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ECMA-315 — 12,65 mm wide magnetic tape cassette for information interchange - Helical scan recording - DTF-2 (December 2000)

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S tandard ECMA-315 December 2000

Standardizing Information

and

Communication

Systems

12,65 mm Wide Magnetic Tape Cassette for Information Interchange - Helical Scan Recording - DTF-2

Phone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http://www.ecma.ch - Internet: [email protected]

S tandard ECMA-315 December 2000

Standardizing

Information

and

Communication

Systems

12,65 mm Wide Magnetic Tape Cassette for Information Interchange - Helical Scan Recording - DTF-2

Phone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http://www.ecma.ch - Internet: [email protected] MB - ECMA-315.DOC -14.03.2002 17:34

Brief History ECMA has produced a series of Standards for cassettes and cartridges containing magnetic tapes of different widths and characteristics. ECMA Standards for cartridges/cassettes recorded in a helical mode are: ECMA-139(1990):

3,81 mm Wide Magnetic Tape Cartridges - Helical Scan Recording - DDS Format

ECMA-146(1990):

3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording - DATA/DAT Format

ECMA-150(1992):

3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording - DDS-DC Format

ECMA-170(1992):

3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording - DDS Format using 60 m and 90 m Length Tapes

ECMA-171(1992):

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

ECMA-198(1995):

3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording - DDS-2 Format using 120 m Length Tapes

ECMA-236(1996):

3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording - DDS-3 Format using 125 m Length Tapes

ECMA-288(1999):

3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording - DDS-4 Format using 155 m Length Tapes

ECMA-169(1992):

8 mm Wide Magnetic Tape Cartridge, Dual Azimuth for Information Interchange - Helical Scan Recording

ECMA-246(1998):

8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording AIT-1 Format

ECMA-247(1998):

8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording HH-1 Format

ECMA-249(1998):

8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording DA-2 Format

ECMA-291(1999):

8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording AIT-1with MIC Format

ECMA-292(1999):

8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording AIT-2with MIC Format

ECMA-293(1999):

8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording Mammoth Tape-2 Format

ECMA-210(1995):

12,65 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording - DATA-D3-1 Format

ECMA-248(1996):

12,65 mm Wide Magnetic Tape Cassette for Information Interchange - Helical Scan Recording - DTF-1 Format

This Standard ECMA-315 describes a cassette containing magnetic tape 12,65 mm wide. The processing of data and method of recording employ technologies developed for recording digital television signals and thus provides high capacity and data rate. Furthermore, the directory and file structure placeholders defined in this ECMA Standard provide for fast search and access to very large sets of data recorded on this magnetic tape as well as providing for disaster recovery in the case of a lost or destroyed directory. The large and small cassettes have maximum capacities of 200 GB and 60 GB respectively. Adopted as an ECMA Standard by the General Assembly of 15 th December 2000.

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Table of contents Section 1 - General

Scope

Conformance Ma g n e t i c t a p e c a s s e t t e Generating system Re c e i v i n g s y s t e m

1 1 1 1

References

4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 4.11 4.12 4.13 4.14 4.15 4.16 4.17 4.18 4.19 4.20 4.21 4.22 4.23 4.24 4.25 4.26 4.27 4.28 4.29 4.30 4.31 4.32 4.33

Definitions A b s o lu te b lo c k n u mb e r a.c. erase a lg o r ith m A p p e n d f ile A p p e n d v o lu me A v e r a g e S ig n a l A mp litu d e ( A S A ) a z i mu t h back surface bit cell b lo c k B l o c k Ma n a g e me n t T a b l e ( B M T ) b yte c a s s e tte c o mp r e s s e d d a ta Co n tr o l T r a c k flux transition position flux transition spacing L o g ic a l tr a c k s e t I D L o g ic a l v o lu me ma g n e tic ta p e Ma s te r S ta n d a r d Re f e r e n c e T a p e ( MS RT ) physical recording density Re f e r e n c e F ie ld ( RF ) S e c o n d a r y S ta n d a r d Re f e r e n c e T a p e ( S S RT ) S ta n d a r d Re f e r e n c e A mp litu d e ( S RA ) S t a n d a r d R e f er e n c e Cu r r e n t ( I r ) T a p e Re f e r e n c e E d g e T e s t Re c o r d in g Cu r r e n t ( T RC) tr a c k tr a c k a n g le Track Set T yp ic a l F ie ld ( T F ) word

1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 4 4 4 4

5.1 5.2

C o n v e n t io n s a n d N o t a t io n s Re p r e s e n ta tio n o f n u mb e r s N a me s

4 4 4

Acronyms

2.1 2.2 2.3

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En v ir o n m e n t a n d s a f e t y T e s tin g e n v ir o n me n t O p e r a tin g e n v ir o n me n t S to r a g e e n v ir o n me n t T r a n s p o r ta tio n Safety F lamma b ility

5 5 5 5 5 6 6

Section 2 - Requirements for the case

D im e n s io n a l a n d m e c h a n ic a l c h a r a c t e r is t ic s o f t h e c a s e 8.1 General 8.2 Type S cassette 8.2.1 O v e r a ll d ime n s io n s 8.2.2 H o ld in g a r e a s 8.2.3 W in d o w 8.2.4 Label areas 8.2.5 Datum areas and datum holes 8.2.6 Support areas 8.2.7 G u id in g g r o o v e s 8.2.8 Re c o g n i t i o n h o le s 8.2.9 W r ite - in h ib it p lu g 8.2.10 P r e - p o s itio n in g s u r f a c e 8.2.11 Ca s s e tte lid 8.2.12 Ca s s e tte r e e l lo c k 8.2.13 Reel access holes 8.2.14 Re e ls 8.2.15 P o s i t i o n o f th e t a p e i n t h e c a s e 8.2.16 T a p e p a th z o n e 8.2.17 Tape access cavity 8.3 Type L cassette 8.3.1 O v e r a ll d ime n s io n s 8.3.2 H o ld in g a r e a s 8.3.3 W in d o w 8.3.4 Label areas 8.3.5 Datum areas and datum holes 8.3.6 Support areas 8.3.7 G u id in g g r o o v e s 8.3.8 Re c o g n i t i o n h o le s 8.3.9 W r ite - in h ib it p lu g 8.3.10 P r e - p o s itio n in g s u r f a c e 8.3.11 Ca s s e tte lid 8.3.12 Ca s s e tte r e e l lo c k 8.3.13 Reel access holes 8.3.14 Re e ls 8.3.15 P o s i t i o n o f th e t a p e i n t h e c a s e 8.3.16 T a p e p a th z o n e 8.3.17 Tape access cavity 8.3.18 C a v i t y f o r c o mp a t i b i l i t y w i t h T y p e S c a s s e t t e

7 7 7 7 8 8 8 9 9 10 11 12 13 13 14 14 15 16 16 16 32 32 32 33 33 33 34 34 35 36 37 37 38 39 39 40 41 41 42

Section 3 - Requirements for the unrecorded tape

58 58 58

7.1 7.2 7.3 7.4 7.5 7.6

9.1 9.2

Mechanical, physical and dimensional characteristics of the tape Ma t e r i a l s T a p e le n g th

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9 . 3 T ap e w id th 9 . 4 W id th an d p o s itio n o f s p licin g tap e 9 . 5 D isco n tin u ity 9 . 6 T a p e th ic k n e s s 9 . 7 L o n g itu d in a l c u r v a tu r e 9 . 8 O u t- o f - p la n e d is to r tio n s 9 . 9 Co a tin g a d h e s io n 9.10 L a ye r - to - la ye r a d h e s io n 9.11 T e n s ile s tr e n g th 9.11.1 Br e a k in g s tr e n g th 9.11.2 Y ie ld s tr e n g th 9.11.3 S tr e n g th o f S p lic e 9.12 Re s id u a l e lo n g a tio n 9.13 Electrical resistance of the coated surfaces 9.14 T a p e w in d

58 58 58 58 59 59 59 60 60 60 60 60 60 60 61

10 Magnetic recording characteristics 10.1 Typical Field (TF1) 10.2 A v e r a g e S ig n a l A mp litu d e ( A S A ) 10.3 Re s o lu tio n 10.4 S i g n a l - t o - n o is e r a t i o ( S / N ) 10.5 Ease of erasure 10.6 T ap e q u a lity 10.6.1 Mis s in g p u ls e s 10.6.2 Mis s in g p u ls e z o n e 10.7 I n h ib ito r ta p e

61 62 62 62 62 62 62 62 62 63

S e c t i o n 4 - R e q u i r e m e n t s f o r a n in t e r c h a n g e d t a p e

11 F o r m a t f o r h e lic a l t r a c k s 11.1 G e n e r a l d e s c r ip tio n o f th e w r ite d a ta p a th 11.2 F o r ma tio n o f a L o g ic a l T r a c k S e t 11.2.1 T yp e s o f in f o r ma tio n tr a c k s e ts 11.2.2 Generation of a Logical Track Set 11.2.3 S u b c o d e d a ta f ie ld 11.2.4 Blo c k Ma n a g e me n t T a b le ( BMT ) 11.2.5 D a ta a n d in f o r ma tio n f ie ld d e f in tio n s 11.3 T r a c k S e t in f o r ma tio n 11.3.1 L o a d in g th e P r o d u c t Co d e A r r a ys 11.4 P r o d u c t c o d e a r r a y p r o c e s s in g 11.4.1 E r r o r c o r r e c tio n me th o d 11.4.2 E r r o r c o r r e c tio n c o d in g f o r C1 P a r ity 11.5 T r a c k a s s ig n me n ts 11.5.1 S e g me n ts /S e c to r s 11.5.2 S yn c Blo c k s 11.5.3 Track interleave 11.5.4 By t e in t e r l e a v e a c r o s s S y n c Bl o c k s 11.5.5 Ra n d o miz a tio n 11.6 F o r ma tio n o f th e c o n te n ts o f a h e lic a l tr a c k 11.6.1 S e g me n t/S e c to r d e ta ils 11.6.2 Ch a n n e l b it c o d in g 11.6.3 I n te r le a v e d - N RZ 1 11.6.4 T r a c k in g P ilo t S ig n a ls ( T P S )

64 64 64 64 66 66 70 70 74 75 77 77 77 78 78 79 80 82 83 83 83 84 84 85

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12 Tr a c k g e o m e t r y 12.1 General 12.2 Helically recorded tracks 12.2.1 L o c a tio n o f th e tr a c k s 12.2.2 T r a c k w id th 12.2.3 T r a c k a n g le 12.2.4 T r a c k p itc h 12.2.5 L o c a tio n o f e le me n ts in th e h e lic a l tr a c k 12.2.6 L o c a tio n o f th e D a ta A r e a Re f e r e n c e P o in t 12.2.7 S tr a ig h tn e s s o f tr a c k s 12.2.8 A z imu th a n g le s 12.2.9 T r a c k in g P ilo t S ig n a ls ( T P S ) 1 2 . 2 . 1 0 A mp litu d e o f s e r v o s ig n a ls 12.3 L o n g itu d in a l tr a c k s g e o me tr y 12.3.1 Co n tr o l T r a c k 12.3.2 T i me Co d e T r a c k s i g n a l s r e c o r d i n g p o s i t i o n

85 85 85 85 86 86 86 87 88 88 88 88 88 88 88 88

13 Method of recording helical tracks 13.1 Physical recording density 13.2 Re c o r d c u r r e n t o p timiz a tio n 13.3 Efficiency of erasure

88 89 89 89

14 M e t h o d o f r e c o r d i n g lo n g i t u d i n a l t r a c k s 14.1 O v e r v ie w 14.2 Co n tr o l T r a c k 14.2.1 S ig n a l 14.2.2 P o la r ity o f ma g n e tis a tio n 14.2.3 A lig n me n t 14.2.4 Re a d s ig n a l a mp litu d e 14.2.5 Q u a l i t y o f t h e Co n tr o l T r a c k 14.3 T ime Co d e T r a c k 14.3.1 Me th o d o f r e c o r d in g th e T ime Co d e T r a c k 14.3.2 P h ys ic a l r e c o r d in g d e n s ity 14.3.3 Bit s h if t 14.3.4 Re a d s ig n a l a mp litu d e 14.3.5 Q u a l i t y o f t h e T i me Co d e T r a c k 14.4 F o r ma t f o r th e T ime Co d e T r a c k 14.4.1 Co u n t b its 14.4.2 P h a s e b it 14.4.3 S yn c h r o n iz in g p a tte r n 14.4.4 S u p p le me n ta l D a ta 14.4.5 E x te n t o f T ime Co d e

89 89 89 89 89 89 90 90 90 90 90 90 91 91 91 91 91 91 91 91

Section 5 - Requirements for recorded information

15 Recorded information 15.1 Re c o r d i n g a r e a 15.2 Ma g n e tic ta p e la yo u t 15.2.1 V a lid d a ta a r e a s 15.2.2 I n v a lid d a ta a r e a s 15.3 P h ys ic a l T S I D 15.3.1 S tr u c tu r e s u r r o u n d in g th e V S I T a r e a 15.3.2 S tr u c tu r e o f th e D I T a r e a

92 92 92 92 92 92 94 94

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15.3.3

S tr u c tu r e o f th e U s e r D a ta A r e a

Section 6 - Write operations

Write retry sequence

17 A p p e n d f ile o p e r a t io n 17.1 A p p e n d v o lu me 17.2 A p p e n d w r ite 17.3 O v e r w r ite 17.4 F ile e x te n s io n ( f ig u r e 6 2 )

96 96 97 97 98

Annex A - Measurement of Signal-to-Noise Ratio

101

Annex B - Representation 8/9 coding patterns

103

A n n e x C - R e c o m m e n d a t io n s f o r Tr a n s p o r t a t io n

110

A n n e x D - I n h i b i t o r Ta p e

112

Section 1 - General 1

Scope This ECMA Standard specifies the physical and magnetic characteristics of magnetic tape cassettes, using magnetic tape 12,65 mm wide so as to provide physical interchange of such cassettes between drives. It also specifies the quality of the recorded signals, the recording method and the recorded format, called Digital Tape Format-2 (DTF-2), thereby allowing data interchange between drives by means of such cassettes. The format supports variable length Logical Records, high-speed search, and the use of a registered algorithm for data compression. This ECMA Standard specifies two sizes of cassette. For the purposes of this ECMA Standard the larger cassette is referred to as Type L, and the smaller as Type S. Together with a standard for volume and file structure, e.g. Standard ECMA-13, this ECMA Standard provides for full data interchange between data processing systems.

2 2.1

Conformance Magnetic tape cassette A claim of conformance with this ECMA Standard shall specify the Type of cassette. It shall be in conformance with this ECMA Standard if:

2.2

—

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

—

the recording on the tape meets the requirements of clauses 11 to 17

Generating system A claim of conformance with this ECMA Standard shall specify which Type(s) of cassette is (are) supported. A system generating a magnetic tape cassette for interchange shall be in conformance with this ECMA Standard if all the recordings that it makes, meet the mandatory requirements of this ECMA Standard. A claim of conformance with this ECMA Standard shall state whether or not one, or more, registered algorithm(s) is (are) implemented and, if so, the registered number(s) of (all) the implemented algorithm(s).

2.3

Receiving system A claim of conformance with this ECMA Standard shall specify which Type(s) of cassette is (are) supported. A system receiving a magnetic tape cassette for interchange shall be in conformance with this ECMA Standard if it is able to handle any recording made on the tape according to this ECMA Standard, and a claim of conformance shall state whether or not one, or more, registered algorithm(s) is (are) implemented and, if so, the registered number(s) of (all) the implemented algorithm(s).

References ECMA-13: 1985

File Structure and Labelling of Magnetic Tapes for Information Interchange

ECMA-287: 1999

Safety of Electronic Equipment

ISO/527-1:1993

Plastics Determination of tensile properties.

ISO/IEC 11576:1994

Information Technology - Procedure for the Registration of Algorithms for the Lossless Compression of Data

SMPTE timecode:

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

JIS-B-7502

Characteristics of plastic goods

Definitions For the purpose of this ECMA Standard, the following definitions apply.

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4.1

Absolute block number A number N allocated to each block, indicating that the block is the Nth block from the beginning of the Logical volume containing it. The first block is number one.

4.2

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

4.3

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

4.4

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

4.5

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

4.6

Average Signal Amplitude (ASA) The average peak-to-peak value of the signal output of a read head measured over a minimum of 1,40 mm of track, exclusive of missing pulses.

4.7

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

4.8

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

4.9

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

4.10

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

4.11

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

4.12

byte An ordered set of bits acted upon as a unit.

4.13

cassette A case containing magnetic tape stored on twin reels.

4.14

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

4.15

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

4.16

flux transition position That point along a track on the magnetic tape that exhibits the maximum free-space flux density normal to the tape surface.

4.17

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

4.18

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

4.19

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

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4.20

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

4.21

Master Standard Reference Tape (MSRT) A tape selected as the standard for Signal Amplitude, Reference Field, Resolution and Signal to Noise Ratio (S/N). NOTE The Master Standard Reference Tape has been established at SONY Corporation.

4.22

physical recording density The number of recorded flux transitions per unit length of track, specified as flux transitions per millimetre (ftpmm).

4.23

Reference Field (RF) The Typical Field of the MSRT. There are two Reference Fields: RF1 is that for a helically recorded track RF2 is that for a longitudinally recorded track.

4.24

Secondary Standard Reference Tape (SSRT) A tape the performance of which is known and stated in relation to that of the MSRT. NOTE Secondary Standard Reference Tapes can be ordered under the Part Number SSRT-DTF-1, from the Sony Corporation, Magnetic Product Group, Data Media Sales Division, 6-7-3S Kitashinagawa, Shinagawa-ku, TOKYO 141, Japan. In principle such tapes will be available for a period of 10 years from the publication of the ECMA Standard. However, by agreement between ECMA and Sony Corporation, this period may be shortened or extended to take account of demand for such SSRTs. It is intended that these SSRTs be used for calibrating tertiary reference tapes for use in routine calibration.

4.25

Standard Reference Amplitude (SRA) The Average Signal Amplitude derived from the MSRT, using the appropriate Test Recording Current and the appropriate physical recording density. There are three SRAs. SRA1 is derived from a helically recorded track, recorded at 3 201 ftpmm with TRC1. SRA2 is derived from a longitudinally recorded track at 20,75 ftpmm with TRC2. SRA3 is derived from a helically recorded track, recorded at 800,3 ftpmm with TRC1.

4.26

Standard Reference Current (Ir) The current that produces a Reference Field. There are two Irs. Ir1 is the current that produces RF1 on a helically recorded track. Ir2 is the current that produces RF2 on a longitudinally recorded track.

4.27

Tape Reference Edge The lower edge of the tape when the magnetic coating is facing the observer and the supply reel is to the observer’s right.

4.28

Test Recording Current (TRC) The current used to record an SRA. There are two Test Recording Currents: TRC1 is 1,1 times Ir1 TRC2 is 1,0 times Ir2

4.29

track A narrow, defined area on the tape along which a series of magnetic transitions may be recorded. A track may be parallel to the Tape Reference Edge or at an angle to it.

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4.30

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

4.31

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

4.32

Typical Field (TF) There are two TFs: In the plot of the ASA against the recording field: TF1 is the minimum recording field giving an ASA equal to 90 % of the maximum ASA at the physical recording density of 3 201 ftpmm on a helically recorded track. TF2 is the value of the recording field for which the increase of ASA resulting from an increase of 1 dB of the recording field falls by 0,5 dB at the physical recording density of 20,75 ftpmm on a longitudinally recorded track.

4.33

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

5 5.1

5.2

Conventions and Notations Representation of numbers •

A measured value is rounded off to the least significant digit of the corresponding specified value. It implies that a specified value of 1,26 with a positive tolerance of 0,01, and a negative tolerance of 0,02 allows a range of measured values from 1,235 to 1,275.

•

Letters and digits in parentheses represent numbers in hexadecimal notation.

•

The setting of a bit is denoted by ZERO or ONE.

•

Numbers in binary notation and bit combinations are represented by strings of digits 0 and 1. Within such strings, X may be used to indicate that the setting of a bit is not specified within the string.

•

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

•

Negative values of numbers in binary notion are given in TWOs complement.

•

In each field the data is processed so that the MSB is processed first. Within each byte the msb (numbered 7 in an 8-bit byte) is processed first. This order of processing applies also to the data input to the Error Detection and Correction circuits and to their outputs, unless otherwise stated.

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

Acronyms ASA CRC BMT BST DIT DM ECC EOD FIT LBOT LEOT LIDT

Average Signal Amplitude Cyclic Redundancy Check Block Management Table Bad Spot Table Directory Information Table Dummy Track Error Correcting Code End of Data File Information Table Logical Beginning of Tape Logical End of Tape Logical ID Table

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lsb LSB msb MSB MSRT NEOT PBOT PEOT SRA SSRT TF TPS TRC TSID UID UT VEOV VIT VSIT

Least Significant Bit Least Significant Byte Most Significant Bit Most Significant Byte Master Standard Reference Tape Near End of Tape Physical Beginning of Tape Physical End of Tape Standard Reference Amplitude Secondary Standard Reference Tape Typical Field Tracking Pilot Signal Test Recording Current Track Set Identification Unique Identifier Update Table Virtual End of Volume Volume Information Table Volume Set Information Table

Environment and safety The conditions specified below refer to ambient conditions immediately surrounding the cassette. Cassettes exposed to environments outside these limits may still be able to function usefully; however, such exposure may cause permanent damage.

