Information technology — 12,65 mm wide magnetic tape cassette for information interchange — Helical scan recording — DTF-2

This International Standard specifies the physical and magnetic characteristics of magnetic tape cassettes, using magnetic tape 12,65 mm wide so as to provide physical interchange of such cassettes between drives. It also specifies the quality of the recorded signals, the recording method and the recorded format, called Digital Tape Format-2 (DTF-2), thereby allowing data interchange between drives by means of such cassettes. The format supports variable length Logical Records, high-speed search, and the use of a registered algorithm for data compression. This International Standard specifies two sizes of cassette. For the purposes of this International Standard the larger cassette is referred to as Type L, and the smaller as Type S. Together with a standard for volume and file structure, e.g. International Standard ISO 1001, this International Standard provides for full data interchange between data processing systems.

Technologies de l'information — Cassette de bande magnétique de 12,65 mm de large pour l'échange d'information — Enregistrement par balayage en spirale — DTF-2

General Information

Status
Published
Publication Date
28-Nov-2001
Current Stage
9093 - International Standard confirmed
Start Date
20-Sep-2007
Completion Date
21-Aug-2020
Ref Project

Buy Standard

Standard
ISO/IEC 20061:2001 - Information technology -- 12,65 mm wide magnetic tape cassette for information interchange -- Helical scan recording -- DTF-2
English language
100 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

INTERNATIONAL ISO/IEC
STANDARD 20061
First edition
2001-12-01
Information technology — 12,65 mm wide
magnetic tape cassette for information
interchange — Helical scan recording —
DTF-2
Technologies de l'information — Cassette de bande magnétique de
12,65 mm de large pour l'échange d'information — Enregistrement par
balayage en spirale — DTF-2
Reference number
ISO/IEC 20061:2001(E)
ISO/IEC 2001
---------------------- Page: 1 ----------------------
ISO/IEC 20061:2001(E)
PDF disclaimer

This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not

be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this

file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this

area.
Adobe is a trademark of Adobe Systems Incorporated.

Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters

were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event

that a problem relating to it is found, please inform the Central Secretariat at the address given below.

