EN 62071:2001

SLOVENSKI SIST EN 62071:2005
STANDARD
januar 2005
Digitalni videokasetni snemalni sistem z zapisovanjem s poševnimi sledmi na
magnetnem traku, širokem 6,35 mm, in komprimiranjem – Format D-7 (IEC
62071:2000)
(istoveten EN 62071:2001)
Helical-scan compressed digital video cassette recording system using 6, 35 mm
magnetic tape - Format D-7 (IEC 62071:2000)
ICS 33.160.40 Referenčna številka
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

EUROPEAN STANDARD EN 62071
NORME EUROPÉENNE
EUROPÄISCHE NORM March 2001
ICS 33.160.40
English version
Helical-scan compressed digital video cassette recording system
using 6,35 mm magnetic tape -
Format D-7
(IEC 62071:2000)
Système de magnétoscope numérique Videokassettensystem mit komprimierter
à cassette à balayage hélicoïdal digitaler Schrägspuraufzeichnung
à signal compressé utilisant la bande auf Magnetband 6,35 mm -
magnétique de 6,35 mm - Format D-7
Format D-7 (IEC 62071:2000)
(CEI 62071:2000)
This European Standard was approved by CENELEC on 2000-11-01. CENELEC members are bound
to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and
notified to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,
Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway,
Portugal, Spain, Sweden, Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2001 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 62071:2001 E
Foreword
The text of document 100B/271/FDIS, future edition 1 of IEC 62071, prepared by SC 100B, Audio,
video and multimedia information storage systems, of IEC TC 100, Audio, video and multimedia
systems and equipment, was submitted to the IEC-CENELEC parallel vote and was approved by
CENELEC as EN 62071 on 2000-11-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2001-08-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2003-11-01
Annexes designated "normative" are part of the body of the standard.
Annexes designated "informative" are given for information only.
In this standard, annexes A to E and ZA are normative and annex F is informative.
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 62071:2000 was approved by CENELEC as a European
Standard without any modification.
__________
- 3 - EN 62071:2001
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of
any of these publications apply to this European Standard only when incorporated in it by
amendment or revision. For undated references the latest edition of the publication referred to
applies (including amendments).
NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
IEC 61834-1 1998 Recording - Helical-scan digital video EN 61834-1 1998
cassette recording system using 6,35 mm
magnetic tape for consumer use (525-60,
625-50, 1125-60 and 1250-50 systems)
Part 1: General specifications
IEC 61834-2 1998 Part 2: SD format for 525-60 and 625-50 EN 61834-2 1998
systems
SMPTE 12M Television, audio and film - Time and--
control code
ITU-R BT.470-6 1998 Conventional television systems - -
ITU-R BT.601-5 1995 Studio encoding parameters of digital--
television for standard 4:3 and wide-
screen 16:9 aspect radios
NORME CEI
INTERNATIONALE
IEC
INTERNATIONAL
Première édition
STANDARD
First edition
2000-11
Système de magnétoscope numérique à cassette
à balayage hélicoïdal à signal compressé utilisant
la bande magnétique de 6,35 mm – Format D-7
Helical-scan compressed digital video cassette
recording system using 6,35 mm magnetic tape –
Format D-7
© IEC 2000 Droits de reproduction réservés ⎯ Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun procédé, any form or by any means, electronic or mechanical,
électronique ou mécanique, y compris la photocopie et les including photocopying and microfilm, without permission in
microfilms, sans l'accord écrit de l'éditeur. writing from the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http://www.iec.ch
CODE PRIX
Commission Electrotechnique Internationale
PRICE CODE XG
International Electrotechnical Commission
Pour prix, voir catalogue en vigueur
For price, see current catalogue