7.1

Testing environment Unless otherwise specified, tests and measurements made on the tape to check the requirements of this Standard shall be made under the following conditions. temperature

23 °C ± 1 °C

relative humidity

48 % to 52 %

conditioning period before use 24 h min.

7.2

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

5 °C to 40 °C

relative humidity

20 % to 80 % non-condensing

wet bulb temperature

26 °C max

The cassette shall be conditioned before use in the operating environment for a time at least equal to the period during which it has been out of the operating environment, up to a maximum of 24 h.

7.3

Storage environment The following conditions shall be observed for storage. temperature:

5 °C to 32 °C

relative humidity:

20 % to 60 %

The stray magnetic field at any point on the tape shall not exceed 4 000 A/m. There shall be no deposit of moisture on or in the cassette.

7.4

Transportation Recommended limits for the environment to which a cassette may be subjected during transportation, and the precautions to be taken to minimize the possibility of damage, are provided in annex C.

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7.5

Safety The cassette and its components shall satisfy the requirements of ECMA-287 when used in the intended manner or in any foreseeable use in an information processing system.

7.6

Flammability The tape and the case components shall be made from materials which, when ignited from a match flame, do not continue to burn in a still carbon dioxide atmosphere.

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Section 2 - Requirements for the case 8

Dimensional and mechanical characteristics of the case

8.1

General The case of the cassette shall comprise — — — — — — — —

an upper half a lower half a lid pivotally mounted on the upper half a latch mechanism for the lid two reels for magnetic tape a locking mechanism for the reels a write-inhibit mechanism recognition holes.

In the drawings, embodiments of the cassettes are shown as examples. For the Type S cassette the dimensions are referred to three orthogonal Reference Planes X, Y, and Z where — — —

The three datum areas A, B and C in the bottom side of the case are in Plane Z Plane X is perpendicular to Plane Z and intersects the centres of datum holes A and B Plane Y is perpendicular to Plane X and Plane Z and intersects the centre of datum hole A.

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

The three datum areas E, F and G in the bottom side of the case are in Plane Z Plane X is perpendicular to Plane Z and intersects the centres of datum holes E and F Plane Y is perpendicular to Plane X and Plane Z and intersects the centre of datum hole E.

Figures 1 to 19 and sub-clause 8.2 define the dimensions of the case and reels for a Type S cassette. Figures 20 to 39 and sub-clause 8.3 define the dimensions of the case and reels for a Type L cassette.

8.2

Type S cassette Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19

8.2.1

is a perspective view seen from the top. is a perspective view seen from the bottom. shows the top side with the lid closed using third angle projection. shows the top side holding and label areas. shows the bottom side with the lid removed. shows the bottom side with the lid closed. shows the details of the recognition holes. shows the details of the write-inhibit plug. shows the detail of the lid release insertion channel. shows the lid unlock force direction. shows the detail of the lid opening insertion channel. shows the lid opening force direction. shows the side view with the lid open. shows the cassette reel. shows the height of reels upon rotation. shows the internal tape path. shows the tape path to measure the extraction force. shows the tape path to measure the friction torque of the take-up reel. shows the tape access cavity requirements.

O v e r a ll d im e n s io n s ( f ig u r e 3 ) The overall dimensions of the case with the lid in the closed position are defined as follows. The total width of the case shall be l1 = 96,0 mm ± 0,3 mm

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The total length of the case shall be mm l 2 = 156,0 mm +−00,,23 mm

The distance from the top of the case to the Reference Plane Z shall be l3 = 25,0 mm ± 0,3 mm The front-top bevel edge shall start in the top side at a distance l4 = 3,0 mm ± 0,5 mm from the front side and shall terminate in the front side at a distance l5 = 5,0 mm ± 0,5 mm from the top side The bottom-front edge of the case shall be rounded with a radius r 1 = 1,0 mm ± 0,1 mm The distance from the rear side to plane X shall be mm l 6 = 9,0 mm +−0,2 0,1 mm

The distance from the right side to plane Y shall be mm l 7 = 8,0 mm +−0,2 0,1 mm

8.2.2

H o ld in g a r e a s ( f ig u r e 4 ) The holding areas, shown cross-hatched, lie in Plane Z and shall be the areas along which the cassette shall be held down when inserted into the drive. The left and right edge holding areas shall extend from the rear side a distance of l8 = 69,4 mm min. The width of the holding surface along the rear edge shall be l9 = 10,2 mm min. The width of the left and right holding surfaces shall be l10 = 5,7 mm min.

8.2.3

W in d o w A window may be provided on the top side so that a part of the reels is visible. The window, if provided, shall not extend beyond the height of the cassette and shall not extend beyond the inner edge of the holding areas.

8.2.4

La b e l a r e a s ( f ig u r e 4 ) A portion of the rear side of the cassette and a portion of the top side of the cassette may be used for labels. The position and the size of the labels shall not interfere with the operation or clearance requirement of the cassette component parts. The area used for labels on the top side shall not extend beyond the inner edges of the holding areas. The position and dimensions of the label area on the rear side are defined as follows. The distance from the top of the case to the top of the label area, and from the bottom of the label area to Plane Z, shall be l11 = 3,0 mm ± 0,3 mm The distance from both the left and right sides of the case to the edges of the label area shall be l12 = 7,0 mm ± 0,3 mm The depth of the top side label depression shall be 0,3 mm max. The depth of the rear side label depression shall be 0,5 mm ± 0,1 mm.

- 9 -

8.2.5

D a t u m a r e a s a n d d a t u m h o le s ( f ig u r e s 5 a n d 6 ) The annular datum areas A, B and C shall lie in plane Z and determine the vertical position of the cassette in the drive. The annular datum area D shall be parallel to datum plane Z and within 0,3 mm of it. Each datum area shall have a diameter d 1 = 10,0 mm ± 0,1 mm and be concentric with the respective datum hole. The centres of datum holes A and B lie in plane X. The centre of datum hole A shall be at the intersection of planes X and Y. The distance from the centre of the datum hole B to plane Y shall be l13 = 140,0 mm ± 0,3 mm The distance from the centre of the datum hole C to plane Y shall be l14 = 120,0 mm ± 0,3 mm The distance from the centre of the datum hole D to plane Y shall be l15 = 20,0 mm ± 0,2 mm The distance from the centre of the datum holes C and D to plane X shall be l16 = 74,0 mm ± 0,2 mm The diameter of datum holes A and D shall be l17 = 5,5 mm +−00,,10 mm mm as shown in section C-C of figure 6

The depth of all four datum holes shall be l19 = 9 mm min. The distance across the flats of datum holes B and C shall be l17 The distance of the elongation in datum holes B and C shall be l18 = 8,00 mm ± 0,15 mm as shown in section E-E of figure 6. 8.2.6

Support areas (figure 5) The cassette support areas are shown cross-hatched, in figure 5. Support areas A, B, C and D shall be coplanar with datum area A, B, C and D, respectively, within ± 0,05 mm. The areas within 1 mm of the edge of the cassette shall not be included in the support areas and shall be recessed from the support areas. The dimensions and position of the support areas shall be defined as follows. The support area surrounding datum hole A shall be defined by l20 = 9,0 mm ± 0,2 mm l21 = 20,0 mm ± 0,2 mm l22 = 10,00 mm ± 0,15 mm l23 = 0,4 mm ± 0,2 mm The support area surrounding datum hole B shall be defined by l20 , l21 and l24 = 130,0 mm ± 0,3 mm l25 = 140,4 mm ± 0,3 mm The support area surrounding datum hole D shall be defined by l26 = 62,0 mm ± 0,2 mm l27 = 72,3 mm ± 0,3 mm l28 = 80,0 mm ± 0,3 mm l29 = 85,0 mm ± 0,3 mm

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l30 = 10,00 mm ± 0,15 mm l31 = 40,0 mm ± 0,2 mm The support area surrounding datum hole C shall be defined by l26, l28, l29 and mm l 32 = 68,0 mm +−0,2 0,5 mm

l33 = 100,0 mm ± 0,3 mm l34 = 130,0 mm ± 0,3 mm 8.2.7

G u id in g g r o o v e s ( f ig u r e 3 a n d 6 ) The cassette shall be provided with four guiding grooves for correct insertion into the drive. The distance from Plane X to the rear edge of the guiding groove on the top side shall be l35 = 2,5 mm ± 0,1 mm The width of top and bottom guiding grooves shall be l36 = 3,0 mm ± 0,1 mm The distance across the flanged opening at the left and right edges of both the top and bottom guiding grooves shall be l37 = 6,0 mm ± 0,3 mm The depth of the top and bottom guiding grooves shall be l38 = 1,4 mm min. The distance from Plane Z to the bottom edge of the right side guiding groove shall be mm l 39 = 11,00 mm -+0,15 0,30 mm

The width of right and left side guiding grooves shall be 0,4 mm l 40 = 3,0 mm -+0,1 mm

The distance from Plane Z to the bottom of the right side flanged opening at the front shall be l41 = 9,0 mm ± 0,3 mm The width of the flanged opening of the right and left guiding grooves at the front shall be l42 = 7,00 mm ± 0,15 mm The distance from the front along the right and left guiding grooves to the termination of the flanges shall be l43 = 8,00 mm ± 0,15 mm The depth of the left and right side guiding grooves shall be l44 = 1,1 mm min. The distance from Plane Z to the bottom of the left flanged opening at the front shall be 0,15 mm l 45 = 14,00 mm -+0,30 mm

The distance from Plane Z to the bottom edge of the left side guiding groove shall be l46 = 12,0 mm ± 0,3 mm The distance from the top side to the extent of chamfer in the bottom of the top guiding groove on the left and right sides shall be l47 = 1,90 mm ± 0,15 mm The angle of the chamfer in the bottom of the top guiding groove at the left and right ends shall be a 1 = 30° ± 3°

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The angle of the flange opening of the top guiding groove at both ends shall be a 2 = 30° ± 3° 8.2.8

R e c o g n it io n h o le s ( f ig u r e 6 a n d 7 ) There shall be 7 recognition holes numbered 1 to 7. The position and dimensions of the recognition holes 1 to 6 are as follows. A line through and locating the centres of holes 6 and 1 shall be l48 = 70,00 mm ± 0,15 mm from Plane Y The centre of hole 6 shall be located l49 = 48,0 mm ± 0,2 mm from Plane X The centres of holes 4 and 5 shall be located l50 = 3,40 mm ± 0,05 mm to the left and right of a line through the centres of holes 1 and 6 The location of a line through the centres of hole 4 and 5 shall be a distance l51 = 3,6 mm ± 0,1 mm from the centre of hole 6 Recognition holes 2 and 3 are D shaped with the flats next to hole 1; the flats shall be a distance l52 = 4,00 mm ± 0,05 mm from the centre of hole 1 The distance of a line through the centres of holes 1, 2 and 3 from Plane X shall be l53 = 56,0 mm ± 0,2 mm The length of the flat of holes 2 and 3 shall be 0,2 mm l54 = 3,4 mm -+0,0 mm

The distance from the flat to the centre and the radius of holes 2 and 3 shall be 0,2 mm l55 = 1,7 mm -+0,0 mm

Holes 1, 2 and 3 contain a tab as shown in view Q of figure 6 in figure 7. The distance from the tab surface to the bottom of the cavity behind the tab shall be l56 = 10 mm min. as shown in section F-F in figure 7. The depth of holes 4, 5 and 6 shall be l57 = 5 mm min. as shown in section G-G of figure 7. The radius of the D holes 2 and 3 shall be 0,2 mm r2 = 1,7 mm -+0,0 mm

The diameter of holes 1, 4, 5 and 6 shall be 0,2 mm d 2 = 3,4 mm -+0,0 mm

Recognition hole 7 is located in the bottom right side of the case shown in view P of figure 6 in figure 7. The distance from Plane Y to the surface of hole 7 nearest to the right edge of the case shall be l58 = 5,8 mm ± 0,2 mm The distance from Plane Y to the surface of hole 7 farthest from the right edge of the case shall be l59 = 1,6 mm ± 0,1 mm The distance from Plane X to the surface of hole 7 nearest to the rear edge of the case shall be 0,5 mm l 60 = 50,0 mm -+0,2 mm

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The distance from Plane X to the surface of hole 7 farthest from the rear edge of the case shall be 0,35 mm l 61 = 57,00 mm -+0,50 mm

The surfaces on the case bottom and right side surrounding recognition hole 7 are slightly recessed. The distance from Plane Y to the edge of the recessed area farthest from the right edge shall be l62 = 0,4 mm ± 0,2 mm The distance from Plane X to the nearest edge of the recessed area along the right edge of the case shall be l63 = 46,0 mm ± 0,5 mm The extent of the recessed area along the right edge of the case shall be l64 = 15,0 mm ± 0,5 mm The inside corners of the recognition hole 7 farthest from the right edge of the case shall have fillets defined by l65 = 1,0 mm ± 0,2 mm as shown in view P of figure 7. The depth of the recess below the bottom and right side surfaces shall be l66 = 0,5 mm max. The depth of recognition hole 7 shall be l67 = 10 mm min. This ECMA Standard prescribes the following states of these recognition holes. — Recognition hole 1 shall be closed. — Recognition hole 2 shall be closed. — Recognition hole 3 shall be closed. — Recognition hole 4 shall be open. — Recognition hole 5 shall be open. — Recognition hole 6 shall be open. — Recognition hole 7 shall be open. Tabs may be used to close the recognition holes. The dimensions of the tabs, if used, shall be as defined in the section F-F of figure 7. The tabs shall withstand an applied force of 2,0 N max. without being punched out. The surface of the tabs shall be recessed from the bottom side a distance l68 = 0,3 mm max. The space around the knockout tab in recognition holes 1, 2 and 3, as viewed in section F-F of figure 7, shall be l69 = 0,7 mm max. 8.2.9

W r it e - in h ib it p lu g ( f ig u r e 8 ) The write-inhibit plug is located on the left side at the bottom of the case as shown in figure 6, view R. The distance in Plane Z from Plane X to the near edge of the write-inhibit plug hole shall be l70 = 52,5 mm ± 0,2 mm The span of the write-inhibit plug hole shall be 0,15 mm l 71 = 7,00 mm -+0,00 mm as shown in view R of figure 8.

The distance on the left side of the case from Plane X to the near edge of the slider opening shall be l72 = 52,8 mm min. The distance on the left side of the case from Plane X to the far edge of the slider opening shall be

- 13 -

l73 = 58,8 mm max. The distance in Plane Z from Plane Y to the inner side of the write-inhibit plug hole shall be l74 = 141,60 mm ± 0,15 mm The distance from the inner side of the write inhibit hole to the slide rail shoulder shall be 0,15 mm l 75 = 5,00 mm -+0,00 mm

The distance on the left side from Plane Z to the far edge of the write-inhibit plug detent hole shall be l76 = 9,4 mm max. The tang on the left side of the body of the write-inhibit plug shall extend l77 = 1,7 mm max. The surface of the write-inhibit plug, when in the write-enable position, shall be recessed from Plane Z a distance l78 = 0,5 mm max. When the write-inhibit plug is pushed down, recording on the tape is inhibited. The distance from Plane Z to the surface of the plug in the write-inhibit position shall be l79 = 4,5 mm min. The write-inhibit plug shall not be deformed by 0,3 mm or more when a force of 2,0 N is applied to the centre of it. The force required to push down or lift up the write-inhibit plug shall be less than 40 N. 8.2.10

P r e - p o s it io n in g s u r f a c e ( f ig u r e s 3 a n d 5 ) The pre-positioning surfaces are parallel to Plane Y in the front of the bottom side and determine the initial location of the cassette as it is inserted into the drive loading slot. The distance of the right side pre-position surface from Plane Y shall be l80 = 1,2 mm ± 0,4 mm as shown in figure 5 The distance of the left side pre-position surface from Plane Y shall be l81 = 137,7 mm ± 0,5 mm The height of the pre-position surfaces above Plane Z shall be l82 = 3,0 mm ± 0,1 mm as shown in figure 3 The distance from Plane X to the front of the left and right pre-position surfaces shall be 0,1 mm l83 = 87,0 mm -+0,2 mm

8.2.11

C a s s e t t e lid ( f ig u r e s 9 , 1 0 , 1 1 , 1 2 a n d 1 3 ) The cassette shall include a lid for protection of the tape during handling, storage and transportation. The lid shall be automatically locked when the lid is closed and it shall be unlocked when the release pin in the drive is inserted into the channel shown in figure 9. The distance from Plane X to the near edge of the lid release insertion channel shall be 0,0 mm l84 = 75,0 mm -+0,3 mm

The distance from Plane Y to the far wall of the lid release insertion channel shall be l85 = 141,8 mm min. The distance from Plane Z to the near wall of the cavity containing the locking mechanism shall be l86 = 2,4 mm max. The distance from Plane Z to the far wall of the cavity containing the locking mechanism shall be

- 14 -

l87 = 5,85 mm min. The design of the locking mechanism is not specified by this ECMA Standard except that it shall be operated by the release pin in the drive. The lid release mechanism shall be actuated when the drive release pin is in the cross-hatched area shown in section J-J and defined by l87 and l88 = 74,2 mm max. l89 = 75,8 mm min. l90 = 3 mm max. The force needed to unlock the lid shall be less than 1 N in the direction shown by figure 10. After the lid is unlocked, the lid shall be open when the lid opening lever in the drive is inserted into the channel shown in figure 11. The distance from Plane X to the near end of the lid opening channel shall be l91 = 77,3 mm max. The distance from Plane Y to the relief edge in the front bottom lid surface shall be l92 = 2,4 mm max. The distance from Plane Y to the right inside wall of the lid shall be l93 = 5 mm min. The distance from bottom side of the case to the front bottom edge of the lid shall be l94 = 0,1 mm ± 0,1 mm The bottom front edge of the lid shall have a flat for the distance defined by l95 = 1,2 mm ± 0,2 mm The inside corner of the lid shall be rounded with a radius r 3 = 1,0 mm ± 0,1 mm The inside front bottom edge of the lid shall be chamfered at an angle defined by a 3 = 30° ± 3° starting at the flat defined by l95 The force needed to open the lid shall be 1,5 N max. in the direction shown in figure 12. The lid rotates around an axis defined in figure 13 by dimensions l96 = 69,0 mm ± 0,5 mm and l97 = 18,0 mm ± 0,5 mm The maximum possible lid opening distance shall be l98 = 29 mm min. 8.2.12

Cassette reel lock (figure 13) The reels shall be locked when the cassette is removed from the tape drive and shall be unlocked when the cassette is inserted into the drive. The design of the locking mechanism is not specified by this ECMA Standard except that the reel shall be completely released when the cassette lid is opened a distance from reference plane Z defined by l99 = 23,5 mm max. The minimum distance required to unlock the reels is not specified.

8.2.13

Reel access holes (figure 6) The case shall have two circular reel access holes in the bottom of the case which shall allow penetration of the drive spindles. The centreline of both reel holes shall be the distance from Plane X defined by l100 = 31,0 mm ± 0,2 mm The distance from Plane Y along the line defined by l100 to the centre of the right reel hole shall be

- 15 -

l101 = 32,0 mm ± 0,2 mm The distance from Plane Y along the line defined by l100 to the centre of the left reel hole shall be l102 = 108,0 mm ± 0,2 mm The diameter of both reel holes shall be d 3 = 33 mm min. 8.2.14

R e e ls ( f ig u r e 1 4 ) The reels shall have a spindle-receiving cavity extending from the bottom side, with inward facing gear teeth for engaging the drive gear, and a round upper cylinder to define the axis of rotation precisely. The diameter of the round upper cylinder in the receiving cavity shall be 0,15 mm d 4 = 11,00 mm -+0,00 mm

The tops of the inside gear teeth shall lie in a cylinder surface with a diameter defined by 0,4 mm d 5 = 14,0 mm -+0,2 mm

The base of the inside gear teeth shall lie in a cylinder surface with a diameter defined by d 6 = 18,0 mm ± 0,2 mm The base surface of the reel is formed by an annular ring with an inside diameter that shall be d 7 = 27,6 mm ± 0,2 mm and an outside diameter that shall be d 8 = 30,0 mm ± 0,2 mm The width of the tops of the inside gear teeth shall be l103 = 2,0 mm ± 0,5 mm The distance from the reel base annular ring to the inside lower flange at the tape hub surface shall be 0,20 mm l104 = 3,75 mm -+0,10 mm

The distance between the lower and upper flanges at the tape hub surface shall be 0,2 mm l105 = 13,5 mm -+0,5 mm

The distance from the reel base annular ring to the top of the inside gear teeth base cylinder shall be l106 = 9,00 mm ± 0,15 mm The distance from the reel base annular ring to the start of the round upper cylinder shall be l107 = 10,5 mm ± 0,3 mm The distance from the reel base annular ring to the top of the round upper cylinder shall be 0,5 mm l108 = 15,0 mm -+0,0 mm

The length of the tops of the gear teeth from the top of the inside gear teeth base cylinder shall be l109 = 6,50 mm ± 0,15 mm The gear teeth side surfaces extend from the base cylinder to the tops cylinder and shall be at an angle with respect to each other defined by a 4 = 60° ± 5° The 6 gear teeth shall be spaced around the base cylinder at an angle defined by a 5 = 60° ± 1° The reels assembled in a cassette shall rotate freely under the condition described in figure 15.