© ISO/IEC 2001

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic

or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's member body

in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.ch
Web www.iso.ch
Printed in Switzerland
ii © ISO/IEC 2001 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/IEC 20061:2001(E)
Contents Page
Section 1 - General 1
1 Scope 1
2 Conformance 1
2.1 Magnetic tape cassette 1
2.2 Generating system 1
2.3 Receiving system 1
3 Normative references 1
4 Terms and definitions 2
4.1 Absolute block number 2
4.2 a.c. erase 2
4.3 algorithm 2
4.4 Append file 2
4.5 Append volume 2
4.6 Average Signal Amplitude (ASA) 2
4.7 azimuth 2
4.8 back surface 2
4.9 bit cell 2
4.10 block 2
4.11 Block Management Table (BMT) 2
4.12 byte 2
4.13 cassette 2
4.14 compressed data 2
4.15 Control Track 2
4.16 flux transition position 2
4.17 flux transition spacing 2
4.18 Logical track set ID 2
4.19 Logical volume 2
4.20 magnetic tape 2
4.21 Master Standard Reference Tape (MSRT) 2
4.22 physical recording density 2
4.23 Reference Field (RF) 2
4.24 Secondary Standard Reference Tape (SSRT) 2
4.25 Standard Reference Amplitude (SRA) 3
4.26 Standard Reference Current (Ir) 3
4.27 Tape Reference Edge 3
4.28 Test Recording Current (TRC) 3
4.29 track 3
4.30 track angle 3
4.31 Track Set 3
4.32 Typical Field (TF) 3
4.33 word 3
5 Conventions and notations 3
5.1 Representation of numbers 3
5.2 Names 3
6 Acronyms 4
7 Environment and safety 4
© ISO/IEC 2001 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/IEC 20061:2001(E)
7.1 Testing environment 4
7.2 Operating environment 4
7.3 Storage environment 5
7.4 Transportation 5
7.5 Safety 5
7.6 Flammability 5
Section 2 - Requirements for the case 5
8 Dimensional and mechanical characteristics of the case 5
8.1 General 5
8.2 Type S cassette 5
8.2.1 Overall dimensions (Figure 3) 6
8.2.2 Holding areas (Figure 4) 6
8.2.3 Window 6
8.2.4 Label areas (Figure 4) 7
8.2.5 Datum areas and datum holes (Figures 5 and 6) 7
8.2.6 Support areas (Figure 5) 7
8.2.7 Guiding grooves (Figures 3 and 6) 8
8.2.8 Recognition holes (Figures 6 and 7) 9
8.2.9 Write-inhibit plug (Figure 8) 10
8.2.10 Pre-positioning surface (Figures 3 and 5) 11
8.2.11 Cassette lid (Figures 9, 10, 11, 12 and 13) 11
8.2.12 Cassette reel lock (Figure 13) 12
8.2.13 Reel access holes (Figure 6) 13
8.2.14 Reels (Figure 14) 13
8.2.15 Position of the tape in the case (Figure 16) 14
8.2.16 Tape path zone (Figures 16 to 18) 14
8.2.17 Tape access cavity (Figure 19) 15
8.3 Type L cassette 30
8.3.1 Overall dimensions (Figure 22) 30
8.3.2 Holding areas (Figure 23) 30
8.3.3 Window 31
8.3.4 Label areas (Figure 23) 31
8.3.5 Datum areas and datum holes (Figures 24 and 25) 31
8.3.6 Support areas (Figure 24) 32
8.3.7 Guiding grooves (Figure 25) 32
8.3.8 Recognition holes (Figure 26) 33
8.3.9 Write-inhibit plug (Figure 27) 34
8.3.10 Pre-positioning surface (Figures 24 and 25) 35
8.3.11 Cassette lid (Figures 28, 29, 30, 31 and 32) 35
8.3.12 Cassette reel lock (Figure 32) 36
8.3.13 Reel access holes (Figure 25) 36
8.3.14 Reels (Figure 33) 37
8.3.15 Position of the tape in the case (Figure 35) 38
8.3.16 Tape path zone (Figures 35 to 37) 38
8.3.17 Tape access cavity (Figure 38) 39
8.3.18 Cavity for compatibility with Type S cassette (Figure 39) 40
Section 3 - Requirements for the unrecorded tape 55
9 Mechanical, physical and dimensional characteristics of the tape 55
9.1 Materials 55
9.2 Tape length 55
9.3 Tape width 55
9.4 Width and position of splicing tape 55
9.5 Discontinuity 55
9.6 Tape thickness 55
9.7 Longitudinal curvature 55
9.8 Out-of-plane distortions 56
iv © ISO/IEC 2001 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/IEC 20061:2001(E)
9.9 Coating adhesion 56
9.10 Layer-to-layer adhesion 57
9.11 Tensile strength 57
9.11.1 Breaking strength 57
9.11.2 Yield strength 57
9.11.3 Strength of splice 57
