SIST EN 61119-1:1999

SLOVENSKI STANDARD
01-april-1999
Digital audio tape cassette system (DAT) -- Part 1: Dimensions and characteristics
(IEC 61119-1:1992)
Digital audio tape cassette system (DAT) -- Part 1: Dimensions and characteristics
Digitales Tonband-Kassetten-System -- Teil 1: Maße und Kennwerte
Système audionumérique à cassette (DAT) -- Partie 1: Dimensions et caractéristiques
Ta slovenski standard je istoveten z: EN 61119-1:1994
ICS:
33.160.30 Avdio sistemi Audio systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEI
NORME
INTERNATIONALE IEC
1119-1
INTERNATIONAL
Première édition
STANDARD First edition
1992-11
à cassette (DAT)
Système audionumérique
Partie 7 :
Dimensions et caractéristiques
Digital audio tape cassette system (DAT)
Part 1:
Dimensions and characteristics
réservés — Copyright — all rights reserved
CEI 1992 Droits de reproduction
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For price, see current catalogue

- 3 --
1119-1©IEC
CONTENTS
Page
FOREWORD
INTRODUCTION
Clause
15 1 Scope and object
2 Normative references
3 Description of the system
4 Test conditions
17 5 Mechanical parameters
17 5.1 Cassette
Dimensions and tolerances 5.1.1
5.1.2 Outside view
5.1.3 Label area 19
5.1.4 Window 19
19 5.1.5 Accidental erasure prevention (AEP)
5.1.6 Recognition holes
5.1.7 Cassette holding area
5.1.8 Groove for loading grip
5.1.9 Tape begin/end detection
5.1.10 Lid
5.1.11 Slider locks
5.1.12 Hub
25 5.2 Tape
5.2.1 Magnetic tape
5.2.2 Leader and trailer tapes
5.2.3 Tape winding
5.2.4 Single hub friction torque
47 6 Track configuration and patterns
47 6.1 Track configuration
6.1.1 Tape speed and number of tracks per second
6.1.2 Track angle
6.1.3 Track pitch
6.1.4 Track length
47 6.1.5 Track centre
47 6.1.6 Head azimuth
6.1.7 Effective recording width 47
6.1.8 Definition of frame 47
49 6.1.9 Optional tracks
1119-1 ©I EC - 5 -
Page
Clause
Signal allocation 6.2
6.2.1 Recording format of track
6.2.2 Positioning accuracy
Recording signals 6.3
53 Inter-block gap (IBG) 6.3.1
53 Preamble, postamble and margin
6.3.2
Automatic track finding (ATF), main data area and sub data area 6.3.3
53 7 Recording parameters
Recording level 7.1
53 Specification 7.1.1
53 Measurement method 7.1.2
55 7.2 Erasing method
Tracking scheme 8
Automatic track finding (ATF) 8.1
8.1.1 Definition
57 8.1.2 ATF signal allocation
8.1.3 Recording signal
Main data area format 9
Main data block format 9.1
9.1.1 Synchronization pattern
67 9.1.2 Main ID (W1, W2)
9.1.3 Main ID parity 69
9.1.4 Main data
9.2 Main data configuration
71 9.2.1 Main data allocation
Recording direction 9.2.2
9.3 Error correction and detection code (C1, C2)
9.3.1 Definition 73
75 Error correction code interleaving format
9.3.2
Parity symbol 77
9.3.3
9.4 Modulatin 79
Parameters 79
9.4.1
Modulation method 79
9.4.2
10 Sub data area format
Sub data block format 93
10.1
10.1.1 Synchronization pattern 93
10.1.2 Sub ID (SW1, SW2) 93
Sub ID parity 95
10.1.3
Sub data 95
10.1.4
1119-1 0 1E - 7 -
Page
Clause
10.2 Sub data configuration
97 10.2.1 Sub data allocation
99 10.2.2 Recording direction
99 10.3 Error correction and detection code (SP)
10.3.1 Definition 99
10.3.2 Error correction code interleaving format
10.3.3 Parity symbol
10.4 Modulation
11 Audio encoding
11.1 Mode application
11.1.1 Audio encoding mode
105 11.1.2 System application
11.2 Source encoding
11.2.1 Emphasis
11.2.2 Number of audio channels
11.2.3 Sampling frequency
11.2.4 Sampling timing
109 11.2.5 Quantization
111 11.3 Word to symbol conversion
11.3.1 Audio data word
11.3.2 48k mode, 44k mode, 44k-WT mode and 32k mode
11.3.3 32k-LP mode
11.3.4 32k-4CH mode
11.4 Interleave format
11.4.1 48k mode, 44k mode, 44k-WT mode and 32k mode
11.4.2 32k-LP mode
11.4.3 32k-4CH mode
12 Sub code encoding for audio use
12.1 Sub code in main ID
12.1.1 101 to 107
12.2 Sub code in sub ID
137 12.2.1 Configuration of sub ID
12.3 Sub code in sub data
139 12.3.1 Pack ID and pack location
12.3.2 Configuration of pack
12.3.3 Assignment of pack item
12.4 Sub code in main data
12.4.1 Recognition word for compact disk (CD) sub code
12.4.2 Sub code for CD format
1119-1 ©I EC – 9 –
Page
Clause
12.5 Application rules of sub code for pre-recorded tape
12.5.1 Classification of sub code recording
12.5.2 Areas along tape longitude
167 12.5.3 Location of pack
12.5.4 Classification of catalog number and ISRC recording
12.5.5 TOC recording
173 12.6 Application rules of sub code for own-recorded tape
12.6.1 Classification of sub code recording
12.6.2 Recording function of sub code
12.6.3 Areas along tape longitude
183 12.6.4 Location of time code pack
183 12.6.5 Details for recording sub code
195 12.6.6 Rules of assemble-recording
12.7 Application rules in playback situation
195 12.7.1 Detection of identification code
12.7.2 Mechanical condition
12.7.3 Shortening play
12.7.4 Display
12.7.5 Rules of searching
12.7.6 Beginning point of playback after searching
Annexes
207 A Transmissivity of the prism
B Measurement method of the force required to open the slider
C Abbreviations
D Explanations
- 11 -
1119-1 © IEC
INTERNATIONAL ELECTROTECHNICAL COMMISSION
DIGITAL AUDIO TAPE CASSETTE SYSTEM (DAT)
Part 1: Dimensions and characteristics
FOREWORD
The formal decisions or agreements of the IEC on technical matters, prepared by Technical Committees on
1)
which all the National Committees having a special interest therein are represented, express, as nearly as
possible, an international consensus of opinion on the subjects dealt with.
They have the form of recommendations for international use and they are accepted by the National
2)
Committees in that sense.
3) In order to promote international unification, the IEC expresses the wish that all National Committees
should adopt the text of the IEC recommendation for their national rules in so far as national conditions will
permit. Any divergence between the IEC recommendation and the corresponding national rules should, as
far as possible, be clearly indicated in the latter.
This International Standard IEC 1119-1 has been prepared by Sub-Committee 60A: Sound
recording, of IEC Technical Committee No. 60: Recording.
The text of this standard is based on the following documents:
DIS Report on Voting
60A(CO)130 60A(CO)135
Full information on the voting for the approval of this standard can be found in the Voting
Report indicated in the above table.
Annexes A and 8 form an integral part of this standard.
Annexes C and D are for information only.