- 16 -

The distance from Plane Z to the annular base reel surface which provides free rotation of the reel when the cassette is loaded into a drive shall be 0,2 mm l110 = 2,4 mm -+0,6 mm

The reels assembled in a cassette shall be spring-loaded with a force F of 1,5 N ± 0,5 N as shown in figure 15. 8.2.15

P o s it io n o f t h e t a p e in t h e c a s e ( f ig u r e 1 6 ) Four tape guides define the tape path inside the cassette. Two guides on the left side, one close to the front opening of the case and one close to the supply reel. Two guides on the right side, one close to the front opening of the case and one near to the take-up reel. The distance from Plane X to a line through the centres of the guides close to the reels shall be l111 = 69,0 mm ± 0,5 mm The distance from Plane Y to the centre of the right guide close to the take-up reel shall be l112 = 12,5 mm ± 0,5 mm The distance from Plane Y to the centre of the left guide close to the supply reel shall be l113 = 128,7 mm ± 0,5 mm The distance from Plane X to a line through the centres of the guides close to the front shall be l114 = 81,0 mm ± 0,5 mm The distance from Plane Y to the centre of the right guide close to the front shall be l115 = 13,0 mm ± 0,5 mm The distance from Plane Y to the centre of the left guide close to the front shall be l116 = 127,0 mm ± 0,5 mm The diameter of all four guides shall be d 9 = 5,0 mm ± 0,3 mm

8.2.16

Ta p e p a t h zo n e ( f ig u r e s 1 6 t o 1 8 ) When the cassette is inserted into the drive, the tape is pulled outside of the case by tape guides. The tape path zone of the case is the zone in which the tape shall be able to move freely. The distance from Plane X to the furthest points defining the zone limit on the left and right in front of the case shall be l117 = 100,0 mm ± 0,2 mm The distance from Plane Y to the right front point defining the zone limit shall be l118 = 7 mm min. The distance from Plane Y to the left front point defining the zone limit shall be l119 = 132 mm min. With a holdback torque of 0,001 N·m applied to a nearly empty reel under the condition described in figure 17, the force required to pull the tape out from the reel (see figure 17) shall not exceed 0,17 N. This specification shall be applied to both the supply and take-up reels. With a holdback tension of 0,3 N applied to the take-up reel nearly full of the tape under the condition described in figure 18, the torque required to wind the tape shall not exceed 0,015 N·m.

8.2.17

Tape access cavity (figure 19) When the cassette is inserted into the drive, tape guides in the drive pull the tape out into the drive tape path. The shape and dimensions of the access cavity for these tape guides shall be defined as follows.

- 17 -

The inside shape of the lid is not specified by this ECMA Standard except that clearance shown crosshatched shall be provided for drive tape threading mechanisms when the lid is opened. The distance from Plane Y to the edge in the bottom side which defines the right extent of the tape access cavity shall be l120 = 14,5 mm ± 0,3 mm The distance from Plane X to the starting point for the right rear surface of the access cavity shall be 0,2 mm l121 = 86,0 mm -+0,5 mm

The distance from Plane Y to the extent of the right rear surface of the access cavity shall be l122 = 27,75 mm max. The distance from Plane X to the curved surface defining the rear extent of the tape access cavity shall be l123 = 70,6 mm max. The distance from Plane X to the surface defining the rear extent of the tape access cavity shall be l124 = 62,1 mm max. The distance from Plane Y to the extent of the left rear surface of the access cavity shall be l125 = 112,25 mm min. The distance from Plane Y to the left-most edge of the tape access cavity in the bottom side shall be l126 = 125,5 mm ± 0,3 mm The width at the end of the centre tape position limit post shall be l127 = 8,7 mm max. The width at the base of the centre tape position limit post shall be l128 = 14,7 mm max. The width of the rearmost surface of the tape access cavity shall be l129 = 26,5 mm min. The distance from Plane X to the inside surface of the centre tape position limit post shall be l130 = 82,5 mm min. The distance from Plane Z to the inside surface of the support for the centre tape position limit post shall be l131 = 19 mm min. The distance from Plane Z to the top inside surface of the support for the centre tape position limit post shall be l132 = 20,8 mm min. The distance from Plane X to the edge in the top side of the case which defines the lid case interface shall be l133 = 77 mm max. The distance from Plane Z to the inside of the case top side shall be l134 = 23 mm min. The distance from Plane Z in the lid area representing the depth of the access cavity shall be l135 = 24 mm min. The distance from Plane Z to the lid edge when the lid is opened shall be

- 18 -

1,5 mm l136 = 27,5 mm -+0,0 mm and shall provide clear entrance to the above defined tape access cavity.

The angle of the fillet at the inside and outside of the corner of the centre tape position limit post shall be a 6 = 35° max. The curvature of the rear tape access cavity surfaces shall have a radius defined by r 4 = 39,6 mm max. and centred at the reel centres.

- 19 -

Take up reel

Right side Lid

Top side Rear side Supply reel

Front side

Left side Bottom side

Figure 1 - Type S cassette top view (lid open)

Bottom side Rear side Left side

Front side

Right side

Top side

Figure 2 - Type S cassette bottom view (lid closed)

- 20 -

l 82

l 44 l 82

l 44

Z l 46

l 42

l 41

Left

Right

l 37

l 36

l 35

l 36

Guiding groove

l 38

l 43

Front

l 40

l 44

l 47

l 44

l 39

l 40

l 47

l 45

A Guiding groove

l 38

Section A - A

Section B - B

Figure 3 - Top side of Type S cassette (lid closed )

- 21 -

l 10

l8 l9

Holding areas

l 12

l 11

Label area

Figure 4 - Top side of Type S cassette, holding and label areas.

- 22 -

Datum area for measurement

Support areas shown hatched (4 places) Y l 81

l 80

l 34 l 33

l 26

l 83

l 29

l 28

l 30

l 32

Datum hole C Datum area C

l 31

l 23

l 26

l 21

l 25

l 20

Datum area A Datum hole A

l 20

l 21

l 27

l 28

l 29

l 83

Datum hole D Datum area D

l 22 l 24

Figure 5 - Bottom side of Type S cassette (lid removed)

Datum area B Datum hole B

- 23 -

l 17

l 19

Section C - C

Y l 14 l 15

l 18

C C

C D C

E C

Guiding Groove

l 101

l 102 l 13

l 47

l18

Section D - D

l 100

l 37

l 16

Section E - E

Figure 6 - Bottom side of Type S cassette (lid closed)

- 24 -

l 52

Recognition hole 3 with tab r2

l 51

l 54

Recognition hole 1 with tab

l 55

Recognition hole 2 with tab

F G

l 53

Recognition hole 4 G l 49

l 50

l 48

Recognition hole 6

Recognition hole 5 View Q (fig 6)

d2 d2

l 57

l 56

l 68

l 69

Section G - G Recognition holes 1 - 6

Section F - F Y l 58

Recognition hole 7

l 59

l 66 l 66

l 65

l 64

l 67

l 65

l 62

l 60

Section H - H

l 63

l 61

l 65

View P (fig 6)

Figure 7 - Details of recognition holes of Type S cassette

- 25 -

l 76

l 71

l 75

l 72

l 70

l 73

l 74

View of the left side Write-enabled position X

View R (fig 6)

l 77

l 78

l 79

Write-inhibited position

Write-enabled position Sections I - I

Figure 8 - Details of write-inhibit plug of Type S cassette

- 26 -

Y l 85 l 81

l 86

l 89

l 88

l 84

l 90 l 87 X

View T (fig 6)

Section J - J

Figure 9 - Lid release insertion channel of Type S cassette

Figure 10 - Direction of force required to unlock the lid with Type S cassette

- 27 -

Y l 93 l 92 l 80

l 95

l 94

K a

l 91

l 95

Section K - K View S (fig 6)

F i g u r e 1 1 - Li d o p e n i n g in s e r t i o n c h a n n e l o f Ty p e S c a s s e t t e

Figure 12 - Direction of force required to open the lid with Type S cassette

- 28 -

l 97

l 99

l 98

l 96

Z Reel lock release position

Fully open position

F ig u r e 1 3 - S id e v ie w o f Ty p e S c a s s e t t e ( lid o p e n ) d8 d4 l 103

l 107

l 109

l 104

l 106

l 108

l 105

Section L - L

Figure 14 - Cassette reel of Type S cassette

- 29 -

l 110

F i g u r e 1 5 - H e i g h t o f t h e r e e l s o f Ty p e S c a s s e t t e w h e n l o a d e d Y l 118

l 119 l 116

l 115

l 111

D FW

l 117

FW D

l 117

l 114

l 112 l 113

F ig u r e 1 6 - I n t e r n a l t a p e p a t h o f Ty p e S c a s s e t t e

- 30 -

Holdback torque

F ig u r e 1 7 - Ta p e p a t h t o m e a s u r e t h e e x t r a c t io n f o r c e o f Ty p e S c a s s e t t e Holdback tension

Holdback torque

F i g u r e 1 8 - Ta p e p a t h t o m e a s u r e t h e f r i c t i o n a l t o r q u e o f t h e t a k e - u p r e e l o f T y p e S c a s s e t t e

- 31 -

l 130

l 131

Y l 132

l 126 l 125

X l 129

Section M - M

l 122

l 128

l 120

l 127

Z N

l 136 l 135

N l 121

l 123

l 124

X l 133

l 123

l 121

r 4

l 134

X Section N - N

F i g u r e 1 9 - Ta p e a c c e s s c a v i t y o f T y p e S c a s s e t t e

- 32 -

8.3

Type L cassette Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 Figure 30 Figure 31 Figure 32 Figure 33 Figure 34 Figure 35 Figure 36 Figure 37 Figure 38 Figure 39

Where dimension is the same as in the S cassette, the S cassette dimension is shown in brackets (=x). 8.3.1

O v e r a ll d im e n s io n s ( f ig u r e 2 2 ) The overall dimensions of the case with the lid closed are as follows. The total width of the case shall be l201 = 145,0 mm ±0,4 mm 0,3 mm The total length of the case shall be l 202 = 254,0 mm -+0,5 mm

The distance from the top of the case to the Reference Plane Z shall be l203 = 25,0 mm ± 0,3 mm (= l3) The front-top bevel edge shall start in the top side at a distance l204 = 3,0 mm ± 0,5 mm (= l4 ) from the front side and shall terminate in the front side at a distance l205 = 5,0 mm ± 0,5 mm (= l5 ) from the top side The bottom-front edge of the case shall be rounded with a radius r 11 = 1,0 mm ± 0,1 mm (= r 1) The distance from the back side to plane X shall be 0,2 mm l 206 = 9,0 mm -+0,1 mm ( = l 6 )

The distance from the right side to plane Y shall be 0,2 mm l207 = 8,5 mm -+0,1 mm

8.3.2

H o ld in g a r e a s ( f ig u r e 2 3 ) The holding areas, shown cross-hatched, in figure 23 shall be the areas along which the cassette shall be held down when inserted in the drive. The left and right edge holding areas shall extend from the rear side a distance of l208 = 118,3 mm min. The width of the holding surface along the rear edge from the left and right sides a distance l212 and shall be l209 = 19,7 mm min. The width of the holding surface along the remainder of the rear edge shall be

- 33 -

l210 = 10 mm min. The width of the left and right holding surfaces shall be l211 = 10,7 mm min. The distance along the rear edge from both left and right sides where the holding area is l209 wide shall be l212 = 77 mm min. 8.3.3

8.3.4

La b e l a r e a s ( f ig u r e 2 3 ) A portion of the rear side of the cassette and a portion of the top side of the cassette may be used for labels. The position and the size of the labels shall not interfere with the operation or clearance requirement of the cassette component parts. The area used for labels on the top side shall not extend beyond the inner edge of the holding areas. The position and dimensions of the label area on the rear side are defined as follows. The distance from the top side of the case to the top of the label area, and from the bottom of the label area to Plane Z, shall be l213 = 3,0 mm ± 0,3 mm (= l11) The distance from both the left and right sides of the case to the edges of the label area shall be l214 = 56,0 mm ± 0,3 mm The depth of the top side label depression shall be 0,3 mm max. The depth of the rear side label depression shall be 0,5 mm ± 0,1 mm.

8.3.5

D a t u m a r e a s a n d d a t u m h o le s ( f ig u r e s 2 4 a n d 2 5 ) The annular datum areas E, F and G shall lie in plane Z. They determine the vertical position of the cassette in the drive. The annular datum area H shall be parallel to datum plane Z and within 0,3 mm of it. Each datum area shall have a diameter d 11 equal to 10,0 mm ± 0,1mm and be concentric with the respective datum hole. The centres of datum holes E and F lie in plane X. The centre of datum hole E shall be at the intersection of planes X and Y. The distance from the centre of the datum hole F to plane Y shall be l215 = 237,00 mm ± 0,15 mm The distance from the centre of the datum hole G to plane Y shall be l216 = 168,5 mm ± 0,3 mm The distance from the centre of the datum hole H to plane Y shall be l217 = 68,5 mm ± 0,2 mm The distance from the centre of the datum holes G and H to plane X shall be l218 = 123,0 mm ± 0,2 mm The diameter of datum holes E, F and H shall be 0,1 mm d 11 = 5,5 mm -+0,0 mm as shown in section C-C of figure 25.

The depth of all four datum holes shall be l221 = 9 mm min. (= l19)

- 34 -

The distance across the flats of datum hole G shall be 0,1 mm l 219 = 5,5 mm -+0,0 mm ( = l17 ) as shown in section C’- C’ of figure 25.

The distance of the elongation in datum hole G shall be l220 = 8,00 mm ± 0,15 mm (= l18) 8.3.6

Support areas (figure 24) The cassette support areas are shown cross-hatched in figure 24. Support areas E, F, G and H shall be coplanar with datum areas E, F, G and H, respectively, within ± 0,05 mm. The areas within 1 mm of the edge of the cassette shall not be included in the support areas and shall be recessed from the support areas. The dimensions and positions of the support areas shall be defined as follows. The support area surrounding datum hole E shall be defined by l222 = 21,0 mm ± 0,2 mm l223 = 21,5 mm ± 0,2 mm The support area surrounding datum hole F shall be defined by l222 and l224 = 215,5 mm ± 0,3 mm The support area surrounding datum hole H shall be defined by l225 = 111,0 mm ± 0,3 mm l226 = 129,0 mm ± 0,3 mm l227 = 134,0 mm ± 0,3 mm l228 = 58,5 mm ± 0,3 mm l229 = 74,5 mm ± 0,3 mm The support area surrounding datum hole G shall be defined by l225, l226, l227 and l230 = 162,5 mm ± 0,3 mm l231 = 178,5 mm ± 0,3 mm

8.3.7

G u id in g g r o o v e s ( f ig u r e 2 5 ) The cassette shall be provided with three guiding grooves for correct insertion into the drive. The width of the bottom rear guiding groove shall be 0,2 mm l 232 = 4,0 mm -+0,0 mm

The distance across the flanged opening at the left and right edges of the bottom rear guiding groove shall be l233 = 7,0 mm ± 0,3 mm The depth of the groove at the flanged opening on the left and right sides of the bottom rear guiding groove shall be l234 = 3,0 mm ± 0,1 mm The depth of the bottom rear groove between the slanted left and right end areas shall be 0,1 mm l 235 = 2,0 mm -+0,0 mm

The distance from Plane Y to the end of the slant in the bottom of groove at the right side end shall be l236 = 16,0 mm ± 0,5 mm The distance from Plane Y to beginning of slant in the bottom of groove at the left side end shall be l237 = 221,0 mm ± 0,5 mm.

- 35 -

The location of the guiding grooves in the bottom side extending from the front on the right and left side shall be defined by l238 = 65,0 mm ± 0,4 mm l239 = 10,0 mm ± 0,2 mm l240 = 40,5 mm ± 0,1 mm 0,0 mm l 241 = 156,0 mm -+0,3 mm

l242 = 12,00 mm ± 0,15 mm The depth of these two grooves from Plane Z shall be l243 = 3,5 mm min. as shown in the front view of figure 25. The angle of the flange opening of the bottom rear guiding groove at both ends shall be a 11 = 30° ± 3° 8.3.8

R e c o g n it io n h o le s ( f ig u r e 2 6 ) There shall be 7 recognition holes numbered 1 to 7 as shown in figure 26. The position and dimensions of the recognition holes 1 to 6 are as follows. A line through and locating the centres of holes 6 and 1 shall be l244 = 118,50 mm ± 0,15 mm from plane Y The centre of hole 6 shall be located l245 = 97,0 mm ± 0,2 mm from Plane X The centres of holes 4 and 5 shall be located l246 = 3,40 mm ± 0,05 mm (= l50) to the left and right of a line through the centres of holes 1 and 6 The location of a line through the centres of holes 4 and 5 shall be a distance l247 = 3,6 mm ± 0,1 mm (= l51 ) from the centre of hole 6 Recognition holes 2 and 3 are D shaped with the flats next to hole 1; the flats shall be a distance l248 = 4,00 mm ± 0,05 mm (= l52 ) from the centre of hole 1 The distance of a line through the centres of holes 1,2 and 3 from Plane X shall be l249 = 105,0 mm ± 0,2 mm The length of the flat of holes 2 and 3 shall be 0,2 mm l 250 = 3,4 mm -+0,0 mm ( = l 54 )

The distance from the centre to the flat of holes 2 and 3 shall be 0,2 mm l 251 = 1,7 mm -+0,0 mm (= l 55 )

Holes 1, 2 and 3 contain a tab as shown in view Q of figure 26. The distance from the tab surface to the bottom of the cavity behind the tab shall be l252 = 10 mm min. (= l56 ) as shown in section F-F in figure 26. The depth of hole 4, 5 and 6 shall be l253 = 5 mm min. (= l57) The radius of the D holes 2 and 3 shall be 0,2 mm r12 = 1,7 mm -+0,0 mm ( = r2 )

The diameter of holes 1, 4, 5 and 6 shall be

- 36 -

0,2 mm d12 = 3,4 mm -+0,0 mm (= d 2 )

Recognition hole 7 is located in the bottom right side of the case shown in figure 25, view P. The distance from the Plane X to the edge of recognition hole 7 nearest to the rear side of the case shall be 0,3 mm l 254 = 99,0 mm -+0,5 mm

The length of the recognition hole 7 shall be 0,5 mm l 255 = 7,0 mm -+0,0 mm

The distance from the Plane Y to the edge of recognition hole 7 farthest from the right side of the case shall be 0,1 mm l 256 = 1,9 mm -+0,3 mm

The width of recognition hole 7 shall be 0,5 mm l 257 = 5,0 mm -+0,0 mm

The depth of recognition hole 7 shall be l258 = 4,5 mm min. This ECMA Standard prescribes the following states of these recognition holes. — Recognition hole 1 shall be closed. — Recognition hole 2 shall be closed. — Recognition hole 3 shall be closed. — Recognition hole 4 shall be open. — Recognition hole 5 shall be open. — Recognition hole 6 shall be open. — Recognition hole 7 shall be open. Tabs may be used to close the recognition holes,. The dimensions of the tabs, if used, shall be as defined in the section F-F of figure 26. The tabs shall withstand an applied force of 2,0 N max. without being punched out. The surface of the tabs shall be recessed from the bottom side of the case a distance l259 = 0,3 mm max. (= l68) The space around the knockout tab in recognition holes 1, 2 and 3, as viewed in section F-F of figure 26, shall be l260 = 0,7 mm max. (= l69) 8.3.9

W r it e - in h ib it p lu g ( f ig u r e 2 7 ) The write-inhibit plug is located on the right side at the bottom of the case as shown in figure 25, view R. The distance in Plane Z from Plane X to the near edge of the write-inhibit plug hole shall be l261 = 85,0 mm ± 0,3 mm The span of the write-inhibit plug hole shall be 0,15 mm l 262 = 7,00 mm -+0,00 mm ( = l 71 ) as shown in view R of figure 25.

The distance on the right side of the case from Plane X to the near edge of the slider opening shall be l263 = 85,3 mm min. The distance on the right side of the case from Plane X to the far edge of the slider opening shall be l264 = 91,3 mm max.

- 37 -

The distance from Plane Y to the inner side of the write-inhibit plug hole shall be l265 = 1,9 mm ± 0,1 mm The distance from the inner side of the write-inhibit hole to the slide rail shoulder shall be 0,15 mm l 266 = 5,00 mm -+0,00 mm ( = l 75 )

The distance on the left side from Plane Z to the far edge of the write-inhibit plug detent hole shall be l267 = 9,4 mm max. (= l76) The tang on the left side of the body of the write-inhibit plug shall extend l268 = 1,7 mm max. (= l77) The surface of the write-inhibit plug, when in the write-enable position, shall be recessed from Plane Z a distance l269 = 0,5 mm max. (= l78) When the write-inhibit plug is pushed down, recording on the tape is inhibited. The distance from Plane Z to the surface of the plug in the write-inhibit position shall be l270 = 4,5 mm min. (= l79) The write-inhibit plug shall not be deformed by 0,3 mm or more when a force of 2,0 N is applied to the centre of it. The force required to push down or lift up the write-inhibit plug shall be less than 40 N. 8.3.10

P r e - p o s it io n in g s u r f a c e ( f ig u r e s 2 4 a n d 2 5 ) The pre-positioning surfaces are parallel to Plane Y in the front of the bottom side and determine the initial location of the cassette as it is inserted into the drive loading slot. The height of the pre-position surfaces above Plane Z shall be l271 = 3,5 mm ± 0,1 mm as shown in the front view in figure 25. The distance from Plane X to the front of the left and right pre-position surfaces shall be 0,2 mm l 272 = 136,0 mm -+0,0 mm as shown in figure 24.