9.12 Residual elongation 57
9.13 Electrical resistance of the coated surfaces 57
9.14 Tape wind 58
10 Magnetic recording characteristics 58
10.1 Typical Field (TF1) 58
10.2 Average Signal Amplitude(ASA) 59
10.3 Resolution 59
10.4 Signal-to-noise ratio (S/N) 59
10.5 Ease of erasure 59
10.6 Tape quality 59
10.6.1 Missing pulses 59
10.6.2 Missing pulse zone 59
10.7 Inhibitor tape 59
11 Format for helical tracks 60
11.1 General description of the write data path (see Figure 42) 60
11.2 Formation of a Logical Track Set 60
11.2.1 Types of information track sets 60
11.2.2 Generation of a Logical Track Set 62
11.2.3 Subcode data field 62
11.2.4 Block Management Table (BMT) 66
11.2.5 Data and information field definitions 66
11.3 Track Set information 70
11.3.1 Loading the Product Code Arrays 70
11.4 Product code array processing 72
11.4.1 Error correction method 72
11.4.2 Error correction coding for C1 Parity 72
11.5 Track assignments 73
11.5.1 Segments/Sectors (Figure 46) 73
11.5.2 Sync Blocks (Figure 47) 74
11.5.3 Track interleave (Figure 48) 74
11.5.4 Byte interleave across Sync Blocks (Figure 49) 77
11.5.5 Randomization 77
11.6 Formation of the contents of a helical track (Figure 50) 78
11.6.1 Segment/Sector details (Figure 47) 78
11.6.2 Channel bit coding 79
11.6.3 Interleaved-NRZ1 (Figure 51) 79
11.6.4 Tracking Pilot Signals (TPS) 79
12 Track geometry 79
12.1 General 79
12.2 Helically recorded tracks 80
12.2.1 Location of the tracks 80
12.2.2 Track width 81
12.2.3 Track angle 81
12.2.4 Track pitch 81
12.2.5 Location of elements in the helical track 82
© ISO/IEC 2001 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO/IEC 20061:2001(E)
12.2.6 Location of the Data Area Reference Point 82
12.2.7 Straightness of tracks 82
12.2.8 Azimuth angles 82
12.2.9 Tracking Pilot Signals (TPS) 82
12.2.10 Amplitude of servo signals 82
12.3 Longitudinal tracks geometry 82
12.3.1 Control Track 82
12.3.2 Time Code Track signals recording position 83
13 Method of recording helical tracks 83
13.1 Physical recording density 83
13.2 Record current optimization 83
13.3 Efficiency of erasure 83
14 Method of recording longitudinal tracks 83
14.1 Overview 83
14.2 Control Track 83
14.2.1 Signal 83
14.2.2 Polarity of magnetisation (Figure 54) 83
14.2.3 Alignment 83
14.2.4 Read signal amplitude 84
14.2.5 Quality of the Control Track 84
14.3 Time Code Track 84
14.3.1 Method of recording the Time Code Track 84
14.3.2 Physical recording density 84
14.3.3 Bit shift 84
14.3.4 Read signal amplitude 84
14.3.5 Quality of the Time Code Track 85
14.4 Format for the Time Code Track 85
14.4.1 Count bits 85
14.4.2 Phase bit 85
14.4.3 Synchronizing pattern 85
14.4.4 Supplemental Data 85
14.4.5 Extent of Time Code 85
Section 5 - Requirements for recorded information 85
15 Recorded information 85
15.1 Recording area (Figure 55) 85
15.2 Magnetic tape layout (Figure 56) 85
15.2.1 Valid data areas 85
15.2.2 Invalid data areas 86
15.3 Physical TSID 86
15.3.1 Structure surrounding the VSIT area 88
15.3.2 Structure of the DIT area 88
15.3.3 Structure of the User Data Area 89
Section 6 - Write operations 89
16 Write retry sequence (Figure 58) 89
17 Append file operation (Figure 59) 90
17.1 Append volume 90
17.2 Append write (Figure 60) 90
17.3 Overwrite (Figure 61) 91
vi © ISO/IEC 2001 – All rights reserved
---------------------- Page: 6 ----------------------
ISO/IEC 20061:2001(E)
17.4 File extension (Figure 62) 92
Annexes
A - Measurement of Signal-to-Noise Ratio 94
B - Representation 8/9 coding patterns 95
C - Recommendations for transportation 99
D - Inhibitor tape 100
© ISO/IEC 2001 – All rights reserved vii
---------------------- Page: 7 ----------------------
ISO/IEC 20061:2001(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, 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.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.

