ISO/IEC 12248:1993

ISO/IEC
INTERNATIONAL
STANDARD
First edition
1993-12-15
Information technology - 3,81 mm wide
magnetic tape cartridge for information
interchange - Helical scan recording -
DATA/DAT-DC format using 60 m and
90 m length tapes
- Cartouche de bande magnetique de
Technologies de I’information
3,$1 mm de /arge pour Mchange d’information - Enregistrement par
Format DATA/DAT-DC utilisant des bandes
balayage en spirale -
de 60 m et 90 m de long
Reference number
ISO/IEC 12248: 1993(E)
ISOIIEC 12248: 1993 (E)
Page
Contents
1 Scope
2 Conformance
Magnetit tape cartridge
21 .
22 . Generating System
Receiving System
23 .
3 Normative references
Definitions
4.1 Absolute Frame Number (AFN)
algorithm
42 l
43 Area ID
4:4 Automatic Track Finding (ATF)
45 . Average Signal Amplitude
azimuth
4:7 back surface
48 . byte
49 cartridge
4’10 Channel Bit
4’11 Codeword
4’12 Data Format ID
4’13 End of Data (EOD)
End of Information (EOI)
4’14
4’15 End of Partition (EOP)
4’16 enti ty
4’17 Error Correcting Code (ECC)
4’18 flux transition Position
4’19 flux transition spacing
4’20 frame
4’21
group
4’22 e Logical Beginning of Tape (LBOT)
0 ISO/IEC 1993
All rights reserved. Unless otherwise specified, no part of this publication may be
reproduced or utilized in any form or by any means, electronie or mechanical, including
photocopying and microfilm, without Permission in writing from the publisher.
ISO/IEC Copyright Office l Case postale 56 l CH-121 1 Geneve 20 l Switzerland
Printed in Switzerland
ISO/IEC 12248: 1993 (E)
4.23 Logical End of Tape (LEOT)
4.24 magnetic tape 3
master reference
4.25 3
4.26 Master Standard Amplitude Calibration Tape 3
4.27 Master Standard Reference Tape
4.28 Optimum Recording Field 3
4.29 partition 3
4.30 partition reference 3
4.31 Physical Beginning of Tape (PBOT) 3
4.32 Physical End of Tape (PEOT) 3
4.33 physical recording density 3
4.34 pre-recording condition 3
4,35 processed record 3
4.36 processed record sequence 3
4.37 processing 3
4.38 record
4.39 Reference Recording Field 3
4.40 Secondary Standard Amplitude Calibration Tape 3
4.41 Secondary Standard Reference Tape 3
4.42 Separator Mark 3
4.43 Standard Referemce Amplitude 4
4.44 tape noise amplitude
4.45 Tape Reference Edge 4
4.46 track
5 Environment and safety 4
Testing environment
51 .
52 . Operating environment
53 . Storage environment
54 . Transportation
Safety
55 .
56 . Flammability
Section 2 - Requirements for the case
6 Dimensional and mechanical characteristics of the case
.
61 General
62 . Overall dimensions
63 . Loading grip
64 . Holding areas
. Notches of the lid
66 . Lid dimensions
67 . Optical detection of the beginning and end of tape
68 . Bottom side
6.8.1 Locking mechanism of the slider
6.8.2 Access holes
6.8.3 Recognition, sub-datum and write-inhibit holes
6.8.4 Datum holes
6.8.5 Access room for tape guides
6.8.6 Holes for accessing the hubs
. . .
ISO/IEC 12248: 1993 (E)
Internal structure of the lower half
6.8.7
6.8.8 Light path
6.8.9 Support areas
6.8.10 Datum areas
6.8.11 Relationship between support and datum areas and Reference Plane Z
69 Hubs
6’10 Leader and trailer attachment
6’11 Interface between the hubs and the drive spindles
6’12 Opening of the lid
Release of the hub locking mechanism
6’13
6’14 . Label areas
Section 3 - Requirements for the unrecorded tape
7 Mechanical, physical and dimensional characteristics of the tape
71 . Materials
72 . Tape length
7.2.1 Length of magnetic tape
Length of leader and trailer tapes
7.2.2
73 . Tape width
74 . Discontinuities -
Total thickness
75 .
76 . Longitudinal curvature
77 . Cupping
78 . Coating adhesion
79 Layer-to-layer adhesion
7’10 . Tensile Strength
7.10.1 Breaking Strength
7.10.2 Yield Strength
7.11 Residual elongation
7.12 Electrical resistance of coated surfaces
Light transmittance of tape
7.13
8 Magnetit recording characteristics
81 . Optimum recording field
. Signal amplitude
83 . Resolution
Overwri te
84 .
002 ftpmm
recording densities of 750,6 and 3
8.4.1 Physical
1 001 ftpmm
densities of 83,4 ftpmm and
8.4.2 Physical recording
85 . Ease of erasure
. Tape quality
8.6.1 Missing pulses
Missing pulse zone
8.6.2
87 . Signal-to-noise ratio (S/N) characteristic
iv
ISOIIEC 12248: 1993 (E)
Section 4 - Format
DATA/DAT-DC format
General
91 .