62071 © IEC:2000 – 3 –
CONTENTS
Page
FOREWORD .15
Clause
1 General. 17
1.1 Scope . 17
1.2 Normative references. 17
1.3 Symbols and abbreviations. 19
1.4 Environment and test conditions. 21
1.5 Reference tapes. 21
1.6 Calibration tapes . 21
2 Video cassette . 23
2.1 Mechanical parameters . 23
2.2 Video tape specification . 77
3 Helical recordings . 79
3.1 Tape speed. 79
3.2 Sectors . 79
3.3 Record location and dimensions . 79
3.4 Helical track record tolerance zones . 79
3.5 Relative positions of recorded information . 79
3.6 Gap azimuth . 91
3.7 Transport and scanner . 91
4 Programme track data. 95
4.1 General. 95
4.2 ITI sector . 119
4.3 Audio sector. 139
4.4 Video sector. 149
4.5 Subcode sector . 157
4.6 Edit gap . 163
5 Audio processing. 165
5.1 Introduction. 165
5.2 Encoding mode . 165
5.3 Audio shuffling . 167
5.4 Audio auxiliary data (AAUX) . 169
5.5 Error correction code addition . 175
6 Video processing. 179
6.1 Introduction. 179
6.2 Video structure. 179
6.3 DCT processing . 203
6.4 Quantization. 207
6.5 Variable length coding (VLC). 213
6.6 Arrangement of a compressed macro block . 213
6.7 Arrangement of a video segment . 221
6.8 Intraframe deshuffling . 225
6.9 Video auxiliary data (VAUX) . 231
6.10 Error correction code addition . 237

62071 © IEC:2000 – 5 –
Clause Page
7 Subcode processing. 239
7.1 Introduction. 239
7.2 Subcode data. 239
7.3 Error correction code addition . 245
8 Longitudinal tracks . 247
8.1 Control track . 247
8.2 Cue track . 249
9 Interface . 251
9.1 Introduction. 251
9.2 Data structure . 251
Annex A (normative) Tape tension . 279
Annex B (normative) Cross-tape track measurement technique. 281
Annex C (normative) Track pattern during insert editing . 287
Annex D (normative) Frequency characteristics of the F track . 289
Annex E (normative) Digital filter. 291
Annex F (informative) Small cassette adapter . 293
Figure 1 – Top and side views of the M cassette . 27
Figure 2 – Top and side views of the L cassette . 29
Figure 3 – Internal structure and tape path for the M cassette . 31
Figure 4 – Internal structure and tape path for the L cassette . 33
Figure 5 – Datum area and support area for the M cassette . 35
Figure 6 – Datum area and support area for the L cassette . 37
Figure 7 – Bottom view of the M cassette. 39
Figure 8 – Bottom view of the L cassette. 41
Figure 9 – Contact area of the ID board for the M cassette. 47
Figure 10 – Contact area of the ID board for the L cassette. 49
Figure 11 – Light path and leader/trailer tape for the M cassette. 51
Figure 12 – Light path and leader/trailer tape for the L cassette. 53
Figure 13 – Reels for the M cassette. 57
Figure 14 – Reels for the L cassette. 59
Figure 15 – Reel lock and release for the M cassette . 61
Figure 16 – Reel lock and release for the L cassette . 63
Figure 17 – Lid lock and release for the M cassette. 65
Figure 18 – Lid lock and release for the L cassette. 67
Figure 19a – Movement of inner lid . 69
Figure 19 – Space of the M cassette for the VTR loading mechanism. 69
Figure 20a – Movement of inner lid . 71
Figure 20 – Space of the L cassette for the VTR loading mechanism. 71
Figure 21 – Lid for the M cassette. 73
Figure 22 – Lid for the L cassette. 75
Figure 23 – Location and dimensions of recorded tracks . 81

