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
...
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