92 . Basic Groups
9.2.1 Basic Groups for Group Format 0
Basic Groups for Group Format 1
9.2.2
93 . Sub-groups
GI Sub-group
9.3.1
9.3.2 G2 Sub-group
G3 Sub-group
9.3.3
9.3.4 G4 Sub-group
Main Data Block
9.3.5
94 . Sub-Data area
9.4.1 Pack Item No. 1
Pack Item No. 2
9.4.2
9.4.3 Pack Item No. 3
Pack Item No. 4
9.4.4
9.4.5 Pack Item No. 5
9.4.6 Pack Item No. 6
Pack Item No. 7
9.4.7
9.4.8 Sub Data Block
Basic Group structure
95 l
9.51 User Data
System Data
9.5.2
9.5.3 Record ID list
Heuristic Recovery Data Area
9.5.4
10 Method of recording
Physical recording density
10.1
10.2 Long-Term average bit cell length
Short-Term average bit cell length
10.3
10.4 Rate of Change
10.5 Bit shift
Read Signal amplitude
10.6
10.7 Maximum recorded Levels
Track geometry
11.1 Track configuration
11.2 Average track pitch
11.3 Variations of the track pitch
Track width
11.4
11.5 Track angle
Track edge linearity
11.6
11.7 Track length
11.8 Ideal tape centreline
11.9 Azimuth angies
V
ISO/IEC 12248: 1993 (E)
12 Recording of blocks on the tape
12.1 Recorded Main Data Block
12.2 Recorded Sub Data Block
Margin Blocks, Preamble Blocks and Postamble Blocks
12.3
12.4 Spacer Blocks
Format of a track
13.1 Track capacity
Positioning accuracy
13.2
13.3 Tracking scheme
14 Group Formats
14.1 Group Format 0
14.2 Group Format 1
Extended Gap Frames
14.3
14.3.1 Extended Leading Gap Frames
Extended Trailing Gap Frames
14.3.2
14.4 Types of Groups
14.4.1 Normal Groups
14.4.2 Spare Groups _
14.4.3 Amble Groups
Header Groups
14.4.4
15 Magnetit tape layout
15.1 Load/Unload Area
15.2 Lead-in Area
15.2.1 Preamble
152.2 Header
15.2.3 Format Parameter Set
15.2.4 Master Reference
15.25 Postamble
15.3 Parti tion
15.3.1 Partition Preamble
Partition Reference
153.2
15.3.3 Partition Postamble
15.3.4 Partition Data
15.3.5 End of Partition (EOP)
15.3.6 Unused Area
15.4 EO1
Repeated Groups
15.5
15.6 Repeated Frames within a Normal Group
Relocation of Defec tive Groups
15.7
15.8 Appending
15.8.1 Seamless appending
15.8.2 Non-seamless appending
15.9 Overwrite
vi
ISO/IEC 12248: 1993 (E)
15.9.1 Overlapped track width 102
15.9.2 Non-overlapped track width
15.9.3 Rules for overwrite 102
Annexes
A - Measurement of the light transmittance of the prisms
B - Recognition holes
C - Means for opening the lid
D - Measurement of light transmittance of tape and leaders
E - Measurement of Signal-to-Noise Ratio 110
F - Method for determining the nominal and the maximum allowable recorded levels
G - Representation of g-bit bytes by 100bit Pattern
H - Measurement of bit shift
J - Recommendations for transportation
K - Method of measuring track edge linearity
L - Read-After-Write
M - Data allocation and C3 parity
vii
ISO/IEC 12248: 1993 (E)
Foreword
ISO (the International Organization for Standardization) and IEC (the Inter-
national 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 estab-
lished by the respective organization to deal with particular fields of technical
activity. ISO and IEC technical committees collaborate in fields of mutual inter-
est. 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. Draft International Standards adopted by
the joint technical committee are circulated to national bodies for voting. Publi-
cation as an International Standard requires approval by at least 75 % of the na-
tional bodies casting a vote.
International Standard ISO/IEC 12248 was prepared by the European Computer
Manufacturers Association (ECMA) (as Standard ECMA- 171) and was adopted,
under a special “fast-track procedure”, by Joint Technical Committee ISO/IEC
JTC 1, Infomtation technology, in parallel with its approval by national bodies
of ISO and IEC.
Annexes A, D, E, F, G, H, K and M form an integral part of this International
Standard. Annexes B, C, J and L are for information only.
. . .
Vlll
ISO/IEC 12248: 1993 (E)
Introduction
ISO/IEC have produced a series of International Standards for cassettes and cartridges containing magnetic tapes of different
width and characteristics. Of these, the following relate to helical scan recording.
ISO/IEC 10777: 1991, 3,81 mm wide magnetic tape cartridge foR information interchange - Helical scan recording -
DDS format
ISO/IEC 113 19: 1993,8 mm wide magnetic tape cartridge for information interchange - Helical scan recording
ISOfIEC 11321: 1992, 3,81 mm wide magnetic tape cartridge for information interchange - Helical scan Recording -
DATAIDAT format
ISOfIEC 11557:1992, 3,81 mm wide magnetic tape cartridge for information interchange - Helical scan recording -
DDS-DC format using 60 m and 90 m length tapes, 2nd edition
ISOfIEC 12246: 1993, 8 mm wide magnetic tape cartridge, dual azimuth format for information interchange - Helical
scan recording
ISO/IEC 12247: 1993, 3,81 mm wide magnetic tape cartridge for information interchange - Helical scan recording -
DDS format using 60 m and 90 m length tapes
ix
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INTERNATIONAL STANDARD
Information technology - 3,81 mm wide magnetic tape cartridge for information
interchange - Helical scan recording - DATA/DAT-DC format using 60 m and
90 m length tapes
Section 1 - General
Scope
This International Standard specifies the physical and magnetic characteristics of a 3,81 mm wide magnetic tape
cartridge to enable interchangeability of such cartridges. It also specifies the quality of the recorded Signals, the
recorded format and the recording method, thereby allowing data interchange between drives by means of such
magnetic tape cartridges. The format used is known as DATA/DAT-DC.