1119-1©IEC –13
INTRODUCTION
The IEC draws attention to the fact that it is probable that the specifications contained in
this standard are the subject of one or more patents.
The IEC has no precise information on the holders of such patents and cannot supply fur-
ther details, but it is expected that the holders of such patents will be prepared to grant
licences under reasonable and non-discriminatory terms.

-15-
1119-1 © IEC
DIGITAL AUDIO TAPE CASSETTE SYSTEM (DAT)
Part 1: Dimensions and characteristics
1 Scope and object
This part of IEC 1119 is applicable to the digital audio tape (DAT) cassette system that
records and/or plays back digital information such as PCM encoded audio and/or other
data.
This part defines those parameters that affect the compatibility between cassettes and the
associated tape recorders. It is also intended as a reference for manufacturers producing
cassettes and/or tape recorders which are intended to conform with the system described
in this part.
2 Normative references
The following normative documents contain provisions which, through reference in this
text, constitute provisions of this part of IEC 1119. At the time of publication, the editions
indicated were valid. All normative documents are subject to revision, and parties to
agreements based on this part of IEC 1119 are encouraged to investigate the possibility of
applying the most recent editions of the normative documents indicated below. Members
of IEC and ISO maintain registers of currently valid International Standards.
Sound system equipment - Part 11: Application of connectors for the
IEC 268-11: 1987,
interconnection of sound system components
Sound system equipment - Part 12: Application of connectors for
IEC 268-12: 1987,
broadcast and similar use
Sound system equipment - Part 15: Preferred matching values for the
IEC 268-15: 1987,
interconnection of sound system components
IEC 958: 1989, Digital audio interface
Digital audio tape cassette system (DAT) - Part 2: DAT calibration tape
IEC 1119-2: 1991,
Digital audio tape cassette system (DAT) - Part 3: DAT tape properties
IEC 1119-3: 1992,
Digital audio tape cassette system (DAT) - Part 4: Method of measure-
IEC 1119-4: 199x,
ment for DAT recorder (under consideration)

- 17 -
1119-1 ©IEC
IEC 1119-5: 199x, Digital audio tape cassette system (DAT) - Part 5: DAT for professional
use (under consideration)
Documentation - International standard recording code (ISRC)
ISO 3901: 1986,
3 Description of the system
The information carrier is a magnetic tape of 3,81 mm width wound on flangeless hubs
which are located in a cassette containing a slider and a lid to protect the tape from
accidental damages. The tape is of the metal powder type or its equivalent. The digital
information is recorded using the helical scanning principle and can be erased by over-
writing. The digital information is read by magnetic heads using an automatic track finding
(ATF) scheme to find and follow tracks. Two track widths and three tape speeds are
defined.
It is possible to record sub code information in a main data area, either with or without
audio signals.
4 Test conditions
Tests and measurements made on the system to verify conformity with the provisions of
this part of IEC 1119 shall be carried out under the following conditions:
- Temperature: 20 °C ± 2 °C
40 % to 60 %
- Relative humidity:
86 kPa to 106 kPa
- Barometric pressure:
- Conditioning before testing: 24 h
5 Mechanical parameters
5.1 Cassette
5.1.1 Dimensions and tolerances
The cassette dimensions and tolerances are specified in figures 2 to 11 on pages 29
to 43.
In these figures, use is made of reference datum planes which are presented in figure 7,
page 39.
C. The X-datum plane is
The Z-datum plane is defined by the datum areas A, B and
defined through the centres of the positioning holes in the datum areas A and B, perpen-
dicular to plane Z. The Y-datum is defined through the centre of the positioning hole in
area A, perpendicular to planes Z and X.

19 —
1119-1 © 1 EC —
Tolerances which are not specified in these figures shall be as in the following table:
Tolerance
(mm)
Length: L
±0,1
6 ?L
30 >_L >6 ±0,2
±0,3
L >30
±1
Angle (°)
5.1.2 Outside view
The outside view is shown in figure 1 on page 27.
5.1.3 Label area
The hatched area given in figure 12 on page 45 is available for the labels of pre-recorded
cassettes.
5.1.4 Window
The window shall be positioned within the label area.
Accidental erasure prevention (AEP)
5.1.5
5.1.5.1 Accidental erasure prevention hole
The cassette shall be provided with an accidental erasure prevention hole as shown in
figure 1 and in accordance with the table in 5.1.5.2.
If an accidental erasure prevention tag is provided, the tag shall be so constructed that it
can withstand an applied force of 0,5 N.
Operation scheme and indication of accidental erasure prevention
5.1.5.2
Accidental erasure prevention may be indicated by a moving part, the colour of which shall
not be red.
The operation scheme of the accidental erasure prevention is specified in the following
table:
Impossible to record
Possible to record
Indication- Indication-
AEP hole
AEP hole
window
window
Open "1"
Closed "0" Closed "0" Open "1"
The position of the indication widow is shown in figure 1, page 27.

