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 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 ISO maintain registers of currently valid International
Standards.
ISOnEC 646: 1991, Information technology - ISO 7-bit coded Character set for information interchange.
Heat-treatable steels, alloy steels andfree-cutting steels - Part 13: Wrought stainless steels.
ISO 683-13: 1986,
Information processing - File structure and labelling of magnetic tapes for information
ISO 1001: 1986,
interchange.
ISO 1302: 1992, Technical drawings - Method of indicating sur$ace texture.
Information technology - Procedure for the registration of algorithms for the lossless compression
ISOnEC 11576: 1994,
of data.
4 Definitions
For the purposes of this International Standard, the following definitions apply.
41 . algorithm: A set of rules for transforming the logical representation of data.
42 . algorithmically Processed Data: Data which has been processed by a defined processing algorithm.
43 . Beginning of Tape (BOT): The Point along the length of the magnetic tape, indicated by the Start of recorded
information.
44 . byte: An ordered set of eight bits (9 encoded bits) that are acted upon as a unit.
45 0 Cyclic Redundancy Check (CRC) Character: A Character represented by two bytes, placed at the end of a byte
string and used for error detection.
46 . Data Records
4.6.1 Processed Data Record (PDR): The data entity resulting from the application of an algorithm to the Logical Data
Record.
4.6.2 Host Data Record: The data entity originally compiled by the host.
4.6.3 Logical Data Record (LDR): The data entity received by the System from the host. It may contain one or several Host
Data Record(s) depending upon action taken by the host to use extended blocks.
4.6.4 User Data Record (UDR): The data entity available to the Packet Former.
When the data has been processed it shall be a PDR.
When the data has not been processed it shall be a LDR.
47 0 End of Tape (EOT): The Point on the tape furthest from BOT up to which recording is allowed.
4.8 Error correcting code (ECC): A mathematical procedure yielding bits used for the detection and correction of errors.
49 a flux transition Position: The Point on the magnetic tape that exhibits the maximum free-space flux density normal
to the tape surface.
4.10 flux transition spacing: The distance along a track between successive flux transitions.
4.11 Frame: A section across all 18 tracks within a Half-Wrap containing logically related bytes.
logical backwards: The direction of tape motion that results in finding a descending Order of LDRs.
4.12
4.13 logical forwards: The direction of tape motion that results in finding an ascending Order of LDRs.
4.14 magnetic tape: A tape that accepts and retains magnetic Signals intended for input, output, and storage of data for
information processing.
4.15 Master Standard Reference Tape: A tape selected as the International Standard for Reference Field, Signal
Amplitude, Resolution, and Overwrite.
NOTE 1 - A Master Standard Reference Tape has been established at the US National Institute of Standards and Technology (NIST).
OISO/IEC ISO/IEC 14251 : 1995 (E)
4.16 packet: A UDR with a Packet ID and Packet Trailer added.
4.17 Pad byte: A byte having a bit Pattern consisting of eight ZEROS.
4.18 physical backward: The direction of tape motion from EOT to BOT. This will be logical forward for Half-Wrap 2.
4.19 physical forward: The direction of tape motion from BOT to EOT. This will be logical forward for Half-Wrap 1.
4.20 physical recording density: The number of recorded flux transitions per unit length of track, e.g. flux transitions
per millimetre (ftpmm).
Processed Data: Data which has been processed by an algorithm.
4.21
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 2 - Secondary Standard Reference Tapes, SRM 3202, have been developed at the National Institute for Standards and Technology (NIST) and are
available from the NIST Office of Standard Reference Materials, Room B3 11, Chemistry Building, National Institute for Standards and Technology,
Gaithersburg, Maryland USA 20899 until the year 2004.
It is intended that these be used for calibrating tertiary reference tapes for use in routine calibration.
4.23 Standard Reference Amplitude (MA): The Average Signal Amplitude from the Master Secondary Reference
Tape when it is recorded with the Test Recording Current on the NIST measurement System at 972 ftpmm.
Traceability to the Standard Reference Amplitude is provided by the calibration factors supplied with each Secondary
Reference Tape.
4.24 Standard Reference Current: The current that produces the Reference Field.
4.25 Tape Reference Edge: The Reference Edge of the tape is the bottom edge when viewing the recording side of the
tape with the hub end (EOT) of the tape to the observer’s right.
