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ECMA-247 — 8 mm wide magnetic tape cartridge for information interchange - Helical scan recording - HH-1 format (June 1998)

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Standard ECMA-247 2 n d E dition - J une 1998

Standardizing

Information

and

Communication

Systems

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

P h o n e : + 4 1 2 2 8 4 9 . 6 0 . 0 0 - F a x : + 4 1 2 2 8 4 9 . 6 0 . 0 1 - U R L : h t t p : / / www. e c m a . c h - I n t e r n e t : h e l p d e s k @ e c m a . c h

Standard ECMA-247 2 n d Ed itio n - J une 1 9 9 8

Standardizing

Information

and

Communication

Systems

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

P h o n e : + 4 1 2 2 8 4 9 . 6 0 . 0 0 - F a x : + 4 1 2 2 8 4 9 . 6 0 . 0 1 - U R L : h t t p : / / www. e c m a . c h - I n t e r n e t : h e l p d e s k @ e c m a . c h MB

E-247-ii.doc

02-07-98 16,14

Brief History

ECMA have produced a series of ECMA standards for cassettes and cartridges containing magnetic tapes of different widths and characteristics. Of these, the following relate to helical scan recording.

ECMA-139 (1990)

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

ECMA-145 (1990)

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

ECMA-146 (1990)

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

ECMA-150 (1991)

3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording - DDS-DC Format using 60 m and 90 m Length Tapes, 2nd Edition

ECMA-169 (1992)

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

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-210 (1995)

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

ECMA-236 (1996)

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

This ECMA Standard specifies a magnetic tape cartridge. The HH-1 format, when recorded on a 8 mm wide tape the length of which is 163 metres, will provide a storage capacity of 20 Gbytes of uncompressed user data or typically 40 Gbytes of compressed user data.

This Standard has been adopted as 2 nd edition of ECMA-247 by the ECMA General Assembly of June 1998.

- i -

Table of contents Section 1 - General

1 Scope

2 Conformance 2.1 Magnetic tape cartridge 2.2 Generating drive 2.3 Receiving drive

1 1 1 1

3 References

4 Definitions 4.1 Absolute Frame Address 4.2 a.c. erase 4.3 algorithm 4.4 Area ID 4.5 Average Signal Amplitude 4.6 azimuth 4.7 back surface 4.8 bit cell 4.9 byte 4.10 cartridge 4.11 Channel bit 4.12 compressed data 4.13 Cyclic Redundancy Check (CRC) character 4.14 Data Format ID 4.15 End of Data (EOD) 4.16 Error Correcting Code 4.17 flux transition position 4.18 flux transition spacing 4.19 Frame 4.20 Logical Beginning of Tape (LBOT) 4.21 Logical Record 4.22 magnetic tape 4.23 Master Standard Reference Tape 4.24 Partition Boundary 4.25 Physical Beginning of Tape (PBOT) 4.26 Physical End of Tape (PEOT) 4.27 physical recording density 4.28 Reference Field 4.29 Secondary Standard Reference Tape (SSRT) 4.30 Standard Reference Amplitude (SRA) 4.31 Standard Reference Current 4.32 Tape Reference Edge 4.33 Test Recording Current 4.34 track 4.35 Typical Field 4.36 uncompressed data

2 2 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4

5 Conventions and notations 5.1 Representation of numbers 5.2 Names

4 4 4

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6 Acronyms

7 Environment and safety 7.1 Testing environment 7.2 Operating environment 7.3 Storage environment 7.4 Transportation 7.5 Safety 7.6 Flammability

5 5 5 5 5 6 6

Section 2 - Requirements for the case

8 Dimensional and mechanical characteristics of the case 8.1 General 8.2 Overall dimension 8.3 Holding areas 8.4 Cartridge insertion 8.5 Window (figure 1) 8.6 Loading grips 8.7 Label areas 8.8 Datum areas and datum holes 8.9 Support areas 8.10 Recognition holes 8.11 Write-inhibit hole 8.12 Pre-positioning surfaces 8.13 Cartridge lid 8.14 Cartridge reel lock 8.15 Reel access holes 8.16 Interface between the reels and the drive spindles 8.17 Light path 8.18 Position of the tape in the case 8.19 Tape path zone 8.20 Tape access cavity 8.21 Tape access cavity clearance requirements