– 21 –
1119-1 ©I EC
5.1.6 Recognition holes
The cassette shall be provided with recognition holes (1) to (4) as shown in figure 1.
distinguish magnetic tape types and magnetic tape
(3)
The recognition holes (1), (2) and
thickness as follows:
– "0" . hole closed;
– "1" . hole open.
Hole Hole
Hole
Remarks
(2) (3)
(1)
Metal powder tape or equivalent / 13 gm thickness
0 0 0
0 Metal powder tape or equivalent / thin tape
0 1
0 0 1 Wide track / 13 gm thickness
Wide track / thin tape
0 1 1
1 X X Reserved
Recognition hole (4) distinguishes pre-recorded tape:
– "0" hole closed: non pre-recorded tape;
– "1" hole open: pre-recorded tape.
When tags are provided for recognition, the tags shall be so constructed that they can
0,5 N.
withstand an applied force of
5.1.7 Cassette holding area
2, page 29.
The cassette holding area is shown in figure
5.1.8 Groove for loading grip
The groove for loading grip is shown in figure 2.
5.1.9 Tape begin/end detection
Two tape end detection systems are provided: the prism system and the direct light path
system are provided. The prism system makes use of light path via a prism installed in the
cassette and the direct light path system makes use of direct light path via the cassette
hole provided on the side of the cassette.
shows both the light paths and the prism position for tape end
Figure 6, page 37,
detection.
800 nm
The transmissivity of the magnetic tape for light of wavelengths between
5 % or less.
and 900 nm shall be
The transmissivity of leader and trailer tapes for light of wavelengths between 800 nm
and 900 nm shall be 60 % or more.

1119-1 ©IEC - 23 -
For the direct light path system, the detection accuracy of the tape begin and end is
1)
determined be the transmissivities of the magnetic tape and the leader and trailer
tapes.
For the prism system, the detection accuracy of the tape begin and end is
2)
determined by the transmissivity of the prism installed in the cassette. The
transmissivity of the prism shall be 50 % or more for 800 nm to 900 nm wavelength
light. The definition of the transmissivity of the prism and the measuring method are
shown in annex A.
5.1.10 Lid
5.1.10.1 Lid configuration
The lid configuration is shown in figure 10, page 43.
5.1.10.2 Force to open the lid
to open the lid and release the hub lock as shown in figure 10 shall be 1,2 N
The force P0
(6 x 10-3 Nm) or less.
5.1.10.3 Minimum height of the lid when open
The minimum height of the lid when open shall be 10,9 mm, as shown in figure 10,
page 43.
5.1.10.4 Dimensions of the hub lock and release
The dimensions of the hub lock and release shall be as shown in figure 11, page 43.
Lid return spring
5.1.10.5
The use of two lid return springs is recommended. If a single lid return spring is used, it
shall be placed on the tape supply side.
5.1.11 Slider locks
The use of two slider locks is recommended. If a single slider lock is used a dummy
groove shall be provided.
5.1.11.1 Force to open the slider
The maximum force to open the slider shall be 2 N. The measurement method is shown in
annex B.
5.1.11.2 Release force of slider lock(s)
The release force of the slider lock shall be 0,5 N or less per slider lock at a pushing
stroke of 0,65 mm.
5.1.11.3 Holding force
The holding force of the slider shall be 0,3 N minimum in the open position.

Oc
1119-1 IEC – 25 –
5.1.12
Hub
The shape and dimensions of the hub shall be as shown in figures 8 and 9, page 41.
5.2 Tape
5.2.1
Magnetic tape
5.2.1.1 Magnetic tape length
The length of the magnetic tape shall be determined by the following equation:
[(1 + 0,005) Vt x (T+ 1) x 60/1 000] +ô m
where
Vt is the tape speed (mm/s)
T is the recording time (min)
5.2.1.2 Magnetic tape width
The magnetic tape width shall be 3,81 ô Ô2 mm.
5.2.1.3 Magnetic tape thickness
The magnetic tape thickness shall be 13 gm ± 1 gm.
5.2.2 Leader and trailer tapes
5.2.2.1 Dimensions
The tape length shall be 60 mm ± 5 mm.
mm.
The tape width shall be 3,81
20,05
5.2.2.2 Retaining force
The retaining force of the splice shall be 5 N or more.
The retaining force of the hub clamp shall be 5 N or more.
5.2.3
Tape winding
The recording side of the tape shall face outwards.
5.2.4 Single hub friction torque
The friction torque of a partially or fully wound hub shall not exceed 0,2 x 10-3 Nm.

1119-1 © IEC – 27 –
a) Top view
Notches for incorrect
insertion prevention
Notches for slider lock relaese
b) Bottom view
Accidental erasure
prevention hole
(restorable)
(4)
Slider lock (1)
(1)
Lid locking part
(locked by slider) NOTE - In case of single slider lock,
a dummy groove shall be provided.
c) Back side view
Indication window of accidental erasure
prevention may be placed in this area
IEC I 002192
Figure 1 – Outside view of DAT cassette

1119-1 ©IEC - 29 -
(54)
4,8 49,2 ± 0,2
0,4 max
C 0,2 max.
0,9 min.
1,5 max.
R
R 0,5 max.
c
E
Co E
E
+ 0,2
Groove depth 0,5
C
c'S
E
C^)
^
Y
II)
V
CO
C*)
Cr
A
C
^
^
2 min.
r-
±
-1\ 0,2
+1
II\\\\„`\\\\`\\\\\^^
R 0,5 max. R 1,5 max.
1,2 6,8 ± 04
CV
a^ a
N
_1
,5
tst
/6C 1003192
NOTES
1 Hs: 10,5 ± 0,2 (at 1 N)
10,9 max. (at free)
Dimensions in millimetres
2 HL Figure 2 - Appearance of cassette, top view (lid closed)

1119-1 ©IEC – 31 –
(55,5)
Window for tape end detector (for prism system)
Window for tape end detector (for prism and direct
light systems)
IEC I004/92
Dimensions in millimetres
Figure 3 - Appearance of cassette, top view (lid open)