62071 © IEC:2000 – 7 –
Page
Figure 24 – Location of the cue and control track recording. 83
Figure 25 – Location and dimensions of the tolerance zone of the helical track recording . 89
Figure 26 – Possible scanner configuration and tape wrap . 93
Figure 27 – Possible recording system configuration with digital interface port. 97
Figure 28 – Sector arrangement on helical track . 99
Figure 29 – Frame and tracks (525/60 system) . 99
Figure 30 – Frame and tracks (625/50 system) . 99
Figure 31 – Frequency characteristics of tracks . 105
Figure 32 – Modulation for the audio sector. 109
Figure 33 – Modulation for the video sector. 111
Figure 34 – Modulation for the subcode sector . 113
Figure 35 – Possible block diagram for signal processing. 115
Figure 36 – Bit stream before interleaved NRZI modulation . 117
Figure 37 – Precoding . 117
Figure 38 – Structure of the ITI sector. 121
Figure 39 – Structure of sync block of the TIA. 135
Figure 40 – Structure of the audio sector . 141
Figure 41 – Structure of sync blocks in the audio sector . 141
Figure 42 – Structure of the video sector. 149
Figure 43 – Structure of sync blocks in the video sector . 153
Figure 44 – Structure of the subcode sector. 159
Figure 45 – Structure of sync blocks in the subcode sector . 161
Figure 46 – Sample for audio data bytes conversion. 167
Figure 47 – Arrangement of AAUX packs in audio auxiliary data. 169
Figure 48 – Data and inner parity of a data sync block . 177
Figure 49 – Data and outer parity of a data sync block for the audio sector. 177
Figure 50 – Transmitting samples for the 525/60 system . 183
Figure 51 – Transmitting samples for the 625/50 system . 185
Figure 52 – DCT block and pixel coordinate . 189
Figure 53 – Rightmost DCT block in the colour-difference signal . 189
Figure 54 – DCT block arrangement . 191
Figure 55 – Macro block and DCT blocks . 191
Figure 56 – Super blocks and macro blocks in one television frame for the 525/60 system . 193
Figure 57 – Super blocks and macro blocks in one television frame for the 625/50 system . 195
Figure 58 – Macro block order in a super block for the 525/60 system . 199
Figure 59 – Macro block order in a super block for the 625/50 system . 199
Figure 60 – Output order of a weighted DCT block . 209

62071 © IEC:2000 – 9 –
Page
Figure 61 – Area numbers . 211
Figure 62 – Arrangement of a compressed macro block . 215
Figure 63 – Arrangement of a video segment after the bit rate reduction . 227
Figure 64 – Video error code . 227
Figure 65 – Relation between the compressed macro block number and
the data sync block. 229
Figure 66 – Arrangement of VAUX packs in VAUX sync blocks . 231
Figure 67 – Data and outer parity of a data sync block for the video sector. 239
Figure 68 – Arrangement of subcode data. 241
Figure 69 – Bit assignment for subcode data and parity. 245
Figure 70 – Recorded control record of waveform timing (525/60 system) . 249
Figure 71 – Recorded control record of waveform timing (625/50 system) . 249
Figure 72 – Data structure for transmission. 253
Figure 73 – Transmission order of a DIF block in a DIF sequence . 255
Figure 74 – Data in the subcode section . 263
Figure 75 – Data in the VAUX section . 265
Figure 76 – Data in the audio section . 271
Figure 77 – Data in the video section . 277
Figure B.1 – Cross-tape measurement technique . 285
Figure B.2 – Correction factors (actual tape speed, tension). 285
Figure B.3 – Track location error plot (example). 285
Figure C.1 – Typical track pattern during insert editing . 287
Figure D.1 – Frequency characteristics of the F track . 289
Figure E.1 – Template for insertion loss frequency characteristic . 291
Figure E.2 – Passband ripple tolerance. 291
Figure F.1 – Top and side view of the adapter. 293
Figure F.2 – Bottom view of the adapter. 295
Figure F.3 – Datum and support areas of the adapter. 297
Figure F.4 – Lid lock and release mechanism of the adapter . 299
Figure F.5 – Lid opening mechanism . 301
Figure F.6 – Light path of the adapter . 301
Table 1 – Mechanical tolerances. 23
Table 2 – Tape length and recording times of M and L cassettes. 25
Table 3 – Identification board for the M cassette . 43
Table 4 – Identification board for the L cassette . 43
Table 5 – Length of leader/trailer tape. 45
Table 6 – Reel spring force. 55
Table 7 – Recording location and dimensions (525/60 system). 85

