ISO/IEC 13421:1993
(Main)Information technology — Data Interchange on 12,7 mm, 48-track magnetic tape cartridges — DLT 1 format
Information technology — Data Interchange on 12,7 mm, 48-track magnetic tape cartridges — DLT 1 format
This International Standard specifies the physical and magnetic characteristics of a 12,7 mm wide, 48-track magnetic tape cartridge, to enable interchangeability of such cartridges. It also specifies the quality of the recorded signals, a format — called Digital Linear Tape 1 (DLT 1) — and a recording method. Together with a labelling standard, e.g. ISO 1001, it allows full data interchange by means of such magnetic tape cartridges.
Technologies de l'information — Échange de données sur cartouches pour bandes magnétiques de 12,7 mm, 48 pistes — Format DLT 1
La présente Norme internationale spécifie les caractéristiques physiques et magnétiques d'une cartouche à bande magnétique de 12,7 mm de large, 48 pistes, dans le but de permettre l'interchangeabilité de telles cartouches. Elle spécifie également la qualité des signaux enregistrés, un format appelé Bande Linéaire Numérique 1 (DLT1) et une méthode d'enregistrement. Associée à une norme d'étiquetage, comme par exemple la Norme internationale ISO 1001 pour la structure de volumes et de fichiers des bandes magnétiques, elle permet un échange total de données au moyen de telles cartouches à bande magnétique.
General Information
Standards Content (Sample)
INTERNATIONAL
ISOJIEC
STANDARD 13421
First edition
1993-12-15
Information technology - Data
interchange on 12,7 mm, 48-track magnetic
tape cartridges - DLT 1 format
Technologies de I’informa tion - khange de donndes SW cartouches
pour bandes magnetiques de 12,7 mm, 48 pistes - Format DLT 1
Reference number
ISO/IEC 13421 :1993(E)
Contents
Page
Section 1 - General
1 Scope
Conformance
2.1 Magnetit tape cartridges
2.2 Generating Systems
Receiving Systems
23 .
3 References
4 Definitions
41 Average Signal Amplitude
4:2 azimuth
back surface
4.3
44 . Beginning-Of-Tape marker (BOT)
45 . byte
46 . cartridge
Cyclic Redundancy Check (CRC) Character
4:8 Early Warning (EW)
Error-Detecting Code (EDC)
4:10 End-Of-Tape marker (EOT)
4.11 Entity
4.12 Error-Correcting Code (ECC)
flux transition Position
4.13
4.14 flux transition spacing
4.15 Logical Block
logical track
4.16
4.17 magnetic tape
4.18 Master Standard Reference Tape
0 TSO/IEC 1993
All rights reserved. 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
ii
4.19 Object
physical block
4.20
physical recording density
4.21
4,22 physical track
4.23 Record
Reference Edge
4.24
4.25 Reference Field
4.26 Secondary Standard Reference Tape
Standard Reference Amplitude (SRA)
4.27
4.28 Standard Reference Current
4.29 Test Recording Current
4.30 Typical Field
Conventions and notations
5.1 Representation of numbers
52 Names
5:3 Acronyms
6 Environment and safety
6.1 Cartridge and tape testing environment
. Cartridge operating environment
. Cartridge storage environment
Safety requirements
64 .
6.4.1 Safeness
6.4.2 Flammability
65 . Transportation
Section 2 - Requirements for the unrecorded tape
7 Mechanical and electrical requirements
7.1 Material
7.2 Tape length
7.3 Width of the tape
7.4 Total thickness of the tape
7.5 Thickness of the base material
7.6 Thickness of the magnetic coating
7.7 Thickness of the back coating
7.8 Tape discontinuity
Longitudinal curvature
7.9
7.9.1 Requirement
7.9.2 Procedure
Out-of-Plane distortions
7.10
7.11 Cupping
7.12 Roughness of the coating surfaces
. . .
Roughness of the back coating surface
7.12.1
7.12.2 Roughness of the magnetic coating surface
7.13 Coating adhesion
Layer-to-layer adhesion
7.14
7.14.1 Requirements
7.14.2 Procedure
Modulus of elasticity
7.15
Requirement
7.151
7el5.2 Procedure
Flexural rigidity
equirement
Procedure
Tensile yield forte
737.2 Procedure
Efectrical resistance
RtXpire-iilent
Rocedure
7.19 Inhibitor tape
7.20 Abrasivity
7.20.1 Requirement
Procedure
7.20.2
7.21 Light transmittance of the tape and the leader
7.22 Coefficient of dynamic friction
7.22.1 Requirements
Procedure for the measurement of the friction between the magnetic surface and the back surface
7.22.2
7.22.3 Procedure for the measurement of the friction between the magnetic surface or the back surface and
Calcium titanate ceramic
8 Magnetit recording characteristics
81 . Typical Field
82 . Signal amplitude
83 . Resolution
.
