ISO/IEC 14251:1995

ISOJIEC
First edition
1995-08-01
Information technology - Data
interchange on 12,7 mm 36-track magnetic
tape cartridges
- khange de donnees SW cartouches de
Technologies de I’information
bande magn&ique de 12,7 mm, 36 pistes
Reference number
ISO/IEC 14251 :1995(E)
ISWIEC 14251 : 1995 (E)
Contents
Section 1 - General
1 Scope
2 Conformance
2.1 Magnetit tape cartridge
2.2 Generating System
2.3 Receiving System
3 References
4 Definitions
4.1 algorithm
4.2 algorithmically Processed Data
4.3 Beginning of Tape (BOT)
4.4 bvte
4.5 Cyclic Redundancy Check (CRC) Character
4.6 Data Records
4.6.1 Processed Data Record (PDR)
4.6.2 Host Data Record
4.6.3 Logical Data Record (LDR)
4.6.4 User Data Record (UDR)
4.7 End of Tape (EOT)
4.8 Error correcting code (ECC)
4.9 flux transition Position
4.10 flux transition spacing
4.11 Frame
logical backwards
4.12
logical forwards
4.13
4.14 magnetic tape
4.15 Master Standard Reference tape
4.16 packet
4.17 pad byte
4.18 physical backward
4.19 physical forward
4.20 physical recording density
@ ISO/IEC 1995
All rights reserved. Unless otherwise specified, no part of this publication mav 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-l 211 Geneve 20 l Switzerland
Printed in S wi tzerland
ISO/IEC 14251: 1995 (E)
OISOAEC
4.21 Processed Data
4.22 Secondary Standard Reference tape
4.23 Standard Reference Amplitude (SRA)
4.24 Standard Reference Current
4.25 Tape Reference Edge
4.26 Test Recording Current
4.27 track
4.28 Typical Field
4.29 transformation
4.30 Wrap
4.31 Half-Wrap
5 Conventions and notations
5.1 Representation of numbers
5.2 Names
5.3 Acronyms
6 Environment and safety
6.1 Cartridge/tape testing environment
6.2 Cartridge operating environment
6.3 Cartridge storage environment
6.4 Safety requirements
6.4.1 Safeness
6.4.2 Flammability
6.5 Transportation
Section 2 - Characteristics of the tapes
7 Characteristics of the tapes
7.1 Material
7.2 Tape length
7.3 Tape width
7.4 Tape discontinuity
7.5 Total thickness of tape
7.6 Base material thickness
7.7 Longitudinal curvature
7.7.1 CST tape
7.7.2 ECCST tape
7.8 Out-of-plane distortions
7.9 Cupping
7.10 Dynamit frictional characteristics
7.10.1 Frictional drag between the recording surface and the back surface
7.10.2 Frictional drag between the tape recording surface and ferrite after environmental cycling
7.11 Coating adhesion
Flexural rigidity
7.12
7.13 Electrical resistance of coated surfaces
7.14 Tape durability
7.15 Inhibitor tape
7.16 Tape abrasivity
7.17 Accelerated life test
7.18 Data integrity test
7.18.1 Requirement
. . .