62071 © IEC:2000 – 11 –
Page
Table 8 – Recording location and dimensions (625/50 system). 87
Table 9 – Parameters for a possible scanner design . 91
Table 10 – Frame and servo information (525/60 system) . 101
Table 11 – Frame and servo information (625/50 system) . 103
Table 12 – Bit stream of ITI preamble for track F . 123
Table 13 – Bit stream of ITI preamble for track F . 125
Table 14 – Bit stream of ITI preamble for track F . 127
Table 15 – Bit stream of the SSA for track F . 129
Table 16 – Bit stream of the SSA for track F . 131
Table 17 – Bit stream of the SSA for track F . 133
Table 18 – Application ID of track information . 135
Table 19 – Pilot frame . 135
Table 20 – Bit stream of the TIA for track F . 135
Table 21 – Bit stream of the TIA for track F . 135
Table 22 – Bit stream of the TIA for track F . 137
Table 23 – Bit stream of ITI postamble for track F . 137
Table 24 – Bit stream of ITI postamble for track F . 137
Table 25 – Bit stream of ITI postamble for track F . 139
Table 26 – ID0 in the audio sector . 143
Table 27 – Audio application ID . 143
Table 28 – Track pair number . 145
Table 29 – Bit assignment of ID codewords. 147
Table 30 – ID data in the video sector . 155
Table 31 – Video application ID . 157
Table 32 – ID data in the subcode sector . 161
Table 33 – Subcode application ID. 161
Table 34 – AAUX data . 171
Table 35 – Mapping of an AAUX source pack. 171
Table 36 – Mapping of an AAUX source control pack . 173
Table 37 – Construction of video signal sampling (4:2:2). 181
Table 38 – Class number and DCT block . 209
Table 39 – Example of classification for reference . 209
Table 40 – Quantization step . 211
Table 41 – Length of codewords . 215
Table 42 – Codewords of variable length coding . 217
Table 43 – Definition of the STA . 219
Table 44 – Codewords of the QNO. 219
Table 45 – VAUX data . 233
Table 46 – Mapping of a VAUX source pack . 233
Table 47 – Mapping of a VAUX source control pack . 235
Table 48 – Mapping of a subcode pack . 241

62071 © IEC:2000 – 13 –
Page
Table 49 – Mapping of a time code pack . 243
Table 50 – Mapping of a binary group pack . 245
Table 51 – ID data in a DIF block. 257
Table 52 – DIF block type . 257
Table 53 – DIF sequence number (525/60 system). 259
Table 54 – DIF sequence number (625/50 system). 259
Table 55 – DIF block number. 259
Table 56 – Data in the header section. 261
Table 57 – DIF blocks and subcode sync blocks . 263
Table 58 – DIF blocks and VAUX data sync blocks . 267
Table 59 – Mapping of a VAUX source pack for interface . 267
Table 60 – Mapping of a VAUX source control pack for interface. 269
Table 61 – DIF blocks and audio data sync blocks . 271
Table 62 – Mapping of an AAUX source pack for interface . 273
Table 63 – Mapping of an AAUX source control pack for interface. 273
Table 64 – DIF blocks and compressed macro block. 277
Table B.1 – Nomenclature and calculation of track location error. 283

