of this International
Standard. Annexes B, C, J and L are for information only.
. . .
Vlll
ISO/IEC 12248: 1993 (E)
Introduction
ISO/IEC have produced a series of International Standards for cassettes and cartridges containing magnetic tapes of different
width and characteristics. Of these, the following relate to helical scan recording.
ISO/IEC 10777: 1991, 3,81 mm wide magnetic tape cartridge foR information interchange - Helical scan recording -
DDS format
ISO/IEC 113 19: 1993,8 mm wide magnetic tape cartridge for information interchange - Helical scan recording
ISOfIEC 11321: 1992, 3,81 mm wide magnetic tape cartridge for information interchange - Helical scan Recording -
DATAIDAT format
ISOfIEC 11557:1992, 3,81 mm wide magnetic tape cartridge for information interchange - Helical scan recording -
DDS-DC format using 60 m and 90 m length tapes, 2nd edition
ISOfIEC 12246: 1993, 8 mm wide magnetic tape cartridge, dual azimuth format for information interchange - Helical
scan recording
ISO/IEC 12247: 1993, 3,81 mm wide magnetic tape cartridge for information interchange - Helical scan recording -
DDS format using 60 m and 90 m length tapes
ix
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INTERNATIONAL STANDARD
Information technology - 3,81 mm wide magnetic tape cartridge for information
interchange - Helical scan recording - DATA/DAT-DC format using 60 m and
90 m length tapes
Section 1 - General
Scope
This International Standard specifies the physical and magnetic characteristics of a 3,81 mm wide magnetic tape
cartridge to enable interchangeability of such cartridges. It also specifies the quality of the recorded Signals, the
recorded format and the recording method, thereby allowing data interchange between drives by means of such
magnetic tape cartridges. The format used is known as DATA/DAT-DC.
This International Standard specifies two types of cartridges which, for the purpose of this International Standard, are
referred to as Type A and Type B.
For Type A, the magnetic tape has a nominal thickness of 13 um and a nominal length of up to 60,5 m.
For Type B, the magnetic tape has a nominal thickness of 9 um a length of up to 92,0 m.
Information interchange between Systems by means of this International Standard also requires the use, at a
minimum, of a labelling and file structure and an interchange code which are agreed upon by the interchange Parties.
It is not within the scope of this International Standard to specify the labelling and file structure, or the interchange
Code.
2 Conformance
2.1 Magnetit tape cartridge
A tape cartridge shall be in conformance with this International Standard if it meets all mandatory requirements
specified herein for either Type A or Type B. The tape requirements shall be satisfied throughout the extent of the
tape.
22 .
Generating System
A System generating a magnetic tape cartridge for interchange shall be entitled to Claim conformance to this
International Standard if all recordings on the tape meet the mandatory requirements of this International Standard. A
Claim of conformance shall state whether cartridges of Type A or Type B or both are supported.
23 . Receiving System
A System receiving a magnetic tape cartridge for interchange shall be entitled to Claim conformance with this
International Standard if it is able to handle any recording made on the tape according to this International Standard.
A Claim of conformance shall state whether cartridges of Type A or Type B or both are supported.
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 arc 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 valid International Standards.
ISO/R 527: 1966, Plastics - Determination of tensile pr0pertie.s
ISO/IEC 646: 1991, Information technology - ISO 7-bit coded Character set for information interchange.
ISO 1302: 1992, Technical drawings - Method of indicating surface texture.
ISOIIEC 12248: 1993 (E)
ISO/IEC 11576: 1993, 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.
41 . Absolute Frame Number (AFN): A sequence number allocated to, and recorded in, each frame.
4.2 algorithm: A set of rules for transforming the logical representation of data.
4.3 Area ID: An identifier for each area of the tape specifying the types of frame written therein.
4.4 Automatic Track Finding (ATF): A method by which tracking is achiev
...