The main task of the joint technical committee is to prepare International Standards. 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.

Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights.

ISO and IEC shall not be held responsible for identifying any or all such patent rights.

ISO/IEC 20061 was prepared by ECMA (as Standard ECMA-315) and was adopted, under a special “fast-track procedure”, by

Joint Technical Committee ISO/IEC JTC 1, Information technology, in parallel with its approval of national bodies of ISO and

IEC.

Annexes A and B form a normative part of this International Standard. Annexes C and D are for information only.

viii © ISO/IEC 2001 – All rights reserved
---------------------- Page: 8 ----------------------
INTERNATIONAL STANDARD ISO/IEC 20061:2001(E)
Information technology — 12,65 mm wide magnetic tape cassette for information
interchange — Helical scan recording — DTF-2
Section 1 - General
1 Scope

This International Standard specifies the physical and magnetic characteristics of magnetic tape cassettes, using magnetic tape

12,65 mm wide so as to provide physical interchange of such cassettes between drives. It also specifies the quality of the

recorded signals, the recording method and the recorded format, called Digital Tape Format-2 (DTF-2), thereby allowing data

interchange between drives by means of such cassettes. The format supports variable length Logical Records, high-speed

search, and the use of a registered algorithm for data compression.

This International Standard specifies two sizes of cassette. For the purposes of this International Standard the larger cassette is

referred to as Type L, and the smaller as Type S.

Together with a standard for volume and file structure, e.g. International Standard ISO 1001, this International Standard

provides for full data interchange between data processing systems.
2 Conformance
2.1 Magnetic tape cassette

A claim of conformance with this International Standard shall specify the Type of cassette. It shall be in conformance with this

International Standard if:

− the case and unrecorded tape meet all the requirements of clause 8 to 10 for that Type

− the recording on the tape meets the requirements of clauses 11 to 17
2.2 Generating system

A claim of conformance with this International Standard shall specify which Type(s) of cassette is (are) supported. A system

generating a magnetic tape cassette for interchange shall be in conformance with this International Standard if all the

recordings that it makes, meet the mandatory requirements of this International Standard. A claim of conformance with this

International Standard shall state whether or not one, or more, registered algorithm(s) is (are) implemented and, if so, the

registered number(s) of (all) the implemented algorithm(s).
2.3 Receiving system

A claim of conformance with this International Standard shall specify which Type(s) of cassette is (are) supported. A system

receiving a magnetic tape cassette for interchange shall be in conformance with this International Standard if it is able to

handle any recording made on the tape according to this International Standard, and a claim of conformance shall state whether

or not one, or more, registered algorithm(s) is (are) implemented and, if so, the registered number(s) of (all) the implemented

algorithm(s).
3 Normative references

The following normative documents contain provisions which, through reference in this text, constitute provisions of this

International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not

apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of

applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the

normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards.

ISO 527-3:1995, Plastics — Determination of tensile properties — Part 3: Test conditions for films and sheets

ISO 1001:1986, Information processing — File structure and labelling of magnetic tapes for information interchange

ISO/IEC 11576:1994, Information technology — Procedure for the registration of algorithms for the lossless compression of

data
© ISO/IEC 2001 – All rights reserved 1
---------------------- Page: 9 ----------------------
ISO/IEC 20061:2001(E)

SMPTE timecode: C98.12 : time and control code for video and audio tape for 525/60 television system

JIS-B-7502 Characteristics of plastic goods
4 Terms and definitions

For the purposes of this International Standard, the following terms and definitions apply.

4.1 Absolute block number: A number N allocated to each block, indicating that the block is the Nth block from the

beginning of the Logical volume containing it. The first block is number one.

4.2 a.c. erase: A process of erasure utilizing alternating magnetic fields of decaying intensity.

4.3 algorithm: A set of rules for transforming the logical representation of data.

4.4 Append file: A new file added from the End of Data (EOD) of a Logical volume.

4.5 Append volume: A Logical volume added after the last Logical volume recorded on the cassette.

4.6 Average Signal Amplitude (ASA): The average peak-to-peak value of the signal output of a read head measured

over a minimum of 1,40 mm of track, exclusive of missing pulses.

4.7 azimuth: The angular deviation, in degrees of arc, of the recorded flux transitions on a track from the line normal to

the track centreline.

4.8 back surface: The surface of the tape opposite to the magnetic coating used to record data.

4.9 bit cell: A distance along the track allocated for the recording of a Channel bit.

4.10 block: A unit of data which is sent to the tape controller when a single write command is executed.