84 Overwrite
8.4.1 Requirement
85 . Peak shift
iv
8.5.1 Requirement
8.5.2 Procedure
9 Tape quality
Missing pulses
91 .
9.1.1 Requirement
issing pulse Zone
9.2
equirement
93 6) Tape durability
General
Bottom side and right side
Back side and Ieft side
Tape reel
Tape Header
Front side
Operation of the cartridge
Section 4 - Requisements for an interchanged tape
Method of recording
11.1 Physical recording density
11.2 Bit cell length
Average bit cell length
11.2.1
11.2.2 Long-term average bit cell length
Short-term average bit cell length
11.2.3
11.3 Flux transition spacing
11.4 Read Signal amplitude
Azimuth
11.5
11.6 Channel skew
12 Tape format
12.1 Reference Edge
12.2 Direction of recording
12.3 Tape layout
12.4 Calibration and Directory Area
12.4.1 Scratch Area
12.4.2 Guard Area Gl
12.4.3 Calibration Tracks Area
12.4.4 Guard Area G2
12.45 Directory Area
12.4.6 Guard Area G3
12.5 Data Area
12.5.1 Physical tracks
12.52 Width of the physical tracks
12.5.3 Logical tracks
12.5.4 Locations of the physical tracks
12.55 Layout of tracks in the Data Area
13 Data format
13.1 Data Bytes
13.2 Logical Blocks
13.3 Data Blocks
13.4 Types of Logical Blocks
13.5 Entities
13.6 Logical Block format
Preamble
13.6.1
13.6.2 Sync
13.6.3 Data Field
13.6.4 Control Field 1 (CFl)
13.6.5 Control Field 2 (CF2)
CRC
13.6.6
13.6.7 Postamble
14 Use of Logical Blocks
14.1 Data Blocks
Tape Mark Blocks
14.2
Filler Blocks
14.3
14.4 , End of Track Blocks (EOTR)
14.5 End of Data Blocks (EOD)
14.6 ECC Blocks
Format of Entities
16 Error handling
Annexes
A - Measurement of light transmittance
B - CRC generation
C - ECC generation
D - Format of Control Field
E - Format of Control Field 2
F - Recommendations for transportation
G - Inhibitor tape
H - Recommendations on tape durability
J - Handling guidelines
vii
ISOIIEC 13421: 1993 (E)
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, govemmental and non-govemmental, in liaison with ISO and IEC, also take gart 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 13421 was prepared by the European Computer Manufacturers Association (ECMA)
(as Standard ECMA- 182) 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 E form an integral part of this International Standard. Annexes F to J are for information only.
Patents
During the preparation of the ECMA Standard, information was gathered on Patents upon which application of the Standard
might depend. Relevant Patents were identified as belonging to Digital Equipment Corporation. I-Iowever, neither ECMA
nor ISO/IEC tan give authoritative or comprehensive information about evidente, validity or scope of patent and like rights.
The patent holders have stated that licences will be granted under reasonable and non-discriminatory terms.
Communications on this subject should be addressed to
Digital Equipment Corporation
334 South Street
Shrewsbury
Massachusetts 015454112
USA
. . .
Vlll
Introduction
International Standards ISO 9661 and ISOLIEC 11559 specify data interchange on 12,7 mm, 1%track magnetic tape
cartridges.
International Standard 13421 concerns a cartridge of a type different from that of those International Standards. Whilst the
magnetic tape is also 12,7 mm wide, it is recorded on 48 physical tracks. Also the format is different from that of these
previous International Standards. It is characterized by the fact that the physical tracks, recorded and read in pairs, constitute
two groups, the first recorded and read in forward direction, the second in reverse direction.
iX
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INTERNATIONAL STANDARD
Information technology - Data interchange on 12,7 mm, 48-track magnetic tape
DLT 1 format
cartridges -
Section 1 - General
1 Scope
This International Standard specifies the physical and magnetic characteristics of a 12,7 mm wide, 48-track magnetic tape
cartridge, to enable interchangeability of such cartridges. It also specifies the quality of the recorded Signals, a format -
called Digital Linear Tape 1 (DLT 1) - and a recording method. Together with a labelling Standard, e.g. ISO 1001, it allows
full data interchange by means of such magnetic tape cartridges.
2 Conformance
2.1 Magnetit tape cartridges
A magnetic tape cartridge shall be in conformance with this International Standard if it satisfies all mandatory requirements
of this International Standard. The tape requirements shall be satisfied throughout the extent of the tape.
2.2 Generating Systems
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 according to 2.1 meet the mandatory requirements of this International
Standard.
23 . Receiving Systems
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 a tape according to 2.1.
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 listed below. Members of IEC and ISO maintain registers of currently valid international Standards.
ISO 1001: 1986 Information processing - File structure and labelling of magnetic tapes for information interchange.