This International Standard specifies two types of cartridges which, for the purpose of this International Standard, are
referred to as Type A and Type B.
For Type A, the magnetic tape has a nominal thickness of 13 um and a nominal length of up to 60,5 m.
For Type B, the magnetic tape has a nominal thickness of 9 um a length of up to 92,0 m.
Information interchange between Systems by means of this International Standard also requires the use, at a
minimum, of a labelling and file structure and an interchange code which are agreed upon by the interchange Parties.
It is not within the scope of this International Standard to specify the labelling and file structure, or the interchange
Code.
2 Conformance
2.1 Magnetit tape cartridge
A tape cartridge shall be in conformance with this International Standard if it meets all mandatory requirements
specified herein for either Type A or Type B. The tape requirements shall be satisfied throughout the extent of the
tape.
22 .
Generating System
A System generating a magnetic tape cartridge for interchange shall be entitled to Claim conformance to this
International Standard if all recordings on the tape meet the mandatory requirements of this International Standard. A
Claim of conformance shall state whether cartridges of Type A or Type B or both are supported.
23 . Receiving System
A System receiving a magnetic tape cartridge for interchange shall be entitled to Claim conformance with this
International Standard if it is able to handle any recording made on the tape according to this International Standard.
A Claim of conformance shall state whether cartridges of Type A or Type B or both are supported.
3 Normative references
The following Standards contain provisions which, through reference in this text, constitute provisions of this
International Standard. At the time of publication, the editions indicated were valid. All Standards arc subject to
revision, and Parties to agreements based on this International Standard are encouraged to investigate the possibility
of applying the most recent editions of the Standards listed below. Members of IEC and ISO maintain registers of
currently valid International Standards.
ISO/R 527: 1966, Plastics - Determination of tensile pr0pertie.s
ISO/IEC 646: 1991, Information technology - ISO 7-bit coded Character set for information interchange.
ISO 1302: 1992, Technical drawings - Method of indicating surface texture.
ISOIIEC 12248: 1993 (E)
ISO/IEC 11576: 1993, Information technology - Procedure for the registration of algorithms for the lossless
compression of data.
IEC 950: 1991, Safety of information technology equipment, including electrical business equipment
4 Definitions
For the purposes of this International Standard, the following definitions apply.
41 . Absolute Frame Number (AFN): A sequence number allocated to, and recorded in, each frame.
4.2 algorithm: A set of rules for transforming the logical representation of data.
4.3 Area ID: An identifier for each area of the tape specifying the types of frame written therein.
4.4 Automatic Track Finding (ATF): A method by which tracking is achieved.
4.5 Average Signal Amplitude: The average peak-to-peak value of the output Signal from the read head at the
fundamental frequency of the specified physical recording density, over a minimum of 7,8 mm of track, exclusive of
missing pulses.
4.6 azimuth: The angular deviation, in degrees, minutes and seconds of arc, made by the mean flux transition line
with the line normal to the centreline of the recorded track.
4.7 back surface: The surface of the tape opposite to the magnetic coating which is used to record data.
48 . byte: An ordered set of bits acted upon as a unit.
49 . cartridge: A case containing magnetic tape stored on twin hubs.
4.10 Channel Bit: A bit after 8-to-10 transformation.
4.11 Codeword: A word which is generated by a processing algorithm. The number of bits in a Codeword is
variable, and is not specified in this International Standard.
4.12 Data Format ID: An identifier specifying which data format is being used on the tape.
4.13 End of Data (EOD): The Point where the host stopped writing data on the tape.
4.14 End of Information (EOI): A group which indicates the end of partition area in a tape.
End of Partition (EOP): A group which indicates the end of data area in a partition.
4.15
4.16 entity: A unit of recorded data, comprising a processed record sequence resulting from the application of a
common processing algorithm.
4.17 Error Correcting Code (ECC): A mathematical algorithm yielding check bytes used for the detection and
correction of errors.
4.18 flux transition Position: That Point which exhibits maximum free-space flux density normal to the tape
surface.
4.19 flux transition spacing: The distance along a track between successive flux transitions.
4.20 frame: A pair of adjacent tracks with azimuth of opposite polarity, in which the track with the positive azimuth
precedes that with the negative azimuth.
4.21 group: A number of frames constituting a recorded unit.
4.22 Logical Beginning of Tape (LBOT): The Point along the length of the tape where the recording of data for
interchange commences.
4.23 Logical End of Tape (LEOT): A Point along the length of the tape which indicates the approach, in the
direction of tape motion, of the partition boundary or physical end of tape.
ISO/IEC 12248: 1993 (E)
4.24 magnetic tape: A tape which will accept and retain magnetic Signals intended for input, output, and storage
purposes on Computers and associated equipment.
4.25 master reference: The area which contains partition information in the tape.