4.11 Block Management Table (BMT): A table included in each Track Set to manage blocks contained in that Track

Set.
4.12 byte: An ordered set of bits acted upon as a unit.
4.13 cassette: A case containing magnetic tape stored on twin reels.

4.14 compressed data: A representation of host-transmitted data after transformation by a data compression algorithm.

4.15 Control Track: A track used for recording the servo control signals.

4.16 flux transition position: That point along a track on the magnetic tape that exhibits the maximum free-space flux

density normal to the tape surface.

4.17 flux transition spacing: The distance along a track between successive flux transitions.

4.18 Logical track set ID: The track set ID assigned to each track set containing data received from the host.

4.19 Logical volume: A data entity received by the generating system from the host.

4.20 magnetic tape: A tape which will accept and retain the magnetic signals intended for input, output, and storage

purposes.

4.21 Master Standard Reference Tape (MSRT): A tape selected as the standard for Signal Amplitude, Reference

Field, Resolution and Signal to Noise Ratio (S/N).

Note - The Master Standard Reference Tape has been established at SONY Corporation.

4.22 physical recording density: The number of recorded flux transitions per unit length of track, specified as flux

transitions per millimetre (ftpmm).

4.23 Reference Field (RF): The Typical Field of the MSRT. There are two Reference Fields:

RF1 is that for a helically recorded track
RF2 is that for a longitudinally recorded track.

4.24 Secondary Standard Reference Tape (SSRT): A tape the performance of which is known and stated in relation

to that of the MSRT.

Note - Secondary Standard Reference Tapes can be ordered under the Part Number SSRT-DTF-1, from the Sony Corporation, Magnetic

Product Group, Data Media Sales Division, 6-7-3S Kitashinagawa, Shinagawa-ku, TOKYO 141, Japan. In principle such tapes will be

available for a period of 10 years from the publication of the International Standard. However, by agreement between ECMA and Sony

Corporation, this period may be shortened or extended to take account of demand for such SSRTs.

It is intended that these SSRTs be used for calibrating tertiary reference tapes for use in routine calibration.

2 © ISO/IEC 2001 – All rights reserved
---------------------- Page: 10 ----------------------
ISO/IEC 20061:2001(E)

4.25 Standard Reference Amplitude (SRA): The Average Signal Amplitude derived from the MSRT, using the

appropriate Test Recording Current and the appropriate physical recording density. There are three SRAs. SRA1 is

derived from a helically recorded track, recorded at 3 201 ftpmm with TRC1. SRA2 is derived from a longitudinally

recorded track at 20,75 ftpmm with TRC2. SRA3 is derived from a helically recorded track, recorded at 800,3 ftpmm

with TRC1.

4.26 Standard Reference Current (Ir): The current that produces a Reference Field. There are two Irs.

Ir1 is the current that produces RF1 on a helically recorded track.
Ir2 is the current that produces RF2 on a longitudinally recorded track.

4.27 Tape Reference Edge: The lower edge of the tape when the magnetic coating is facing the observer and the supply

reel is to the observer’s right.

4.28 Test Recording Current (TRC): The current used to record an SRA. There are two Test Recording Currents:

TRC1 is 1,1 times Ir1
TRC2 is 1,0 times Ir2

4.29 track: A narrow, defined area on the tape along which a series of magnetic transitions may be recorded. A track may

be parallel to the Tape Reference Edge or at an angle to it.

4.30 track angle: The angle between the centreline of a helically recorded track and the Tape Reference Edge.

4.31 Track Set: A set of four consecutive helical tracks uniquely identified by a track set identification.

4.32 Typical Field (TF): There are two TFs:
In the plot of the ASA against the recording field:

TF1 is the minimum recording field giving an ASA equal to 90 % of the maximum ASA at the physical recording density of 3

201 ftpmm on a helically recorded track.

TF2 is the value of the recording field for which the increase of ASA resulting from an increase of 1 dB of the recording field

falls by 0,5 dB at the physical recording density of 20,75 ftpmm on a longitudinally recorded track.

4.33 word: A group (or set) of four 8-bit bytes, numbered 0 to 3, byte 3 being the most significant.