ISO 1302:1992 Technical drawings - Method of indicating surface texture.
4 Definitions
For the purpose of this International Standard, the following definitions apply.
41 . Average Signal Amplitude: The average peak-to-peak value of the output Signal from the read head at the
physical recording density of 1 674 ftpmm measured over a minimum length of track of 25,4 mm, exclusive of missing
pulses.
4.2 azimuth: The angular deviation, in minutes of arc, of the mean flux transition line of the recording on a track
from the line normal to the Reference Edge.
4.3 back surface: The surface of the tape opposite the magnetic coating which is used to record data.
4.4 Beginning-Of-Tape marker (BOT): A hole punched on the centreline of the tape towards the end nearest to the
leader.
a unit.
4.5 byte: An ordered set of bits acted upon as
NOTE 1 - In this International Standard, all bytes are 8-bit bytes.
4.6 cartridge: A case containing a Single supply reel of 12,7 mm wide magnetic tape with a leader attached at the
outer end.
47 .
Cyclic Redundancy Check (CRC) Character: A 64-bit Character, generated by a mathematical computation, used
for error detection.
4.8 Early Warning (EW): A Signal generated by the drive indicating the approaching end of the recording area.
4.9 Error-Detecting Code (EDC): A mathematical computation yielding check bytes used for error detection.
4.10 End-Of-Tape marker (EOT): A hole punched on the centreline of the tape towards the end farthest from the
leader.
4.11 Entity: A group of ten Logical Blocks treated as a logical unit and recorded on a logical track.
4.12 Error-Correcting Code (ECC): A mathematical computation yielding check bytes used for the correction of
errors detected by the CRC and the EDC.
normal surface.
4.13 flux transition The Point which exhibits the maximum free-space flux density to the tape
4.14 flux transition spacing: The distance on the magnetic tape between successive flux transitions.
4.15 Logical Block: The two physical blocks simultaneously on, or read from, the two physical tracks ofa
logical track.
4.16 logical track: A pair of physical tracks that are written or read simultaneously.
4.17 magnetic tape: A tape that accepts purposes on
magnetic Signals intended for input, output, and storage
Computers and associated equipment.
4.18 Master Standard Reference Tape: A tape selected as the Standard for reference field, Signal amplitude,
resolution, peakshift, and overwrite characteristics.
NOTE 2 - The Master Standard Reference Tape has been established by Digital Equipment Corporation.
4.19 Object: A Record or a Tape Mark Block.
4.20 physical block: A set of contiguous bytes recorded on a physical track and considered as a unit.
flux transitions per unit length of track, expressed in flux
4.21 physical recording density: The number of recorded
transitions per millimetre (ftpmm).
4.22 physical track: A longitudinal area on the tape along which a series of magnetic Signals tan be recorded.
4.23 Record: A collection of User Bytes, the number of which is determined by the host.
4.24
Reference Edge: The bottom edge of the tape when viewing the magnetic coating of the tape with the BOT to the
left and the EOT to the right of the observer.
4.25 Reference Field: The Typical Field of the Master Standard Reference Tape.
4.26 Secondary Standard Reference Tape: A tape the characteristics of which are known and stated in relation to
those of the Master Standard Reference Tape.
NOTE 3 - Secondary Standard Reference Tapes tan be ordered under reference SSRT/DLTl until the year 2003 from Digital Equipment Corporation, Tapes
Products Group, 334 South Street, Shrewsbury, Mass. 01545, USA.
It is intended that these be used for calibrating tertiary reference tapes for routine calibration.
4.27 Standard Reference Amplitude (SRA): The Average Signal Amplitude from the Master Standard Reference Tape
when it is recorded with the Test Recording Current at 1 674 ftpmm.
4.28 Standard Reference Current: The current that produces the Reference Field.
4.29
Test Recording Current: The current that is 1,1 times the Standard Reference Current.
4.30
Typical Field: In the plot of the Average Signal Amplitude against the recording field at the physical recording
density of 1674 ftpmm, the minimum field that Causes an Average Signal Amplitude equal to 95 % of the maximum
Average Signal Amplitude.
5 Conventions and notations
51 . Representation of numbers
The following conventions and notations apply in this International Standard, unless otherwise stated.
- In each block and in each field the bytes shall be arranged with Byte 1, the least significant, first. Within each byte the
bits shall be arranged with Bit 1, the least significant, first and Bit 8, the most significant bit, last. This Order applies to
the data, and to the input and output of the error-detecting and error-correcting Codes, and to the cyclic redundancy
characters.
Letters and digits in parentheses represent numbers in hexadecimal notation.
-
The setting of bits is denoted by ZERO or ONE.
- Numbers in binary notation and bit Patterns are represented by strings of ZEROS and ONEs shown with the most
significant bit to the left.
52 .
Names
The names of basic elements, e.g. specific fields, are written with a capital initial letter.