4.26 Test Recording Current: The current that is 1,5 times the Standard Reference Current.
4.27 track: A longitudinal area on the tape along which a series of magnetic Signals tan be recorded.
4.28 Typical Field: In the plot of the Average Signal Amplitude against the Recording Field at the physical recording
density of 972 ftpmm, the minimum field that Causes an Average Signal Amplitude equal to 85 % of the maximum Average
Signal Amplitude.
transformation: The manipulation of Host Data Records before formatting. It includes the operations of processing,
4.29
the formation of packets and the concatenation of packets.
4.30 Wrap: A set of 36 tracks, 18 of which are recorded from BOT to EOT and 18 of which are recorded from EOT to
BOT in a sequential manner.
4.31 Half-Wrap: A set of 18 tracks which are recorded concurrently in the same direction. The tape contains two Half-
Wraps; Half-Wrap 1 is recorded from BOT towards EOT and Half-Wrap 2 is recorded from EOT towards End of Volume
(EOV).
5 Conventions and notations
. Representation of numbers
The following conventions and notations apply in this International Standard, unless otherwise stated.
- In each field the bytes shall be arranged with Byte 1, the most significant, first. Within each byte the bits shall be arranged
with Bit 1, the most significant, first and Bit 8, the least significant bit, last. This Order applies to the data, and to the input
and output of the error correcting Codes and cyclic redundancy Codes.
-
Letters and digits in parentheses represent numbers in hexadecimal notation.
The setting of binary bits is denoted by ZERO or ONE.
-
- Numbers in binar-y notation and bit combinations are represented by strings of ZEROS and ONEs with the most significant
bit to the left.
52 . Names
The names of entities are given with a capital initial letter.

ISO/IEC14251:1995(E) OISO/IEC
53 . Acronyms
BDM Beginning of Data Mark
BOT Beginning of Tape
CRC Cyclic Redundancy Check
CST Cartridge System Tape
Error Correction Code
ECC
ECCST Extended Capacity Cartridge System Tape
EDM End of Data Mark
EOT End of Tape
End of Volume
EOV
IBG Interblock Gap
ID Identifier or Identification
LDR Logical Data Record
Narrow Band Signal-to-Noise Ratio
NB-SNR
PDR Processed Data Record
RBW Resolution Bandwidth
SRA Standard Reference Amplitude
UDR User Data Record
VBW Video Band Width
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 equipment.
61 . Cartridgehape testing environment
tests and measurements made on the tape cartridge to check the requirements of this International
Unless otherwise stated,
Standard shall be carried out under the following conditions
23 "Ck2"C
temperature:
40 % to 60 %
relative humidity:
conditioning period
before testing: 24 h
62 . Cartridge operating environment
Cartridges used for data interchange shall be capable of operating under the following conditions
temperature: 16 “C to 32 “C
relative humidity: 20 % to 80 %
wet bulb temperature: 25 “C max.
The average temperature of the air immediately surrounding the tape shall not exc& 40,5 “C.
NOTE 3 - Localized tape temperatures in excess of 49 “C may Cause tape darnage.
Conditioning
before operating: If a cartridge has been exposed during storage andfor transportation
to conditions outside the above values, it shall be conditioned for a period of
at least 24 h Prior to use.
63 l Cartridge storage environment
Cartridges used for data interchange shall be stored under the following conditions.
5 “C to 32 “C
temperature:
5 %to80%
relative humidity:
wet bulb temperature: 26 “C max.
ISOLIEX 14251: 1995 (E)
OISO/IEC
64 . Safety requirements
6.4.1 Safeness
The cartridge and its components shall not constitute any safety or health hazard when used in its intended manner or in any
foreseeable misuse in an information processing System.
6.4.2 Flammability
The cartridge and its components shall be made from materials which, if ignited from a match flame, do not continue to bum in
a still carbon dioxide atmosphere.
Transportation
65 l
This International Standard does not specify Parameters for the environment in which cartridges should be transporte& Annex
H gives some recommendations for transportation.
Section 2 - Characteristics of the tapes
Characteristics of the tapes
There are two types of tapes specified by this International Standard. The tape used in an ECCST cartridge is langer and
thinner than that used in a CST cartridge. ECCST cartridges are differentiated from CST cartridges by the larger tape
circumference when the tape is completely wound on the supply reel and by the two coloured cartridge case. Where there are
differentes between the two cartridges, they are denoted in this International Standard.