1119-1 © 1 EC — 33 —
45,2 ± 0,2
10 ± 0,1
)
Lc)
O O
II
portion to I id
E E Push
,
N
^ V opening
t
^ III
A
- J
.
co
il
%-,i—
C?
0 10 (2x)
^ N O
N
-H
O
CD O
+1 ^
c
vrn
,^ 0 9 ± 0,1 (2x)
-: I
J
C- J
J ^
,E
; Y
E ^
^ Q
ü
^.^éi■
^ A ^- I
-tr o o i
Q + ` 10 ±0,1 J,
-4- N ^ > I
"
^(}^^, n
^
± 0,2
47,2
(49,2)
54 ± 0,3
*ws< w
**W
L •
(0 10)
1,5 min.
ole
►^^`^^^^^^^^^^►^^^
\\\\\\\^► ^
."
.mmoni
^^ i
^
4s^ o
07;7 o
-H
12 max. +0,5
0 8
to
o
- 0,1
0,8
q
o
Section EE
Section JJ IEC I005/92
Dimensions in millimetres
Figure 4 – Appearance of cassette, bottom view (lid closed)

-35-
1119-1 © I EC
0 2,5.(4x) (Xl
Recognition hole
o
29 ± 0,15
- 0,15
+ +0,1 2
2,8 x 3 5
0 0
+0,1 025
+0,05 Pe
2,55 x 3,5
0 0 WI
Accidental erasure
prevention hole
Datum hole (main),
hi
4So
7 + 0,7
o
(Maximum movement)
ô
E
^ Datum holes (sub)
rn
o
N:
e^
5,6 min.
^
PI
T-,
f-
_.
i
x
+0,05
ci
iZS 25
el
o
C
0,6
(8 +
Depth from
I ZI
o
^
E
^
E
0 1 min.
Section CC Section CC
Section AA Section BB
,(punch out)
IEC 1076/92
Dimensions in millimetres
Figure 5 - Appearance of cassette, bottom view (lid open)

37 –
1119-1 © IEC –
6.4 max.
3,9
7,65 ± 0,1 NOTE - Upper shell and lid are removed in the drawing.
[1] Centres of tape guiding posts coincide with main datum hole
centres.
[2] The hub lock brake illustrated is an example.
The hub ratchet illustrated is an example.
[3]
Dimensions in millimetres
Figure 6 – Inner structure of cassette (tape path and light path)

1119-1 © I EC
- 39 -
!EC 1008192
Dimensions in millimetres
NOTES
1 The crosshatched areas 5 mm in diameter are datum areas.
2 Datum plane Z shall be determined by datum area A, B and C.
3 The line hatched areas, which are support areas, shall be coplanar (or parallel) in datum plane Z with
the following dimensions:
A'=0± 0,05; B'=0± 0,05; C' = 1,1 ± 0,05
Figure 7 - Datum area
1119-1 ©IEC –41 –
View H
4So 0
0 8,8_ 0,1
1EC 1009/92
Dimensions in millimetres
Figure 8 – Hub
Reel spindle
X
^
E
(O
;^^i
n
^.
---
^^^^
/EC 1 010192
^
Clearance a - b = max.1,2
min.1,0
Clearance c - d = max.1,3
Dimensions in millimetres
Figure 9 – Hub clearance and limit of reel spindle height

43 —
1119-1 © I EC —
1EC 1011192
Dimensions in millimetres
Figure 10 – Lid configuration when rotated and opened over 90°
7,5
1EC 1012192
Hub released position
Hub locked position
Dimensions in millimetres
Figure 11 – Hub lock and release

1 119-1 © lEC -
45 -
28,9
28,9
5,2
5,2
^--
R 0,5 (2x)
1EC 1013192
Dimensions in millimetres
NOTE - When the label is attached to the label area, the size of the cassette shall not exceed the
maximum outer dimensions.
Figure 12 - Label area of pre-recorded cassette

1119-1 ©IEC - 47 -
6 Track configuration and patterns
6.1 Track configuration
The helical track pattern is formed by tape travel and rotation of a pair of inclined heads,
one of which has a plus, and the other a minus azimuth angle.
The track configuration is shown in figure 13 on page 49.
6.1.1 Tape speed and number of tracks per second
The speed of the magnetic tape and the number of tracks recorded per second are as
follows:
Tape speed
Mode Number of tracks/s
mm/s
8,150 ± 0,5 % 200/3
Normal track (normal speed)
% 100/3
Normal track (half speed) 4,075 ± 0,5
200/3
12,225 ± 0,5 %
Wide track
6.1.2 Track angle
The angle of the track at the nominal tape speed of 8,150 mm/s or 4,075 mm/s shall
be 6° 22'59,5" in normal track mode and 6° 23' 29,4" in the wide track mode with the
nominal tape speed of 12,225 mm/s.
6.1.3 Track pitch
The pitch of the tracks shall be 13,591 µm in the normal track mode and 20,41 µm in the
wide track mode.
6.1.4 Track length
The length of the track shall be 23,501 mm in the normal track mode and 23,471 mm in
the wide track mode.
6.1.5 Track centre
The centre of the track shall be 1,905 mm from the reference edge.
6.1.6 Head azimuth
The azimuth angle of the head gap shall be ± (20° ± 15').
6.1.7 Effective recording width
The effective recording width on the magnetic tape shall be 2,613 mm.
Definition of frame
6.1.8
A frame consists of a plus azimuth track and the following minus azimuth track.