53 . Acronyms
BOT Beginning of Tape
CF1 Control Field 1
CF2 Control Field 2
CRC Cyclic Redundancy Check (Character)
ECC Error-Correcting Code
EDC Error-Detecting Code
EOD End of Data
End of Tape
EOT
End of Track
EOTR
EW Early Warning
FCTl Forward Calibration Track 1
FCT2 Forward Calibration Track 2
Logical End of Tape
LEOT
Modified Frequency Modulation
MFM
RCTI Reverse Calibration Track 1
RCT2 Reverse Calibration Track 2
Standard Reference Amplitude
SRA
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 drive.
61 . Cartridge and tape testing environment
Unless otherwise stated, tests and measurements made on the cartridge and tape to check the requirements of this
International Standard shall be carried out under the following conditions:
-
temperature: 23 OC f 2 OC
-
relative humidity: 40 % to 60 %
-
conditioning before testing: 24 h
62 . Cartridge operating environment
Cartridges used for data interchange shall be capable of operating under the following conditions:
-
temperature: 10 OC to 40 OC
-
relative humidity: 20 % to 80 %
-
wet bulb temperature:
25 OC max.
NOTE 4 - Localized tape temperatures in excess of 49 “C may Cause tape darnage.
If during storage and/or transportation a cartridge has been exposed to conditions outside the above values, it shall be
conditioned before use by exposure to the operating environment for a time equal to, or greater than, the time away from the
operating environment up to a maximum of 2 h. There shall be no deposit of moisture on or in the cartridge.
63 . Cartridge storage environment
,ing conditions:
Cartri dges shall be stored under the follow
-
temperature: 16 OC to 32 OC
-
relative humidity: 20 % to 80 %
-
26 OC max.
wet bulb temperature:
Tapes intended for archiving data for one year or more shall be stored under the following conditions:
-
temperature: 18”Cto26”C
-
relative humidity: 20 % to 60 %
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.
64 . Safety requirements
6.4.1 Safeness
The cartridge and its components shall not constitute any safety or health hazard when used in the intended manner, or
through 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
burn in a still carbon dioxide atmosphere.
65 . Transportation
This International Standard does not specify Parameters for the environment in which cartridges should be transported.
Annex F gives some recommendations for transportation.
Section 2 - Requirements for the unrecorded tape
7 Mechanical and electrical requirements
7.1 Material
The tape shall consist of a base material (oriented polyethylene terephthalate film or its equivalent) coated on one surface
with a strong yet flexible layer of ferromagnetic material dispersed in a suitable binder. The other surface of the cartridge
shall be coated with a non-ferromagnetic conductive coating.
7.2 Tape length
The length of the tape shall be 355 m min. and 365 m max.
73 . Width of the tape
The width of the tape shall be 12,649 mm =f: 0,010 mm.
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.
7.4 Total thickness of the tape
The total thickness of the tape at any Point shall be between 12,0 Pm and 14,0 Pm.
7.5 Thickness of the base material
The thickness of the base material shall be between 9,0 Pm and 11 Pm.
Thickness of the magnetic coating
7.6
The thickness of the magnetic coating shall be between 2,0 Pm and 3,0 Pm.
7.7 Thickness of the back coating
The thickness of the back coating shall be between 0,4 Pm and 0,9 Pm.
7.8 Tape discontinuity
There shall be no discontinuities in the tape between the BOT and EOT such as those produced by tape splicing or
perforations.
7.9 Longitudinal curvature
The longitudinal curvature is measured as the departure of the Reference Edge of the tape from a straight line along the
longitudinal dimension of the tape in the plane of the tape surface.
7.9.1 Requirement
Any deviation of the Reference Edge from a straight line shall be continuous and shall not exceed 0,038 mm within any
229 mm length of tape.
7.9.2 Procedure
Measure at a tension of 1,39 N k 0,28 N in a test fixture equipped with two guides spaced at 229 mm. The two guides shall
be spring-loaded to Position the Reference Edge of the tape against two edge control surfaces. Measure the maximum
deviation of the Reference Edge of the tape from the line drawn between the two control surfaces.
7.10 Out-of-Plane distortions
All visual evidente of out-of-plane distortion shall be removed when the tape is subjected to a uniform tension of 0,6 N.
Out-of-plane distortions are 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.
7.11 Cupping
The departure across the width of the tape from a flat surface shall not exceed 0,76 mm.
Procedure
Cut a 1,0 m 2 0,l m length of tape. Condition it for a minimum of 3 hours in the test environment by hanging it so that both
surfaces are freely exposed to the test environment. From the centre Portion of the conditioned tape tut a test piece of
approximately 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 13,0 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.
ISO/IEC 1342lrl993 (E)
7.12 Roughness of the coating surfaces
7.12.1 Roughness of the back coating surface
The back coating surface shall have an arithmetic average roughness Ra between 0,005 Pm and 0,025 p-n (ISO 1302:N 2).