The distance of the right side pre-position surface from Plane Y shall be l273 = 3,5 mm min. The distance of the left side pre-position surface from Plane Y shall be l274 = 233,5 mm max. 8.3.11

C a s s e t t e lid ( f ig u r e s 2 8 , 2 9 , 3 0 , 3 1 a n d 3 2 ) The cassette shall include a lid for protection of the tape during handling, storage and transportation. The lid shall be automatically locked when the lid is closed and it shall be unlocked when the release pins in the drive are inserted into both of the left and right bottom front channels shown in figure 28. The distance from Plane Y to the farthest edge of the left side lid release insertion channel shall be l275 = 237,5 mm max. The distance from Plane Y to the inside edge of the right side lid release insertion channel shall be l276 = 3,5 mm min. The distance from Plane Y to the outside edge of the right side lid release insertion channel shall be l277 = 0,5 mm min. The distance from Plane X to the near edge of both lid release insertion channels shall be 0,0 mm l 278 = 124,0 mm -+0,3 mm

- 38 -

The distance from Plane Z to the near wall of the cavities containing the locking mechanisms shall be l279 = 2,4 mm max. (= l86) The distance from Plane Z to the far wall of the cavity containing the locking mechanism shall be l280= 5,85 mm min. (= l87) The design of the locking mechanism is not specified by this ECMA Standard except that it shall be operated by the release pin in the drive. The lid release mechanisms shall be actuated when the drive release pins are in the cross-hatched area shown in sections J’-J’ and J-J of figure 28 and defined by l279 and l281 = 123,2 mm max. l282 = 124,8 mm min. l283 = 3 mm max. (= l90) The force needed to unlock the lid shall be less than 1 N in the directions shown by figure 29. After the lid is unlocked, the lid shall be open when the lid opening lever in the drive is inserted into the channel shown in figure 30. The distance from Plane X to the near end of the lid opening channel shall be l284 = 126,3 mm max. The distance from Plane Y to the right inside wall of the lid opening channel shall be l285 = 42,1 mm ± 0,2 mm The distance across the lid opening channel shall be l286 = 5,20 mm ± 0,15 mm The distance from bottom side of the case to the front bottom edge of the lid shall be l287 = 0,1 mm ± 0,1 mm (= l94) The bottom front edge of the lid shall have a flat for the distance defined by l288 = 1,2 mm ± 0,2 mm (= l95) The depth of the lid opening channel in the front side of the main case shall be l289 = 19,5 mm min. The inside front bottom edge of the lid shall be chamfered at an angle defined by a 12 = 30° ± 3° (= a 3 ) starting at the flat defined by l287 The force needed to open the lid shall be 1,5 N max. in the direction shown in figure 31. The lid rotates around the axis defined in figure 32 by dimensions l290 = 118,0 mm ± 0,5 mm l291 = 18,0 mm ± 0,5 mm The maximum possible lid opening distance shall be l292 = 29 mm min. 8.3.12

Cassette reel lock (figure 32) The reels shall be locked when the cassette is removed from the tape drive and shall be unlocked when the cassette is inserted into the drive. The design of the locking mechanism is not specified by this ECMA Standard except that the reel shall be completely released when the cassette lid is opened from reference plane Z defined by l293 = 23,5 mm max. The minimum distance required to unlock the reels is not specified.

- 39 -

8.3.13

Reel access holes (figure 25) The case shall have two circular reel access holes which shall allow penetration of the drive spindles. The dimension and positions of the access holes shall be The centreline of both reel holes shall be the distance from Plane X defined by l294 = 55,5 mm ± 0,2 mm The distance from Plane Y along the line defined by l293 to the centre of the right reel hole shall be l295 = 56,0 mm ± 0,2 mm The distance from Plane Y along the line defined by l293 to the centre of the left reel hole shall be l296 = 181,0 mm ± 0,2 mm The diameter of both reel holes shall be d 13 = 42,5 mm ± 0,2 mm

8.3.14

R e e ls ( f ig u r e 3 3 ) The reels shall have a spindle-receiving cavity extending from the bottom side, with inward facing gear teeth for engaging the drive gear and a round upper cylinder to define the axis of rotation precisely. The diameter of the round upper cylinder in the receiving cavity shall be 0,15 mm d14 = 11,00 mm -+0,00 mm ( = d 4 )

The tops of the inside gear teeth shall lie in a cylinder surface with a diameter defined by 0,4 mm d15 = 14,0 mm -+0,2 mm (= d 5 )

The base of the inside gear teeth shall lie in a cylinder surface with a diameter defined by d 16 = 18,0 mm ± 0,2 mm (= d 6) The base surface of the reel are formed by two concentric annular rings. The smaller ring inside diameter shall be d 17 = 27,6 mm ± 0,2 mm (= d 7) and the outside diameter shall be d 18 = 30,0 mm ± 0,2 mm (= d 8) The larger ring inside diameter shall be d 19 = 37,6 mm ± 0,2 mm and the outside diameter shall be d 20 = 40,0 mm ± 0,2 mm The width of the tops of the inside gear teeth shall be l2967= 2,0 mm ± 0,5 mm (= l103) The distance from the reel base annular ring to the inside lower flange at the tape hub surface shall be 0,20 mm l 298 = 3,75 mm -+0,10 mm ( = l104 )

The distance between the lower and upper flanges at the tape hub surface shall be 0,2 mm l 299 = 13,5 mm -+0,5 mm ( = l105 )

The distance from the reel base annular ring to the top of the inside gear teeth base cylinder shall be l300 = 9,00 mm ± 0,15 mm (= l106) The distance from the reel base annular ring to the start of the round upper cylinder shall be l301 = 10,5 mm ± 0,3 mm (= l107) The distance from the reel base annular ring to the top of the round upper cylinder shall be

- 40 -

0,5 mm l 302 = 15,0 mm -+0,0 mm ( = l108 )

The length of the tops of the gear teeth from the top of the inside gear teeth base cylinder shall be l303 = 6,50 mm ± 0,15 mm (= l109) The gear teeth side surfaces extend from the base cylinder to the tops cylinder and shall be at an angle with respect to each other defined by a 13 = 60° ± 5° (= a 4) The 6 gear teeth shall be spaced around the base cylinder at an angle defined by a 14 = 60° ± 1° (= a 5) The reels assembled in a cassette shall rotate freely under the condition described in figure 34. The distance from Plane Z to the annular base reel surface which provides free rotation of the reel when the cassette is loaded into a drive shall be l304 = 2,4 mm ± 0,2 mm The reels assembled in a cassette shall be spring loaded with a force F of 3,5 N ± 0,5 N as shown in figure 34. When the cassette is inserted into the drive, the parts which are pressed to the reels shall extend beyond the height of the cassette. The parts shall not rotate with the reels. Their dimensions and position shall be defined by d 21 = 10 mm min. and l305 = 1,5 mm max. 8.3.15

P o s it io n o f t h e t a p e in t h e c a s e ( f ig u r e 3 5 ) Four tape guides define the tape path inside the cassette. Two guides on the left side, one close to the front opening of the case and one close to the supply reel. Two guides on the right side, one close to the front opening of the case and one near to the take-up reel. The distance from Plane X to a line through the centres of the guides close to the reels shall be l306 = 122,0 mm ± 0,5 mm The distance from Plane Y to the centre of right guide close to the take-up reel shall be l307 = 56,0 mm ± 0,5 mm The distance from Plane Y to the centre of the left guide close to the supply reel shall be l308 = 181,0 mm ± 0,5 mm The distance from Plane X to a line through the centres of the guides close to the front side of the case shall be l309 = 130,0 mm ± 0,5 mm The distance from Plane Y to the centre of the right guide close to the front side of the case shall be l310 = 61,5 mm ± 0,5 mm The distance from Plane Y to the centre of the left guide close to the front side of the case shall be l311 = 175,5 mm ± 0,5 mm The diameter of the two front-most guides shall be d 22 = 5,0 mm ± 0,3 mm (= d 9) The diameter of the two guides closer to the reels shall be d 23 = 6,0 mm ± 0,3 mm

- 41 -

8.3.16

Ta p e p a t h zo n e ( f ig u r e s 3 5 t o 3 7 ) When the cassette is inserted into the drive, the tape is pulled outside of the case by tape guides. The tape path zone of the case is the zone in which the tape shall be able to move freely. The distance from Plane X to the furthest points defining the zone limit on the left and right in front of the case shall be l312 = 149,0 mm ± 0,2 mm The distance from Plane Y to the right front point defining the zone limit shall be l313 = 41,5 mm min. The distance from Plane Y to the left front point defining the zone limit shall be l314 = 180,5 mm min. With a holdback torque of 0,001 N·m applied to a nearly empty reel under the condition described in figure 36, the force required to pull the tape out from the reel shall not exceed 0,17 N. This specification shall be applied to both the supply and take-up reels. With a holdback tension of 0,3 N applied to the take-up reel nearly full of the tape under the condition described in figure 37, the torque required to wind the tape not exceed 0,03 N·m.

8.3.17

Tape access cavity (figure 38) When the cassette is inserted into the drive, tape guides in the drive pull out the tape into the drive tape path. The shape and dimensions of the access cavity for these tape guides shall be defined as follows. The inside shape of the lid is not specified by this ECMA Standard except that clearance shown crosshatched shall be provided for drive tape threading mechanisms when the lid is opened l330 from datum plane Z. The distance from Plane Y to the starting point for the right rear surface of the access cavity shall be l315 = 63,0 mm ± 0,3 mm The distance from Plane X to the starting point for the right rear surface of the access cavity shall be 0,2 mm l 316 = 135,0 mm -+0,5 mm

The distance from Plane Y to the extent of the right rear surface of the access cavity shall be l317 = 76,25 mm max. The distance from Plane X to start of the radiused surface which defines the rear-most extent of the tape access cavity shall be l318 = 119,7 mm max. The distance from Plane X to the surface defining the rear-most extent of the tape access cavity shall be l319 = 111,1 mm max. The distance from Plane Y to the extent of the left rear surface of the access cavity shall be l320 = 160,75 mm min. The distance from Plane Y to the edge in the bottom side which defines the left-most extent of the tape access cavity shall be l321 = 174,0 mm ± 0,3 mm The width at the end of the centre tape position limit arm shall be l322 = 8,7 mm max. (= l127) The width at the base of the centre tape position limit arm shall be l323 = 14,7 mm max. (= l128) The width of the rearmost surface of the tape access cavity shall be

- 42 -

l324 = 26,5 mm min. (= l129) The distance from Plane X to the inside surface of the centre tape position limit post shall be l325 = 131,5 mm min. The distance from Plane Z to the inside surface of the support for the centre tape position limit post shall be l326 = 19 mm min. (= l131) The distance from Plane Z to the top inside surface of the support for the centre tape position limit post shall be l327 = 20,8 mm min. (= l132) The distance from Plane X to the edge in the top side of the case which defines the lid case interface shall be l328 = 126 mm max. The distance from Plane Z to the inside of the case top side shall be l329 = 23 mm min. (= l134) The distance from Plane Z in the lid area representing the depth of the access cavity shall be l330 = 24 mm min. ( = l135) The distance from Plane Z to the lid edge which when the lid is opened shall provide the above defined tape access cavity shall be 1,5 mm l 331 = 27,5 mm -+0,0 mm (= l136 )

The angle of the fillet at the inside and outside of the corner of the centre tape position limit post shall be a 15 = 35° max. (= a 6) The curvature of the rear tape access cavity surfaces shall have a radius defined by r 13 = 39,6 mm max. (= r 4 ) and centred at the reel centres. The centre points for generating the two radiused surfaces shall be defined by l332 = 80,0 mm ± 0,3 mm l333 = 80,5 mm ± 0,3 mm l334 = 156,5 mm ± 0,3 mm as shown in figure 38. 8.3.18

C a v it y f o r c o m p a t i b i l i t y wi t h Ty p e S c a s s e t t e ( f i g u r e 3 9 ) The Type L cassette shall have the cavities for the cassette support guides, the lid opening lever, and the lid unlocking pin provided for Type S cassette. Their positions and dimensions shall be defined as follows. The relief in the bottom side near the right side shall be defined by l335 = 14,5 mm ± 0,2 mm l336 = 31,0 mm ± 0,3 mm l337 = 45,5 mm ± 0,3 mm l338 = 15,5 mm ± 0,2 mm l339 = 25,0 mm ± 0,3 mm l340 = 35,0 mm ± 0,3 mm The relief in the bottom side near the left side shall be defined by l335, l336, l337 and l341 = 202,0 mm ± 0,4 mm l342 = 212,0 mm ± 0,4 mm l343 = 221,5 mm ± 0,4 mm

- 43 -

The depth of the cavities for the cassette support guides for Type L cassette shall be 0,5 mm ± 0,2 mm. The distance from Plane X to the edge of the lid opening lever cavity shall be 0,0 mm l 344 = 120,0 mm -+0,3 mm

The distance from Plane Y to the right edge of the lid opening lever cavity shall be l345 = 186,7 mm max. The distance from Plane X to the left edge of the lid opening lever cavity shall be l346 = 190,3 min. The depth of the lid opening lever cavity shall be l347 = 6 mm min.

- 44 -

Take-up reel Right side

Top side

Lid

Rear side

Supply reel

Front side

Left side Bottom side

F ig u r e 2 0 - Ty p e L c a s s e t t e t o p v ie w ( lid o p e n ) Bottom side Left side Rear side

Front side

Right side

Top side

F ig u r e 2 1 - Ty p e L c a s s e t t e b o t t o m v ie w ( lid c lo s e d )

- 45 -

l 205

l 206

l 201

l 204

r11

l 207

l 203

l 202 Z

F ig u r e 2 2 - To p s id e o f Ty p e L c a s s e t t e ( lid c lo s e d )

- 46 -

l 208

l 209

Holding area

l 210

l 212

l 214

Label area

l 213

l 214

l 211

l 213

l 211

F ig u r e 2 3 - To p s id e o f Ty p e L c a s s e t t e , h o ld in g a n d la b e l a r e a s

- 47 -

d 11

Datum area for measurement

Support areas shown hatched (4 places) Y l 274 l 231 l 230 l 229

Datum hole H Datum area H

l 228

Datum hole G Datum area G

l 272

l 225 l 222

l 222

l 227

l 225

l 226

l 227

l 272

l 226

l 273

Datum hole E Datum area E

l 223 l 224

F ig u r e 2 4 - Bo t t o m s id e o f Ty p e L c a s s e t t e ( lid r e m o v e d )

Datum hole F Datum area F

- 48 -

l 243

l 271

l 243

l 271

l 241

l 240 l 216 l 217

l 242 l 239

l 242

l 233

D l 236

l 295 l 296 l 237 l 215

Section C - C

Section C' - C'

l 235

Section D - D

F ig u r e 2 5 - Bo t t o m s id e o f Ty p e L c a s s e t t e ( lid c lo s e d )

l 234

l 221

l 237

l 235

l 221

l 234

l 219

l 236 d 11

l 232

a 11

l 238

l 294

l 233

l 238

l 218

l 239

l 220

Section E - E

- 49 -

l 248 l 251

Recognition hole 2 with tab

Recognition hole 1 with tab

l 251

r12

F 12

l 249

l 247

l 250

Recognition hole 3 with tab

l 245

Recognition hole 4 G

l 244

l 246 X

Recognition hole 5

Recognition hole 6 View Q (fig 25) d12

d12

l 253

l 252

l 259

l 260

Section G - G Section F - F

l 257

Recognition holes 1 - 6

l 256

l 254

l 258

l 255

Recognition hole 7

Section H - H X

View P (fig 25)

F ig u r e 2 6 - D e t a ils o f r e c o g n it io n h o le s o f Ty p e L c a s s e t t e

- 50 -

Y l 265

l 262

l 266

l 263

l 267

l 261

l 264

View of the right side Write-enabled position X

View R (fig 25)

l 268

l 270

l 269

Write-enabled position

Write-inhibited position Section I - I

F ig u r e 2 7 - D e t a ils o f wr it e - in h ib it p lu g o f Ty p e L c a s s e t t e

- 51 -

Y l 275 l 274

l 277

l 276

l 279

l 283

l 280

l 282

l 278

l 281

l 282

l 279

l 278

l 281

Section J' - J'

View S & T (fig 25)

Section J - J

F i g u r e 2 8 - Li d r e l e a s e i n s e r t i o n c h a n n e l o f Ty p e L c a s s e t t e

Figure 29 - Direction of force needed to unlock the lid with Type L cassette

- 52 -

l 285

l 286

l 289

l 288

l 287

l 284

a 12

Section K - K

F i g u r e 3 0 - Li d o p e n i n g in s e r t i o n c h a n n e l o f Ty p e L c a s s e t t e

Opening direction measuring range: 0 to 29 mm

Figure 31 - Direction of force needed to open the lid with Type L cassette X

l 291

l 293

l 292

l 290

Z Reel lock release position

Fully open position

F ig u r e 3 2 - S id e v ie w o f Ty p e L c a s s e t t e ( lid o p e n )

- 53 -

d14

l 302

l 299

Datum

d17 d18 d19 d20

Section L - L

d 16

a13

d 15

a 14

Figure 33 - Cassette reel of Type L cassette

l 301

l 297

l 300

l303

l 298

- 54 -

F d 21 l 305

d 21

l 304

Supply side

Take-up side

F i g u r e 3 4 - H e i g h t o f t h e r e e l s o f Ty p e L c a s s e t t e w h e n l o a d e d Y l 314 l 311 l 310 l 313

d 22

d 22 d 23

d 23

l 307

l 312

l 306

l 309

l 312

l 308

F ig u r e 3 5 - I n t e r n a l t a p e p a t h o f Ty p e L c a s s e t t e

- 55 -

Holdback torque

F ig u r e 3 6 - Ta p e p a t h t o m e a s u r e t h e e x t r a c t io n f o r c e o f Ty p e L c a s s e t t e Holdback tension

Holdback torque

F i g u r e 3 7 - Ta p e p a t h t o m e a s u r e t h e f r i c t i o n a l t o r q u e o f t h e t a k e - u p r e e l o f T y p e L c a s s e t t e

- 56 -

Y l 321 l 320 l 317

l 322

l 315

r 13

l 332

l 319

l 324

l 318

l 333 l 334

X l 328 15

l 329

l 330

l 331

l 327

l 326

l 316

l 323

Z l 325

Section M - M

Section N - N

F i g u r e 3 8 - Ta p e a c c e s s c a v i t y o f T y p e L c a s s e t t e

- 57 -

l 347

Section V - V

l 346 l 345 Lock pin relief cavity

Lid opening relief cavity

l 336

X l 335

l 337

l 344

S cassette support relief cavities

l 338 l 339 l 340

l 341 l 342 l 343

F ig u r e 3 9 - Bo t t o m s id e o f Ty p e L c a s s e t t e ( lid c lo s e d )

- 58 -

Section 3 - Requirements for the unrecorded tape 9 9.1

Mechanical, physical and dimensional characteristics of the tape Materials The recordable area of the tape shall consist of a polyethylene terephthalate base material (or equivalent) coated on one side with a strong yet flexible layer of ferromagnetic material dispersed in a suitable binder. The back surface may be coated. The leader tape and trailer tape shall contain a metal foil providing more than 200 S conductivity per square so that the magnetic tape motion can be stopped when the foil is detected.

9.2

Tape length The length of magnetic tape between PBOT and PEOT shall be in the range For Type S :

between 290 m and 292 m

For Type L :

between 890 m and 892 m

The lengths of leader and trailer tapes shall be the lengths between the splice points and the outside of the case when attached to the hubs. Leader tape length shall be in the range For Type S :

between 220 mm and 280 mm

For Type L :

between 260 mm and 300 mm

Trailer tape length shall be in the range

9.3

For Type S :

between 50 mm and 80 mm

For Type L :

between 70 mm and 100 mm

Tape width The width of the magnetic tape shall be 12,650 mm ± 0,005 mm, l348 in figure 52. The width of the leader tape and trailer tape shall be 12,65 mm ± 0,03 mm. Procedure for measuring the width of the magnetic tape. 1) Cover a section of the tape with a glass microscope slide 2) Measure the width with no tension applied to the tape, using a calibrated microscope, profile projector, or equivalent, having an accuracy of at least 1 µm. 3) Repeat the measurement at five or more different points along a length of tape of 1,0 m min. 4) The tape width is the average of the widths measured.

9.4

Width and position of splicing tape The width of the splicing tape and its position across the width of the leader/trailer and magnetic tapes shall be such that the bottom edge of the splicing tape shall be no more than 0,60 mm max above the bottom edge of the other tapes and the top edge of the splicing tape shall be no more than 0,60 mm max below the top edge. Neither edge of the splicing tape shall extend beyond the edges of the leader/trailer and magnetic tapes.

9.5

Discontinuity There shall be no discontinuities in the tape between the PBOT and PEOT, such as those produced by tape splicing or perforations.