Material
71 .
The tape shall consist of a base material (oriented polyethylene terephthalate film or its equivalent) coated on one side with a
strong yet flexible layer of ferromagnetic material dispersed in a suitable binder. The back surface of CST tape may also be
coated with a ferromagnetic or non-ferromagnetic material. ECCST tape shall not be coated on the back surface.
72 . Tape length
The minimum length of the tape shall be
165 m
For CST tape:
For ECCST tape: 332 m
73 . Tape width
The width of tape shall be
For CST tape: 12,650 mm + 0,025 mm
12,570 mm + 0,025 mm
For ECCST tape:
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.
Tape discontinuity
74 .
There shall be no discontinuities in the tape such as those produced by tape splicing or perforations.
75 . Total thickness of tape
The total thickness of the tape shall be in the following ranges
For CST tape: 0,025 9 mm to 0,033 7 mm
0,016 1 mm to 0,018 0 mm
For ECCST tape:
76 . Base material thickness
The nominal thickness of the base material for the tape shall be
For CST tape: 0,023 4 mm
0,014 2 mm
For ECCST tape:
@ISO/IEC
ISO/IEC 14251 : 1995 (E)
77 . Longitudinal curvature
7.7.1 CST tape
The radius of curvature of the edge of the CST tape shall not be less than 33 m.
Procedure:
Allow a 1 m length of tape to unroll and assume its natura1 curvature on a flat smooth surface. Measure the maximum deviation
from the concave edge of the tape to its chord. The deviation shall not be greater than 3,8 mm. This deviation corresponds to
the minimum radius of 33 m if measured over an arc of circle.
7.7.2 ECCST tape
The radius of curvature of the edge of the ECCST tape shall not be less than 33,75 m.
Procedure:
Allow a 0,90 m length of tape to unroll and assume its natura1 curvature on a flat smooth surface. Measure the maximum
deviation from the concave edge of the tape to its chord. The deviation shall not be greater than 3,0 mm. This deviation
corresponds to the minimum radius of 33,75 m if measured over an arc of circle.
78 . Out-of-plane distortions
All visual evidente of out-of-plane distortion shall be removed when the tape is subjected to the uniform tension specified
below. Out-of-plane distortions arc 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.
For CST tape: 0,6 N
For ECCST tape: 0,4 N
79 . Cupping
The departure across the width of tape from a flat surface shall not exceed 0,3 mm.
Procedure:
Cut a 1 ,O m + 0,l m length of tape. Condition it for a minimum of 3 h in the test environment by hanging it so that the surfaces
are freely exposed to the test environment. From the centre Portion of the conditioned tape tut a test piece of 25 mm length.
Stand the test piece on its end in a cylinder which is at least 25 mm high with an inside diameter of 13,O mm + 0,2 mm. 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.
7.10 Dynamit frictional characteristics
In the tests of 7.10.1 and 7.10.2 the specified forces of 1 ,O N and 1,50 N, respectively, comprise both the forte component of
the dynamic fnction and the forte of 0,64 N applied to the test piece of tape.
NOTE 4 - Particular attention should be given to keeping the surfaces clean.
7.10.1 Frictional drag between the recording surface and the back surface
The forte required to move the recording surface in relation to the back surface shall not be less than 1 ,O N.
Procedure:
Wrap a test piece of tape around a 25,4 mm diameter circular mandrel with the back surface of the test piece facing
a)
outwards in such a manner that the test piece will not slide.
b) Place a second test piece of the same type of tape, with the recording surface facing inwards, around the first test piece for a
total wrap angle of 90”.
c) Apply a forte of 0,64 N to one end of the outer test piece. Secure its other end to a forte gauge which is mounted on a
motorized linear slide.
d) Drive the slide at a Speed of 1 mm/s.
Frictional drag between the tape recording surface and ferrite after environmental cycling
7.10.2
The forte required to move the tape at a Point 1,34 m from the leader block of the cartri shall not be greater than 1,5 N. The
4F
forte required at a Point 4,3 m from
the junction of the tane with the c artridge hub shall not exceed 6,O N.
OISOIIEC
ISOIIEC 14251: 1995 (E)
Procedure:
Wind tape on to a spool hub of diameter 50 mm to an outside diameter of 97 mm with a winding tension of 2,2 N + 0,2 N
a>
for CST tape and 1,8 N + 0,2 N for ECCST tape.