62071 © IEC:2000 – 15 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HELICAL-SCAN COMPRESSED DIGITAL VIDEO CASSETTE
RECORDING SYSTEM USING 6,35 mm MAGNETIC TAPE –
FORMAT D-7
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International Organization
for Standardization (ISO) in accordance with conditions determined by agreement between the two
organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62071 has been prepared by subcommittee 100B: Audio, video and
multimedia information storage systems, of IEC technical committee 100: Audio, video and
multimedia systems and equipment.
The text of this standard is based on the following documents:
FDIS Report on voting
100B/271/FDIS 100B/278/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.
Annexes A, B, C, D and E form an integral part of this standard.
Annex F is for information only.
The committee has decided that the contents of this publication will remain unchanged
until 2006. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
62071 © IEC:2000 – 17 –
HELICAL-SCAN COMPRESSED DIGITAL VIDEO CASSETTE
RECORDING SYSTEM USING 6,35 mm MAGNETIC TAPE –
FORMAT D-7
1 General
1.1 Scope
This International Standard specifies the content, format and recording method of the data
blocks containing video, audio and associated data which form the helical records on 6,35 mm
tape in cassettes, as specified in SMPTE 306M.
In addition, this standard specifies the content, format and recording method for longitudinal
cue and control tracks.
One video channel and two independent audio channels are recorded in the digital format.
Each of these channels is designed to be capable of independent editing.
The video channel records and reproduces a component television signal in the 525-line
system with a frame frequency of 29,97 Hz (hereinafter referred to as 525/60 system) and the
625-line system with a frame frequency of 25,00 Hz (hereinafter referred to as the 625/50
system).
Prior to recording, the digital video signal is compressed to a DV based 25 Mb/s bit stream, as
specified in SMPTE 314M.
1.2 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 IEC
and ISO maintain registers of currently valid International Standards.
IEC 61834-1:1998, Recording – Helical-scan digital video cassette recording system using
6,35 mm magnetic tape for consumer use (525/60, 625/50, 1125/60 and 1250/50 systems) –
Part 1: General specifications
IEC 61834-2:1998, Recording – Helical-scan digital video cassette recording system using
6,35 mm magnetic tape for consumer use (525/60, 625/50, 1125/60 and 1250/50 systems) –
Part 2: SD format for 525/60 and 625/50 systems
SMPTE 12M: Television, audio and film – Time and control code
ITU-R BT.470-6:1998, Conventional television systems
ITU-R BT.601-5:1995, Studio encoding parameters of digital television for standard 4:3 and
wide-screen 16:9 aspect ratios

62071 © IEC:2000 – 19 –
1.3 Symbols and abbreviations
AAUX Audio auxiliary data
AP1 Audio application ID
AP2 Video application ID
AP3 Subcode application ID
APT Track application ID
Arb Arbitrary
ASA AUX source pack
ASC AAUX source control pack
B/W Black-and-white flag
CGMS Copy generation management system
DBN DIF block number
DCT Discrete cosine transform
DIF Digital interface
DSF DIF sequence flag
ECC Error correction code
EFC Emphasis channel flag
EOB End of block
IDP ID parity
ITI Initial track information
LF Locked mode flag
PF Pilot frame
QNO Quantization number
QU Quantization
Res Reserved for future use
SMP Sampling frequency
SSA Start sync area
SSYB Subcode sync block number
STA Status of the compressed macro block
Syb Sync block number
TF Transmitting flag
TIA Track information area
Trp Track pair number
VAUX Video auxiliary data
VLC Variable length coding
VS VAUX source pack
VSC VAUX source control pack
VSM Vibrating sample magnetometer