6 6 7 7 7 8 8 8 9 10 10 11 11 11 13 14 14 15 16 16 16 16

Section 3 - Requirements for the Unrecorded Tape

9 Mechanical, physical and dimensional characteristics of the tape 9.1 Materials 9.2 Tape length 9.2.1 Magnetic tape 9.2.2 Leader and trailer tapes 9.2.3 Splicing tape 9.3 Tape width 9.3.1 Width of magnetic tape 9.3.2 Width of leader and trailer tapes 9.3.3 Width and position of splicing tape 9.4 Discontinuities 9.5 Thickness 9.5.1 Thickness of the magnetic tape 9.5.2 Thickness of leader and trailer tape 9.5.3 Thickness of the splicing tape 9.6 Longitudinal curvature 9.7 Cupping

33 33 33 33 33 33 33 33 33 33 33 33 33 34 34 34 34

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9.8 Coating adhesion 9.9 Layer-to-layer adhesion 9.10 Tensile strength 9.10.1 Breaking strength 9.10.2 Yield strength 9.11 Residual elongation 9.12 Electrical resistance of coated surfaces 9.13 Tape winding 9.14 Light transmittance of tape 9.15 Media Recognition System (MRS)

34 35 35 35 35 35 35 36 36 36

10 Magnetic recording characteristics 10.1 Typical Field 10.2 Signal amplitude 10.3 Resolution 10.4 Overwrite 10.5 Ease of erasure 10.6 Tape quality 10.6.1 Missing pulses 10.6.2 Missing pulse zone 10.7 Signal-to-Noise Ratio (SNR)

37 38 38 38 38 38 38 38 39 39

Section 4 - Requirements for an interchanged tape

11 Format 11.1 General 11.2 Information Matrix 11.2.1 Loading the Information Matrix 11.3 Sync Block 11.3.1 Sync Block Data 11.3.2 Sync Block Header 11.3.3 Sync Block Header in Preamble Zone 11.4 Data Zone 11.4.1 Identification and arrangement of Information Blocks in the Data Zone of a Frame 11.4.2 Identification and arrangement of Sync Blocks in Data Zone of a Track

39 39 40 41 54 54 54 55 55 55 55

12 Method of recording 12.1 Physical recording density 12.2 Long-term average bit cell length 12.3 Short-term average bit cell length 12.4 Rate of change 12.5 Bit shift 12.6 Read signal amplitude 12.7 Recording current

56 56 56 57 57 57 57 57

13 Track geometry 13.1 Track configuration 13.2 Average track pitch 13.3 Variations of the track pitch 13.4 Track width 13.5 Track angle 13.6 Track edge linearity 13.7 Track length

57 57 58 58 58 58 58 58

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13.8 Data Zone reference 13.9 Azimuth angles

59 59

14 Recording pattern 14.1 Recorded Sync Block 14.2 Preamble Zone 14.3 Postamble Zone

59 59 59 59

15 Format of a track 15.1 Track capacity 15.2 Positioning accuracy 15.3 Tracking scheme

59 59 59 60

16 Layout of a Single Data Space tape 16.1 Frame type 16.1.1 Data Frame 16.1.2 Gap Frame 16.1.3 Long File Mark Frame 16.1.4 Short File Mark Frame 16.1.5 Set Mark Frame 16.1.6 End of Data Frame 16.1.7 Format Frame 16.1.8 Data Frame in System Area 16.2 Device Area 16.3 Reference Area 16.4 System Area 16.4.1 Guard Band No.1 16.4.2 System Log Preamble 16.4.3 System Log 16.4.4 System Log Postamble 16.4.5 Guard Band No.2 16.4.6 Data Area Preamble 16.5 Data Area 16.5.1 Long File Mark 16.5.2 Short File Mark 16.5.3 Set Mark 16.5.4 Write operation 16.5.5 Append and overwrite operations 16.5.6 Rewritten Frames 16.6 EOD Area 16.7 Post-EOD Area

60 60 60 60 60 60 60 60 60 60 60 60 61 61 61 61 61 61 61 61 61 61 61 62 62 62 62 62

17 Layout of a partitioned tape 17.1 Overall magnetic tape layout 17.1.1 Device Area 17.1.2 Partition 1 17.1.3 Partition 0 17.2 Partition Identification