9.6

Tape thickness The total thickness of the magnetic tape shall be between 10,2 µm and 11,2 µm. The thickness of the leader and trailer tapes shall be 45 µm max.

- 59 -

9.7

Longitudinal curvature The radius of curvature of the edge of the magnetic tape shall be 50 m min. Procedure for measuring the longitudinal curvature of tape. 1) Allow a 1,0 m length of the tape to unroll and assume its natural curvature on a flat smooth surface. 2) Measure the deviation from a 1,0 m chord. The deviation shall not be greater than 2,5 mm. This deviation corresponds to the minimum radius of curvature of 50 m if measured over an arc of a circle.

9.8

Out-of-plane distortions All visual evidence of out-of-plane distortion shall be removed when the magnetic tape is subjected to a uniform tension of 0,31 N ± 0,05 N. Out-of-plane distortions are local deformation which cause portions of the tape to deviate from the plane of the surface of the tape. They are most readily observed when the tape is lying on a flat surface and under no tension.

9.9

Coating adhesion The force required to peel any part of the coating from the tape base material shall not be less than 0,1 N. Procedure 1) Take a test piece of the tape approximately 380 mm long and scribe a line through the recording coating across the width of the tape 125 mm from one end. 2) Using a double-sided pressure sensitive tape, attach the full width of the test piece to a smooth metal plate, with the recording surface facing the plate, as shown in figure 40. 3) Fold the test piece over 180°, attach the metal plate and the free end of the test piece to the jaws of a universal testing machine and set the speed of jaw separation to 254 mm/min. 4) Note the force at which any part of the coating first separates from the base material. If this is less than 0,1 N, the tape has failed the test. If the test piece peels away from the double-sided pressure sensitive tape before the force exceeds 0,1 N, an alternative type of double-sided pressure sensitive tape shall be used. 5) If the back surface of the tape is coated, repeat 1) to 4) for the back coating. R e c o rd in g s u rfa c e

1 2 5 m m

S c rib e d lin e

P re s s u re - s e n s itiv e T a p e

Figure 40 - Measurement of coating adhesion

- 60 -

9.10

Layer-to-layer adhesion There shall be no tendency for the test piece to stick or for the coating to peel. Procedure 1) Attach one end of a test piece of magnetic tape of length 1,0 m to the surface of a glass tube of external diameter 36 mm. 2) Wind the test piece on to the tube at a tension of 0,9 N. 3) Store the wound test piece in a temperature of 45 °C ± 3 °C and a relative humidity of 80% for 4 h. 4) Store for a further 24 h in the Testing Environment. 5) Apply a force of 0,1 N to the free end of the test piece and allow it to unwind slowly.

9.11

Tensile strength The measurements shall be made in accordance with ISO/527-1. The length of the test piece shall be 200 mm. The rate of elongation for all tensile tests shall be 100 mm/min - ISO/527-1, rate D.

9.11.1

Br e a k in g s t r e n g t h Load the test piece until the breaking point of the test piece is reached. The force required to reach that point is the breaking strength of the tape. The breaking strength of magnetic tape shall be 38 N min. The breaking strength of leader and trailer tapes shall be 50 N min.

9.11.2

Y ie ld s t r e n g t h The tensile yield force shall be taken as the force required to elongate the sample by 5%. The tensile yield strength of the magnetic tape shall be 15 N min. The tensile yield strength of the leader and trailer tapes shall be 30 N min.

9.11.3

9.12

S t r e n g t h o f S p lic e The spliced portion of the magnetic tape and the leader and trailer tapes shall withstand a tension of TBD N min.

Residual elongation The residual elongation, expressed as a percentage of the original length, shall be 0,20 % max. Measure the initial length of a test piece of approximately 1 m with an applied tensile force of 0,2 N max. For 10 minutes, apply an additional force of 10 N. Remove the additional force and measure the length after a further 10 minutes.

9.13

Electrical resistance of the coated surfaces The electrical resistance of the recording surface of the magnetic tape, measured on any square area of tape, shall be less than 1 x 10 12 Ω for a back-coated tape. The electrical resistance of the back-coating, if present, measured on any square area of tape, shall be less than 5 x 10 7 Ω. Procedure (see figure 41) 1) Condition a test piece of tape in the test environment for 24 h. 2) Position the test piece over two 24-carat gold-plated, semicircular electrodes having a radius r = 25,4 mm and a finish of at least N4, so that the recording surface is in contact with each electrode. The electrodes shall be placed parallel to the ground and parallel to each other at a distance d = 12,65 mm between their centres.

- 61 -

3) Apply the force of 1,62 N to each end of the test piece. 4) Apply a DC voltage of 50 V ± 10 V across the electrodes and measure the resulting current flow. From this value, determine the electrical resistance. 5) Repeat for a total of five positions along the test piece and average the five resistance readings. For back-coated tape repeat the procedure with the back-coating in contact with the electrodes. When mounting the test piece ensure that no conducting paths exist between the electrode except that through the coating under test.

F 93-0050-B

Figure 41 - Measurement of electrical resistance

9.14

Tape wind The magnetic recording surface of the tape shall face outward from the case and reels.

Magnetic recording characteristics The requirements for the helically recorded tracks are more demanding than those for the longitudinal tracks; it is deemed to be sufficient to carry out tests on the helically recorded tracks only. The magnetic recording performance is defined by the testing requirements given in the following clauses. The positive azimuth tracks shall be used: tracks A, C, E and G. When performing the tests, the head output or the resultant signal shall be measured on the same relative pass for both a tape calibrated to the MSRT and the tape under test ( read-while-write, or on equipment without read-while-write capability, on the first forward pass) on the same equipment. The following conditions shall apply to all tests of magnetic recording performance, unless otherwise stated: - tape condition

a.c. erased to 2 % or less of the SRA

- head/tape speed

13,43 m/s ± 0,05 m/s

- head width

(write) : (read) :

23,0 µm ± 1,5 µm 30,0 µm ± 1,5 µm

- gap azimuth

(+) (-)

: :

+15,450 ° ± 0,167 ° -15,350 ° ± 0,167 °

- gap length

(write) : (read) :

0,30 µm ± 0,05 µm 0,15 µm ± 0,05 µm

- 62 -

- tape tension

0,196 N ± 0,029 N

- recording current

TRC1

10.1

Typical Field (TF1) TF1 shall be between 80 % and 120 % of RF1. Traceability to the RF1 is provided by the calibration factors supplied with each SSRT.

10.2

Average Signal Amplitude(ASA) The ASA at the physical recording density of 6 349 ftpmm shall be between 80 % and 120 % of SRA1. Traceability to SRA1 is provided by the calibration factors supplied with each SSRT.

10.3

Resolution The ratio of the ASA at the physical recording density of 6 349 ftpmm to that at the physical recording density of 1 587 ftpmm shall be between 80 % and 120 % of the same ratio for the MSRT. Traceability to the resolution of the MSRT is provided by the calibration factors supplied with each SSRT.

10.4

Signal-to-noise ratio (S/N) The Signal-to-noise ratio is the average rms read signal amplitude divided by the average integrated rms noise amplitude, expressed in decibels. Average rms read signal amplitude S/N = 20 log

dB Average integrated rms noise amplitude

Requirement: The S/N for the tape under test (S/N tape ) shall be better than -2 dB relative to the S/N for the MSRT (S/N MSRT) when measured according to the procedure defined in annex A. Traceability to the (S/N MSRT) is provided by the calibration factors supplied with each SSRT.

10.5

Ease of erasure When a tape has been recorded at 1 587 ftpmm with TRC1 and passed through a longitudinal steady erasing field of 320 000 A/m, any remaining signal shall not exceed 2 % of SRA3.

10.6 10.6.1

Tape quality M is s in g p u ls e s A missing pulse is a loss of read signal amplitude. A missing pulse exists when the base-to-peak amplitude is 25 %, or less, of half the ASA for the physical recording density of 6 349 ftpmm on the same tape.

10.6.2

M i s s i n g p u l s e zo n e A missing pulse zone commences with 7 consecutive missing pulses and ends when 28 consecutive flux transitions are read or when a length of 0,038 mm of track has been measured. If a missing pulse zone continues beyond 0,038 mm a further missing pulse zone shall be counted. A missing pulse zone does not continue from one track to another. Requirement: The average missing pulse zone rate shall be less than one missing pulse zone for each 5 x 10 6 flux transitions recorded at the physical recording density of 6 349ftpmm. The average missing pulse zone rate is the total number of missing pulse zones divided by the total number of flux transitions recorded on the tape.

- 63 -

10.7

Inhibitor tape This ECMA Standard does not specify parameters for assessing whether or not a tape is an inhibitor tape. However, annex D gives further information on inhibitor tapes.

- 64 -

Section 4 - Requirements for an interchanged tape 11

Format for helical tracks

11.1

General description of the write data path (see figure 42) The host system, operating under one of several directory file system structures, views the tape drive system as a logical storage system. The host expects the logical storage system to support the following capabilities      

data blocks as a minimum unit of data transfer data file as a concatenation of data blocks file demarcation directory of file locations in a volume management information of files multiple volumes

This format provides a generic set of placeholder tables and track types to contain such information with specific definitions of their usage and location. All track types provided by this format are processed into a Track-Set-pair comprising eight helical tracks, uniquely identified by a TSID, represent the minimum recorded and retrieved unit of information. The processing of information preparatory to recording begins with the identification of the type of Logical Track Set to be created and proceeds through the following processes   

11.2 11.2.1

generation of a Logical Track Set data protection processing within product code array buffers formation of the contents of a helical track.

Formation of a Logical Track Set Ty p e s o f in f o r m a t io n t r a c k s e t s There are 11 types of information track sets. 1. Volume Set Information Table (VSIT) track set

7. User Data track set

2. Volume Information Table (VIT) track set

8. File Mark track set

3. Badspot Table (BST) track set

9. Set Mark track set

4. Logical ID Table (LIDT) track set

10. Dummy (DM) track set

5. File Information Table (FIT) track set

11. End of Data (EOD) track set

6. Update Table (UT) track set This tape format supports multiple logical volumes within one physical volume. A VSIT at the beginning of the tape contains information to manage one or more logical volumes on this tape. The VSIT has location information for each logical volume on the tape. A logical volume consists of a Directory Information Table (DIT) followed by the User Data area. The DIT contains information to locate and manage files within the logical volume and comprises the VIT, BST, LIDT, FIT and UT. The demarcation of files may be defined by the host to be either a File Mark or a Set Mark and for some purposes of this ECMA Standard may be collectively referred to as a Tape Mark (TM). EOD Track Sets identify the end of recorded data area in a logical volume as indicated by the host. DM Track Sets identify fill areas on the tape where continuous control track signals are required and are transparent to the host.

- 65 -

Host

TSID, Write retry, Append Identify type of Track Set to be processed

Interface Type of Track Set

Subcode generator

Logical Track Set generator

BMT generator

Sync Pattern Sync Block ID Outer ECC (C2) Inner ECC (C1) Track Interleave Sync Block Byte Interleave Randomization

Product code array buffers

8/9 Channel coding

Preamble Run-up

Sector formation

Track distribution TPS (B and D only) A

Write channel D

Precode filter

Track - A

Track - B

Track - C

Track - D

Figure 42 - Dataflow of record information processing

- 66 -

11.2.2

G e n e r a t io n o f a Lo g ic a l Tr a c k S e t The structure of a Logical Track Set is shown in figure 43. A Logical Track Set shall contain all of the elements destined for 4 helical tracks and occupy 234 080 bytes (58 520 words). Logical Track Set Words will be used for the following field definitions. The Logical Track Set comprises Word 0 - A tape format identifier which shall be set to (FFFF0001), the format of this ECMA Standard. Words 1 to 34 - A Subcode data field containing administrative information associated with this Track Set. Words 35 to 58 515 - An Information field and Block Management Table (BMT). The BMT contains the data block information for the contents of the Information Field. The BMT is located within the Information Field. The Logical Track Set is terminated with Words 58 516 to 58 518 - Reserved set to all ZEROs Word 58 519 - An end code of 4 bytes which shall be set to (0F0F0F0F). The information in a Logical Track Set is processed in 16 product code arrays. 234 080 Bytes = 58 520 Words End code of Logical Track Set (0F0F0F0F) Format Identifier (FFFF0001) 1 Word 136 Bytes

Reserved 3 Words 233 924 Bytes

34 Words

8 192 Words max

Subcode Data field

1 Word

Information field

34 35

Block Management Table

58 515

Word identification number

58 519

Figure 43 - The Logical Track Set 11.2.3

Subcode data field The Subcode data field shall contain the following information associated with this Logical Track Set. The Subcode shall consist of 34 Words, and contain the following information. Word 1

Track Set Type Identifiers (TSID)

Word 1 shall be set to the following bit patterns (TSID) to identify the different types of Track Set. •

The Volume Set Information Table (VSIT) shall be identified by

(00FFFFFF)

•

The Volume Information Table (VIT) shall be identified by

(00FFFF00)

•

The Bad Spot Table (BST) shall be identified by

(FF00FF00)

•

The Logical ID Table (LIDT) shall be identified by

(FFFF0000)

•

The File Information Table (FIT) shall be identified by

(00FF00FF)

- 67 -

•

The Update Table (UT) shall be identified by

(00FF0000)

•

The User Track Set (User) shall be identified by

(0000FFFF)

•

The File Mark Track set (FM) shall be identified by

(0000FF00)

•

The Set Mark Track set (SM) shall be identified by

(FF00FFFF)

•

The Dummy Track Set (DM) shall be identified by

(00000000)

•

The End of Data Track Set (EOD) shall be identified by

(000000FF)

Word 2

Logical Track Set Count

Word 2 shall be the count of all Logical Track Sets from the LBOT, starting with 1 for the first one and incremented by 1 for each Logical Track Set, except for Dummy Track Sets and EOD Track Sets. The most significant bit of Word 2 shall be the Append Flag A. This bit shall be set to Word 3

ONE in the first Track Set of appended data ZERO in all other Track Sets (See also 18.2 and Figure 58)

File number

Word 3 shall be a count of the number of files, starting with 1. It shall be increased by 1 for each file of the logical volume. Word 4

Data Block Count

In User Track Sets, Word 4 shall specify the number of data blocks of the Track Set, i.e. the number of Block Management Tables (BMT) entries. In all other Track Sets, Word 4 shall be set to (00000001) Word 5

Unique Identification Number (UID) of a Logical Volume

In User Track Sets, File Mark Sets, Set Mark Sets, Dummy Track Sets and EOD Track Sets, Word 5 shall be set to a Unique Identification Number (UID) for the logical volume assigned by the initialization process. In all other Track Sets, Word 5 shall be set to (00000000). Word 6

Count of Overwrites of a Logical Volume

Word 6 shall be a count of the number of times a logical volume has been overwritten in each of the User Track Set, File Mark Track Set, Set Mark Track Set, Dummy Track Set and End of Data Track Set. In all other Track Sets, Word 6 shall be set to (00000000). Word 7

Count of Write Retries

Bits 0 to 30 shall be a count of the number of times, starting with 1, that a write retry has taken place in a logical volume. Bit 31 shall be the Retry Flag W. This bit shall be set to Word 8 and 9

ONE in the first Track Set of rewritten data ZERO in all other Track Sets

Drive Vendor Unique ID

Words 8 and 9 are intended for the specification of a unique drive vendor identifier. This ECMA Standard does not define the format of this information, except by specifying that Word 8 shall consist of bytes 0 to 3 and Word 9 of bytes 4 to 7. If Words 8 and 9 are both set to (0000000), they indicate that no such identifier is specified. The interpretation of other settings requires agreement between the interchange parties.

- 68 -

Word 10 to 14

Logical volume number

Words 10 to 14 are intended for the specification of a logical volume number. This ECMA Standard does not define the format of this information. If Words 10 to 14 are all set to (0000000) they indicate that no logical volume number is specified. The interpretation of other settings requires agreement between the interchange parties. Word 15

Unique Identifier of the tape

Word 15 is intended for the specification of a Unique Identifier (UID) of the tape assigned by the initialization process. This ECMA Standard does not define the format of this information. If Word 15 is set to (0000000) it indicates that no such identifier is specified. The interpretation of other settings requires agreement between the interchange parties. Word 16

Count of Overwrites of the Cassette

Word 16 is intended for the specification of a count of the total number of overwrite operations on the tape. This ECMA Standard does not define the format of this information. If Word 16 is set to (00000000) it indicates that no such count is specified. The interpretation of other settings requires agreement between the interchange parties. Word 17

Logical ID Table (LIDT) available

Word 17 shall be set to Word 18

(FFFFFFFF) if a LIDT has been generated (00000000) if no LIDT has been generated

BMT for Block Search Operations

Word 18 shall be set to

Word 19

(FFFFFFFF) if the use of the BMT is effective for block search operations (00000000) if the use of the BMT is not effective for block search operations

Format Type

Word 19 shall be set to (00000005) to indicate that the format of the cassette is DTF-2 as specified by this ECMA Standard. Word 20

Creation Time

Word 20 is intended for the specification of a creation time. This ECMA Standard does not define the format of this information. If Word 20 set to (0000000) it indicates that the creation time is not specified. The interpretation of other settings requires agreement between the interchange parties. Word 21

Number of Mounts

Word 21 shall specify the number of mounts of the cassette, stating with 1. This number shall be increased by 1 for the cassette. Word 22

Count of Read Retries

Word 22 shall be a count of the number of times, starting with 1, a read retry as taken place in the logical volume. Word 23

Count of Recoveries

Word 23 shall be a count of the number of times, starting with 1, a recovery as taken place in the logical volume. Word 24

Recovery Failures

Word 24 shall be set to Word 25 to 34

(FFFFFFFF) if a recovery failure has occurred (00000000) if no recovery failure has occurred

Reserved

Words 25 to 34 shall be set to (00000000).

- 69 -

Table 1 - Word definition summary of Subcode data fields DIT

ID Word / Contents

VSIT

VIT

BST

LIDT

FIT

USER

File Mark

Set Mark

Dummy

EOD

(00FFFFFF)

(00FFFF00)

(FF00FF00)

(FFFF0000)

(00FF00FF)

(00FF0000)

(0000FFFF)

(0000FF00)

(FF00FFFF)

(00000000)

(000000FF)

1 2

Identification Logical TSID

File number

(FFFFFFFF)

Number of BMT entries

(00000001)

Initialization UID volume number

(00000000)

Initialization UID of this logical volume

Overwrite count for volume

(00000000)

Overwrite count of this logical volume

Write retry count

Write Retry Count and Write Retry Flag W.

Vendor UID 0-3

(00000000), unless agreed otherwise between the interchange parties.

9 Vendor UID 4-7 10-14 Logical volume number 15 Initialized UID. of tape 16 Overwrite count 17 LIDT use flag 18 Block operation type 19 Format type 20 Creation time 21 Number of mounts 22 Number of read retries 23 Number of recoveries 24 Recovery failed flag 25-34 Reserved

(00000000), unless agreed otherwise between the interchange parties. (00000000), unless agreed otherwise between the interchange parties.

Increment by one for each track set and append file flag ‘A’.

Not incremented File number

Block number

(00000001)

(00000000), unless agreed otherwise between the interchange parties. (00000000), unless agreed otherwise between the interchange parties. (00000000) or (FFFFFFFF) (00000000) or (FFFFFFFF) (00000005) (00000000) Incremented mount count Incremented read retry count Incremented recovery count (00000000) or (FFFFFFFF) (00000000)

(FFFFFFFF)

- 70 -

11.2.4

Blo c k M a n a g e m e n t Ta b le ( BM T) The data blocks of a Logical Volume are numbered consecutively, starting with 1. The number allocated to each data block is called the Absolute Block Number. The data blocks of a Logical Volume are contained either in one Logical Track Set or more than one Logical Track Set. The BMT contains the information required for locating and retrieving data blocks. The User Logical Track Set shall contain up to 2 048 user data blocks. All other Track Sets shall contain a single data block. The information required for managing each data block is as follows: •

The Absolute Block Number of the data block in this Logical volume

•

The starting address of the data block. The number of bytes from the beginning of the information field.

•

The number of bytes of the data block in this Logical Track Set.

•

A Link bit (L), set to ONE indicating that the data block extends to the next Track Set or set to ZERO when contained in this Track Set.

•

A Start bit (S), set to ONE indicating that the data block begins in this Track Set or set to ZERO when carried over from the preceding Track Set.

•

The total number of bytes of the data block. The BMT shall contain information for only those data blocks in the Information field and be constructed from the end of the Information field towards the beginning with the 1st data block management information being placed in words 58 512 to 58 515. (see figure 43)

11.2.4.1

11.2.4.2

11.2.5

BM T f o r V S I T , V I T , B S T , L I D T , F I T , U T , T M , D M a n d E O D Word 58 515 shall contain the total number of bytes in the data block. Word 58 514

shall contain the number of bytes in the data block in this Track Set, recorded in bits 0 to 29. Bit 30 shall be a flag bit S and bit 31 shall be a flag bit L.

Word 58 513

shall contain the start address of the data block and shall be set to (00000000).

Word 58 512

shall contain the absolute block number of the data block.

BM T f o r t h e U s e r d a t a Tr a c k S e t t y p e Word 58 515 shall contain the total number of data bytes in the 1st data block. Word 58 514

shall contain the number of data bytes in the 1st data block which is included in this Track Set, recorded in bits 0 to 29. Bit 30 shall be a flag bit S and bit 31 shall be a flag bit L.