62071 © IEC:2000 – 21 –
1.4 Environment and test conditions
Tests and measurements made on the system to check conformity with the requirements of
this standard shall be carried out under the following conditions:
– Temperature: 20 °C ± 1 °C
– Relative humidity: (50 ± 2) %
– Barometric pressure: from 86 kPa to 106 kPa
– Tape conditioning: not less than 24 h
– Center tape tension: 0,09 N ± 0,02 N (see annex A)
1.5 Reference tapes
Blank tape to be used for calibration recordings may be purchased from the following
1)
manufacturer :
Company
Matsushita Electric Industrial Co., Ltd.
Audio and Video Systems Division
2 15, Matsuba cho, Kadoma city,
Osaka 571 Japan
TEL.: +81 6 901 1161
FAX.: +81 6 905 4048
TLX.: +81 6 529 4690
Part number
TBA
1.6 Calibration tapes
Manufacturers of video tape recorders designed for this format specification may sell
calibration tapes meeting the following requirements.
1.6.1 Record locations and dimensions
Tolerances shown in table 5 or table 6 will be reduced by 50 %.
1.6.2 Calibration signals
Two sets of signals shall be recorded on the calibration tape:
a) A series of conventional test signals
Video : 100 % colour bars
Audio: 1 kHz tone at 20 dB below full level
Cue: 1 kHz tone at reference level
10 kHz tone at reference level
b) A signal of constant recorded frequency (i.e. half the Nyquist frequency) only with tracks of
field 0, segment 0 for the purpose of mechanical alignment
___________
1)
This information is given for the convenience of users of this International Standard and does not constitute an
endorsement by the IEC of the product named. Equivalent products may be used if they can be shown to lead to
the same results.
62071 © IEC:2000 – 23 –
1.6.3 Purchase
1)
The calibration tape may be purchased from the following manufacturer :
Company
Matsushita Electric Industrial Co., Ltd.
Audio and Video Systems Division
2 15, Matsuba cho, Kadoma city,
Osaka 571 Japan.
TEL.: +81-6 901 1161
FAX.: +81-6 905 4048
TLX.: +81-6 529 4690
Part number
for 525/60 system
– Conventional test: TBA
– Mechanical alignment: TBA
for 625/50 system
– Conventional test: TBA
– Mechanical alignment: TBA
2 Video cassette
2.1 Mechanical parameters
2.1.1 General specifications
2.2.2.1 The dimensions of the two cassettes used for recording shall be in accordance with
figures 1 to 22.
2.1.1.2 The general tolerances for dimensions, except those for which tolerances are
otherwise specified, shall be as indicated in table 1.
Table 1 – Mechanical tolerances
Length Tolerance
mm
over to mm
0 30
±0,1
30 50
±0,15
±0,2
Angle
±1,0°
2.1.1.3 The two sizes of cassettes shall be identified as:
– Medium: M
– Large: L
NOTE Annex F shows the adaptor size for the small cassette which is specified in IEC 61834-1.
___________
1)
This information is given for the convenience of users of this International Standard and does not constitute an
endorsement by the IEC of the product named. Equivalent products may be used if they can be shown to lead to
the same results.
62071 © IEC:2000 – 25 –
2.1.1.4 Tape length and record times for the two cassette sizes shall be as given in table 2.
Table 2 – Tape length and recording times of M and L cassettes
Tape D-7 record times Length
Cassette
min m
M12 +1
24 +1
33 +1
46 +1
66 +1
L34 +1
66 +1
94 +1
126 +2
2.1.1.5 The magnetic coating on the tape shall face out of the cassette, as specified in figures
3 and 4.
2.1.2 Datum plane
2.1.2.1 Datum plane Z is determined by datum areas A, B and C, as specified in figures 5
and 6.
2.1.2.2 Datum plane X shall be orthogonal to datum plane Z and shall run through the center
of datum hole (A) and datum hole (B), as specified in figures 7 and 8.
2.1.2.3 Datum plane Y shall be orthogonal to both datum plane X and datum plane Z and shall
run through the center of datum hole (A), as specified in figures 7 and 8.
2.1.3 Window and labels
2.1.3.1 Window and label areas shall be as specified in figures 1 and 2.
2.1.3.2 Labels attached to the cassette shall not extend beyond the external dimensions, as
shown in figures 1 and 2.
2.1.3.3 Labels shall not interfere with the ID board or accidental erasure prevention hole for
users or manufacturers.
2.1.3.4 Labels shall not interfere with the hub drive and support mechanism.

62071 © IEC:2000 – 27 –
Incorrect insertion prevention groove for direction X
Incorrect insertion prevention
incline for direction Y
Section A-A
Changer grip
Incorrect insertion
Prevention recess for direction Z
Detail B
Note 6 Note 7
Window area Label area
Holding area 1 Holding area 2
IEC  1908/2000
Dimensions in millimetres
NOTE 1 Maximum outside dimension of the shells.
NOTE 2 The tolerance applies to the region up to 6,7 mm from datum plane Z.
NOTE 3 The dimension applies to the upper half.
NOTE 4 The tolerance applies to the region up to 6,7 mm from datum plane Z. The general tolerance applies
beyond 6,7 mm.
NOTE 5 The lid width shall be smaller than the shell width.
NOTE 6 The cassette shall be held in the recorder/player within the area indicated.
NOTE 7 When the lid is open, a portion of this area may not be available for the cassette holding mechanism
(see figure 19).
NOTE 8 The surface roughness of holding areas 1 and 2 shall not exceed 40 µm Rmax.
NOTE 9 The indication of the accidental erasure prevention shall be placed in this area (see figure 9 for the
accidental erasure prevention dimensions).
Figure 1 – Top and side views of the M
...