5 Conventions and notations
5.1 Representation of numbers

• A measured value is rounded off to the least significant digit of the corresponding specified value. It implies that a

specified value of 1,26 with a positive tolerance of 0,01, and a negative tolerance of 0,02 allows a range of measured

values from 1,235 to 1,275.
• Letters and digits in parentheses represent numbers in hexadecimal notation.
• The setting of a bit is denoted by ZERO or ONE.

• Numbers in binary notation and bit combinations are represented by strings of digits 0 and 1. Within such strings, X may

be used to indicate that the setting of a bit is not specified within the string.

• Numbers in binary notation and bit combinations are shown as Words with the MSB to the left, and with the msb in each

byte to the left.
• Negative values of numbers in binary notion are given in TWOs complement.

• In each field the data is processed so that the MSB is processed first. Within each byte the msb (numbered 7 in an 8-bit

byte) is processed first. This order of processing applies also to the data input to the Error Detection and Correction

circuits and to their outputs, unless otherwise stated.
5.2 Names

The names of entities, e.g. specific tracks, fields, etc., are given with a capital initial.

© ISO/IEC 2001 – All rights reserved 3
---------------------- Page: 11 ----------------------
ISO/IEC 20061:2001(E)
6 Acronyms
ASA Average Signal Amplitude
CRC Cyclic Redundancy Check
BMT Block Management Table
BST Bad Spot Table
DIT Directory Information Table
DM Dummy Track
ECC Error Correcting Code
EOD End of Data
FIT File Information Table
LBOT Logical Beginning of Tape
LEOT Logical End of Tape
LIDT Logical ID Table
lsb Least Significant Bit
LSB Least Significant Byte
msb Most Significant Bit
MSB Most Significant Byte
MSRT Master Standard Reference Tape
NEOT Near End of Tape
PBOT Physical Beginning of Tape
PEOT Physical End of Tape
SRA Standard Reference Amplitude
SSRT Secondary Standard Reference Tape
TF Typical Field
TPS Tracking Pilot Signal
TRC Test Recording Current
TSID Track Set Identification
UID Unique Identifier
UT Update Table
VEOV Virtual End of Volume
VIT Volume Information Table
VSIT Volume Set Information Table
7 Environment and safety

The conditions specified below refer to ambient conditions immediately surrounding the cassette. Cassettes exposed to

environments outside these limits may still be able to function usefully; however, such exposure may cause permanent damage.

7.1 Testing environment

Unless otherwise specified, tests and measurements made on the tape to check the requirements of this Standard shall be made

under the following conditions.
temperature 23 °C ± 1 °C
relative humidity 48 % to 52 %
conditioning period before use 24 h min.
7.2 Operating environment

Cassettes used for data interchange shall be operated under the following conditions:

temperature 5 °C to 40 °C
relative humidity 20 % to 80 % non-condensing
wet bulb temperature 26 °C max

The cassette shall be conditioned before use in the operating environment for a time at least equal to the period during which it

has been out of the operating environment, up to a maximum of 24 h.
4 © ISO/IEC 2001 – All rights reserved
---------------------- Page: 12 ----------------------
ISO/IEC 20061:2001(E)
7.3 Storage environment
The following conditions shall be observed for storage.
temperature: 5 °C to 32 °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

cassette.
7.4 Transportation

Recommended limits for the environment to which a cassette may be subjected during transportation, and the precautions to be

taken to minimize the possibility of damage, are provided in annex C.
7.5 Safety

The cassette and its components shall satisfy the requirements of ECMA-287 when used in the intended manner or in any

foreseeable use in an information processing system.
7.6 Flammability

The tape and the case components shall be made from materials which, when ignited from a match flame, do not continue to

burn in a still carbon dioxide atmosphere.
Section 2 - Requirements for the case
8 Dimensional and mechanical characteristics of the case
8.1 General
The case of the cassette shall comprise
− an upper half
− a lower half
− a lid pivotally mounted on the upper half
− a latch mechanism for the lid
− two reels for magnetic tape
− a locking mechanism for the reels
− a write-inhibit mechanism
− recognition holes.
In the drawings, embodiments of the cassettes are shown as examples.