1119-1 © I EC - 49 -
6.1.9 Optional tracks
The width of each optional track including the edge guard (0,1 mm) shall be 0,5 mm.
Edge guard II
Tape motion
Optional track II
Main track to optional
r
track guard
INKAS
Plus azimuth 8a
m
Minus azimuth 8 b
CO
Main track to optional
track guard
Reference edge
Optional track 1
of tape
Edge guard I
1EC 1 014192
A = tape width
W = effective recording width
L = track length
track pitch
P =
B = track centre
C = optional track I
D = optional track II
edge guard I
E =
F = edge guard II
8 = track angle
8a , 8b = head gap azimuth angle
Figure 13 – Track configuration (view on magnetic sensitive side)

-51 -
1119-1 ©IEC
6.2 Signal allocation
6.2.1 Recording format of track
The format of a track shall be in accordance with the following table.
360 channel bits.
A track consists of 196 blocks, each of which is composed of
bits modulation as specified
Main data blocks and sub data blocks are encoded with 8 - 10
Consequently, one block in these areas corresponds to 288 data bits.
in 9.4 and 10.4.
Area Contents Number of blocks
Marginal area Margin 1
Sub area 1 Preamble 1
Sub data area 1
Postamble 1
IBG 1 3 (2)
ATF area 1
5 (7,5)
ATF 1
3 (1,5)
IBG 2
Head
196 blocks
Preamble 2 2
Main area
motion
Main data area
3 (2)
ATF area 2 IBG 3
5 (7,5)
ATF 2
3 (1,5)
IBG 4
Sub area 2 Preamble 3
Sub data area 2
Postamble 2 1
Marginal area Margin 2
automatic track finding
ATF:
inter-block gap
IBG:
NOTE - The numbers in parentheses are for wide track mode.
6.2.2 Positioning accuracy
mm in the direction of tape
±0,0267
The positioning accuracy of any track shall be within
(± blocks along the track) as measured from the track centre.
width
shall not be erased.
When editing the existing ATF 1 and ATF 2
6.3 Recording signals
The recording signal may be regarded as a succession of channel bits, each of which is of
duration ch.
The waveform of each signal is shown below, and since the significance of the recorded
signal is independent of polarity, either the waveforms given below or their inverses are
permitted.
1119-1 ©IEC - 53 -
Inter-block gap (IBG)
6.3.1
The recording signal of IBG (1, 2, 3 and 4) is a continuous square wave with a succession
of duration 3 Tch as shown below.
3 T
^
3 Toh I 3 Tch ( I 3Tch
• ► ►^ ^
^ • I
(
6.3.2 Preamble, postamble and margin
The recording signal of preamble (1, 2 and 3), postamble (1 and 2) and margin (1 and 2) is
a continuous square wave with a succession of duration as shown below.
ch
Tch Tch Ton Tch Tch c h Tch ch Tch Ton ch Tch
6.3.3 Automatic track finding (ATF), main data area and sub data area
The recording signals of ATF (1 and 2), main data area and sub data area (1 and 2) are
specified below.
ATF: see ATF in 8.1.
Main data area: see main data area format in clause 9.
Sub data area: see sub data area format in clause 10.
7 Recording parameters
Recording level
7.1
7.1.1 Specification
The recording level is specified as a playback output level per unit track width in relation
to the calibration tape. The playback output level of the square wave recorded on the
reference tape by circuitry and heads of the equipment under test should be identical to
that of the calibration tape at the frequencies with wavelengths of 72 Tch , 18 Tch , 12
Tch,
6 Tch and 4 Tch , respectively. Only 72 Tch corresponds to the pilot signal duration.
7.1.2 Measurement method
The playback output level is defined as the fundamental frequency output level of the
playback signal obtained from a tape.

- 55 -
1119-1 ©IEC
The recording level of a system is specified in order to guarantee the compatibility of
cassettes and equipment.
Residual level is not negligible even after overwriting if the previously recorded level was
too high and may cause some trouble. In particular, the remainder of the pilot signal
may cause mistracking. The recording level shall be as close as possible to that of
72 Tch
the calibration tape though its tolerance is not specified. In particular the recording level of
shall not exceed that of the calibration tape.
the pilot signal 72 Tch
In actual equipment, recording signals are continuous square waves with wavelengths
in the ATF area and are 8 to 10 modulated signals with
of 72 Tch , 18 Tch , 12 Tch or 6 Tch
spread spectrum in the main data area and the sub data area. However, the recording
level shall be adjusted using the continuous square waves signals with wavelengths of
12 Tch , 6 Tch and 4 Tch.
72 Tch , 18 Tch ,
7.2 Erasing method
Recorded signals shall be erasable by the overwrite method.
8 Tracking scheme
Automatic track finding (ATF)
8.1
8.1.1 Definition
Tracking is achieved by the automatic track finding (ATF) method. The ATF signal is
allocated to two areas, one before and one after the main area, and both are separated
from other data area by inter-block gaps (IBG).
2 and f3 ) and a space signal (f4).
The ATF signal consists of pilot signal (f1 ), sync signals (f
The ATF signal allocation pattern repeats every four tracks, which corresponds to a pair of
frames with even and odd address, each frame having plus and minus azimuth tracks.
The tracking error detecting algorithm is as follows. First, the frequency and length of the
sync signal is detected. Then the crosstalk signal from the pilot signal of an adjacent track
is sampled. After a fixed period, the crosstalk signal of another adjacent track is sampled.
The difference between the two crosstalk levels is the tracking error.
Two ATF signal allocation formats are provided, one for normal mode and the other for
wide track mode.
1119-1 ©I EC - 57 -
ATF signal allocation
8.1.2
The ATF signal allocations for normal and wide track modes are given in figures 14a
and 14b on pages 59 and 61, respectively. The numerals indicate the number of unit block
length.
are used in the plus and minus azimuth tracks, respectively. The
Sync signals f2 and 13
length of sync signal is 0,5 block in even frames and 1 block in odd frames.
In the wide track mode, the track pitch is 1,5 times that of the normal track mode, and thus
the relative position between adjacent tracks differs from one mode to the other.
8.1.3 Recording signal
1 ), the sync signals (f2 and 13) and the space
The recording signals of the pilot signal (f
) are continuous square waves with a succession of durations, of 36
signal (f4
Tch, ch,
ch and 3 ch, respectively and are shown in figure 15 on page 63.
6 T
ATF 2 ATF 1
Tape motion
I 2 I blocks
1 1 1 1 1 1 1 2 1 2 I1 1
IBG4 f4 f3 f^ IBG3 Frame in odd address IBG2 f^ f4 f3 IBG1
(B)
2 111111 I 2
I BG3 IBG2
(A) IBG4 ft f4 Frame in odd address f2 f^ IBG1