Word 58 513

shall contain the start address (number of bytes from beginning of User data field) of the 1st data block in User data field of this Track Set. In the case of this 1st data block, the content of this word shall be set to (00000000)..

Word 58 512

shall contain the absolute block number of the 1st data block in user data field of this Track Set.

Words 50 324 to 58 511

shall contain the management information for 2nd to 2047th data blocks, if present.

Words 50 320 to 50 323

shall contain the management information for the 2 048th data block, if present.

D a t a a n d in f o r m a t io n f ie ld d e f in it io n s The contents of the Information Field for Track Sets in the User Data Area are transmitted by the host. This applies to the User Data, File Mark, Set Mark, DM and EOD Track Set types. The content of the Information Field is defined in VSIT, VIT, BST, LIDT, FIT and UT Track Set types as follows.

- 71 -

11.2.5.1

VSIT The structure of Volume Set Information Table (VSIT) area on tape is as follows 1) The VSIT contains the logical volume set information for a physical volume. 2) The physical Track Set of the VSIT area shall be incremented starting at the TSID representing ZERO for a physical volume. 3) A VSIT area consists of 1 Track Set recorded 1000 times. 4) A VSIT contains information of one or more logical volumes. Words 35 to 79

shall be set to (00000000).

Word 80

shall contain the starting TSID of this tape.

Word 81

shall contain the physical TSID of last data block on this tape.

Words 82 to 97

shall contain the count of Logical Volumes on this tape.

Word 98

shall be set to (00000000).

Word 99

shall contain the starting physical TSID of the 1st Logical Volume.

Word 100

shall contain the last physical TSID of the 1st Logical Volume.

Word 101

shall contain the starting physical TSID of the 2nd Logical Volume if present, otherwise set to (00000000).

Word 102

shall contain the last physical TSID of the 2nd Logical Volume if present, otherwise set to (00000000).

Words 103 to 2 144

shall contain the starting and last physical TSIDs of the 3rd to 1 023rd Logical Volumes if present, otherwise set to (00000000).

Word 2 145

shall contain the starting physical TSID of the 1 024th Logical Volume if present, otherwise set to (00000000).

Word 2 146

shall contain the last physical TSID of the 1 024th Logical Volume if present, otherwise set to (00000000).

Word 2 147

shall contain the UID number of this tape issued at the time of initialization.

Word 2 148

shall contain the count of overwrites incurred by this tape.

Words 2 149 to 58 511

shall be set to (00000000).

Words 58 512 to 58 515 shall contain the BMT for this VSIT Track Set. 11.2.5.2

VIT The Volume Information Table (VIT) is structured as follows Words 35 to 38

shall be set to (00000000).

Words 39 to 78

shall contain the Volume Label.

Word 79

shall contain the starting physical TSID of the 1st data block in this Logical Volume.

Word 80

shall contain the last physical TSID of the EOD in the last data block in this Logical Volume.

Word 81

shall contain the last block number in the BMT for the track set containing the last data block.

Words 82 to 289

shall be set to (00000000).

Word 290

shall contain the UID number of this volume issued at the time of initialization.

Word 291

shall contain the count of overwrites of this Logical Volume.

- 72 -

Word 292

shall contain the LIDT indicator, see Word 17.

Word 293

shall contain the Block Search Operation indicator, see Word 18.

Word 294

shall be set to (00000005), identifying the Format Type DTF-2.

Word 295

shall be set to (00000002).

Word 296

The content of this word is a matter of agreement between interchange parties.

Words 297 to 8 226

shall be set to (00000000).

Words 8 227 to 8 250

shall contain Mount Information as follows 8 227: Mount count 8 228 - 8 230: reserved 8 231 - 8 250: information regarding the last five mounts (date/Controller ROM version /Drive vendor UID Information). The format of this information is a matter of agreement between interchange parties. The default value shall be (00000000).

Words 8 251 to 16 418

shall be set to (00000000).

Word 16 419

shall contain the total count of read retries in this Logical Volume.

Word 16 420

shall contain the number of recoveries by this Logical Volume.

Word 16 421

shall contain the Recovery failed flag, set to (FFFFFFFF) if true, otherwise set to (00000000).

Words 16 422 to 58 511

shall be set to (00000000).

Words 58 512 and 58 515 shall contain the BMT for this VIT Track Set. 11.2.5.3

BS T The Bad Spot Table (BST) shall contain the location information of "logically invalid" data. Logically invalid data occupies an area of tape, which has been identified as flawed and that source data has been rewritten and validated with the same Logical TSID at some following point. (See figure 44. 'Data A' is logically invalid data.) The write retry process creates a logically invalid data location on the tape. Logically invalid data is also called a "Bad spot". The beginning of a Bad spot is the 1st physical TSID and the end is the last physical TSID. Two Words in the BST shall identify the UD Track Set type and location of a Bad spot —

The 1st physical TSID, shall bits 0 to 30 of the 1st location word

—

Error type flag E, bit 31 shall be set to ONE for UD data error, otherwise set to ZERO

—

The last physical TSID, shall occupy bits 0 to 31 of the 2nd location word.

Byte 3 1st Word 2nd Word

bit 31 is E flag

Byte 2

Byte 1

Byte 0

1st physical TSID of the Bad Spot last physical TSID of the Bad Spot

- 73 -

... n-1 n ...

Logical TSID

n+1 n n+1 ...

DIT Bad spot BST A

Figure 44 – Bad spot table usage The BST shall be constructed as follows

11.2.5.4

Word 35

the msb of byte 3 shall be the E Error type flag, the 1st physical TSID of the 1st bad spot shall occupy the LSBs.

Word 36

The last physical TSID of the 1st bad spot shall occupy the LSBs.

Words 37 to 58 509

shall contain the information for the 2nd to 29 238th bad spots, as required, otherwise set to ZERO.

Words 58 510 and 58 511

shall contain the information of the last bad spot, 29 239th, in this BST, if required, otherwise set to ZERO.

Words 58 512 to 58 515

shall contain the BMT for this BST Track Set.

LI D T The Logical ID Table (LIDT) data table may be used for fast block space and locate operations. The LIDT shall contain pointers occupying four Words, as defined by the following information: −

the Logical TSID count incremented from the LBOT, starting with 1, on all track set types except DM and EOD

−

the physical TSID

−

the number of files in this logical volume, starting with 1

−

the block number in the BMT of the physical Track Set, which is the 1st block of this pointer.

This LIDT shall be constructed as follows, otherwise set to ZERO. Byte 3 st

Byte 2

Byte 1

1 Word

Logical TSID

2nd Word

Physical TSID

3 Word

File number

4th Word

block number in BMT for 1st block of 1st pointer

Byte 0

Words 35 to 38

shall contain the information for the 1st pointer

Words 39 to 42

shall contain the information for the 2nd pointer.

Words 43 to 58 505

shall contain the information for the 3rd to 14 618th pointers.

Words 58 506 to 58 509

shall contain the information for the 14 619th pointer.

Word 58 510 and 58 511

shall be set to (00000000).

Words 58 512 to 58 515

shall contain the BMT for this LIDT Track Set.

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11.2.5.5

FIT The File Information Table (FIT) shall contain pairs of two types of data which locate a Tape Mark (TM). The nth data pair corresponds to the nth TM from the beginning of the volume. -

W((n-1)x2) the nth TM physical TSID The Set Mark bit (S in W(2n-2) bit 31 of the nth TM physical TSID) shall be set to ONE, when the nth TM is a Set Mark and set to ZERO, when the nth TM is a File Mark.

W((n-1)x2+1) Absolute block number of the nth TM.

The FIT shall be constructed as follows, otherwise set to ZERO Byte 3 st

1 Word

bit 31 is S flag

2nd Word

11.2.5.6

11.3

Byte 2

Byte 1

Byte 0

Physical TSID of nth TM block number in BMT of the nth TM

Words 35 and 36

shall contain the physical TSID of the 1st TM.

Words 37 to 58 509

shall contain the information for the 2nd to 29 238th TMs.

Words 58 510 and 58 511

shall contain the information for the 29 239th TM.

Words 58 512to 58 515

shall contain the BMT for this FIT Track Set.

UT The Update Table (UT) shall be used for indication of update status. This UT shall be checked by the receiving system to assure proper correspondence of directories to data file locations in this volume. Word 35

shall be set to (FFFFFFFF) when updating this volume is in process and set to (00000000) for update complete and ready for system export and data interchange.

Words 36 to 58 511

shall be set to (00000000).

Words 58 512 to 58 515

shall contain the BMT for this UT Track Set.

Track Set information The Track Set information is placed sequentially into eight Product Code Arrays. All subsequent record processing of Track Set information uses the location information defined as follows. Each array shall contain 104 horizontal rows each of 192 bytes. The position of each byte in the array has an address of the form (W:X:Y). Array locator W shall identify one of eight arrays with a value 0 for the first array 7 for the last array. Column locator X shall identify the column in the array as one of 192 values 0 for the first and left-most column which contains identifier ID0 1 for the second column, which is reserved for identifier ID1, etc. 191 for the last and right-most column 4

columns are added at the left side to contain the sync pattern.

columns are added at the right side to contain the Inner ECC C1 Parity.

Row locator Y shall identify one row of 104 rows in the array 0 for the first and top-most row 1 for the second row, etc. 103 for the last and bottom-most row Columns 2 to 191 contain Logical Track Set data in rows 0 to 76 and Outer ECC C2 Parity in rows 77 to 103.

- 75 -

The 104 rows are divided into 4 groups of 26 rows each. Each group is assigned to one of four tracks in a Track Set, see figure 45. The identification number of the Sync Blocks and Sector numbers (defined in 11.5.4) are assigned in the following location information, see figures 46, 48 and 49. 11.3.1

Lo a d in g t h e P r o d u c t C o d e A r r a y s Information data shall be loaded into the Product Code Arrays starting with Array 0, Row 0, Column 2 sequentially filling the rows of one array before proceeding to the next until all arrays are full. Array 0, Row 0

(0:2:0) (0:3:0) .... (0:191:0)

Array 0, Row 1

(0:2:1) (0:3:1) .... (0:191:1) ....

Array 7, Row 103

(7:2:103) (7:3:103) .... (7:191:103)

- 76 -

204 Bytes 4 Bytes

User Data (14 630 Bytes)

I P a t t e r n

190 Bytes

0 1

S y n c 104 Rows

12 Bytes

2 Bytes

Row numbers (Y)

77 Rows

Inner ECC

D C1 Parity 76 77

Outer ECC C2 Parity

27 Rows

103 012

Column numbers (X)

191 192

203

ID0 Sync block number ID1 Reserved

(a)

Contents of a Product Code Array

26 Rows S y n c P a t t e r n

Track A

Track B

User Data (14 630 Bytes)

Inner ECC C1 Parity

Track C

Track D Outer ECC C2 Parity

(b) Track assignment of a Product Code Array

Figure 45 - ECC Block Data (Processor)

- 77 -

11.4

Product code array processing Information is sequentially loaded into the user data area of 8 product code arrays. Sync blocks are formed comprising sync pattern, identification bytes, C2 Parity and C1 Parity. Sync block bytes are interleaved and randomized to form a channel sync block. One Segment comprise 8 product code arrays.

11.4.1

Er r o r c o r r e c t i o n m e t h o d The C2 Parity shall consist of 27 bytes derived from the 77 bytes in rows 0 to 76 of a column in the Product Code Array. Bytes in Column 2

(0:2:0) to (0:2:76) are processed with RS (104,77) to produce 27 bytes to be placed in the same column from (0:2:77) to (0:2:103).

The C1 Parity shall consist of 12 bytes derived from the 192 bytes of each row for the 104 rows of the ID and Source Information. Bytes in Row 0 11.4.1.1

(0:0:0) to (0:191:0) are processed with RS (204,192) to produce 12 bytes to be placed in the same row from (0:192:0) to (0:203:0)

Er r o r c o r r e c t i o n c o d i n g f o r C 2 P a r i t y The Outer ECC is a Reed-Solomon code denoted RS(104,77) The Galois Field shall be GF(2 8) Field Generator Polynomial shall be p( x ) = x 8 + x 4 + x 3 + x 2 + x 0 where xn are place-keeping variables in GF(2 1), binary field The Code Generator Polynomial shall be

(

)(

)( )( )( ( x + a )( x + a )( x + a )( x + a ) ( x + a )( x + a )

G ( x ) = ( x + 1)( x + a ) x + a 2 x + a 3 x + a 4 x + a 5 x + a 6 x + a 7 8

)

where a is given by (02) in GF(2 8) Outer error code parity K 26 , K 25 , K 10 , K 9 , K 8 , K 7 , K 6 , K 5 , K 4 , K 3 , K 2 , K 1 , K 0 ,

in K 26 x 26 + K 25 x 25 ++ K 1 x 1 + K 0 x 0 are obtained as the remainder after dividing x27D(x) by G(x) where

D( x ) = B 76 x 76 + B 75 x 75 ++ B1 x + B 0

The polynomial of the full code is B 76 x 103 + B 75 x 102 ++ B1 x 28 + B 0 x 27 + K 26 x 26 + K 25 x 25 ++ K 1 x + K 0

where B76 to B0 represent the 77 bytes of user data in rows 0 to 76 of the Product Code Arrays and K 26 to K 0 represent the 27 bytes of outer error code. The 27 bytes K 26 to K 0 shall be placed in rows 77 to 103 of the Product Code Arrays 11.4.2

Er r o r c o r r e c t i o n c o d i n g f o r C 1 P a r i t y The Inner ECC is a Reed-Solomon code denoted RS(204,192) The Galois Field shall be GF(2 8) Field Generator Polynomial shall be p( x ) = x 8 + x 4 + x 3 + x 2 + x 0 where xn are place-keeping variables in GF(2 1), binary field

- 78 -

The left-most term is "oldest" in time computationally and the first written on tape; The Code Generator Polynomial shall be

(

)(

G ( x ) = ( x + 1)( x + a ) x + a 2 x + a 3 x + a 4 x + a 5 x + a 6 x + a 7

( x + a )( x + a )( x + a )( x + a ) 8

)

where error code parity K 11 , K 10 , K 9 , K 8 , K 7 , K 6 , K 5 , K 4 , K 3 , K 2 , K 1 , K 0 in K11x11 + K10x10 + … + K1x + K0

are obtained as the remainder after dividing x 12 D( x ) by G(x)

where

D(x) = I 0 x191 +I 1 x190 + B189 x189 + … + B1 x + B0

The polynomial of the full code is I0x203 + I1x202 + B189x201 + … B0x12 + K11x11 + K10x11 + K10x10 + … + K1x + K0

where I 0 and I 1 represent the 2 bytes of sync full code block identification B189 to B0 represent the 190 bytes of sync block source information and K 11 to K 0 represent the 12 bytes of inner error code parity S y n c p a tte rn

S o u rc e In fo rm a tio n

C 1 P a rity

ID 0 :

S y n c B lo c k N u m b e r (C o m m o n in a ll T ra c k s ) S y n c b lo c k n u m b e r in 1 s t S e c to r: 2 5 5 to 1 5 2 S y n c b lo c k n u m b e r in 2 n d S e c to r: 1 2 7 to 2 4

ID 1 :

b it 7 -3 : S e g m e n t In fo rm a tio n (0 to 3 1 ) b it 2 -0 : S e c to r

S e g m e n t In fo rm a tio n : b it 7 -4 s h a ll c o n ta in th e v a lu e in b its 3 -0 o f th e T S ID b it 3 s h a ll b e s e t to 0 fo r e v e n s e g m e n t, 1 fo r o d d s e g m e n t E v e n S e g m e n t

O d d S e g m e n t

ID 0 = 2 5 5 to 1 5 2

1 2 7 to 2 4

ID 0 = 2 5 5 to 1 5 2

1 2 7 to 2 4

T ra c k A :

S e c to r = 0

S e c to r = 1

S e c to r = 0

S e c to r = 1

T ra c k B :

S e c to r = 2

S e c to r = 3

S e c to r = 2

S e c to r = 3

T ra c k C :

S e c to r = 4

S e c to r = 5

S e c to r = 4

S e c to r = 5

T ra c k D :

S e c to r = 6

S e c to r = 7

S e c to r = 6

S e c to r = 7

Figure 46 - Segment / Sector Details

11.5

Track assignments A Logical Track Set shall occupy 4 tracks on the tape identified as Track A, Track B, Track C and Track D. Each track shall comprise 4 Sectors.

11.5.1

S e g m e n t s /S e c t o r s ( f ig u r e 4 6 ) There are 2 Segments (16 Sectors) in a Track Set, numbered as follows:

- 79 -

Segment: even/odd Sector : 0 to 7 Each Segment shall comprise 8 Sectors. One Sector shall comprise the following elements a Preamble and 104 Sync Blocks Sector number 0 and 1 of even segment and odd segment shall be assigned to Track A Sector number 2 and 3 of even segment and odd segment shall be assigned to Track B Sector number 4 and 5 of even segment and odd segment shall be assigned to Track C Sector number 6 and 7 of even segment and odd segment shall be assigned to Track D. 2 0 4 B y te s

4 B y te s

2 B y te s

1 2 B y te s

1 9 0 B y te s

S y n

U s e r D a ta (1 4 6 3 0 B y te s ) c I P

1 0 4 R o w s

D a

In n e r E C C

7 7 R o w s

C 1 P a rity

t t e r

O u te r E C C n

S y n c p a tte rn 4 B y te s

C 2 P a rity

S o u rc e In fo rm a tio n 1 9 0 B y te s

2 B y te s ID 0 : ID 1 :

2 7 R o w s

In n e r E C C 1 2 B y te s

S y n c B lo c k N u m b e r (2 5 5 to 1 5 2 , 1 2 7 to 2 4 ) S e g m e n t/S e c to r In fo rm a tio n In n e r C o d e B lo c k (2 0 4 B y te s ) S y n c B lo c k (2 0 8 B y te s )

Figure 47 - Sync Block 11.5.2

S y n c Blo c k s ( f ig u r e 4 7 ) Each Sync Block shall comprise 208 Bytes arranged in the following elements Sync Pattern of 4 Bytes and the Inner Code Block. The Inner Code Block shall comprise 204 Bytes arranged in the following elements Sync Block ID of 2 Bytes Source Information field of 190 Bytes and Inner ECC of 12 Bytes. The Sync Block ID and Source Information are identified in the 8 product code arrays. The Sync Pattern is not identified in the product code arrays and is not included in the error protection process.

- 80 -

11.5.3

Tr a c k in t e r le a v e ( f ig u r e 4 8 ) The interleave of data shall be accomplished across the 4 helical tracks of a Track Set. The Sync Blocks (832 blocks) of the 4 helical tracks are identified in the eight Product Code Arrays ((0 to 7), 1 Segment). Each Product Code Array shall be divided into four areas (see figure 45(b)), equal to the content of four helical tracks. The arrangement of Sync Blocks in the two sectors of each track are sequentially assigned from each of the eight Product Code Arrays (0 to 7). A recorded track shall begin with the following product code array assignment. Track A

Product Code Array 0

Track B

Product Code Array 6

Track C

Product Code Array 4

Track D

Product Code Array 2

NOTE This track interleave operation together with C2 ECC provides the possibility of correcting the data in error of one entire track. Helical track A Track 0 1 2 3 4 5 6 7 0 - - - B Track 6 7 0 1 2 3 4 5 - - - - C Track 4 5 6 7 0 1 2 3 - - - - D Track 2 3 4 5 6 7 0 1 - - - - -

Product Code Array (0 to 7) 0

First Sync block for each helical track

Figure 48 - Track Interleave

- 81 -

Track Sync Blocks Track A- Sync Blocks Sector No. Sync Block No. 0 0 0

255 254 253

0 0 0

248 247 246

0 1

152 127

Byte address (W:X:Y) (0:0:0) (0:1:0) (0:2:0) ..... (0:190:0) (0:191:0) (1:0:0) (1:1:0) (1:2:0) ..... (1:190:0) (1:191:0) (2:0:0) (2:1:0) (2:2:0) ..... (2:190:0) (2:191:0) ..... (7:0:0) (7:1:0) (7:2:0) ..... (7:190:0) (7:191:0) (0:0:1) (0:1:1) (0:2:1) ..... (0:190:1) (0:191:1) (1:0:1) (1:1:1) (1:2:1) ..... (1:190:1) (1:191:1) ..... (7:0:12)(7:1:12)(7:2:12) ..... (7:190:12)(7:191:12) (0:0:13)(0:1:13)(0:2:13) ..... (0:190:13)(0:191:13) ..... (7:0:25)(7:1:25)(7:2:25) ..... (7:190:25)(7:191:25)

Track B- Sync Blocks Sector No. Sync Block No. 2 2 2

255 254 253

2 2 2

248 247 246

2 3

152 127

Byte marker (W:X:Y) (6:0:26)(6:1:26)(6:2:26) ..... (6:190:26)(6:191:26) (7:0:26)(7:1:26)(7:2:26) ..... (7:190:26)(7:191:26) (0:0:26)(0:1:26)(0:2:26) ..... (0:190:26)(0:191:26) ..... (5:0:26)(5:1:26)(5:2:26) ..... (5:190:26)(5:191:26) (6:0:27)(6:1:27)(6:2:27) ..... (6:190:27)(6:191:27) (7:0:27)(7:1:27)(7:2:27) ..... (7:190:27)(7:191:27) ..... (5:0:38)(5:1:38)(5:2:38) ..... (5:190:38)(5:191:38) (6:0:37)(6:1:39)(6:2:39) ..... (6:190:39)(6:191:39) ..... (5:0:51)(5:1:51)(5:2:51) ..... (5:190:25)(5:191:51)

Track C- Sync Blocks Sector No. Sync Block No. 4 4 4

255 254 253

4 4 4

248 247 246

4 5

152 127

Byte marker (W:X:Y) (4:0:52)(4:1:52)(4:2:52) ..... (4:190:52)(4:191:52) (5:0:52)(5:1:52)(5:2:52) ..... (5:190:52)(5:191:52) (6:0:52)(6:1:52)(6:2:52) ..... (6:190:52)(6:191:52) ..... (3:0:52)(3:1:52)(3:2:52) ..... (3:190:52)(3:191:52) (4:0:53)(4:1:53)(4:2:53) ..... (4:190:53)(4:191:53) (5:0:53)(5:1:53)(5:2:53) ..... (5:190:53)(5:191:53) ..... (3:0:64)(3:1:64)(3:2:64) ..... (3:190:64)(3:191:64) (4:0:13)(4:1:65)(4:2:65) ..... (4:190:65)(4:191:65) ..... (3:0:77)(3:1:77)(3:2:77) ..... (3:190:77)(3:191:77)

Track D- Sync Blocks Sector No. Sync Block No.