63 63 63 63 64 64

Annex A - Measurement of light transmittance of tape and leaders

Annex B - Measurement of Signal-to-Noise Ratio

- v -

Annex C - Representation of 8-bit bytes by 10-bit patterns

Annex D - Measurement of bit shift

Annex E - Measurement of track edge linearity tolerance

Annex F - Recommendations for transportation

Annex G - Example of the content of a Data Block in the System Area

- vi -

Section 1 - General 1

Scope This ECMA Standard specifies the physical and magnetic characteristics of an 8 mm wide magnetic tape cartridge so as to provide physical interchange of such cartridges between drives. It also specifies the quality of the recorded signals, the recording method and the recorded format - called HH-1 format - thereby allowing for full data interchange between drives by means of such magnetic tape cartridges. Information interchange between systems also requires, as a minimum, agreement between the interchange parties upon the interchange code(s) and the specifications of the structure and labelling of the information on the interchanged cartridge.

2 2.1

Conformance Magnetic tape cartridge A tape cartridge shall be in conformance with this ECMA Standard if it meets all the mandatory requirements specified herein. The tape requirements shall be satisfied throughout the extent of the tape.

2.2

Generating drive A drive generating a magnetic tape cartridge for interchange shall be in conformance with this ECMA Standard if all recordings on the tape meet the mandatory requirements of this ECMA Standard. A claim of conformance shall state which of the following optional features are implemented and which are not

the performing of a Read-After-Write check and the recording of any necessary rewritten frames; the generation of ECC3 Blocks. In addition a claim of conformance shall state

whether or not, registered data compression algorithm(s) are implemented within the system and are able to compress data received from the host, and

the registered identification number(s) of the implemented algorithm(s). 2.3

Receiving drive A drive receiving a magnetic tape cartridge 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. In particular it shall

be able to recognize rewritten frames and to make available to the host, data and File Marks from only one of these frames;

be able to recognize a ECC3 Block, and ignore it if the system is not capable of using ECC3 check bytes in a process of error correction;

be able to recognize compressed data, identify the algorithm used, and make the algorithm registration number available to the host;

be able to make compressed data available to the host. In addition a claim of conformance shall state

whether or not the system is capable of using ECC3 check bytes in a process of error correction; whether or not one or more decompression algorithm(s) are implemented within the system, and are able to be applied to compressed data prior to making such data available to the host;

the registered identification number(s) of the data compression algorithm(s) for which a complementary data decompression algorithm is implemented.

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whether or not the system is capable of updating the System Log(s) if the Write-inhibit Hole state so permits.

References ISO 527-1:1993

Plastics - Determination of tensile properties - Part 1: General principles.

ISO 1302:1992

Technical Drawings - Method of indicating surface texture on drawings.

ISO/IEC 11576:1994

Information Technology - Procedure for the registration of algorithms for the lossless compression of data.

ECMA-129 (1994)

Information Technology Equipment - Safety

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

4.1

Absolute Frame Address A sequence number, encoded in the Frame.

4.2

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

4.3

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

4.4

Area ID Identifier of an area of the tape.

4.5

Average Signal Amplitude The average peak-to-peak value of the output signal from the read head at the specified physical recording density over a minimum of 20,7 mm of track, exclusive of missing pulses.

4.6

azimuth The angular deviation, in degrees of arc, made by the mean flux transition line with a line normal to the centreline of the recorded track.

4.7

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

4.8

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

4.9

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

4.10

cartridge A case containing magnetic tape stored on twin hubs.

4.11

Channel bit A bit after 8-10 transformation.

4.12

compressed data Data which has been subjected to a compression algorithm.

4.13

Cyclic Redundancy Check (CRC) character A 16-bit character obtained from a mathematical calculation and used for error detection.

4.14

Data Format ID An identifier specifying which data format is being used on the tape.

- 3 -

4.15

End of Data (EOD) The point on the tape at the end of the Frame which contains the last user data.

4.16

Error Correcting Code A mathematical computation yielding check bytes used for the detection and correction of errors.

4.17

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

4.18

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

4.19

Frame A pair of adjacent tracks with azimuths of opposite polarity, in which the track with the positive azimuth precedes that with the negative azimuth.

4.20

Logical Beginning of Tape (LBOT) The point along the length of the tape where a recording of data for interchange commences.