0,5 0,5
12I 2,511
11.51 I 11 2 I
IBG4 f4 1 f^ IBG3 Frame in even address IBG2 f^ f4
f3 IBG1
(B)
0,5 0,5
2,5 2 I I 1 15 1 1 1 1 2 1
Frame in even address
(A) IBG4 f4 I BG3 IBG2
ft f4 f2 f4 ft IBG1
1 1 1 1 1 1 1 2 1
Frame in odd address
(B) IBG4 f4 f4 ft IBG3 IBG2 f^ f4 f3 IBG1
Head motion
IEC I 01519
(A): plus azimuth track
(B): minus azimuth track
View of magnetic sensitive side
Figure 14a — ATF signal allocation (normal track mode)

ATF 2 ATF 2
i^
/
0,5"
Tape motion
1,5 I 2 3 I blocks
I I1
(B) IBG4 f4 f3 f4 IBG3 Frame in odd address IBG2 f^ f4 f3 IBG1
0,5
3 I1,5I1I 3
2 I
I11I 3
(A) IBG4 f^ f4 f4 IBG3 Frame in odd address IBG2 f4 f2 14 f^
IBG1
0,5 0,5 0,5
3 I 3,5
I 2 I I 2 I 3 I I I
I BG4 f4 f4 IBG3 Frame in even address IBG2 f^
f4 IBG1
(B)
0,5 0,5 0,5
2 I
I 3 1 3'5 I I I 1 2 1 1
(A) IBG4 f^ f4 f2 f4 IBG3 Frame in even address IBG2 f4 f2 f4 f^ IBG1
0,5
I1,5I1 2 3
I I 3 11II
(B) I BG4 f4 f4 f^ IBG3 IBG2 ft f4 f3 14 IBG1
Frame in odd address
^ Head motion
IEC 1016192
(A): plus azimuth track
minus azimuth track
(B):
View of magnetic sensitive side
Figure 14b — ATF signal allocation (wide track mode)

Pilot signal (ft)
36 T
ch Tch
►^ ►
Sync signal of plus
azimuth track (f2)
9 Tch oil • 9 Tch ► 1
Sync signal of minus
azimuth track (13)
6 Tch 6 Tch
Space signal (14)
3 Tc AI-4443
Tch
1EC 1017192
duration of one channel bit
Ton =
Figure 15 — Recording signal in ATF

1119-1 ©IEC - 65 -
9 Main data area format
9.1 Main data block format
main data block consists of a sync, which corresponds to one symbol, two symbols of
A
(D
main ID (W1, W2), one symbol of main ID parity and 32 symbols of main data
ij, P. Qii)•
One symbol is composed of 8 bits. Recording direction is MSB first as shown below.
-► Recording direction (in each block)
P i .,
Main ID Main data (D i., Qi1)
Sync Main ID
256 bits (32 symipols)
parity
W1 W2
I
8 bits
8 bits 8 bits , 8 b is 8 bits 8 bits 8 bits , - i
MSB LSB
1 data block = 8 + 8 + 8 + 8 + (8 x 32) = 288 data bits i = 0, 1,2,., 127
= 0, 1, 2., 31
9.1.1 Synchronization pattern
sync of 8-bit data corresponds to a 10-channel bit synchronization pattern defined in a
A
channel bit domain (see table 1, page 81).
Sync (8 data bits)
4 rJ, 4 ►^:
oh âh
0 0
duration of one channel bit
ôh =
i 0
^ --
Synchronization pattern
10Tch
1119-1 ©IEC - 67 -
(W1, W2)
9.1.2 Main ID
9.1.2.1 Configuration of main ID
Main ID is composed of 8-block units as shown below.
W2
W1
B4 B3 B2 B1 BO
B4 B3 B2 B1 BO B7 B6 B5
B7 B6 B5
0 00
Frame address 0 X X X X Format ID
XX 0 01
0 X X
0 X X X X 01
Frame address
X X 01 1
0 X X
0 0
0 X X X X1 Frame address
X1 0 1
0 X X X
X X X X1 1 0
Frame address
X X1 1 1
0 X X
LSB
LSB MSB
MSB
9.1.2.2 Block address
The B7 of W2 is an identification bit for the type of block.
0: main data block;
1: sub data block.
The other 7 bits, B6 (MSB) - BO (LSB), of W2 are identification bits for a main data block
address (0 to 127) in one track.
9.1.2.3 Frame address
Frame address is a 4-bit code, B3 (MSB) - BO (LSB), of W1 in an even address block.
Frame address is a binary count modulo 16 (1111 is followed by 0000). Both azimuth
tracks of a frame carry the same frame address.
9.1.2.4 Format ID
Format ID is a 2-bit code (B7, B6) in W1 of block address XXXX000.
Format ID is a category code, which shows an application of main ID and main data.
00: for audio use;
01: for data use;
10: reserved;
11: reserved.
1119-1 ©IEC -69-
Main ID parity
9.1.3
Main ID parity is an error detection code for W1 and W2.
Main ID parity is W10 W2. (Q : modulo 2)
Main data
9.1.4
One main data block consists of 32 symbols of main data.
There are two types of symbols:
1) data (DO;
2) parity
(Qin,
is the block address of the main
j" indicates the location of symbols in a track. "i"
Suffix "i,
data block in track. "j" is the symbol number of the main data in a block along the record-
ing direction.
There are three types of blocks:
1) data only;
2) data + parity;
parity only.
3)
Main data configuration
9.2
Number of main data blocks in each track is 128.
Block with even address between 0 and 51, and between 76 and 127 are composed of
32 data (Di Di,
0 . 31).
Blocks with odd address between 0 and 51, and between 76 and 127 are composed of
24 data (Di Di, and 8 C1 parity
(P
i, 24 ••• Pi, 31)'
0 . 23)
Blocks with even address between 52 and 75 are composed of 32 C2 parity (Qi
0 .
Qi, 31 )-
Blocks with odd address between 52 and 75 are composed of 24 C2 parity (Q
i, 0 . Qi, 23)
and 8 C1 parity
(P i 24 ••• Pi, 31)
Main data in one track consists of 2912 symbol data, 672 symbol C2 parities and
512 symbol Cl parities. Parity is used for error detection and correction codes for data.