OISOfIEC
ISO/IEC 14251 : 1995 (E)
7.18.2 Procedure
7.19 Pre-recording condition
7.20 Magnetit recording characteristics
7.20.1 Typical field
7.20.2 Signal amplitude
7.20.3 Resolution
7.20.4 Overwrite
7.205 Narrow-band signal-to-noise ratio (NB-SNR)
7.21 Tape quality
7.21.1 Missing pulses
7.21.2 Missing pulse zones
7.21.3 Coincident Missing Pulse Zones
Section 3 - Cartridge
8 Dimensional and mechanical characteristics of the cartridge
8.1 Overall dimensions
8.2 Write-inhibit mechanism
8.3 Label area(s) of the rear side
8.3.1 Implementation of a Single label
as
8.3.2 Implementation for two label are
8.4 Label area of the top side
8.5 Case opening
8.6 Locating notches
8.7 Locating areas
8.8 Inside configuration of the case around the case opening
8.9 Other extemal dimensions of the case
8.10 Central window
8.11 Stacking ribs
8.12 Recessed area
8.13 Flexibility of the case
8.13.1 Requirements
8.13.2 Procedure
8.14 Tape reel
8.14.1 Locking mechanism
8.14.2 Axis of rotation of the reel
8.14.3 Metallic insert
8.14.4 Toothed rim
8.14.5 Hub of the reel
8.14.6 Relative positions
8.14.7 Characteristics of the toothed rim
8.15 Leader block
8.16 Attachment of the tape to the leader block
8.17 Latching mechanism
8.18 Tape wind
8.19 Wind tension
8.20 Circumference of the tape reel
8.21 Moment of inertia
8.22 Cartridge case colours
Section 4 - Recording method and formats

OISO/IEC ISO/IEC 14251 : 1995 (E)
9 Method of recording
9.1 Physical recording density
9.2 Bit cell length
9.3 Average bit cell length
9.3.1 Long-term average bit cell length
9.3.2 Short-term average bit cell length
9.4 Rate of Change of the short-term average bit cell length
9.5 Bit cell peak Position
9.6 Bit shift
9.7 Total Character skew
9.8 Read Signal amplitude
9.9 Coincident missing pulse zones
10 Track format
10.1 Number of tracks
10.2 Track positions
10.3 Track width
10.4 Azimuth
10.5 Track identification
11 Packet format
11.1 Packets
11.2 Packet ID
11.3 UDR
11.4 Packet trailer
11.4.1 Packet trailer when data has been processed
11.4.2 Packet trailer when the data has not been processed
12 Data block format
12.1 Data part
12.1.1 Packet bytes
12.1.2 Count field bytes
12.1.3 Block ID bytes
12.2 Allocation of the bytes of the data block to frames
12.2.1 Prefix frames
12.2.2 Data frames
12.2.3 Residual frame 1
12.2.4 Residual frame
12.2.5 Suffix frames
12.3 Error correction code (ECC)
12.4 Recording of 8-bit bytes on the tape
12.5 Recorded data block
12.5.1 Preamble
12.5.2 Beginning of data mark (BDM)
12.5.3 Resync control frame
12.5.4 End of data mark (EDM)
12.5.5 Postamble
12.6 Maximum data density
13 Tape format
V
OISO/IEC
ISO/IEC 14251 : 1995 (E)
13.1 Zones
13.2 Density ID mark
13.3 VOLID mark
13.4 ID separator mark
gap
13.5 Interblock
13.6 Erase gap
13.6.1 Normal erase gap
13.6.2 Extended erase gap
13.7 Tape mark
13.8 Wrap marks
13.9 Mark merge
13.9.1 IBG followed by a tape mark
13.9.2 Tape mark followed by an IB6
13.9.3 IBG followed by a erase gap
13.9.4 Erase gap followed by an IBG
13.9.5 IBG followed by a Wrap Mark
13.9.6 Wrap mark followed by an IBG
13.9.7 IBG followed by a VOLID mark ONE or ZERO
13.9.8 VOLID mark ONE or ZERO followed by an IBG
13.9.9 Summary of the relationship between interblock gaps, erase gaps, tape marks, and wrap marks
13.10 End of Data Block
13.11 Recording Area
Annexes
A- Tape abrasivity measurement procedure
B- Pre-recording condition
Representation of 8-bit bytes by 9-bit Patterns
C-
D- Measurement of bit shift
E- Implementation of a CRC
F- Calculation of a physical Position indicator
G- Media Type Label
H- Recommendations for transportation
Inhibitor cartridge
J-
K - Recommendations on tape durability
L - Summary of data flow
M - Accelerated life test
vi
o ISO/IEC
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. 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.