For the Type S cassette the dimensions are referred to three orthogonal Reference Planes X, Y, and Z where

− The three datum areas A, B and C in the bottom side of the case are in Plane Z

− Plane X is perpendicular to Plane Z and intersects the centres of datum holes A and B

− Plane Y is perpendicular to Plane X and Plane Z and intersects the centre of datum hole A.

For the Type L cassette the dimensions are referred to three orthogonal Reference Planes X, Y, and Z where

− The three datum areas E, F and G in the bottom side of the case are in Plane Z

− Plane X is perpendicular to Plane Z and intersects the centres of datum holes E and F

− Plane Y is perpendicular to Plane X and Plane Z and intersects the centre of datum hole E.

Figures 1 to 19 and sub-clause 8.2 define the dimensions of the case and reels for a Type S cassette.

Figures 20 to 39 and sub-clause 8.3 define the dimensions of the case and reels for a Type L cassette.

8.2 Type S cassette
Figure 1 is a perspective view seen from the top.
Figure 2 is a perspective view seen from the bottom.
Figure 3 shows the top side with the lid closed using third angle projection.
Figure 4 shows the top side holding and label areas.
Figure 5 shows the bottom side with the lid removed.
© ISO/IEC 2001 – All rights reserved 5
---------------------- Page: 13 ----------------------
ISO/IEC 20061:2001(E)
Figure 6 shows the bottom side with the lid closed.
Figure 7 shows the details of the recognition holes.
Figure 8 shows the details of the write-inhibit plug.
Figure 9 shows the detail of the lid release insertion channel.
Figure 10 shows the lid unlock force direction.
Figure 11 shows the detail of the lid opening insertion channel.
Figure 12 shows the lid opening force direction.
Figure 13 shows the side view with the lid open.
Figure 14 shows the cassette reel.
Figure 15 shows the height of reels upon rotation.
Figure 16 shows the internal tape path.
Figure 17 shows the tape path to measure the extraction force.

Figure 18 shows the tape path to measure the friction torque of the take-up reel.

Figure 19 shows the tape access cavity requirements.
8.2.1 Overall dimensions (Figure 3)

The overall dimensions of the case with the lid in the closed position are defined as follows. The total width of the case shall be

l = 96,0 mm ± 0,3 mm
The total length of the case shall be
+0,2 mm
l =156,0 mm
-0,3 mm
The distance from the top of the case to the Reference Plane Z shall be
l = 25,0 mm ± 0,3 mm
The front-top bevel edge shall start in the top side at a distance

l = 3,0 mm ± 0,5 mm from the front side and shall terminate in the front side at a distance

l = 5,0 mm ± 0,5 mm from the top side
The bottom-front edge of the case shall be rounded with a radius
r = 1,0 mm ± 0,1 mm
The distance from the rear side to plane X shall be
+0,2 mm
l = 9,0 mm
6 −0,1 mm
The distance from the right side to plane Y shall be
+0,2 mm
l = 8,0 mm
7 −0,1 mm
8.2.2 Holding areas (Figure 4)

The holding areas, shown cross-hatched, lie in Plane Z and shall be the areas along which the cassette shall be held down when

inserted into the drive. The left and right edge holding areas shall extend from the rear side a distance of

l = 69,4 mm min.
The width of the holding surface along the rear edge shall be
l = 10,2 mm min.
The width of the left and right holding surfaces shall be
l = 5,7 mm min.
8.2.3 Window

A window may be provided on the top side so that a part of the reels is visible. The window, if provided, shall not extend

beyond the height of the cassette and shall not extend beyond the inner edge of the holding areas.

6 © ISO/IEC 2001 – All rights reserved
---------------------- Page: 14 ----------------------
ISO/IEC 20061:2001(E)
8.2.4 Label areas (Figure 4)

A portion of the rear side of the cassette and a portion of the top side of the cassette may be used for labels. The position and

the size of the labels shall not interfere with the operation or clearance requirement of the cassette comp

...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.