This measurement shall be made using a contacting stylus of radius 12,5 Fm with a 20 mg load, and a 254 pm cutoff range.
7.12.2 Roughness of the magnetic coating surface
The magnetic coating surface shall have an arithmetic average roughness Ra between 0,005 0 Pm and 0,012 5 Pm (ISO
1302: N 3). For this measurement, the contacting stylus radius shall be 12,5 Pm with a 20 mg load, and a 254 Pm cutoff
range.
7.13 Coating adhesion
The forte required to peel any part of the coating from the tape base material shall not be less than 0,2 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
magnetic coating (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 min.
d) Note the forte at which any part of the coating first separates from the base material. If this is less than 0,2 N, the test
has failed. If the test piece peels away from the double-sided pressure sensitive tape before the forte exceeds 0,2 N, an
alternative type of double-sided pressure sensitive tape shall be used.
e) Repeat a) to d) for the back coating.
Recording surface Scribed line
/
/
Pressufe-sensitive
k-425 mmd
tape
Figure 1 - Measurement of the coating adhesion
ISO/IEC 1342lrl993 (E)
7.14 Layer-to-layer adhesion
Layer-to-layer adhesion refers to the tendency of a layer, when held in close proximity to the adjacent layer, to bond itself to
an adjacent layer so that free and smooth Separation of the layers is difficult.
7.14.1 Requirements
There shall be no evidente of delamination or other darnage to the coatings.
7.14.2 Procedure
Fasten one end of a 914 mm length of tape, magnetic coating inwards, to a horizontally mounted stainless steel
a>
cylinder with a low cold-flow adhesive material.
The dimensions (see figure 2) of the cylinder shall be
b)
- diameter: 12,7 n-rm;
- length: 102 mm.
Attach a mass of 1 000 g to the opposite end of the tape.
Attach, 25,4 mm above the mass, a narrow Strip of double-sided adhesive tape to the magnetic coating.
Slowly rotate the cylinder, so that the tape Winds uniformly around it into a compact and even roll. The double-sided
tape secures the end and prevents unwinding when the mass is removed.
The cylinder with the tape shall then be exposed to the temperature and humidity cycle given in table 1.
f)
Table 1 - Temperature and humidity cycle
Time Temperature RH
85 %
16 h to 18 h 54 “C
4h 54 OC 10 % or less
1 hto2h 21 OC 45 %
Open the end of the roll and remove the double-sided adhesive tape.
g>
Release the free end of the tape.
h)
The outer one or two wraps shall spring loose without adhesion.
.
Hold the free end of the tape and allow the cylinder to fall, thereby unwinding the tape.
J)
The tape shall show no coating delamination, except for the 51 mm of tape nearest to the cylinder.
kl
Figure 2 - Measurement of layer-to-layer adhesion
Modulus of elasticity
7.15
The modulus of elasticity (Young’s modulus) is the ratio of stress to strain in the longitudinal direction.
7.15.1 Requirement
The modulus of elasticity shall be between 5 500 N/mm2 and 8 500 N/mm2.
7.152 Procedure
Clamp a test piece of tape at least 178 mm in length with an initial 102 mm Separation between the jaws of a universal
testing machine with a nominal crosshead Speed of 3 mm/min. Calculate the modulus using the chord of the curve between
the forte at 0 % and 1 % elongation.
7.16 Flexural rigidity
Flexural rigidity is the ability of the tape to resist bending in the longitudinal direction.
7.16.1 Requirement
The flexural rigidity of the tape in the longitudinal direction shall be between 05 x los3 N . mm and 2,9 x 10B3 N . rm-n.
7.16.2 Procedure
Calculate the flexural rigidity D from the following equation:
E x t”
-
-
D
where
E = modulus of elasticity obtained from 7.14;
t = measured thickness of the tape in millimetres;
V = Poisson’s ratio, set to 0,33.
7.17 Tensile yield forte
The tensile yield forte required to elongate the test piece by 3 % shall not be less than 14,7 N.
7.17.1 Procedure
Use a static-weighing-constant-rate-of-grip Separation tester capable of indicating the load with an accuracy of * 2 %.
Clamp a test piece of tape at least 178 mm long with an initial 102 mm Separation between the jaws. Elongate the test piece
at a rate of 51 mm/min. until a minimum elongation of 10 % is reached. The forte required to produce an elongation of 3 %
is the tensile yield forte.
7.18 Electrical resistance
7.18.1 Requirement
The electrical resistance of any Square area of the magnetic coating shall
-
be greater than 50 x 106 Q;
-
not exceed 50 x 1012 SZ .
The electrical resistance of any Square area of the back coating shall
- not exceed 100 x 106 Q.