1119-1 © IEC -71 -
9.2.1 Main data allocation
76 77 126 127
0 1 2 3 51 52 53 75
•
0 77,0 ' ' D 126,0 D127,0
00,0 D1,0 D2,o D3,0 051,0 Q52,0 Q53,0 Q75,0 076,0
D127,1
1 D 51,1 Q52,1 Q53,1 Q75,1 D76,1 D77,1 D 126,1
D0,1 D 1,1 D2,1 D3,1
2 76,2 D772 0 126,2 D127,2
D02 0 2,2 D D51,2 Q52,2 Q53,2 Q75,2 D
12 D 32
D
D51,3 052,3 053,3 075,3 D76,3 D 77,3 D 126,3 D127,3
D0,3 D 1,3 23 D3,3
4 77,4 D 126,4 D127,4
2,4 03,4 D51,4 Q52,4 053,4 Q75,4 D76,4 D
Do,4 D1,4 0
D51,5 Q52,5 Q53,5 075,5 D76,5 77,5 0126,5 0127,5
00,5 01,5 02,5 D3,5
76,6 D 77,6 D126,6 D127,6
1,6 02,6 D3,6 D51,6 Q52,6 Q53,6 Q75,6 D
00,6 D
7 D77,7 D126,7 D127,7
D51,7 Q52,7 Q53,7 Q 75,7 D76,7
00,7 D7,7 D2,7 D3,7
Q 75,8 D 76,8 D 77,8 126,8 D127,8
00,8 D1,8 02,8 D3,8 D51,8 Q52,8 Q53,8
9 00,9
77,9 D126,9 D127,9
3,9 D51,9 Q52,9 053,9 Q75,9 D76,9 D
2,9 D
D1,9 0
10 Q75,10 76,10 D77,10 0126,10 D127,10
D0,10 D1,10 D2,10 D3,10 D51,10 Q52,10 Q53,10
11 126,11 D 127,11
3,11 D51,11 Q52,11 Q53,11 Q75,11 D 76,11 D77,11 D
Do,11 D1,11 D2,11 D
12 0
76,12 D77,12 126,12 D127,12
D0,12 D1,12 D212 D3,12 051,12 Q52,12 Q53,12 Q75,12 D
13 126,13 D127,13
D51,13 52,13 Q53,13 075,13 76,13 D77,13 D
D0,13 D1,13 D2,13 D3,13 Q
14 D76,14 077,1 D 126,14 D127,14
D0,14 D 1,14 D2,14 0314 051,14 052,14 Q53,14 Q75,14
1 block
15 126,15 D 127,15
D51,15 Q52,15 Q53,15 Q75,15 D76,15 D77,15 D
D0,15 D1,15 02,15 D3,15
(= 32 symbols)
127,16
16 Q75,16 D76,16 D77,16 D 126,16 D
D0,16 D1,16 D2,16 D3,16 D51,16 Q52,16 Q53,16
17 76,17 D77,17 D 126,17 D127,17
D0,17 0117 D2,17 D3,17 D51,17 Q 52,17 Q53,17 Q75,17
18 126,18 D127,18
D51,18 Q 52,18 253.18 Q75,18 D76,18 077,18 D
D0,18 D1,16 D2,18 D3,18
19 0 0 D76,19 D77,1 0126,19 D127.19
00,19 01 1 9 2,19 3,19 D51,19 Q52,19 Q53,19 Q75,19
20 0 D127,20
51,20 Q5220 253,20 Q75,20 D76,20 077,20 D126,2o
D0,20 D1,20 D2,20 D3,20
07621 D7721 D126,21 D12721
00,21 D121 D2,21 D321 05121 Q52,21 Q53,21 275,21
126,22 D127,22
22 D51,22 052,22 253,22 275,22 76,22 D77,22 D
D0,22 D1,22 D2,22 D322
0 0
23 0 0 0 76,2 077,23 12623 12723
0,23 0123 2,23 0323 51,23 052.23 253,23 Q75.23 D
24 51,24 2 P53.24 P75,24 D76,24 P77,24 D126,24 P127,24
D0,24 P1,24 D224 P3,24 P 52,24
25 P77.25 D12625 P127,25
P1,25 D P3.25 P5125 252.25 P53,25 P75.25 76,25
D025 2.25
P7526 D76,26 P77,26 012826 P127,26
00,26 P1,26 0226 P3,26 P51,26 Q52,26 P53.26
P
126,27 P127,27
27 P P51,27 Q52,27 53,27 P75,27 D76,27 P77,27 D
D0,27 P127 D2,27 327
7628 P77,28 0 126,28 P127,28
0028 P128 D P3,28 P51,28 Q52,2B P5328 P7528
2.28
P127,29
29 P1,29 D2,29 P3,29 P51,29 252,29 P53,29 P75,29 D76,29 P77,29 0 126,29
D0,29
76,30 P77,30 D126,30 P127,30
30 0,30 P1,30 D2,30 P3,30 P51,30 252,30 P53,30 P75,30 D
31 126,31 P127,31
P51,31 252,31 P53,31 P7531 D76,31 P77,31 D
00,31 P 1,31 02,31 P3,31
r t1
r
128 blocks
D: data
P: Cl parity (see 9.3)
Q: C2 parity (see 9.3)
- 73 -
1119-1©IEC
9.2.2 Recording direction
The data shall be recorded from block address 0 to 127.
(C1, C2)
9.3 Error correction and detection code
Definition
9.3.1
C1: GF (28) Reed-Solomon Code (32, 28, 5);
GF (28) Reed-Solomon Code (32, 26, 7).
C2:
8) by the following polynomial.
The calculation is defined on GF (2
3 + X2 + 1
g (X) = X 8 + X4 + X
8) is defined as follows:
A primitive element a in GF (2
a=(0 0 0 0 0 0 1 0)
2 a 1 a°
a7 a6 a5 a4 a3 a
1119-1 © I EC - 75 -
Error correction code interleaving format
9.3.2
Interleave distance of Cl code is two symbols and that of C2 code is four blocks.
1 Z2S DIOCKS
.4 •
4 blocks
•
C2
^^
D0.0
D4,O D
D 1,0 8,O ll D 124,O
D0,2 D 1,2
I
2 symbols
D04 D14
D
0,s D 1,s
D0,8 D18
D0,10 D 1,10
D0,12 D 1,12
D0,14 D 1,14
1 block
(= 32 symbols)