4.26 Master Standard Amplitude Calibration Tape: A pre-recorded tape on which the Standard Signal amplitudes
have been recorded in the tracks of positive azimuth, 23,0 pm wide, at nominal track pitch, on an AC-erased tape.
NOTE 1 - The tape includes recordings made at 83.4 ftpmm, 333.6 ftpmm, 500.4 ftpmm, 1001 ftpmm and 1501 ftpmm.
NOTE 2 - The Master Standard Amplitude Calibration Tape has been established by the Sony Corporation.
4.27 Master Standard Reference Tape: A tape selected as the Standard for Reference Recording Field, Signal
Amplitude, Resolution Overwrite and Signal-to-Noise Ratio.
NOTE 3 - The Master Standard Reference Tape has been established by the Sony Corporation.
4.28 Optimum Recording Fieid: In the plot of Average Signal Amplitude against the recording field at the physical
recording density of 3002 ftpmm, the field that Causes the maximum Average Signal Amplitude.
4.29 partition: Partition of a tape in which user data is recorded.
4.30 partition reference: The area which contains group information in the partition.
4.31 Physical Beginning of Tape (PBOT): The Point where the leader tape is joined to the magnetic tape.
4.32 Physical End of Tape (PEOT): The Point where the trailer tape is joined to the magnetic tape.
4.33 physical recording density: The number of flux transitions per unit length of track, expressed in flux
transitions per millimetre (ftpmm).
4.34 pre-recording condition (maximum recorded levels): The recording levels above which a tape intended for
interchange shall not previously have been recorded.
4.35 processed record: A sequence of Codewords which result from the application of processing to data.
processed records which Start on an 8-bit boundary
4.36 processed record sequence: A sequence of one or more
and end on a subsequent 8-bit boundary.
4.37 processing: The use of an algorithm to transform host data into Codewords.
record: Related data treated as a unit of information.
4.38
4.39 Reference Recording Field: The Optimum recording field of the Master Standard Reference Tape.
4.40 Secondary Standard Amplitude Calibration Tape: A tape pre-recorded as defined for the Master Standard
Amplitude Calibration Tape; the Outputs of which are known and stated in relation to that of the Master Standard
Amplitude Calibration Tape.
NOTE 4 - The Secondary Standard Amplitude Calibration Tape tan be ordered from the Sony Corporation, Audio Device Business Department,
Component Marketing Group 4-10-18, Takanawa, Minato-ku, Tokyo 108, Japan, under Part Number TY-7000 G until the year 2000. It is intended
that these be used for calibrating tertiary tapes for use in routine calibration.
4.41 Secondary Standard Reference Tape: A tape the Performance of which is known and stated in relation to that
of the Master Standard Reference Tape.
NOTE 5 - A Secondary Standard Reference Tape tan be ordered from the Sony Corporation, Audio Device Business Department, Component
Marketing Group 4-10-18. Takanawa, Minato-ku, Tokyo 108, Japan, under Part Number RSD 1079 until the year 2000. It is intended that these be
used for calibrating tertiary tapes for use in routine calibration.
4.42
Separator Mark: A record containing no user data, which is used to separate data.
ISO/IEC 12248: 1993 (E)
4.43 Standard Reference Amplitude: The Average Signal Amp1 itude from the tracks of positive azimuth of the
recording density.
Master Standard Amplitude Calibration Tape at a specified physical
noise from total noise in
4.44 tape noise amplitude: The tape noise amplitude is the subtractive value of amplifier
Ims.
4.45 Tape Reference Edge: The bottom edge of the tape when viewing the recording side of the tape with the
PEOT of the tape to the observer’s right.
4.46 track: A diagonally positioned area on the tape along which a series of magnetic Signals may be recorded.
5 Environment and safety
Unless otherwise stated, the conditions specified below refer to ambient conditions in the air immediately
surrounding the cartridge.
51 . Testing environment
Unless otherwise stated, tests and measurements made on the tape cartridge to check the requirements of this
International Standard shall be carried out under the following conditions:
: 23 OC zt 2 OC
temperature
relative humidity : 40 % to 60 %
conditioning period before testing : 24h
Operating environtient
52 .
Cartridges used for data interchange shall be capable of operating under the following conditions:
: 5 OC to 45 OC
temperature
relative humidity : 20 % to 80 %
wet bulb temperature : 26 OC max.
There shall be no deposit of moisture on or in the cartridge.
Conditioning before operating:
If a cartridge has been exposed during storage and/or transportation to a condition outside the above values, before
use the cartridge shall be conditioned 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.
NOTE 6 - Rapid variations of temperatwe simuld be avoided”.
53 . Storage environment
For long term or archived storage of cartridges the following conditions shall be observed:
temperature : 5 OC to 32 OC
relative humidity :I 20 % to 66 %
maximum wet bulb temperature
:’ 26 OC max.
The stray magnetic field at any Point on the tape shall not exceed 4 000 A/m. There shall be no deposi t of moisture
on or in the cartridge.
54 .
Transportation
Recommended limits for the environment to which a cartridge may be subjected during transportation, and the
precautions to be taken to minimize the possibility of darnage, are provided in annex J.

ISOIIEC 12248: 1993 (E)
55 . Safety
The cartridge and its components shall satisfy the requirements sf IEC 950.
56 l Flammability
The cartridge and its components shall be made from material which, if ignited from a match flame, do not continue
to burn in a still carbon dioxide atmosphere.