Repeat the following two Steps five times:
b)
- Store for 48 h at a temperature of 50 “C and a relative humidity of 10 % to 20 %.
- Condition in the testing environment for 2 h and rewind with a tension of 2,2 N & 0,2 N for CST tape and 1,8 N + 0,2 N
for ECCST tape.
Condition the tape for 48 h at a temperature of 30,5 “C and a relative humidity of 85 %. The tape shall remain in this
C>
environment for Steps d) and e).
Apply a forte of 0,64 N to one end of a test piece of not more than 1 m, taken 1,34 m from the leader block. Pass the test
piece over a ferrite rod of diameter 25,4 mm with the recording surface in contact with the rod for a total wrap angle of 90”.
The rod shall be made from the ferrite specified in annex A. It shall be polished to a roughness value Ra of 0,05 Pm
(roughness grade N2, ISO 1302). Pu11 the other end of the test piece horizontally at 1 mm/s.
Repeat step d) for a similar test piece taken 4,3 m from the junction of the tape with the cartridge hub.
e>
7.11 Coating adhesion
The forte required to peel any part of the coating from the tape base material shall not be less than 1,5 N.
Procedure:
a) 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.
b) Using a double-sided pressure sensitive tape, attach the full width of the test piece to a smooth metal plate, with the
recording surface facing the plate, as shown in figure 1.
c) Fold the test piece over 180°, 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 m.
d) Note the forte at which any part of the coating first separates from the base material. If this is less than 1,5 N, the test has
failed. If the test piece peels away from the double-sided pressure sensitive tape before the forte exceeds 1,5 N, an
alternative type of double-sided pressure sensitive tape shall be used.
e) If the back surface of the tape is coated, repeat a) to d) for the back coating.

OISOIIEC
ISO/IEC 14251 : 1995 (E)
n
I /
. .
I
I.
I.
Pressurc-sensitive tape
>
C------ 125 rm-n
930120-A
Figure 1 - Coating adhesion test
7.12 Flexural rigidity
The flexural rigidity of the tape in the longitudinal direction shall be
For CST tape 0,06 to 0,16 Nmm2
0,03 to 0,14 Nmm2
For ECCST tape
Procedure:
Clamp a 180 mm test piece of tape in a universal testing machine, allowing a 100 mm Separation between the machine jaws. Set
Calculate the flexural rigidity using the slope of the
the jaw Separation Speed at 5 mm per minute. Plot forte against distance.
curve between 2,2 N and 6,7 N by the formula
AF/WT
-
-
E
WL
wT3
--
-
I
Flexural rigidity = EI
Where
M is the Change in forte in Newtons
T is the measured thickness in millimetres
W is the measured width in millimetres
ALJL is the Change in the length of the test piece between the jaws divided by the original length between the jaws.
7.13 Electrical resistance of coated surfaces
The electrical resistance of any Square area of the recording surface shall be within the range
-
105sZ to 5 x 108Q for non-backcoated tapes.
-
lO5Q to 5 x 109fi for backcoated tapes.
The electrical resistance of any backcoating shall be less than 106Q.
Procedure:
Condition a test piece of tape to the test environment for 24 h. Position the test piece over two 24-carat gold-plated, semi-
25,4 mm and a finish of at least N4 such that the recording surface is in contact with each
circular electrodes having a radius r =
OISO/IEC
ISOIIEC 14251 : 1995 (E)
electrode. These electrodes shall be placed parallel to the ground and parallel to each other at a distance d = 12,7 mm between
their centres as shown in figure 2. Apply a forte F of 1,62 N to each end of the test piece. Apply a DC voltage of 500 V + 10 V
across the electrodes and measure the resulting current flow. From this value, determine the electrical resistance.
Repeat for a total of five positions along the test piece and average the five resistance readings. For back-coated tape repeat the
procedure with the backcoating in contact with electrodes.
V
V
F F
93-0122-A
Figure 2 - Electrical resistance test
When mounting the test piece, make Sure that no conducting paths exist between the electrodes except that through the coating
under test.
NOTE 5 - Particular attention should be given to keeping the surfaces clean.
7.14 Tape durability
This International Standard does not specify Parameters for assessing tape durability. However, a recommended procedure is
described in annex K.