Byte marker (W:X:Y)

6 6 6

255 254 253

(2:0:78)(2:1:78)(2:2:78) ..... (2:190:78)(2:191:78) (3:0:78)(3:1:78)(3:2:78) ..... (3:190:78)(3:191:78) (4:0:78)(4:1:78)(4:2:78) ..... (4:190:78)(4:191:78)

6 6 6

248 247 246

6 7

152 127

(1:0:90)(1:1:90)(1:2:90) ..... (1:190:90)(1:191:90) (2:0:91)(2:1:91)(2:2:91) ..... (2:190:91)(2:191:91)

..... (1:0:103)(1:1:103)(1:2:103) .... (1:190:103)(1:191:103)

..... (1:0:78)(1:1:78)(1:2:78) ..... (1:190:78)(1:191:78) (2:0:79)(2:1:79)(2:2:79) ..... (2:190:79)(2:191:79) (3:0:79)(3:1:79)(3:2:79) ..... (3:190:79)(3:191:79) .....

- 82 -

11.5.4

By t e in t e r le a v e a c r o s s S y n c Blo c k s ( f ig u r e 4 9 ) Byte interleave shall be accomplished on the data of the Inner Code Block as follows The Track A,

Sync Block 255

(0:0:0) (0:1:0) (0:2:0) .....

Sync Block 254

(1:0:0) (1:1:0) (1:2:0) .....

Sync Block 253

(2:0:0) (2:1:0) (2:2:0) .....

Sync Block 252

(3:0:0) (3:1:0) (3:2:0) ..... , etc.

are byte interleaved into The Track A,

Sync Block 255’

(0:0:0) (1:1:0) (2:2:0) .....

Sync Block 254’

(1:0:0) (2:1:0) (3:2:0) .....

Sync Block 253’

(2:0:0) (3:1:0) (0:2:0) .....

Sync Block 252’

(3:0:0) (0:1:0) (1:2:0) ..... , etc.

4 sync blocks of 1 product code array are interleaved by 1 byte unit except in the Sync pattern. NOTE Byte interleave together with C1 ECC provides the possibility of correcting a burst error of up to 24 bytes per four sync blocks. Sync pattern 4 Bytes

ID 2 Bytes

Source Information 190 Bytes

Inner ECC 12 Bytes -----

Sync Block: a SY SY SY SY IDA IDA A0 A1 A2 A3 A4 A5 A6

- - - -a2 - a3 a4 a5 a6 a7 a8 a9 a10 a11

Sync Block: b SY SY SY SY IDB IDB B0 B1 B2 B3 B4 B5 B6

- - - -b2 - b3 b4 b5 b6 b7 b8 b9 b10 b11

Sync Block: c SY SY SY SY IDC IDC C0 C1 C2 C3 C4 C5 C6

- - - -c2 - c3 c4 c5 c6 c7 c8 c9 c10 c11

Sync Block: d SY SY SY SY IDD IDD D0 D1 D2 D3 D4 D5 D6

- - - -d2 - d3 d4 d5 d6 d7 d8 d9 d10 d11

.........

Byte Interleave

Sync Block: a' SY SY SY SY IDA IDB C0 D1 A2 B3 C4 D5 A6

- - - -c2- d3 a4 b5 c6 d7 a8 b9 c10 d11

Sync Block: b' SY SY SY SY IDB IDC D0 A1 B2 C3 D4 A5 B6

- - - -d2 - a3 b4 c5 d6 a7 b8 c9 d10 a11

Sync Block: c' SY SY SY SY IDC IDD A0 B1 C2 D3 A4 B5 C6

- - - -a2 - b3 c4 d5 a6 b7 c8 d9 a10 b11

Sync Block: d' SY SY SY SY IDD IDA B0 C1 D2 A3 B4 C5 D6

- - - -b2- c3 d4 a5 b6 c7 d8 a9 b10 c11

Figure 49 - Byte Interleave across Sync Blocks

- 83 -

11.5.5

R a n d o m iza t io n The Inner Code Block (ID, Source information, inner code) of each sector shall be randomized to average the 1/0 distribution. The Preamble and Sync Pattern are not randomized. Randomization shall be accomplished by XORing the serial byte stream to be recorded with the serial byte stream to be generated by the following polynomial equation. G(x)=x8+x4+x3+x2+x0 (in GF(2)) The left-most term shall enter the division computation first. The polynomial shall be preset to (80) at the end of every Sync Pattern. NOTE With the data stream set to all ZEROs the computation will generate a byte sequence beginning with (80), (38), (D2), (81), (49) and so on.

11.6

Formation of the contents of a helical track (figure 50) Channel sync blocks are interleaved across the 4 assigned areas of the 8 arrays to form data streams for Tracks A,B,C and D. These data streams are then 8/9 encoded to form the Channel bits. The contents of a track comprises 4 sectors formed from the Channel sync blocks, with each preceded by a preamble. A Track Pilot Signal (TPS) is added between the sectors of Tracks B and D. The Channel bits are then subjected to a precode filter process prior to being applied to the write heads.

11.6.1

S e g m e n t /S e c t o r d e t a ils ( f ig u r e 4 7 ) The Sector shall contain a Preamble and 104 Sync Blocks, resulting in 195 768 Channel bits. The 16 Sectors of a Track Set shall be numbered as follows Track A 0 for the 1 st sector, 1 for the 2 nd sector and shall be components of the even segment 0 for the 3 rd sector, 1 for the 4 th sector and shall be components of the odd segment Track B 2 for the 1 st sector, 3 for the 2 nd sector and shall be components of the even segment 2 for the 3 rd sector, 3 for the 4 th sector and shall be components of the odd segment Track C 4 for the 1 st sector, 5 for the 2 nd sector and shall be components of the even segment 4 for the 3 rd sector, 5 for the 4 th sector and shall be components of the odd segment Track D 6 for the 1 st sector, 7 for the 2 nd sector and shall be components of the even segment 6 for the 3 rd sector, 7 for the 4 th sector and shall be components of the odd segment

11.6.1.1

P r e a m b le The Preamble shall comprise 120 times 9 Channel bits set to ONE.

11.6.1.2

S y n c Blo c k s Sync Blocks shall comprise a Sync Pattern of 4 times 9 Channel bits and a Data Field of 204 times 9 Channel bits. The Sync Pattern symbols are not found in the 8/9 coding table of annex B. These symbols shall provide a magnetization pattern which is distinctly different than all other data. The order of recording the Sync Pattern shall be lsb 100010101 000000001 011100100 000001011 msb The Data Field shall comprise 2 bytes of Sync Block ID followed by 190 bytes of source information derived according to "Source information of Sync Block"(figure 46), both protected by 12 bytes of inner error code, all of which are processed as defined in 11.7. The Sync Block ID byte 0 shall indicate the Sync Block and Sector position within the track set. Refer to figures 49 and 50. The Sync Block ID byte 1 shall indicate Track Set ID, Segment and Sector information as follows:

- 84 -

bits 7 to 4 shall contain the value in bits 3 to 0 of the TSID bit 3 shall be set to Zero for an even segment and One for an odd segment bits 2 to 0 shall contain the sector number starting with 0 The 104 Sync Blocks of the 1st sector shall be numbered sequentially starting with 255 and ending with 152 in all four tracks of a track set. The 104 Sync Blocks of the 2nd sector shall be numbered sequentially starting with 127 and ending with 24 in all four tracks of a track set. R e c o rd in g d ire c tio n 2 n d S e c to r, e v e n s e g m e n t

1 s t S e c to r, e v e n s e g m e n t

P re a m b le

1 T ra c k

1 0 4 S y n c B lo c k s

T P S

P re a m b le

1 0 4 S y n c B lo c k s

1 s t S e c to r, o d d s e g m e n t

P re a m b le

1 0 4 S y n c B lo c k s

2 n d S e c to r, o d d s e g m e n t

P re a m b le

T P S

1 0 4 S y n c B lo c k s

B a n d D T ra c k s P re a m b le (1 2 0 B y te s )

R u n -u p se q u e n c e 1 2 0 x 9 C h a n n e l b its

D a ta F ie ld (In n e r C o d e B lo c k )

1 S y n c b lo c k (2 0 8 B y te s )

S y n c p a tte rn 4 x 9 C h a n n e l b its

S o u rc e In fo rm a tio n 1 9 0 x 9 C h a n n e l b its

2 x 9 C h a n n e l b its

C 1 P a rity 1 2 x 9 C h a n n e l b its

Figure 50 - Contents of a Helical Track 11.6.2

C h a n n e l b i t c o d i n g ( a n n e x B) The 8/9 coding shall be as shown in Annex B. The Channel bit stream is recorded at a maximum physical recording density of 6 349 ftpmm.

11.6.3

I n t e r le a v e d - N R Z1 ( f ig u r e 5 1 ) 8/9 coded data shall be processed with a precode circuit to generate Interleaved-NRZ1. The 9-bit Channel bit stream shall be subjected to the following precode filtering.

Interleaved NRZ1 OUT

NRZ1 IN

Figure 51 - precode circuit

- 85 -

Data out of the precode circuit shall be recorded to the tape. 11.6.4

Tr a c k i n g P i l o t S i g n a l s ( T P S ) The first TPS shall be a nominal 666 kHz signal (99,2 ftpmm) recorded twice on tracks B and F. The second TPS shall a nominal 444 kHz signal (66,2 ftpmm) recorded twice on tracks D and H.

Track geometry

12.1

General Two types of track shall be recorded on the tape, helically recorded tracks and longitudinally recorded tracks. Helically recorded tracks contain user data. The longitudinally recorded Control Track provides accurate positioning information to the drive servo. The longitudinally recorded Time Code Track provides unique identification of the longitudinal position on tape, and thus enables fast searches to be carried out. The configuration of the tracks is shown in figure 52.

12.2

Helically recorded tracks Each track shall comprise four sectors with a tracking pilot signal included on tracks B,D,F and H.

12.2.1

Lo c a t io n o f t h e t r a c k s The distance from the lower edge of the helical tracks to the Tape Reference Edge shall be l349 = 1,241 mm ± 0,010 mm The distance from the upper edge of the helical tracks to the Tape Reference Edge shall be l350 = 11,491 mm ± 0,010 mm The effective width of the helically recorded area shall be the distance between two lines parallel to the Tape Reference Edge, one passing through the centreline of, and at the end of, the helical track, and the other passing through the centreline at the beginning of the Preamble at the start of the helically recorded area, and shall be l351 = 10,213 mm nominal The distance from the lower edge of the helically recorded area to the Tape Reference Edge shall be l352 = 1,250 mm ± 0,010 mm

- 86 -

Figure 52 - Location and dimensions of recorded tracks 12.2.2

Tr a c k wid t h The width of each helical track shall be mm l353 = 0,019 mm +−00,,002 003mm

12.2.3

Tr a c k a n g le The angle of each track relative to the Tape Reference Edge shall be θ = 4,610°

12.2.4

Tr a c k p it c h The distance between the centrelines of adjacent tracks A and B (C and D), measured perpendicular to the track centreline shall be l354 = 0,019 mm ± 0,002 mm The distance between the centreline of track A in Track Set n to the centreline of track A in Track Set n+1 shall be l355 = 0,152 mm nominal

- 87 -

The distance between the centrelines of track A and track C in Track Set n shall be l356 = 0.038 mm nominal

Tape Motion

l355

Control Track

l354

A l356 l353

Head Motion

l365

l357

l362 l361

l366

Time Code Track l358

l363

l367 l359

Negative azimuth angle: Tracks B, D, F and H

Positive azimuth angle: Tracks A, C, E and G

Figure 53 - Location and dimensions of helical track elements 12.2.5

Lo c a t io n o f e le m e n t s in t h e h e lic a l t r a c k The length of each sector shall be l357 = 30,644 mm nominal The total length of helical track shall be l358 = 127,166 mm nominal The distance from the Preamble pattern to the start of the Sector at the start of a helical track shall be l359 = 0,170 mm ± 0,045 mm The distance from the start of the first Sector of a helical track to the Data Area Reference Point shall be l360 = 0,000 mm ± 0,045 mm The distance from the start of the first Sector to the start of the second Sector of a helical track shall be

- 88 -

l361 = 32,412 mm ± 0,045 mm The distance from the start of the first Sector to the start of the third Sector of a helical track shall be l362 = 63,940 mm ± 0,045 mm The distance from the start of the first Sector to the start of the fourth Sector of a helical track shall be l363 = 96,352 mm ± 0,045 mm 12.2.6

Lo c a t i o n o f t h e D a t a A r e a R e f e r e n c e P o i n t The Data Area Reference Line shall be a line parallel to the Tape Reference Edge and spaced l364 = 1,264 mm (nominal) from it. The Data Area Reference point for track A of a Track Set is at the intersection of the Data Area Reference Line and the centreline of the track.

12.2.7

S t r a ig h t n e s s o f t r a c k s The centreline of a recorded track shall be contained within two parallel straight lines 6 µm apart.

12.2.8

A zim u t h a n g le s The recorded bit positive azimuth angle for tracks A and C shall be +15,484° ± 0,167° The recorded bit negative azimuth angle for tracks B and D shall be -15,316° ± 0,167° These values of the azimuth angles result from the bits having been recorded with the tape in motion longitudinally with helical recording heads.

12.2.9

Tr a c k i n g P i l o t S i g n a l s ( T P S ) The length of the TPS in tracks B, D, F and H shall be l365 = 0,864 mm The distance from the start of first Sector to the start of the first TPS in tracks B, D, F and H shall be l366 = 30,769 mm ± 0,045 mm The distance from the start of first Sector to the start of the second TPS in tracks B, D, F and H shall be l367 = 94,709 mm ± 0,045 mm

1 2 . 2 . 1 0 A m p lit u d e o f s e r v o s ig n a ls The Tracking Pilot Signal amplitude averaged over any TPS shall be between 80 % and 120 % of SRA3.

12.3

Longitudinal tracks geometry

12.3.1

C o n t r o l Tr a c k The distance from the lower edge of the Control Track to the Tape Reference Edge shall be l368 = 12,05 mm ± 0,08 mm The distance between the Control Track flux transition as defined in 14.2 and the Data Area Reference Point of the first helical track of the Track Set to which it belongs shall be l369 = 175,79 mm ± 0,10 mm

12.3.2

Ti m e C o d e Tr a c k s i g n a l s r e c o r d i n g p o s i t i o n The distance from the upper edge of the Time Code Track to the Tape Reference Edge shall be l370 = 0,60 mm ± 0,09 mm The distance between the leading edge of bit 0 of the Time Code and the Data Area Reference Point of the first helical track of the Track Set to which it refers shall be l369.

Method of recording helical tracks The method of recording shall be −

a ONE is represented by a flux transition at the centre of a bit cell.

- 89 −

a ZERO is represented by the absence of flux transitions in the bit cell.

NOTE The first flux transition on the helical tracks may be of either polarity.

13.1

Physical recording density The maximum physical recording density shall be 6 349 ftpmm. The resulting nominal bit cell length is 0,158 µm.

13.2

Record current optimization The record current shall be optimized such that the read signal amplitude averaged over a minimum of 2 560 flux transitions at 3 201 ftpmm, exclusive of missing pulses, shall be between 84 % and 120 % of SRA1.

13.3

Efficiency of erasure In all erased areas the full width of the tape shall be a.c. erased in the direction of tape motion. After erasure, the read signal amplitude shall be no greater than 2% of the average signal amplitude recorded at the physical recording density of 800,3 ftpmm (SRA3) on the same tape.

Method of recording longitudinal tracks

14.1

Overview The Control Track provides accurate positioning information to the drive servo. The Time Code Track provides unique identification of the longitudinal position on tape and thus enables fast search capability.

14.2

Control Track

14.2.1

S ig n a l The Control Track shall be recorded with a series of constant flux levels alternating in polarity at each Track Set, and completing one cycle in two Track Sets. The flux transitions provide the control timing reference points. The transitions shall be aligned with the helical track Data Area Reference Point as shown in figures 52 and 53.

14.2.2

P o la r it y o f m a g n e t is a t io n ( f ig u r e 5 4 ) The polarity of the flux during time interval E shall be such that the south poles of the magnetic domain should point in the direction of normal tape travel and, similarly, during time interval F the north pole shall be thus oriented.

14.2.3

A lig n m e n t Transitions from south poles (interval E) to north poles (interval F) of the magnetic domains shall be such that they occur at the even Track Set Data Area Reference Points of the A-Track. Similarly, transitions from north to south poles occur at odd Track Set Data Area Reference Points of the A-Track.

- 90 -

Tape motion Control Track

Head motion

Time Code Track l369

E Control

S NN S

N SS N

1 Track Set

1 Track Set 2 Track Sets

Time Code

1 frame / 1 cycle

Figure 54 - Longitudinal Tracks 14.2.4

R e a d s ig n a l a m p lit u d e The average read signal amplitude, taken over 200 flux transitions, exclusive of missing pulses, shall be between 80 % and 130 % of SRA2. A missing pulse is defined as one read as 50% or less of SRA2.

14.2.5

Q u a l i t y o f t h e C o n t r o l Tr a c k A missing pulse zone begins with a missing pulse and ends when 4 consecutive flux transitions, which are not missing pulses, have been detected. The length of a missing pulse zone shall not exceed 30 mm.

14.3 14.3.1

Time Code Track Method of recording the Time Code Track The method of recording on the tape shall be −

a ZERO is represented by a flux transition at the beginning of a bit cell

−

a ONE is represented by a flux transition at the beginning of a bit cell followed by a transition at the centre of the bit cell.

14.3.2

Physical recording density The nominal maximum physical recording density shall be 84,53 ftpmm. The resulting bit cell length is 11,83 µm.

14.3.3

Bit s h if t The maximum displacement of any ONEs zero crossing, exclusive of missing pulses, from its expected position as defined by the nominal bit cell length, shall not exceed 25%.

- 91 -

14.3.4

R e a d s ig n a l a m p lit u d e The average read signal amplitude, taken over 800 flux transitions, exclusive of missing pulses, shall be between 80 % and 130 % of SRA2.

14.3.5

Q u a lit y o f t h e Tim e C o d e Tr a c k In any group of 8 Time Codes, at least 6 shall not have been corrupted by missing pulses or bit shift.

14.4

Format for the Time Code Track The Time Code Track shall contain a unique Time Code for each Track Set pair. Each Time Code shall comprise 80 bits.

14.4.1

C o u n t b it s The count of Track Set pairs shall be contained in eight groups of count bits. Bits 0 to 3 Bits 8 and 9 Bits 10 and 11 Bits 16 to 19 Bits 24 to 26 Bits 32 to 35 Bits 40 to 42 Bits 48 to 51 Bits 56 and 57

14.4.2

shall express, in binary notation, a count of units of Track Set pairs, in the range 0 to 9 shall express, in binary notation, a count of tens of Track Set pairs, in the range 0 to 2 shall be set to ZERO shall express, in binary notation, a count of units of seconds, in the range 0 to 9 shall express, in binary notation, a count of tens of seconds, in the range 0 to 5 shall express, in binary notation, a count of units of minutes, in the range 0 to 9 shall express, in binary notation, a count of tens of minutes, in the range 0 to 5 shall express, in binary notation, a count of units of hours, in the range 0 to 9 shall express, in binary notation, a count of tens of hours, in the range 0 to 3

P h a s e b it Bit 27 shall be set such that there is an even number of ZEROs in the 80-bit Time Code. The first Track Set pair of VSIT shall have all count bits set to ZERO.

14.4.3

S y n c h r o n izin g p a t t e r n Bits 64 to 79 shall be set to the synchronizing pattern 0011111111111101

14.4.4

Supplemental Data The eight groups of Supplemental Data, bits 4 to 7, 12 to 15, 20 to 23, 28 to 31, 36 to 39, 43 to 47, 52 to 55 and 58 to 63 shall be set all ZERO’s.