- Requirements for the case
Section 2
Dimensional and mechanical characteristics of the case
61 . General
The case of the cartridge shall comprise:
- an upper half- a lower half,
- a slider movably mounted on the lower half,
-
a lid pivotally mounted on the upper half.
In the drawings, using third angle projection, an embodiment of the cartridge is shown as an example.
Figure 1
is a perspective view of the cartridge seen from the top.
Figure 2 is a perspective view of the cartridge seen from the bottom.
Figure 3 is-a partial view of the rear side.
Figure 4 is a schematic view showing the Reference Planes X, Y, and 2.
Figure 5 Shows the front side.
Figure 6 Shows the top side with the lid in closed Position.
Figure 7 Shows the left side.
Figure 8 Shows the top side with the lid in open Position.
Figure 9 Shows the left side with the lid in open Position.
Figure 10 Shows the bottom side with the lid and the slide in closed Position.
Figure 11 Shows the bottom side with the lid and the slider in open Position.
Figure 12 is a view from the top of the inside of the lower half with the upper half removed.
Figure 13 is a view of the bottom half with the lid and the slider in open Position.
Figure 14 is a view of the left side with the lid and the slider in open Position.
Figure 15 is a top view of a hub.
is a side view of a hub with partial Cross section.
Figure 16
Figure 17 is a partial Cross-section through a hub and both halves of the case showing the interface with the
drive spindle.
Figure 18 Shows at a larger scale the lid in the open Position.
Figure 19, 20 show at a larger scale the functional relationship between the lid and the locking mechanism of
the hubs.
Figure 21, 22 show the label areas on the top and the rear side.
The dimensions are referred to three orthogonal Reference Planes X, Y, and 2 (figure 4).
62 . Overall dimensions (figures 6 and 7)
The Overall dimensions of the case with the lid in the closed Position shall be:
= 73,0 mm * 0,3 mm
= 54,O mm * 0,3 mm
L2
= 10,5 mm * 0,2 mm
L3
ISO/IEC 12248: 1993 (E)
The edges formed by the rear side and left and right sides shall be rounded off with a radius
= 1,5 mm max.
Rl
The two edges of the lid shall be rounded off with a radius
= 0,5 mm max.
R2
63 . Loading grip (figure 6)
The top side shall have a loading grip for loading and positioning the cartridge into the drive. The Position and
dimensions of the loading grip shall be
L = 25,5 mm & 0,3 mm
= 10 mm min.
L5
= 5,0 mm * 0,2 mm
L6
L, = 2,0 mm min.
The depth of the loading grip below surface of the top side shall be
+W
0,5 mm mm
- 0.0
64 . Holding areas (figure 6)
The two areas shown shaded in figure 6 shall be the areas along which the cartridge shali be held down when inserted
in the drive. Their positions and dimensions shall be
= 6,0 mm =f: 0,l mm
L8
= 5,0 mm * 0,l mm
L9
65 . Notches of the lid (f’igures 5 and 8)
The lid shall have two pairs of notches.
The first pair of notches, the slider leck release notches, allows elements of the drive to release the locking
mechanism of the slider. The positions and dimensions of these notches shall be
L = 0,4 mm max.
= 3,0 mm min.
bl
= 1,2 mm * 0,l mm
b2
= 49,8 mm & 0,2 mm
b3
The second pair of notches, the slider movement notches, allows elements of the drive to move the slider from closed
to open Position (see also 6.8.1). The positions and dimensions of these notches shall be
L = 3,0 mm min.
= 0,9 mm min.
b4
= 7,5 mm * 0,l mm
L15
= 36,00 mm * 0,15 mm
L16
66 . Lid dimensions (figures 6 to 8)
The lid is shown in closed Position in figures 6 and 7. Its dimensions shall be
ISO/IEC 12248: 1993 (E)
L = 1,2 mm * 0,l mm
= 6,8 mm * 0,4 mm
L18
L = 1,l mm * 0,l mm
= 2,0 mm * 0,l mm
L20
= 6,4 mm k 0,2 mm
L21
= 1,5 mm * 0,l mm
L22
= 6,8 mm * 0,4 mm
R3
The lid shall have a chamfer of 45O with a length of
1,5 mm * 0,l mm
L23 =
There shall be a dimensional relationship between the height L24 shown in figure 7, which includes the slider and the
upper half, and the height L,, of the lid. When a vertical forte of 1 N is exerted on the upper half the following
conditions shall be met
= 10,5 mm * 0,2 mm
L24
When no forte is exerted
10,9 mm max.
L24 =
In figure 8 the lid is shown in open Position. The distance from the front edge of the lid to the rear side shall be
= 55,5 mm * 0,3 mm
L26
67 . Optical detection of the beginning and end of tape (figures 9 and 12)
Means for the Optical detection of the beginning and end of tape shall be provided. These shall consist of a pair of
windows on the left and right sides of the case (see also figure 18). The design of these windows allows this detection
for two different drive designs:
- either a light Source and a detector are provided in the drive on each side of the cartridge, in which case the light
enters the case through the upper windows, falls on a prism (see section A-A) mounted inside the case which
reflects this light so that it goes through the tape and falls on the detector through the lower window; the light
transmittance of the prism shall be greater than 50 % of that of a reference prism when measured as specified in
annex A,
-
or, the light of a light Source within the drive Passes through the tape from inside the cartridge and falls through
the lower windows on to the detectors placed on each side of the case.