7.18.2 Procedure
Condition a test piece of tape in the test environment for 24 h. Position the test piece over two 24-carat gold-plated (see
figure 3), semi-circular electrodes having a radius r = 25,4 mm and a finish of at least N4, so that the recording surface is in
contact with each 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. Apply a forte F of 1,62 N to each end of the test piece. Apply a d.c. voltage of
100 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 the back coating repeat
the procedure with the back surface in contact with the electrodes.
F
F
Figure 3 - Measurement of electrical resistance
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.
Inhibitor tape
7.19
This International Standard does not specify Parameters for assessing whether or not a tape is an inhibitor tape. However,
annex G gives further information on inhibitor tapes.
7.20 Abrasivity
Tape abrasivity is the tendency of the magnetic coating to wear the magnetic heads.
7.20.1 Requirement
The depth of the wear Pattern in a ferrite wear bar shall be less than 1,27 w.
7.20.2 Procedure
A test piece 61 m in length shall be passed for 100 Passes (50 cycles) over a rectangular bar of manganese zinc ferrite (see
figure 4). The bar shall be 0,3 mm wide and its top surface shall be rounded off with a radius r. = 5 mm. The tape Speed
shall be 2,54 m./s, the tension shall be nominally 1,3 N and the wrap angle shall be 12”. The wear depth is measured with a
profilometer across the width of the tape path.
NOTE 6 - Manganese zinc ferrite should be available commercially from Philips Ceramic Division in Saugerties (NY) under Order part number 3H7. This
information is given for the convenience of the users of this International Standard and does not constitute an endorsement by ISO or IEC of this product.
.
--
f
Figure 4 - Measurement of abrasivity (not to scale)
7.21 Light transmittance of the tape and the leader
The light transmittance of the tape and the leader shall be less than 5 % when measured according to the method specified in
annex A.
7.22 Coefficient of dynamic friction
The coefficient of dynamic friction is measured between the surfaces of the tape, and Calcium titanate ceramic.
7.22.1 Requirements
Between the magnetic surface and the back surface : greater than 0,20
Between the magnetic surface and other surfaces: 0,lO to 0,40
Between the back surface and Calcium titanate: 0,lO to 0,25
7.22.2 Procedure for the measurement of the friction between the magnetic surface and the back surface
a) Wrap a first piece of tape around a Calcium titanate ceramic cylinder (Ra = 0,05 Pm) of diameter 25,4 mm and wrap it
with a total wrap angle of more than 90’ with the back surface outwards.
b) Wrap a second test piece, with the magnetic surface inwards, around the first test piece with a total wrap angle of 90’.
c) Exert on one end of the outer test piece a forte of 0,54 N.
d) Attach the other end to a forte gauge mounted on a linear slide.
e) Drive the slide at a Speed of 1 mm/s.
f) Connect the forte gauge to a Plotter to record the results.
7.22.3 Procedure for the measurement of the friction between the magnetic surface or the back surface and Calcium
titanate ceramic
Wrap a piece of tape around a Calcium titanate ceramic cylinder (Ra = 0,05 Pm) of diameter 25,4 mm and wrap it with
a>
a total wrap angle of 90’ with the magnetic surface or the back surface, as appropriate, inwards.
Exert on one end of the test piece a forte sf 0,54 N.
b)
Attach the other end to a forte gauge mounted on a linear slide.
C>
Drive the slide at a Speed of 1 mm/s.
d)
Connect the forte gauge to a Plotter to record the results.
e)
\
NOTE 7 - Calcium titanate ceramic should be available commercially from Philips Ceramic Division in Saugerties (NY) under Order part Ca Ti. This
information is given for the convenience of users of this International Standard and does not constitute an endorsement by ISO or IEC of this product.
8 Magnetit recording characteristics
The magnetic recording characteristics shall be defined by testing the requirements given below.
When performing the 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 on equipment without read-
while-write capability, on the first forward-read-pass) on the same equipment.
rhe following conditions shall apply to the testing of all magnetic recording characteristics, unless otherwise noted.
tape condition: a.c. erased to 2 % or less of the Average Signal Amplitude
tape Speed: 2,54 m/s
within the written track
read track:
gap alignment: within 5’ between the mean write transitions and the read gap
write gap length: 2,0 Pm * 0,3 p
write gap width: 0,216 mm * 0,010 mm
0,36 Fm i: 0,lO p
read gap length:
read gap width: 0,102 mm * 0,010 mm
tape tension: 1,14 N * 0,14 N
recording current: Test Recording Current
physical recording densities: 2f= 1674 ftpmm + 33 ftpmm, corresponding to 2,126 MHz k 2 %
lf = 837 ftpmm + 16 ftpmm, corresponding to 1,063 MHz + 2 %
Bandwidth of the read
3,2 MHz
amplifier:
81 .
Typical Field
The Typical Field shall be between 75 % and 125 % of the Reference Field.