International Standard ISO/IEC 14251 was prepared by the European Computer
Manufacturers Association (as Standard ECMA-196) 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 G form an integral part of this International Standard. Annexes H to
M are for information only .
vii
Introduction
The following International Standards specify data interchange on 12,7 mm wide magnetic tape cartridges:
ISO/IEC 9661: 1994, Information technology - Data interchange on 12,7 mm wide magnetic tape cartridges - 18 tracks, 1 491
bytes per millimetre
Data interchange on 12,7 mm wide 18- track magnetic tape cartridges -
ISOLIEC 11559: 1993, Information technology -
Extended format
ISO/IEC 13421: 1993, Information technology - Data interchange on 12,7 mm, 48-track magnetic tape cartridges - DLT 1
formst
ISOIIEC 13962: 1995, Information technology - Data interchange on 12,7 mm, 112-track magnetic tape cartridges - DLT 2
formst
This International Standard is related to further developments of cartridges containing 12,7 mm magnetic tape. It incorporates
most of the requirements of ISO/IEC 11559, together with extensions and modifications which specify the additional features
that allow higher capacities to be achieved.
Two types of cartridge are defined within this International Standard. For one of the types, the requirements for the case and the
tape are identical with those in ISO/IEC 11559. The second type conforms to different requirements which are defined in this
International Standard. This International Standard also specifies a recording method and format for use with either type.
It is not intended that this International Standard replaces ISOLIEC 11559. Existing cartridges which conform to ISO/IEC
11559 will continue to do so and will not conform to all the requirements of this International Standard. Drives which write and
read according to this International Standard may have the ability to accept and read cartridges conforming to ISO/IEC 9661 or
ISO/IEC 11559.
. . .
Vlll
INTERNATIONAL STANDARD 0 ISO/IEC
ISOIIEC 14251:1995(E)
Information technology - Data interchange on 12,7 mm 364rack magnetic tape
cartridges
Section 1 - General
1 Scope
This International Standard specifies the physical and magnetic characteristics of 12,7 mm wide, 36-track magnetic tape
cartridges to enable interchangeability of such cartridges. It also specifies the quality of the recorded sign&, the formst and the
recording method, thus allowing, together with International Standard ISO 1001 or equivalent, full data interchange by means
of such magnetic tape cartridges.
This International Standard specifies two types of cartridge which, for the purposes of this International Standard, a.re referred
to as Cartridge System Tape (CST) and Extended Capacity Cartridge System Tape (ECCST), and contah tape of different
thicknesses and lengths.
CST cartridges have a nominal uncompressed capacity of approximately 400 Mbytes.
ECCST cartridges have a nominal uncompressed capacity of approximately 800 Mbytes.
This International Standard specifies extensions and modifications to the recorded format that is described in International
Standard ISO/IEC 11559.
These extensions and modifications
-
increase the number of tracks recorded on the tape from 18 to 36. Actual recordings will be made 18 tracks at a time
requiring two complete Passes of the tape, one from the beginning of tape to the end of tape and the other from the end of
tape to the beginning of tape;
-
specify a different method of defining the ECC characters used to detect and correct errors when the data is read from the
tape.
2 Conformance
21 . Magnetit tape cartridge
A magnetic tape cartridge is in conforrnance with this International Standard if:
-
the cartridge meets all the requirements of clauses 6 to 8 for either one of the two types of magnetic tape cartridge;
-
the recording on the tape meets the requirements of clauses 9 to 13;
-
for each recorded packet the algorithm used for processing the data therein, if Processed Data has been recorded, is defined
and the identification is included in Byte 13 of the Packet ID of this packet (see 11.2). This identification shall conform to
ISO/IEC 11576.
22 . Generating System
A System generating a magnetic tape cartridge for interchange shall be entitled to Claim conformance with this International
Standard if all the recordings that it makes on a tape meet the mandatory requirements of this International Standard. A Claim of
conformance shall state which types of magnetic tape cartridges it is capable of recording, whether or not one, or more,
registered algorithms are implemented and, if so, the registered identifiers of all implemented algorithms. It shall also state
whether it is capable of generating the optional VOLID Mark information.
Receiving System
23 .
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 and specifies which of
the two types of magnetic tape cartridges it is capable of reading. In particular it shall
be able to retrieve data from individual packets within the extended blocks;
- be able to recognize that the data has been processed, to identify the algorithm(s) used, restore the data to its original form
or to indicate to the host that it cannot do so;
A Claim of conformance shall state whether or not one, or more, registered algorithm(s) is (are) implemented and, if so, the
registered identifier(s) of all implemented algorithms. It shall also state whether it is capable of using the optional VOLID Mark
information.
OISOnEC
ISO/IEC 14251: 1995 (E)
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
...