The positions and dimensions of these windows allow the cartridge to be used with drives implementing either
System, they shall be
= 6,20 mm * 0,lO mm
L27
= 7,65 mm k 0,lO mm
L28
+ 0,20
= 1,50mm mm
L29
- 0,oo
= 3,9 mm * 0,l mm
L30
= 1,8 mm i 0,l mm
L31
= 7,0 mm i 0,2 mm
L32
ISO/IEC 12248: 1993 (E)
= 2,5 mm min.
L33
Dimension L32 specifies the Position of the rear edge of the windows relative to Reference Plane Y. Dimension L,,
shall be measured relative to this rear edge.
68 . Bottom side (figures 10 and 11)
The bottom side is shown in figure 10 with the lid and the slider in closed Position and in figure 11 with both in the
open Position.
The dimension L,, of the bottom half, L,, of the slider and L36 of the lid shall satisfy the following conditions
= 73,0 mm f: 0,3 mm
L34
6.8.1 Locking mechanism of the slider
The cartridge shall have a locking mechanism for the slider which locks it in the closed and open positions. The
design of this mechanism is not specified by this International Standard, except for the different forces acting on the
slider, and for its detent.
The slider shall be spring-loaded by a spring holding it in closed Position when it is unlocked. The forte required to
operate the slider shall not exceed 2 N.
The slider shall have two grooves with an opening at both ends. The detent of the locking mechanism shall protrude
through these openings so as to hold the slider in both open and closed positions. The detent shown in Cross section
C-C is only an example of implementation.
The grooves are parallel to Reference Plane 2 and aligned with the slider leck release notches of the lid. The
positions and dimensions of the grooves and of the openings for the detent of the locking mechanism when the slider
is in the closed Position shall be
1,2 mm i 0,l mm
L37 =
= 49,8 mm i: 0,2 mm
L38
10,O mm * 0,l mm
L39 =
+ 0,5
2,0 mm mm
L40 =
- 0.1
= 3,0 mm min.
L41
= 1,5 mm min.
L42
= 0,8 mm * 0,l mm
L43
+ 0,5
= 0,8 mm mm
L44
- 0.1
A = 45O min.
= 0,65 mm f: 0,05 mm
L45
The Position and dimensions of the openings for the detent when the slider is held in the open Position are determined
by L,,, L,,, L,,, and L,,.
In the closed Position of the slider, the maximum forte to be exerted on the detent in a direction perpendicular to
Reference Plane Z and over a stroke of 0,65 mm shall be 0,5 N max.
ISO/IEC 12248: 1993 (E)
In the open Position of the slider the holding forte shall be 0,3 N min.
6.8.2 Access holes
The slider shall have two circular access holes (see section B-B) which, in the open Position of the slider, allow
Penetration of the drive spindles into the hubs. The diameters of these access holes shall be
d = 10,O mm * 0,2 mm
12,0 mm max.
d, =
6.8.3 Recognition, sub-datum and write-inhibit holes
The bottom half shall have a number of holes on an edge at its rear. This edge shall be defined by
= 45,2 mm k 0,2 mm
L46
L = 49,2 mm k 0,2 mm
The centres of these holes lie on a line perpendicular to Reference Plane Y at a distance from Reference Plane X of
= 47,2 k 0,2 mm
L48
6.8.3.1 Recognition holes
There shall be four recognition holes numbered from 1 to 4 as shown in figure 10. Their Position and dimensions shall
be
= 2,5 mm i 0,l mm
d3
= 1,0 mm f: 0,l mm
L49
= 56,0 mm k 0,3 mm
L50
= 4,0 mm * 0,l mm
L51
= 1,0 mm * 0,l mm
L52
= 3,0 mm min.
L53
All recognition holes shall have the Cross-section shown in Cross-section F-F in figure 11 for recognition hole No. 1
One of the two cross-sections F-F Shows a recognition hole closed by mean s of a plug, the other Shows it with the
1 withstand an applied forte of 0,5 N max. without being punched out.
plug punched out. These plugs shal
This International Standard prescribes the following states of these holes:
Recognition holes No. 1 and No. 3 shall be closed
Recognition hole No. 2 shall be closed for Type A cartridges
Recognition hole No. 2 shall be open for Type B cartridges
Recognition hole No. 4 may be open or closed
Other combinations of the recognition holes 1, 2, and 3 are reserved for future applications (see annex B).
6.8.3.2 Write-inhibit hole
The Position and dimensions of the write-inhibit hole shall be
= 2,5 mm k 0,l mm
d4
56,0 mm k 0,3 mm
L50 =
When the write-inhibit hole is open, recording on the tape is inhibited, when it is closed recording is enabled.
ISO/IEC 12248: 1993 (E)
The write-inhibit hole shall have the cross-section shown in cross-section F-F in figure 11 for recognition hole No. 1.
One of the two Cross-sections F-F Shows the hole closed by means of a plug, the other Shows it with the hole punched
out. These plugs shall withstand an applied forte of 0,5 N max without being punched out.
The case may have a movable element allowing to open and close the write-inhibit hole. If present, this element shall
be such that the state of write-inhibit hole is visible (see figure 3 as an example). Such an element shall be neither
broken nor moved by a forte smaller than 0,5 N.
Regardless of whether a plug or a movable element is used to select the open and closed states of the write-inhibit
hole, the following dimensions from Cross-section F-F shall define the closed and open states, respectively.