Traceability to the Reference Field is provided by the calibration factors supplied with each Secondary Standard Reference
Tape.
ISOAEC 13421:1993 (E)
82 . Signal amplitude
The Average Signal Amplitude shall be between 85 % and 115 % of the SRA.
Traceability to the SRA is provided by the calibration factors supplied with each Secondary Standard Reference Tape.
83 . Resolution
The ratio of the average Signal amplitude at the physical recording density of 1 674 ftpmm to that at the physical recording
density of 837 ftpmm shall be between 90 % 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 supplied with
each Secondary Standard Reference Tape.
84 . Overwrite
Overwrite is the ratio of the residual Signal of the average Signal amplitude recorded at 837 ftpmm after being overwritten at
1 674 ftpmm to the average Signal amplitude of the 837 ftpmm Signal.
8.4.1 Requirement
The overwrite for the tape shall be less than 110 % 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.
85 . Peak shift
Peak shift is measured as the time displacement from nominal of the ONEs transitions in the MFM-recorded Pattern
1101101 lO.
8.5.1 Requirement
For a peak shift ratio of n % of the Master Standard Reference Tape, the measured peak shift ratio shall be between (n-2) %
and (n+2) %.
Traceability to the peak shift ratio of the Master Standard Reference Tape is provided by the calibration factors supplied
with each Secondary Standard Reference Tape.
8.5.2 Procedure
The time interval measurements shall be averaged over 250 ONE-ONE-ZERO Patterns taken at a sampling rate of 96 times
.
2f
tl. The time between the last ONE in the ONE-
The time between adjacent peaks in the ONE-ONE interval is denoted as
ONE interval to the last ONE in the following ONE-ONE interval is denoted as to.
3$- t()
Peak shift = 2t x 100%
ISO/IEC 1342ltl993 (E)
Figure 5 - Measurement of peak shift
9 Tape quality
91 . 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 less
than 35 % half of the Average Signal Amplitude for the preceding 25,4 mm of tape.
9.1.1 Requirement
The average missing pulse rate shall be less than 20 missing pulses for any recorded length of track of 100 m.
92 . Missing pulse zone
A missing pulse zone is a sequence of missing pulses exceeding 100 mm.
9.2.1 Requirement
Missing pulse zones shall not occur.
93 . Tape durability
This International Standard does not specify Parameters for assessing tape durability. However, a recommended procedure is
described in annex H.
Section 3 - Mechanical specifications of the tape cartridge
10 General
The tape cartridge shall consist of the following elements
- a case
- a reel for the magnetic tape
- a locking mechanism for the reel
-
a magnetic tape wound on the hub of the reel
- a write-inhibit mechanism
-
a tape leader
Dimensional characteristics are specified for those Parameters deemed mandatory for interchange and compatible use of the
cartridge. Where there is freedom of design, only the functional characteristics of the elements described are indicated.
Where they are purely descriptive the dimensions are referred to three reference planes A, B, and C forming a geometrical
trihedral. Where the dimensions are related to the Position of the cartridge in the drive, they may be referenced to another
surface of the cartridge.
In the enclosed drawings a typical implementation is represented in third angle projection.
Figure 6 Shows a general view of the cartridge.
Figure 7 Shows the reference planes A, B, C.
Figure 8 Shows the bottom side of the cartridge.
Figure 9 Shows the right side of the cartridge.
Figure 10 Shows the back side of the cartridge,
Figure 11 Shows the left side of the cartridge.
Figure 12 Shows a partial Cross-section of the cartridge in locked Position.
Figure 13 Shows a partial Cross-section of the cartridge in operating Position.
Figure 14 Shows the leader-to-tape connection.
Figure 15 Shows the splice of the leader-to-tape connection.
Figure 16 Shows the leader.
Figure 17 Shows the front side of the cartridge.
Shows the back side of the cartridge with partial tut.
Figure 18
Figure 19 Shows the top side of the cartridge with partial tut and the door open.
Figure 6 Shows a general view of the cartridge. When it is not in the operating Position, the reel of magnetic tape is locked
and cannot rotate. When loaded into the drive, the back side is introduced first and the front side remains visible during
Operation. During the loading process the tape reel is unlocked and the Position of the cartridge within the drive is fixed by
elements of the drive engaging with corresponding elements of the case.
The Position of the case relative to the reference planes A, B and C is shown in figure 7. The top side lies in reference plane
A, the right side lies in reference plane B and the back side lies in reference plane C.
10.1 Bottom side and right side (figures 8 and 9)
The Overall dimensions of the cartridge shall be
l, = 105,79 mm * 0,20 mm
l2 = 105,41 mm + 0,20 mm
l3 = 25,40 mm + 0,25 rm-n
The bottom side shall have a window the dimensions and the Position of which shall be defined by
l4 = 6,25 mm + 0,lO mm
1, = 4,85 mm Z!I 0,05 mm
!6 = 84,07 mm * 0,20 mm
t7 = 3,81 mm f 0,05 mm
This window allows one of the fingers of the drive to penetrate into the case for partially unlocking the reel of
tape (see 10.6).