7.15 Inhibitor tape
This International Standard does not specify Parameters for assessing whether or not a tape is an inhibitor tape. However, annex
J gives further information on inhibitor tapes.
7.16 Tape abrasivity
Tape abrasivity is the tendency of the tape to wear the tape transport and head. The length of the wear Pattern on a wear bar
shall not exceed 56 Pm when measured as specified in annex A.
7.17 Accelerated life test
This International Standard does not specify Parameters for assessing whether or not a tape withstands long-term storage and
extreme environmental operating conditions. However, a recommended procedure is described in annex M.
7.18 Data integrity test
The Object of the data integrity test is to demonstrate that the tape will withstand continued tape movement in the drive within
the environmentally stressed operating conditions without loss of recorded data. Data is written in the forward direction
between BOT and EOT, and then the tape is moved multiple Passes the full operating length, after which the data is re-read to
check for the generation of errors.
7.18.1 Requirement
There shall be no more than eight additional temporar-y read errors on any read pass. There shall be no generation of permanent
read errors.
7.18.2 Procedure
a) Allow cartridges to acclimatize at room temperature and re-tension the tape by driving it one time back and forth between
the BOT and EOT to remove any loose wraps.
OISO/IEC
ISO/IEC14251:1995 (E)
Place the test hardware and cartridge to be tested in a 30,O “C + 2,0°, 85 % rh environment for 24 h.
W
Write Data Blocks containing 32K bytes each on the cartridge from BOT to EOT in the forward direction only. Read the
C>
data while writing and save the error information.
File-Protect the cartridge.
From EOT backup the tape 50 Data Blocks and note the Block ID.
e>
Run high-speed Passes at 4 m/s to 5 m/s to the Block ID noted in step e). Then do a high-speed rewind to BOT. Repeat this
f)
high-speed pass 50 times.
Read the data from the entire tape and save the error information.
g>
Repeat Steps f) and g) 4 times for a total of 250 high-speed Passes from BOT to the noted Block ID and back to BOT and 5
h)
full length read Passes. Save the error information for comparison against the original error information.
Compare the read data results for all five read Passes against the original data of step c).
i>
7.19 Pre-recording condition
Prior to recording data for testing purposes, or to testing, erase the tape utilizing altemating magnetic fields of decaying levels
(anhysteretic process) to ensure that the remanent magnetic moment of the recording surface does not exceed 20 % of the
maximum remanent magnetic moment. Annex B specifies the method of measurement.
In addition, no low density transitions shall be present on the tape and the tape shall have been erased Prior to the first time it
was used for recording.
7.20 Magnetit recording characteristics
The magnetic recording characteristics shall be defined by the testing requirements given below.
When performing these 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 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: pre-recording condition
-
tape Speed: not greater than 2,5 m/s
-
within the written track
read track:
-
azimuth alignment: not greater than 6’ between the mean write transitions and the read gap
-
write gap length: 1 ,O Pm + 0,2 Fm
-
write head Saturation density: 0,34 T + 0,03 T
- tape tension
CST tape: 2,2 NIL 0,2 N
1,8N+0,2N
ECCST tape:
-
recording current: Test Recording Current
7.20.1 Typical Geld
The Typical Field of the tape shall be between 90 % and 110 % of the Reference Field.
Traceability to the Reference Field is provided by the calibration factors supplied with each Secondary Standard Reference
Tape.
7.20.2 Signal amplitude
The Average Signal Amplitude at the physical recording density of 972 ftpmm shall be between 70 % and 140 % of the SRA.
Traceability to the SRA is provided by the calibration factors supplied with each Secondary Standard Reference Tape.
7.20.3 Resolution
The ratio of the Average Signal Amplitude at the physical recording density of 1 458 ftpmm to that at the physical recording
density of 972 ftpmm shall be between 80 % and 120 % 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.
OISO/IEC
ISOiIEC 14251 : 1995 (E)
7.20.4 Overwrite
Overwrite is the ratio of the Average Signal Amplitude of the residual of the fundamental frequency of a tone Pattern after
being overwritten at 972 ftpmm to the Average Signal Amplitude of the 972 ftpmm Signal. The Average Signal Amplitude of
the tone Pattern is the peak-to-peak amplitude of the sinusoidal Signal with equal rms power.
7.20.4.1 Requirement
The overwrite for the tape shall be less than 120 % 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.