4.21

Logical Record Related data, from the host, treated as a unit of information.

4.22

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

4.23

Master Standard Reference Tape A tape selected as the standard for a Reference Field, Signal Amplitude, Resolution, Overwrite and Signalto-Noise Ratio. Note The Master Standard Reference Tape has been established by the Reliability Center for Electronic Components of Japan (RCJ).

4.24

Partition Boundary The point along the length of a magnetic tape at which partition 1 ends and partition 0 commences.

4.25

Physical Beginning of Tape (PBOT) The point where the leader tape is joined to the magnetic tape.

4.26

Physical End of Tape (PEOT) The point where the trailer tape is joined to the magnetic tape.

4.27

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

4.28

Reference Field The Typical Field of the Master Standard Reference Tape.

4.29

Secondary Standard Reference Tape (SSRT) A tape the performance of which is known and stated in relation to that of the Master Standard Reference Tape. Note Secondary Standard Reference Tapes can be ordered from RCJ, 1-1-12 Hachiman-cho, Higashikurume, Tokyo 203, Japan, under Part Number JRM 6143 until the year 2006. In principle such tapes will be

- 4 -

available for a period of 10 years from the first version of this Standard. However, by agreement between ECMA and RCJ, this period may be shortened or extended to take account of demand for such SSRTs. It is intended that these be used for calibrating tertiary reference tapes for use in routine calibration.

4.30

Standard Reference Amplitude (SRA) The Average Signal Amplitude derived from the Master Standard Reference Tape when using the Test Recording Current and the recording density of 3 658,1 ftpmm. Traceability to the SRA is provided by the calibration factors supplied with each Secondary Standard Reference Tape.

4.31

Standard Reference Current The current that produces the Reference Field.

4.32

Tape Reference Edge The lower edge of the tape when viewing the recording surface of the tape, with the BOT splice to the observer's left.

4.33

Test Recording Current The current that is used to record an SRA. It is 1,3 times the Standard Reference Current.

4.34

track A diagonally positioned area on the tape along which a series of magnetic signals may be recorded.

4.35

Typical Field In the plot of Average Signal Amplitude against the recording field at the physical recording density of 3 658,1 ftpmm, the minimum field that causes the Average Signal Amplitude equal to 90% of the maximum Average Signal Amplitude.

4.36

uncompressed data Data which has not been subjected to a compression algorithm.

5 5.1

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 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 with the most significant byte to the left and with the most significant bit in each byte to the left.

Negative values of numbers in binary notation are given in TWO’ s complement. In each field the data is processed so that the most significant byte (byte 0) is processed first. Within each byte the most significant bit (numbered 7 in an 8-bit byte) is processed first. This order of processing applies also to the data input to the Error Detection and Correction circuits and to their outputs, unless otherwise stated.

5.2

Names The names of basic elements, e.g. specific fields, are given with a capital initial letter.

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Acronyms BOT CRC ECC EOD LBOP LBOT LEOP LEOT PBOP PEOP PBOT PEOT SNR SSRT

Beginning of Tape Cyclic Redundancy Check Error Correcting Code End of Data Logical Beginning of Partition Logical Beginning of Tape Logical End of Partition Logical End of Tape Physical Beginning of Partition Physical End of Partition Physical Beginning of Tape Physical End of Tape Signal-to-Noise-Ratio Secondary Standard Reference Tape

Environment and safety The conditions specified below refer to ambient conditions immediately surrounding the cartridge. Cartridges 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 cartridge to check the requirements of this ECMA Standard shall be carried out under the following conditions: temperature: relative humidity: conditioning period before testing:

7.2

23 o C 2 o C 40 % to 60 % 24 h

Operating environment Cartridges used for data interchange shall be capable of operating under the following conditions: temperature: relative humidity: wet bulb temperature:

5 o C to 45 o C 20 % to 80 % 26 o C max.

There shall be no deposit of moisture on or in the cartridge. Conditioning before operating: If a cartridge has been exposed during storage and/or transportation to a condition outside the above values, before use the cartridge shall be conditioned in the operating environment for a time at least equal to the period during which it has been out of the operating environment, up to a maximum of 24 h. Note Rapid variations of temperature should be avoided.