L52 = 1,0 mm * 0,l mm
L,, = 3,0 mm min.
6.8.3.3 Sub-datum holes
These holes are used to Position the cartridge in the drive. Their Position and dimensions shall be as follows:
- The hole seen below the write-inhibit hole in figure 11 shall have an elongated form and the same cross-section
E-E as shown for the other hole.
= 45,5 mm * 0,2 mm
L54
+ 0,l
= 3,5 mm mm
L55
- 0,o _
+ 0,05
= 2,50 mm mm
L56
- 0,oo
- The Position and dimensions of the other sub-datum hole shall be
+ 0,05
d, = 2,50 mm mm
- 0,oo
= 1,0 mm min.
d6
5,5 mm * 0,l mm.
L57 =
2,0 mm min.
L58 =
1,2 mm min.
L59 =
The edge of both sub-datum holes shall have a chamfer of
0,2 mm * 0,l mm.
6.8.4 Datum holes
The lower half has two datum holes also used to Position the cartridge within the drive. One of them has an elongated
form, the other is circular. Cross-section AD-D shown for the latter also applies to the former. Their Position and
dimensions shall be
51,0 mm * 0,l mm
L60 =
+ 0.05
= 2,80 mm mm
L61
- 0,oo
+ 0,l
mm
= 3,5 mm
L62
- 0.0
ISOhEC 12248: 1993 (E)
3,0 mm min.
L63 =
+ 0.05
mm
= 2,80 mm
d7
- 0,oo
The upper edge of both datum holes shall have a chamfer of 0,2 mm * 0,l mm.
6.8.5 Access room for tape guides
When the cartridge is inserted into the drive, tape guides in the drive are pulling out the tape toward the heads of the
drive. The shape and dimensions of the access room provided by the cartridge for these tape guides shall be (see also
6.8.7.5):
= 3.1 mm max.
L64
= 5,6 mm min.
L65
= 11,0 mm max.
L66
+ 0,7
mm
L = 7,0 mm
- 0,o
6,7 mm min.
L68 =
a = 45"f 1”
= 47,9 nim min.
L69
+ 0,oo
mm
= 3,30 mm
L70
- 0.15
6.8.6 Holes for accessing the hubs
The lower half has two holes through which the spindles of the drive tan access the hubs the slider is in the
open Position. The positions and dimensions of these holes shall be
d, = 9,0 mm * 0,l mm
= 29,00 mm i: 0,15 mm
L7,
10,5 mm * 0,l mm
L72 =
= 30,O mm * 0,l mm
L73
6.8.7 Internal structure of the lower half (figure 12)
In figure 12 the different elements of the inside of the lower half are shown. There shall be a locking mechanism for
the hobs to prevent them from rotating when the lid is in the closed Position. The design of this locking mechanism is
not specified by this International Standard, thus it is not shown in figure 12. Locking and unlocking of the hubs shall
depend upon the Position of the lid as specified in 6.13.
6.8.7.1 Diameter of the wound tape
The diameter of the tape wound on a hub shall be
d, = 36,5 mm max.
6.8.7.2 Tape wind
The magnetic surface of the tape shall face outwards.
ISOIIEC 12248: 1993 (E)
6.8.7.3 Tape motion
The forward direction of tape motion is from the left side of the cartridge to its right side (see figures 1 and 2).
6.8.7.4 Guide posts
The tape shall pass around two guide posts in the cartridge, the axes of which are perpendicular to Reference Plane Z
and Passes through the centres of the datum holes. The Position and dimensions of these guide posts shall be:
their positions are determined by that of the centres of the datum holes,
- their Cross-section shall be circular with a radius
= 3,0 mm * 0,l mm
R4
over an angle of 180° in clockwise sense starting at angle
= 45"* 1”
P
-
their cross-section over the other half of 180’ is not specified by this International Standard.
6.8.7.5 Position of the tape in the case (view A)
When the tape runs from one guide post to the other it shall remain between two planes parallel to Reference Plane Z.
The distance of these planes to Reference Plane 2 shall be
1,4 mm min.
L74 =
= 6,4 mm max.
L75
The design centre for the Position sf the tape centreline is
= 39 mm
L7 6
The height of the ac.cess room specified in. 6.8.5 for the tape guides shall be
+ O:,S
=. 8,0 mm mrn
L7 7
- 0,o
6.8.7.6 Tape path zone
When the cartridge is inserted into the drive, the tape is pulled outside the case by tape guides as mentioned above. It
is then no longer in contact with the guide posts. The tape path zone of the case is the zone in which the tape must be
able to move freely. This zone is defined by
= 5,5 mm i 0,l mm
L78
= 56,5 mm * 0,3 mm
L79
= 8,0 mm & 0,2 mm
L80
6.8.8 Light path (figure 12)
As specified in 6.7 there is a lower window in the right and left sides of the case through which light having passed
through the tape tan pass and fall on a detector of the drive. In Order to ensure that the corresponding light path is not
obstructed by inner elements of the case, its configuration in this zone shall be as follows:
The Position and dimension of the lower window are specified by L,, and L,, (see figure 9). The dimensions
= 1,s mm max.
L8l
= 5,0 mm min.
Lt32
ensure that no elements of the case obstruct the light path.