7.20.4.2 Procedure:
Record a tone Pattern which shall be the following sequence of flux transitions.
1 0 0 0 0 1 0 0 0
1 \ \
\ d ’
3,
, , *
Ul
where al = 1,029 Pm
a2 = 0,5 14 Pm
Figure 3 - Tone Pattern
Record a 972 ftpmm Signal over the tone Pattern. Measure the Average Signal Amplitude of the residual of the fundamental
frequency of the tone Pattern (one sixth of the frequency of the 972 fipmm Signal) and the Average Signal Amplitude of the 972
ftpmm Signal. Both amplitude measurements shall be made using suitable filters.
7.20.5 Narrow-band signal-to-noise ratio (NB-SNR)
The narrow-band signal-to-noise ratio is the Average Signal Amplitude rms power divided by the average integrated (side
band) rms noise power, and is expressed decibels.
7.20.5.1 Requirement
The NB-SNR shall be equal to, or greater than, 30 dB when normalized to a track width of 410 Fm. The normalization factor is
dB(410) = dB(W) + 10 log 41O/W, where W is the track width used when measuring dB(W).
7.20.5.2 Procedure
The NB-SNR shall be measured using a spectrum analyzer with a resolution bandwidth (RBW) of 1 kHz and a Video bandwidth
(VBW) of 10 Hz. The tape Speed shall be 762 mm/s for the frequencies specified below.
The NB-SNR shall be measured as follows
Measure the read-Signal amplitude of the 972 Signal, a minimum of 150 samples over a minimum length of
-
ftpmm
tape of 46 m.
- On the next pass (read only) measure the rms noise power over the same section of tape and integrate the rms noise power
(normalizing for the actual resolution bandwidth) over the range from 332 kHz to 366 kHz.
For other tape Speeds all frequencies shall be linearly scaled.
7.21 Tape quality
exposure to storage and transportation environments) is defined by the testing
The tape quality (including the effects of
requirements given in the following clauses. The followin g conditions shall apply to all quality testing requirements.
operating environment
- environment:
- tape condition: pre-recording condition
2m/s
- tape Speed:
- write track width: greater than, or equal, to the read track width
- read track width : 190 Fm + 2,5 Fm
972 ftpmm
- physical recording density:
- write gap length : l,O~m+0,2~m
ISO/IEC 14251 : 1995 (E) OISO/IEC
-
not greater than 6’ between the mean write transitions and the read gap
azimuth alignment :
-
write head Saturation density: 0,34 T + 0,03 T
-
recording current: Test Recording Current
- format: 36 tracks
- tape tension
2,2 N + 0,2 N
CST tape:
ECCST tape: 1,8N+0,2N
7.21.1 Missing pulses
A missing pulse is a loss of read Signal amplitude. A missing pulse exists when the base-to-peak read Signal amplitude is 25 %,
or less, of half the Average Signal Amplitude for the preceding 25,4 mm of tape.
7.21.2 Missing pulse zones
A Missing Pulse Zone begins with a missing pulse and ends when 64 consecutive flux transitions, which are not missing pulses,
are detected or a length of 1 mm of tape has been measured.
The Missing Pulse Zone rate shall be less than one in 8 x 106 flux transitions recorded.
7.21.3 Coincident Missing Pulse Zones
For purposes of measuring Coincident Missing Pulse Zones, the 36 tracks are divided into four 9-track groups as shown below.
A simultaneous Missing Pulse Zone condition on two or more tracks of a 9-track group is a Coincident Missing Pulse Zone.
The first group shall comprise physical tracks 1,5,9, 13, 17,21,25,29, and 33.
The second group shall comprise physical tracks 3,7, 11, 15, 19,23, 27, 3 1, and 35.
The third group shall comprise physical tracks 2, 6, 10, 14, 18, 22, 26, 30, and 34.
The fourth group shall comprise physical tracks 4, 8, 12, 16,20,24,28,32, and 36.
If a Coincident Missing Pulse Zone occurs at the same time in the first and second group of tracks and the third or fourth group
of tracks, it shall be considered as a Single Coincident Missing Pulse Zone. Its length shall begin with the Start of the earliest
Coincident Missing Pulse Zone and terminate with the end of the latest Coincident Missing Pulse Zone.
No tape shall have more than 12 Coincident Missing Pulse Zones.
No Coincident Missing Pulse Zone
...