A positioning hole on the bottom side and a guiding notch, followed by a positioning notch in the right side determine the
Position of the cartridge in the drive.
The dimensions and the Position of the positioning hole shall be defined by
= 21,59 mm z!z OJO mm
‘8
+ 0,13
= 4,45 mm
e9
- 0,oo mm
l,, = 2,79 mm * 0,05 mm
111 = 44,58 mm + 0,20 mm
The dimensions and the Position of the positioning notch shall be defined by
Q2 = 5,56 mm f 0,lO mm
t13 = 33,30 mm + 0,20 mm
114 = 5,08 mm z!z 0,lO mm
h, = 9,02 mm L- 0,lO mm
A, = 14” +30’
The dimensions and the Position of the guiding notch shall be defined by
t15 = 859 mm + 0,lO mm
&6 = 24,64 mm + 0,lO mm
Q7 = 1,50 mm * 0,05 mm
A, = 45’ AI 30’
A, = 14” If: 30’
The right side shall have an indicator connected to the manually operable write-inhibit switch described in 10.5. The
dimensions and the Position of this indicator shall be defined by
$8 = 8,64 mm f 0,lO mm
l,, = 5,08 mm + 0,lO mm
120 = 86,ll mm & 0,20 mm
121 = 10,16 mm + 0,lO mm
Writing is enabled when the surface of the indicator is substantially flush with the cartridge Wall. When this surface is
recessed by at least 5,l mm writing is inhibited. When a forte of up to 1,O N is exerted perpendicularly on the centre of the
surface of the indicator, it shall not recede by more than 0,5 mm from reference plane B.
10.2 Back side and left side (figures 10 and 11)
The back side shall have a window the dimensions and Position of which shall be
!22 = 8,76 mm f 0,lO mm
!23 = 4,25 mm If: 0,lO mm
!2d = 4,45 mm * OJO mm
!25 = 8,89 mm + 0,lO mm
This window allows a further finger of the drive to penetrate into the case to finally unleck the reel of tape (see also 10.6).
A door shall be rotatably mounted at the corner of the back side and the left side. It is described in 10.6.
ISO/IEC 1342lrl993 (E)
The left side shall have an edge the Position and length of which shall be
lz6 = 61,47 mm + 0,20 mm
+ 0,13
tz7 = 9,65 mm
_ o o. mm
10.3 Tape reel (figures 8,12 and 13)
The bottom side of the case shall have a circular window through which the drive spindle contacts the hub of the reel and
transmits torque. The diameter of this window shall be
d, = 35,05 mm + 0,08 mm
The Position of its centre shall be defined by
th9 = 50,42 mm + 0,31 mm
lTo = 52,83 mm sf- 0,lO mm
The interface between the spindle and the hub is provided by 48 evenly spaced teeth in the hub. In the non-operating
Position, the surface of the hub shall be recessed from the outside surface of the case by
tz8 = 0,38 mm rf: 0,05 mm
The tooth Profile consists of straight flanks. The envelope dimensions of the teeth shall be
d, = 23,88 mm + 0,13 mm
d, = 29,21 mm + 0,13 mm
da = 34,29 mm f 0,13 mm
A, = 22” k 30’
A,=15”+30’
where d, is the pitch diameter of the teeth.
In the operating Position the surface of the hub shall be at a distance
lz9= 23,55 mm + 0,lO mm
from reference plane A.
10.4 Tape leader (figures 14,15 and 16)
The positions of the BOT and EOT relative to the leader/tape connection and to the physical end of the tape shall be as
follows.
The BOT shall be at a distance
130= 8 690 mm i 150 mm
from the leader/tape connection.
The EOT shall be at a distance
131= 2 540 mm kl27 mm
from the physical end of the tape, which is fixed to the hub of the reel. Both the BOT hole and EOT hole shall have a
diameter
ds = 4,78 mm $- 0,lO mm
Figure 15 Shows the relative positions of the tape, the leader and the splice tape. They shall be defined by
11,81 mm min.
‘32=
20,32 mm max.
133= 0,25 mm max.
!34= 0,41 mm max.
135= 0,OO mm min.
136= 0,20 mm max.
Dimensions ! 34, e35 and !36 are related to, and depend on, each other. Dimension !35 expresses the requirement that the
splice tape shall in no case extend beyond the edges of either the tape or the leader.
There shall be no yield of the splice when a forte of 22,2 N max. is applied in longitudinal direction across the splice.
Figure 16 Shows the dimensions of the leader which shall be
+ 0,oo
e37 = 12,65 mm
- 0,lO mm
e3*= 309,63 mm + 0,3
...
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