7.3

Storage environment The following conditions shall be observed during storage of cartridges : temperature: relative humidity:

5 o C to 32 o C 20 % to 60 %

The stray magnetic field at any point on the tape shall not exceed 4000 A/m. There shall be no deposit of moisture on or in the cartridge.

7.4

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

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7.5

Safety The cartridge and its components shall satisfy the requirements of IEC 950 when used in the intended manner or in any foreseeable use in an information processing system.

7.6

Flammability The cartridge and its components shall be made from materials which, if ignited from a match flame, do not continue to burn in a still carbon dioxide atmosphere.

Section 2 - Requirements for the case 8 8.1

Dimensional and mechanical characteristics of the case General The cartridge shall consist of the following elements:

a case recognition holes a write inhibit mechanism twin reels containing magnetic tape a locking mechanism for the reels

Dimensional characteristics are specified for those parameters deemed to be mandatory for interchange and compatible use of the cartridge. Where there is freedom, of design, only the functional characteristics of the elements described are indicated. In the figures a typical implementation is represented in third angle projections. 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 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24

is a perspective view of the cartridge seen from the top. is a perspective view of the cartridge seen from the bottom. is a perspective view of Reference Planes X, Y and Z. shows the front side with the lid closed. shows the left side with the lid closed. shows the top side with the lid closed. shows the right side with the lid closed. shows the rear side with the lid closed. shows the bottom side, datum and support areas. shows the bottom side with the lid removed. is the enlarged view of the datum and recognition holes. are the cross-sections through the light path holes, the recognition holes and the write-inhibit hole. shows details of the lid when closed, rotating and open. shows the details of the lid release insertion channel. shows the lid lock release requirements. shows the reel lock release requirements. shows the reel unlock force direction. shows the lid release force direction. shows the lid opening force direction. shows the light path and light window. shows the internal tape path and light path. shows the cartridge reel and a cross-section view of the cartridge reel. is a cross-section view of the cartridge reel interface with the drive spindle. shows the tape access cavity clearance requirements.

The dimension are referred to three orthogonal Reference Planes X, Y and Z (see figure 3). Plane X is perpendicular to Plane Z and passes through the centres of the Datum Holes A and B. Plane Y is perpendicular to Plane X and Plane Z and passes through the centre of Datum Hole A. Datum area A, B and C shall lie in Plane Z.

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8.2

Overall dimension (figures 5 and 6) The length of the case shall be l 1 = 62,5 mm 0,3 mm The width of the case shall be l 2 = 95,0 mm 0,2 mm The distance from the top of the case to Plane Z shall be l 3 = 15,0 mm 0,2 mm The distance from the rear side to Plane X shall be l 4 = 47,35 mm 0,15 mm The distance from the right side to Plane Y shall be l 5 = 13,0 mm 0,1 mm

8.3

Holding areas The holding areas shown hatched in figure 6 shall be the areas along which the cartridge shall be held down when inserted into the drive. The distance of the holding areas from Plane X shall be l 6 = 12,0 mm max. The width when measured from the edge of the case shall be l 7 = 3,0 mm min.

8.4

Cartridge insertion The cartridge shall have asymmetrical features to prevent insertion into the drive in other than the correct orientation. These consist of an insertion channel, a recess and an incline. The insertion channel (figures 4 and 14) shall provide for an unobstructed path, when the lid is closed and locked, to unlock the lid. The distance of the insertion channel from Plane Y shall be l 8 = 79,7 mm 0,2 mm There shall be a chamfer at the beginning of the insertion channel defined by l 9 = 1,0 mm 0,1 mm l 16 = 1,5 mm 0,1 mm An additional chamfer further into the insertion channel shall be defined by l 10 = 0,7 mm 0,1 mm l 17 = 1,0 mm 0,1 mm l 18 = 3,8 mm 0,1 mm The innermost width of the channel shall be l 11 = 1,0 mm min. The thickness of the lid shall be l 12 = 1,2 mm 0,1 mm There shall be a chamfer on the lid defined by l 13 = 0,8 mm 0,1 mm l 14 = 1,2 mm 0,1 mm The lid shall extend from the case a distance of l 15 = 0,5 mm 0,1 mm