ISODEC 12248: 1993 (E)
6.8.9 Support areas (figure 13)
When the cartridge is inserted into the drive and held in Position by forces perpendicular to Reference Plane Z acting
on the holding areas (see 6.4), it shall be supported by three supporting areas A’, B’ C’ on its bottom side, shown
shaded in figure 13. The Position and dimensions of these areas shall be as follows:
- Areas A’ and B’ are not specified by this International Standard because they on Parts of the lower half for
does not specify requirements.
which this International Standard
- Area C’ shall be defined by
1,0 mm * 0,I mm
L83 =
= 49,0 mm * 0,3 mm
L84
6.8.10 Datum areas (figure 13)
There shall be two annular datum surfaces A and B and one circular such surface C. All three datum areas shall lie in
Reference Plane Z. Their Position and dimensions shall be:
- Datum area A shall be centred on the intersection of Reference Planes X, Y, and Z, its inner diameter shall be d,
(see 6.8.4 and figure 11), its outer diameter shall be
= 5,0 mm k 0,l mm
d
- Datum area B shall be centred on the intersection of Reference Planes X and Z at a distance L6() (see 6.8.4 and
figure 11) from the centre of datum area A. Its inner dimensions shall be L6t and L62, its outer diameter shall be
d
10.
Datum area C shall be centred on a Point defined by
= 42,0 mm =t 0,3 mm
L85
25,5 mm k 0,3 mm
L86 =
Its diameter shall be d,,.
6.8.11 Relationship between support and datum areas and Reference Plane Z (figure 14)
Support area A’ shall be coplanar with datum area A within 0,l mm.
Support area B’ shall be coplanar with datum area B within 0,l mm.
Support area C’ shall be parallel to Reference Plane 2 within 0,l mm. It shall be at a distance
1,lO mm * 0,05 mm
L87 =
from Reference Plane Z.
69 . Hubs (figures 15, 16)
The dimensions of the hub shall be
+ 0,OS
= 6,60 mm mm
- 0,oo
+ 0,o
= 8,8 mm mm
dl2
- 0.1
d = 15,OO mm * 0,05 mm
= 6O”k 1’
P
ISO/IEC 12248: 1993 (E)
= 45Of 1”
+ 0,l
2,5 mm mm
L88 =
- 0.0
+ 0.20
= 2,60 mm mm
L89
- 0,oo
The two cylindrical surfaces with diameters d, 1 and d13 shall be Co-axial within 0,05 mm.
The torque necessary to rotate the hub with a partially or fully wound tape shall be 0,0002 Nern max.
6.10 Leader and trailer attachment
The material of the leader and trailer and their attachment to the hubs and to the tape shall be such that when
subjected to a forte of 5 N max. they will neither break nor be detached from the hubs or the tape.
6.11 Interface between the hubs and the drive spindles (figure 17)
The interface between the hubs and the spindles shown in figure 17 in Cross-section is specified in terms of the
following relationships:
1,2 mm max.
d
15 - dl4 =
1,0 mm min.
L,, - L,, = 1,3 mm max.
NOTE7- It is expected that the top of the drive spindle will not penetrate within the hub beyond a distance Ld = 7,65 mm max above
Reference
Plane 2.
6.12 Opening of the lid (figure 18)
When the lid is opened its lower front edge moves along an arc of a circle with radius
= 9,6 mm k 0,2 mm
R5
The centre of rotation is defined by L,, and L,,. The end Position of the lid, i.e. when it is fully open, is defined by
= 10,9 mm * 0,2 mm
L92
= 0,3 mm * 0,l mm
L93
= 6,3 mm i 0,2 mm
L94
The forte F required to open the lid shall not exceed 1,2 N. It shall be applied at a distance
= 5,0 mm * 0,l mm
L95
measured parallel to Reference Plane Z from centre of rotation of radius R, (see also annex C).
6.13 Release of the hub locking mechanism (figures 19, 20)
As mentioned in 6.8.7 the design of the locking mechanism for the hubs is not specified by this International
Standard, except that it shall be connected to the lid so that the hubs are locked or unlocked as a function of the
angular Position of the lid.
When the lid rotates from the closed to the open Position (clockwise as seen in figures 19, 20) the hubs shall remain
locked as long as the lid has not reached the Position defined by
= 7,0 mm
L96
= 7,5 mm * 0,2 mm
L97
ISO/IEC 12248: 1993 (E)
The hubs shall be completely released as soon as the lid has reached the Position defined by
10,3 mm
L98 =
= 6,6 mm i: 0,2 mm
L99
6.14 Label areas (f’igures 21,22)
On top and rear sides of the case there shall be an area on which adhesive Iabels tan be placed. The dimensions of
these areas shall be
L = 28,9 mm max.
= 5,2 mm min.
ho1
= 43,4 mm max.
bo2
= 39,4 mm max.
bo3
8,8 mm max.
bo4 =
= 0,5 mm min.
R6
‘fop Side Losding grip
\
Lefc Side
% , ,,,
/
Tide z
,ht Sidc
Writc-inhibit
IndiciMor
Rcar Si&
Figure 3 - Partial view
Slider
of the rear side
Figure t -
view
Botturn Side
’ ilK
Front Si&
Recognition 1 fok No 4
Weite-inhibit ) 101~ , \
Suh-dit um
tiote
Figure 2 -
Bottom view
Figure 4 - Reference Planes X, Y, 2

ISO/IEC 12248: 1993 (E)
Figure 7 - Left side, lid closed
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