14.4.5

Ex t e n t o f Tim e C o d e Time Code shall be recorded continuously over the range of n-142 to n+26 with reference to Helical Track Set ID(n) as a minimum.

- 92 -

Section 5 - Requirements for recorded information 15

Recorded information

15.1

Recording area (figure 55) The recording area shall be defined as the area between the Logical Beginning of Tape (LBOT) and the Logical End of Tape (LEOT). The distance from the physical BOT (PBOT) to LBOT shall be l371 = 17,0 m ± 0,5 m. The distance from the physical EOT(PEOT) to LEOT shall be l372 = 20,0 m max.

15.2

Magnetic tape layout (figure 56) There are Valid data areas and Invalid data areas in the recording area.

15.2.1

V a lid d a t a a r e a s There are five kinds of Valid data areas as follows. Run-up areas, VSIT area, DIT area, Data area and Virtual End of Volume (VEOV) area. The Run-Up area shall be that distance during which the scanner servo stabilizes. The length of Run-Up Area shall be l373 = 0,80 m ± 0,05 m. The VSIT area shall contain 10 Track Sets as defined in 11.2.5.1. A Run-Up Area shall precede a VSIT. The starting Physical TSID of VSIT shall be 0. An area reserved for Write Retries shall be within the VSIT and contain 90 Track Sets min and shall be l374 = 0,2 m min. The DIT area shall contain 40 Track Sets as defined in 15.3.2. A Run-Up Area shall precede a DIT. The Data area shall be defined as that area after the Position Tolerance Band of the DIT and before Near EOT (NEOT). The NEOT position is implementation dependent. The VEOV area shall be defined as that area between NEOT and LEOT. The VEOV area shall be for recording user data, and any necessary processing which requires recording data on the magnetic tape. The recording session shall be terminated within this VEOV area.

15.2.2

I n v a lid d a t a a r e a s The data in an Invalid area (i.e. helical track data, control data) shall be ignored in interchange. Invalid areas are those between PBOT and LBOT, and those between LEOT and PEOT. The Position Tolerance Band is an invalid data area and shall be used to provide the positioning tolerance for the protection of the valid data from erasure when updating the management tables (VSIT and DIT). The size of a Position Tolerance Band shall be l375 = 0,35 m ± 0,05 m.

15.3

Physical TSID The Physical TSID Time Code signal recorded in the Time Code track shall be converted into hexadecimal data. Each recorded Time Code spans the distance of two Physical Track Sets. A ZERO or ONE shall be

- 93 -

appended to the Time Code before the conversion to identify the first and second Physical Track Sets respectively. The Time Code value for the first Physical TSID of the VSIT shall be set to ZEROs.

PBOT l371

LBOT Run up area VSIT Position Tolerance Run up area DIT Position Tolerance Run up area Data area of Volume 1 Position Tolerance Run up area DIT Position Tolerance Run up area

Data area of Volume N NEOT Implementation dependent

Virtual end of volume area

LEOT l372

PEOT

F ig u r e 5 5 - M a g n e t ic t a p e la y o u t in m u lt ip le v o lu m e s

- 94 -

PBOT l371

LBOT Run up area

l373

TSID 0 VSIT

10 Track sets

more than 90 Track sets l374

Reserved for retry area Position Tolerance

l375

l373

Run up area

DIT

Data area

Figure 56 - Location of VSIT

15.3.1

Structure surrounding the VSIT area The structure of areas containing the VSIT shall comprise the following a Run-up area the VSIT a reserved area for Write Retries a Position Tolerance Band and a Run-up area for the following DIT.

15.3.2

Structure of the DIT area The DIT contains volume and file information in this volume. The DIT shall include following five tables. VIT - Volume Information Table 1 Track Set BST - Bad spot table 1 Track Set LIDT - Logical ID table 1 Track Set FIT - File information table 20 Track Sets Reserved 16 DM Track Sets UT - Update table 1 Track Set A DIT area shall comprise 40 track sets.

- 95 -

A DIT shall be recorded at least 3 times and at most 1000 times.

DIT

VIT

BST

LIDT

FIT

Reserved

40 Track sets

Figure 57 - Structure of the DIT area 15.3.3

Structure of the User Data Area The User Data Area shall consist of User Data Track Sets TM Track Set, identified as either a File Mark or Set Mark Track Set TM Track Set shall be preceded and followed by DM Track Sets EOD Track Sets Dummy Track Sets Dummy track sets shall be used to fill areas where continuous recording of the control track is required. The end of the recorded data shall be indicated by writing 16 or more EOD track sets consecutively on the tape.

- 96 -

Section 6 - Write operations 16

Write retry sequence (figure 58) To ensure that the quality of recording is sufficient for successful recovery, the write retry sequence may be applied in the recording process. The information (data, subcode) of a failed Track Set and of following Track Sets may be rewritten into a new physical track location. If a failed Track Set and following Track Sets are subjected to the write retry process, they shall be rewritten without erasing the original Track Sets. The start TSID and the ending TSID of the original recorded Track Sets shall be registered into the BST as logically invalid Track Sets. Write retry good data

Valid data

Next data

Data with errors

Logical TSID 1 999

2 000

2 065

2 000

2 065

2 066

14 999

15 000

15 065

15 066

15 131

15 132

Physical TSID

Registered into Bad spot table as invalid ID

Figure 58 - Write retry sequence

Append file operation (figure 59) There are four ways to write a new file on the recorded tape.

17.1

Append volume A new DIT and Logical Volume may be constructed following the last Logical Volume recorded on the tape as follows. −

A Run-Up Area shall be recorded after EOD of the last Logical Volume on the tape.

−

The new DIT and Logical Volume shall be written following the Run-Up Area.

−

The start Physical TSID of the new VIT and the last Physical TSID of the volume shall be registered in the VSIT.

- 97 -

EOD

DIT

Last Logical Volume of this cassette Append volume

EOD

DIT

EOD

DIT

Run-up area

Figure 59 - Append volume 17.2

Append write (figure 60) A new file may be appended to the current Logical Volume as follows. −

The file shall be written starting from the end of the first Track Set of the previously recorded 16 or more EOD Track Sets.

−

The ‘A’ bit of the Subcode data field of the first Logical Track Set of the appended file shall be set to ONE.

−

The data of LIDT and FIT shall be updated.

The append operation shall be inhibited if the appending of a file would result in the overwriting of a following Logical Volume. EOD

DIT

TM & Dummy New File

EOD (1 track set)

TM & Dummy Append write

DIT

Appended New File

EOD

DIT

TM & Dummy Valid Logical Volume

Figure 60 - Append write 17.3

Overwrite (figure 61) A new file may be written over a previously recorded file as follows −

The file shall be written following one DM Track Set at the end of the original recorded TM.

- 98 −

The Overwrite counter shall be incremented by 1 in the Subcode data fields of User data, TM, EOD and DM Track Sets of the newly recorded file.

−

The data in LIDT and FIT shall be updated.

If the newly recorded file is shorter than the overwritten original recorded data, the remaining data shall become invalid data and ignored in interchange.

Dummy (1 track set)

DIT DM

File

New File

TM DM

EOD

DM TM DM

Dummy (1 track set)

DIT DM

File

New File

DM TM DM

Previously recorded data

Invalid data

Figure 61 - Overwrite 17.4

File extension (figure 62) A file may be recorded as an extension to the current Logical Volume as follows. −

The file shall be written following one DM Track Set at the end of the previously recorded data, overwriting the previously recorded TM.

−

The Overwrite counter shall be incremented by 1 in the Subcode data fields of User data, TM, EOD and DM Track Sets of the newly recorded file.

−

The data in LIDT and FIT shall be updated.

If the newly recorded file is shorter than the overwritten original recorded data, the remaining data shall become invalid data and ignored in interchange.

- 99 -

DIT DM

File N

TM DM

File N Extend

File N+1

TM DM

DM TM DM

DIT DM

File N

File N Extend

EOD

DM TM DM

EOD

Previously recorded data

F ig u r e 6 2 - Ex t e n d f ile

EOD

TM DM

EOD

- 100 -

- 101 -

Annex A (normative)

Measurement of Signal-to-Noise Ratio

Unless otherwise stated, the test condition are those defined in clause 10.

A.1

Procedure The Signal-to-Noise Ratio shall be measured using a spectrum analyzer with a resolution bandwidth of 10 kHz. 1) a.c. erase the tape prior to testing. 2) Record the tape at 6 349 ftpmm 3) Measure the Average Signal Amplitude (Stape) on the next pass (read only). 4) Measure the total noise level (Ntotal) at 41,3 MHz. 5) Measure the read channel noise level (N amp) at 41,3 MHz without a tape loaded but with the scanner motor running. Tape Noise: N TAPE =

N AMP NTAPE

( N TOTAL ) 2 − ( N AMP ) 2

shall be less than 70 %.

The Signal-to-Noise Ratio is S N TAPE = 20 log

S TAPE (dB) . N TAPE

6) Take the average of at least 64 successive measurements to determine the Signal-to-Noise Ratio for the tape (S/N TAPE) 7) Repeat steps 1 to 6 for the Secondary Standard Reference Tape, to obtain S/N MSRT. The Signal-to-Noise Ratio characteristic is (S/NTAPE) - (S/NMSRT) dB 8) This difference shall meet the requirement of 10.4.

- 102 -

- 103 -

Annex B (normative)

Representation 8/9 coding patterns Decimal (Hex)

8-bit

9-bit

Bytes

MSB

LSB

MSB

LSB

(00)

00000000

011000100

(01)

00000001

111000100

(02)

00000010

100100100

(03)

00000011

010100100

(04)

00000100

110100100

(05)

00000101

101100100

(06)

00000110

011100100

(07)

00000111

111100100

(08)

00001000

010010100

(09)

00001001

110010100

(0A)

00001010

011010100

(0B)

00001011

111010100

(0C)

00001100

100110100

(0D)

00001101

010110100

(0E)

00001110

110110100

(0F)

00001111

101110100

(10)

00010000

011110100

(11)

00010001

111110100

(12)

00010010

010001100

(13)

00010011

110001100

(14)

00010100

101001100

(15)

00010101

011001100

(16)

00010110

111001100

(17)

00010111

100101100

(18)

00011000

010101100

(19)

00011001

110101100

(1A)

00011010

101101100

(1B)

00011011

011101100

(1C)

00011100

111101100

(1D)

00011101

100011100

(1E)

00011110

010011100

(1F)

00011111

110011100

(20)

00100000

101011100

(21)

00100001

011011100

- 104 -

Decimal (Hex)

8-bit

9-bit

Bytes

MSB

LSB

MSB

LSB

(22)

00100010

111011100

(23)

00100011

100111100

(24)

00100100

010111100

(25)

00100101

110111100

(26)

00100110

101111100

(27)

00100111

011111100

(28)

00101000

111111100

(29)

00101001

100100010

(2A)

00101010

101100010

(2B)

00101011

011100010

(2C)

00101100

010010010

(2D)

00101101

110010010

(2E)

00101110

011010010

(2F)

00101111

111010010

(30)

00110000

100110010

(31)

00110001

010110010

(32)

00110010

110110010

(33)

00110011

101110010

(34)

00110100

011110010

(35)

00110101

111110010

(36)

00110110

110001010

(37)

00110111

101001010

(38)

00111000

011001010

(39)

00111001

111001010

(3A)

00111010

100101010

(3B)

00111011

110101010

(3C)

00111100

101101010

(3D)

00111101

011101010

(3E)

00111110

111101010

(3F)

00111111

100011010

(40)

01000000

010011010

(41)

01000001

110011010

(42)

01000010

101011010

(43)

01000011

011011010

- 105 -

Decimal (Hex)

8-bit

9-bit

Bytes

MSB

LSB

MSB

103

LSB

(44)

01000100

111011010

(45)

01000101

100111010

(46)

01000110

010111010

(47)

01000111

110111010

(48)

01001000

101111010

(49)

01001001

011111010

(4A)

01001010

111111010

(4B)

01001011

011000110

(4C)

01001100

111000110

(4D)

01001101

100100110

(4E)

01001110

010100110

(4F)

01001111

110100110

(50)

01010000

101100110

(51)

01010001

011100110

(52)

01010010

111100110

(53)

01010011

010010110

(54)

01010100

110010110

(55)

01010101

011010110

(56)

01010110

111010110

(57)

01010111

100110110

(58)

01011000

010110110

(59)

01011001

110110110

(5A)

01011010

101110110

(5B)

01011011

011110110

(5C)

01011100

111110110

(5D)

01011101

010001110

(5E)

01011110

110001110

(5F)

01011111

101001110

(60)

01100000

011001110

(61)

01100001

111001110

(62)

01100010

100101110

(63)

01100011

010101110

100

(64)

01100100

110101110

101

(65)

01100101

101101110

102

(66)

01100110

011101110

(67)

01100111

111101110

- 106 -

Decimal (Hex)

8-bit

9-bit

Bytes

MSB

LSB

MSB

139

LSB

104

(68)

01101000

100011110

105

(69)

01101001

010011110

106

(6A)

01101010

110011110

107

(6B)

01101011

101011110

108

(6C)

01101100

011011110

109

(6D)

01101101

111011110

110

(6E)

01101110

100111110

111

(6F)

01101111

010111110

112

(70)

01110000

110111110

113

(71)

01110001

101111110

114

(72)

01110010

011111110

115

(73)

01110011

111111110

116

(74)

01110100

010010001

117

(75)

01110101

110010001

118

(76)

01110110

111010001

119

(77)

01110111

100110001

120

(78)

01111000

010110001

121

(79)

01111001

110110001

122

(7A)

01111010

101110001

123

(7B)

01111011

111110001

124

(7C)

01111100

110001001

125

(7D)

01111101

101001001

126

(7E)

01111110

011001001

127

(7F)

01111111

111001001

128

(80)

10000000

100101001

129

(81)

10000001

110101001

130

(82)

10000010

101101001

131

(83)

10000011

011101001

132

(84)

10000100

111101001

133

(85)

10000101

100011001

134

(86)

11000110

010011001

135

(87)

11000111

110011001

136

(88)

10001000

101011001

137

(89)

10001001

011011001

138

(8A)

10001010

111011001

(8B)

10001011

100111001

- 107 -

Decimal (Hex)

8-bit

9-bit

Bytes

MSB

LSB

MSB

175

LSB

140

(8C)

10001100

010111001

141

(8D)

10001101

110111001

142

(8E)

10001110

101111001

143

(8F)

10001111

011111001

144

(90)

10010000

111111001

145

(91)

10010001

011000101

146

(92)

10010010

111000101

147

(93)

10010011

100100101

148

(94)

10010100

010100101

149

(95)

10010101

110100101

150

(96)

10010110

101100101

151

(97)

10010111

011100101

152

(98)

10011000

111100101

153

(99)

10011001

010010101

154

(9A)

10011010

110010101

155

(9B)

10011011

011010101

156

(9C)

10011100

111010101

157

(9D)

10011101

100110101

158

(9E)

10011110

010110101

159

(9F)

10011111

110110101

160

(A0)

10100000

101110101

161

(A1)

10100001

011110101

162

(A2)

10100010

111110101

163

(A3)

10100011

010001101

164

(A4)

10100100

110001101

165

(A5)

10100101

101001101

166

(A6)

10100110

011001101

167

(A7)

10100111

111001101

168

(A8)

10101000

100101101

169

(A9)

10101001

010101101

170

(AA)

10101010

110101101

171

(AB)

10101011

101101101

172

(AC)

10101100

011101101

173

(AD)

10101101

111101101

174

(AE)

10101110

100011101

(AF)

10101111

010011101

- 108 -

Decimal (Hex)

8-bit

9-bit

Bytes

MSB

LSB

MSB

211

LSB

176

(B0)

10110000

110011101

177

(B1)

10110001

101011101

178

(B2)

10110010

011011101

179

(B3)

10110011

111011101

180

(B4)

10110100

100111101

181

(B5)

10110101

010111101

182

(B6)

10110110

110111101

183

(B7)

10110111

101111101

184

(B8)

10111000

011111101

185

(B9)

10111001

111111101

186

(BA)

10111010

100100011

187

(BB)

10111011

101100011

188

(BC)

10111100

011100011

189

(BD)

10111101

010010011

190

(BE)

10111110

110010011

191

(BF)

10111111

011010011

192

(C0)

11000000

111010011

193

(C1)

11000001

100110011

194

(C2)

11000010

010110011

195

(C3)

11000011

110110011

196

(C4)

11000100

101110011

197

(C5)

11000101

011110011

198

(C6)

11000110

111110011

199

(C7)

11000111

110001011

200

(C8)

11001000

101001011

201

(C9)

11001001

011001011

202

(CA)

11001010

111001011

203

(CB)

11001011

100101011

204

(CC)

11001100

110101011

205

(CD)

11001101

101101011

206

(CE)

11001110

011101011

207

(CF)

11001111

111101011

208

(D0)

11010000

100011011

209

(D1)

11010001

010011011

210

(D2)

11010010

110011011

(D3)

11010011

101011011

- 109 -

Decimal (Hex)

8-bit

9-bit

Bytes

MSB

LSB

MSB

Decimal (Hex)

LSB

8-bit

9-bit

Bytes

MSB

LSB

MSB

LSB

212

(D4)

11010100

011011011

234

(EA)

11101010

110110111

213

(D5)

11010101

111011011

235

(EB)

11101011

101110111

214

(D6)

11010110

100111011

236

(EC)

11101100

011110111

215

(D7)

11010111

010111011

237

(ED)

11101101

111110111

216

(D8)

11011000

110111011

238

(EE)

11101110

010001111

217

(D9)

11011001

101111011

239

(EF)

11101111

110001111

218

(DA)

11011010

011111011

240

(F0)

11110000

101001111

219

(DB)

11011011

111111011

241

(F1)

11110001

011001111

220

(DC)

11011100

011000111

242

(F2)

11110010

111001111

221

(DD)

11011101

111000111

243

(F3)

11110011

100101111

222

(DE)

11011110

100100111

244

(F4)

11110100

010101111

223

(DF)

11011111

010100111

245

(F5)

11110101

110101111

224

(E0)

11100000

110100111

246

(F6)

11110110

101101111

225

(E1)

11100001

101100111

247

(F7)

11110111

011101111

226

(E2)

11100010

011100111

248

(F8)

11111000

111101111

227

(E3)

11100011

111100111

249

(F9)

11111001

100011111

228

(E4)

11100100

010010111

250

(FA)

11111010

010011111

229

(E5)

11100101

110010111

251

(FB)

11111011

110011111

230

(E6)

11100110

011010111

252

(FC)

11111100

101011111

231

(E7)

11100111

111010111

253

(FD)

11111101

011011111

232

(E8)

11101000

100110111

254

(FE)

11111110

111011111

233

(E9)

11101001

010110111

255

(FF)

11111111

100111111

- 110 -

Annex C (informative)

Recommendations for Transportation

C.1

Environment It is recommended that during transportation the cassettes are kept within the following conditions: Temperature:

-40 °C to 45 °C

Relative humidity:

5 % to 80 %

Maximum wet bulb temperature: 26 °C There should be no condensation in or on the cassette.

C.2

Hazards Transportation of tape cassettes involves three basic potential hazards.

C.2.1

Impact loads and vibrations The following recommendations should minimize damage to tape cassettes during transportation. Avoid mechanical loads that would distort the cassette shape. Avoid dropping the cassette more than 1 m. Cassettes should be fitted into a rigid box containing adequate shock-absorbent material. The final box should have a clean interior and a construction that provides sealing to prevent the ingress of dirt and water. The orientation of the cassettes inside the final box should be such that the axes of the tape reels are horizontal. The final box should be clearly marked to indicate its correct orientation.

C.2.2

Extremes of temperature and humidity Extreme changes in temperature and humidity should be avoided whenever possible. Whenever a cassette is received it should be conditioned in the operating environment for a period of at least 24 h.

C.2.3

Effects of Stray Magnetic Fields A normal spacing of not less than 80 mm should exist between the cassette and the outer surface of the shipping container to minimize the risk of corruption.

- 111 -

- 112 -

Annex D (informative)

Inhibitor Tape

An inhibitor tape is any tape that degrades the performance of the tape drive or other tapes. Certain tape characteristics can contribute to poor tape drive performance. Tapes that exhibit these characteristics may not give satisfactory performance, can result in excessive errors and can interfere with the subsequent performances of other tapes. Tapes to be used in this cassette should not be inhibitor tapes.

D.1

Inhibitor characteristics These characteristics include: •

High abrasivity.

•

High friction to tape path components.

•

Poor edge conditions.

•

Excessive tape wear residual products.

•

Electrostatic charge build-up to the tape or tape path components.

•

Interlayer slippage.

•

Transfer of recording surface coating to the back of the next tape layer.

•

Separation of tape constituents causing deposits that may lead to tape sticking or poor performance of other tapes.

Free printed copies can be ordered from: ECMA 114 Rue du Rhône CH-1204 Geneva Switzerland Fax: Email:

+41 22 849.60.01 [email protected]

Files of this Standard can be freely downloaded from the ECMA web site (www.ecma.ch). This site gives full information on ECMA, ECMA activities, ECMA Standards and Technical Reports.

ECMA 114 Rue du Rhône CH-1204 Geneva Switzerland See inside cover page for obtaining further soft or hard copies.

ECMA-315 — 12,65 mm wide magnetic tape cassette for information interchange - Helical scan recording - DTF-2 (December 2000)

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