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The distance from the left side of the case to the lid lock shall be l 19 = 0,2 mm 0,2 mm The height of the insertion area shall be l 20 = 2,3 mm min. + 0,2 mm

l 21 = 2,5 mm - 0,0 mm

The recess is located on the right side of the cartridge. The position and dimensions (figures 5, 7 and 10) shall be defined by l 22 = 7,5 mm max. l 23 = 11,0 mm 0,2 mm l 24 = 1,5 mm 0,1 mm The depth of the recess shall be l 25 = 1,5 mm 0,1 mm The incline (figure 13a) is part of the lid structure. The distance of the incline from Plane X shall be defined by + 0,0 mm

l 26 = 7,7 mm - 2,5 mm

The angle of the incline shall be a 1 = 20 o 1 o The incline shall end when it intersects the radius r 3 (see clause 8.13).

8.5

Window (figure 1) A window may be provided on the top side so that parts of the reels are visible. The window, if provided, shall not extend beyond the height of the cartridge.

8.6

Loading grips (figures 5 and 7) The cartridge shall have recessed loading grips on each side to aid an automatic loading mechanism. The distance from Plane X to the centreline of the loading grip shall be l 28 = 39,35 mm 0,20 mm; The distance from Plane Z on the bottom side and from the top side shall be l 29 = 1,5 mm 0,1 mm; The width of the indent shall be l 30 = 5,0 mm 0,3 mm; The depth of the indent shall be l 31 = 2,0 mm 0,2 mm; and the angle of the indent a 2 = 90 o 5 o .

8.7

Label areas (figures 6 and 8) A portion of the rear side of the cartridge and a portion of the top side of the cartridge may be used for labels. The position and the size of the labels shall not interfere with the operation or clearance requirements of the cartridge component parts.

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The area used for labels on the top side shall not extend beyond the inner edge of the holding areas defined by l 6 and l 7 . The position and dimensions of the label area on the rear side shall be defined by l 32 = 0,5 mm min. l 33 = 1,5 mm min. l 34 = 80,0 mm max. The depth of the label area s shall be 0,3 mm max.

8.8

Datum areas and datum holes The annular datum areas A, B and C shall lie in Plane Z (see figures 9, 10 and 11). They determine the vertical position of the cartridge in the drive. Each shall have a diameter d 1 equal to 6,0 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 the circular datum hole A shall be at the intersection of planes X and Y (see figure 10). The distance from the centre of datum hole B to Plane Y (see figure 9) shall be l 35 = 68,0 mm 0,1 mm The distance from the centre of the circular datum hole C to Plane Y (see figure 11) shall be l 36 = 10,20 mm 0,05 mm The distance from the centre of datum hole D to Plane Y (see figure 11) shall be l 37 = 79,2 mm 0,2 mm The distance from the centres of datum holes C and D to Plane X (see figure 10) shall be l 38 = 36,35 mm 0,08 mm The thickness of the case in the datum areas shall be l 39 = 1,2 mm 0,1 mm The diameter at the bottom of datum hole A and datum hole C shall be l 40 = 2,6 mm min. The depth of the holes shall be l 42 = 4,0 mm min. The upper diameter of datum holes A and C shall be + 0,05 mm

l 44 = 3,00 mm - 0,00 mm

This diameter shall be to a depth of l 41 = 1,5 mm min. There shall be a chamfer around the outside of datum hole A and datum hole C defined by l 43 = 0,3 mm max. a 3 = 45 o 1 o The width at the bottom of datum holes B and D shall be l 40 . The depth of the holes shall be l 42 . The dimensions at the top of the holes shall be l 45 = 3,5 mm 0,1 mm

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+ 0,05 mm

l 46 = 3,00 mm - 0,00 mm

r 1 = 1,75 mm 0,05 mm This width shall be to a depth l 41 . There shall be a chamfer around the outside of datum holes B and D defined by l 43 and a 3 .