D0,16 D 1,16
D0,18 D1,18
D0,20 D 1,20
D0,22 D 1,22
D0,24 P1,24
D0,26 P1,26
D0,28 P 1,28
D0,30 P 1,30
(!
C1
1119-1 ©IEC - 77 -
9.3.3 Parity symbol
Parity symbols are defined so as to satisfy the following equations.
HxVP P =O
H0 x VQ =O
Parity check matrix
1 1 1 1 1 1 1 1 1 1 1`
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
15 a14 a13 a12 al l a10
aa1 a30 a2s a28 a27 a26 a25 a24a23 a22 a21 a20 a19 a18a17 a16 a
7 6 4
a9 a8 a a a5 a a3 a2 a 1
H P =
aaa 1
a a a a a a a aa a a x a aa a a a a a a a aa aaa62 60 58 56 54 52 50 4846 44 42 40 38 36 34 32 30 28 26 24 22 20 1816 14 12 10 8 6 4
a2
a51 48 a 45 a42 a39 a36 a33 a30 a27a24 a21 a18a15 a12a9 a6 a3 1 '
a93 a90 a 87 84 81 78 75 72 a a a a aa a a a69 66 63 60 a57.a 54 a
1 1 1 1 1 ^
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
11 al0
27 a26 a25 a24 a23 a22 a21 a20 a19 a18 a17 a16 a15 a14 a13 a12
a31 a30 a29 a28 a
a a9 a8 a7 a6 a5 a4 aa a2 a1
40 a38 a36 a34 a32 a30 x28 a26 a24 a22 a20 a18 a16a14a12 a
a62 a60 a58 «56 a54 a52 a50 a48 a46 a44 a42 a
a8 a6 â a2 1
HQ =
36 a33 a30 a27 a24 a21 a18 a15 a12 a9 a6 a3 1
81 a78 a75 a72 a69 a66 a63 a60 a57 a54 a51 a48 a45 a42 a39 a
a93 a90 a87 a84 a
a a4 1 a a a a a a a a a a a a a a a a a a a a a a aaaa aa 96 92 88 84 80 76 7z 68 64 60 56 52 48 44 40 36 32 28 24 20 16 12 8
x 124 120 116 112 108 104 100
60 55 50 45 403530 25 20 15 10 a a a a a a a a a a a5 1
1s5 150 145 140 135 130 125 120 115 110 105100 a a a a a a a a a a a 95 a90 a 85 a80 a a 75 70 a65 a
x x
Codeword
i ^ i ^
D2k, / Dm, n
m + 4, n
D2k , l + 2 D
D2k, /+4 Dm+8, n
D m
+ 12, n
D2k, /+ 6
D2k, /+ 8 Dm + 16, n
Generator polynomial
m D2k, 1+ 10 D + 20, n
D /+ 12 Dm + 24, n 3
2k ,
2k, /+ 14 Dm+28, n
â) P: Cl parity
G (X) = 1L (X -
D
2k, /+ 16 m + 32, n i=0
m +36,n
D2k,/+18 D
D2k, /+ 20 D m + 40, n i
Q: C2 parity
G0 (X) = 76 (X - a) D
m + 44, n Dzk, /+ 22 i =0
D2k, /+24 Dm + 48, n
m + 52, n
D2k, /+ 26 Q
D2k, / + 28 Qm + 56, n
Q
VP = m + 60, n D2k , /+ 30 VQ -
Where
D2k + 1, / Qm + 64, n
k= 0, 1, ., 63
D 2k + 1, /+2 Q m +68, n
I = 0, 1
D2k+1, 1 + 4 Qm+72,n
m= 0,1,2,3
D2k + 1, I+ 6 Dm + 76, n
1+8 Dm + 80, n D2k + 1, in case k = 26, 27, ., 37
D2k + 1,1+ 10 D m + 84, n ii = Q
In the V P matrix , D
ii•
D m
D2k+1,/+12 +88,n incasem= 0,2
D2k+1,/+14 D m+ 92,n n=0,1,.,31
/ + 16 Dm + 96, n D2k+1, in case m = 1,3
D2k+1,/+18 D m +100,n n=0, 1,., 23
° Dm + 104, n
2k+1,/+20
D2k + 1, /+ 22 D m + 108, n
+ 1, /+ 24 Dm + 112, n
P2k
P2k + 1, /+ 26 D m + 116, n
m + 120, n
P2k + 1, l+ 28 D
2k +1,/+3% ^m+124,n/
\
1119-1 ©IEC
- 79 -
9.4 Modulation
9.4.1 Parameters
The modulation scheme is 8 to 10 modulation. The characteristics are shown below.
min. Tmax. max, min. Tw Xmin. Xmax.
DC component
0,8T 3,2T 4 0,8 T 0,67 2,66 free
time interval of one data bit 0,8T= 1
T:
Tch
minimum time interval between transitions
Tmin.:
Tmax.: maximum time interval between transitions
detection window
T:
Amin.: minimum wavelength (gm)
Xmax.: maximum wavelength (pm)
9.4.2 Modulation method
The modulation table is shown in table 1 on page 81. The codeword is selected by the
dataword and Q'. Q' is Q output of the previous codeword.
The modulated waveform is made from the codeword stream according to the NRZI rule.
Dataword
8 t
Q'
Modulation table
Q
One symbol delay
Codeword
Example
FF (Q' = -1)
Sync (Q' = -1) FF (Q'=1)
Dataword
Q output
1 1 1 1 1 1 0 1 0 1 0
Codeword 0 1 0 0 0 1 0 0 0 1 1 0 1 1 1 1 0 1 0
Modulated
waveform
1119-1 © IEC -81 -
Table 1 - 8 to 10 modulation table
Dataword: 8-bit data
Codeword: encoded code to NRZI modulator selected by Q' (Q information from
the previous code)
...