8.9

Support areas (figure 9) The cartridge Support areas are shown shaded in figure 9. Support areas A’, B’ and C’ shall be coplanar with Datum areas A, B and C, respectively, within 0,1 mm. Support area D’ shall be coplanar with Plane Z within 0,15 mm. The areas within l 49 of the edge of the cartridge shall be recessed from the Support Areas. l 49 = 0,5 mm 0,1 mm Support areas A’ and B’ shall extend from Plane X towards the front of the case a distance l 47 = 10,0 mm 0,1 mm Support areas A’ and B’ shall extend from the centre of the Datum holes toward the outside of the case a distance l 47 . Support areas A’ and B’ shall extend from the centre of the Datum holes toward the inside of the case a distance of l 48 = 11,0 mm 0,1 mm Support areas A’ and B’ shall extend from Plane X toward the rear of the case a distance of l 50 = 7,0 mm 0,1 mm The distance of Support areas C’ and D’ from Plane X shall be l 51 = 30,0 mm 0,1 mm The dimensions of Support areas C’ and D’ shall be defined by l 47 and l 52 = 5,5 mm 0,1 mm l 53 = 64,5 mm 0,2 mm

8.10

Recognition holes (figures 10, 11 and 12) There shall be 5 recognition holes numbered 1 to 5 as shown in figure 11. The centre of recognition hole 1 shall be defined by l 54 = 43,35 mm 0,15 mm l 57 = 6,4 mm 0,1 mm The centre of recognition hole 2 shall be defined by l 54 and l 57 . The centre of recognition hole 3 shall be defined by l 54 and l 58 = 79,0 mm 0,2 mm The centre of recognition hole 4 shall be defined by l 55 = 3,7 mm 0,1 mm l 56 = 2,3 mm 0,1 mm The centre of recognition hole 5 shall be defined by l 55 and l 56 . All recognition holes shall have the cross-section E-E and F-F shown in figure 12 and shall have a diameter of 3,0 mm 0,1 mm. The depth of a closed recognition hole below Plane Z shall be

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+0,3 mm

l 59 = 1,2 mm - 0,1 mm

The depth of an open recognition hole below Plane Z shall be l 60 = 5,0 mm min. One of the cross-sections shows a recognition hole closed by a plug. The other shows one hole with the plug punched out and the other hole closed by a plug. These plugs shall withstand an applied force of 0,5 N max. without being punched out. This ECMA Standard prescribes the following states of these holes.

8.11

Recognition hole 1 shall be closed. Recognition hole 2 shall be open Recognition hole 3 shall be open Recognition hole 4 shall be closed. Recognition hole 5 shall be open.

Write-inhibit hole (figures 11 and 12) The centre of the Write-inhibit hole shall be defined by l 54 and l 61 = 10,0 mm 0,1 mm The diameter of the hole shall be 3,0 mm 0,1 mm. The depth of a closed Write-inhibit hole below Plane Z shall be l 59 . The depth of an open Write-inhibit hole below Plane Z shall l 60 When the Write-inhibit hole is open, recording on the tape is inhibited. When it is closed, recording is enabled. The case may have a movable element allowing the write-inhibit hole to be opened or closed. If present, this element shall be such that the state of the write-inhibit hole shall be visible (see figure 8 as an example). The write-inhibit hole closure shall be constructed to withstand a force of 0,5 N. The force required to open or close the write-inhibit hole shall be between 1 N and 15 N.

8.12

Pre-positioning surfaces (figures 4 and 10) These surfaces determine the position of the cartridge when it is inserted into the drive loading slot. The distance from Plane Z to the surface on which the tape reference edge rests (figure 4) shall be + 0,0 mm

l 62 = 2,4 mm - 0,1 mm

Positioning of the cartridge relative to Plane Y shall be controlled by the surfaces defined by l 63 = 1,0 mm 0,1 mm l 64 = 69,0 mm 0,2 mm Positioning of the cartridge relative to Plane X shall be controlled by the surfaces defined by l 65 = 14,65 mm 0,10 mm The position and angle of the chamfer at the edge of this surface shall be defined by l 66 = 13,15 mm 0,10 mm a 4 = 45 o 1 o

8.13

Cartridge lid (figures 6 and 13) The cartridge shall have a lid for protection of the tape during handling, storage and transportation. The lid consists of two parts, the main part and an auxiliary part. The main part rotates around axis A (see figure 13) the position of which is fixed relative to the case.

- 12 -

The location of axis A shall be defined by + 0,05 mm

l 27 = 0,55 mm - 0,10 mm

l 67 = 7,5 mm 0,1 mm The auxiliary part rotates around axis B the position of which is fixed relative to the main part of the lid and moves with it. When the lid is in the closed position, the location of axis B shall be defined by l 68 = 7,0 mm 0,1 mm l 69 = 10,1 mm 0,1 mm The rotation of the auxiliary part is controlled by a cam at each end to give the path indicated in figure 13. The auxiliary part, when fully opened, shall allow a clearance of l 70 = 14,8 mm min. + 0,2 mm

l 71 = 11,5 mm - 0,0 mm

l 72 = 1,2 mm 0,1 mm When the lid is completely open, neither part shall extend above a plane located l 73 above and parallel to Plane Z. l 73 = 22,3 mm max. The angle to the bottom of the lid from Plane Z when the lid is completely open shall be +1

a 5 = 85 oo -2

When the lid is in a partially open position, neither part shall extend above a plane located l 74 above and parallel to Plane Z. l 74 = 22,5 mm max. The path of the top of the lid as it opens shall be defined by r 2 = 14,9 mm max. The start point of the incline on the case that meets the lid (cross-section B-B in figure 6) shall be defined by l 75 = 8,4 mm max. The height of the lid from Plane Z (figure 13) shall be + 0,0 mm

l 76 = 15,2 mm - 0,5 mm

The front of the lid measured from Plane X shall be + 0,0 mm

l 77 = 15,3 mm - 0,3 mm

The inside of the lid shall provide clearance for the tape defined by l 78 = 13,15 mm 0,10 mm The top front of the lid shall have a radius r 3 . The centre of the radius shall be axis A. + 0,0 mm

r 3 = 14,7 mm - 0,3 mm

- 13 -

The design of the locking mechanism is not specified by this ECMA Standard except that is shall be operated by a release pin in the drive. The lid release mechanism shall be actuated when the drive release pin is in the shaded area (see figure 15) defined by l 79 = 2,0 mm 0,1 mm l 80 = 8,2 mm 0,2 mm l 81 = 0,7 mm 0,2 mm a 6 = 30 o 1 o The force required to unlock the lid lock shall not exceed 0,25 N in the direction shown in figure 18. The force required to open the lid shall not exceed 1,0 N in the direction shown in figure 19.

8.14

Cartridge reel lock (figure 16) The reels shall be locked when the cartridge is removed from the tape drive. The design of the locking mechanism is not specified by this ECMA Standard except that it shall be operated by a release pin in the drive. The locking mechanism shall be accessed through a rectangular hole in the case (see figure 10) defined by the centreline from Plane Y l 82 = 34,5 mm 0,1 mm; the top from Plane X l 83 = 35,85 mm 0,15 mm; and l 84 = 4,0 mm 0,1 mm l 85 = 6,5 mm min. The dimension of the locking mechanism shall be defined by + 0,3 mm

l 86 = 3,2 mm - 0,2 mm

l 87 = 4,0 mm 0,1 mm a 7 = 60,0 o 1,0 o The reels shall be locked when the operating face of the release pin is located l 88 from Plane X. + 2,0 mm

l 88 = 39,0 mm - 0,0 mm

The reels shall be unlocked when the operating face of the release pin is located l 89 from Plane X. + 0,50 mm

l 89 = 41,75 mm - 0,00 mm

In this position there shall be a clearance of l 90 between the locking mechanism and the inside of the rear wall of the cartridge. l 90 = 0,5 mm min. The pin used to move the locking mechanism shall penetrate the cartridge a distance of l 91 = 7,8 mm max. The cavity of the locking mechanism shall be defined by l 92 = 4,0 mm 0,1 mm r 4 = 0,3 mm max.

- 14 -

The force required to unlock the reel lock in the direction shown in figure 17 shall not exceed 1,0 N.

8.15

Reel access holes (figure 10) The case shall have two circular reel access holes which shall allow penetration of the drive spindles. The positions of the access holes shall be defined by l 93 = 23,00 mm 0,05 mm l 94 = 11,40 mm 0,05 mm l 95 = 46,2 mm 0,1 mm The diameter of the holes shall be d 2 = 18,80 mm 0,05 mm

8.16

Interface between the reels and the drive spindles The drive spindles (see figures 22 and 23) shall engage the reels in the area defined by l 96 = 11,75 mm 0,15 mm l 97 = 8,30 mm 0,05 mm l 98 = 0,6 mm 0,1 mm l 99 = 0,3 mm 0,1 mm l 100 = 1,10 mm 0,05 mm l 101 = 0,6 mm max. l 102 = 5,4 mm 0,1 mm l 103 = 4,4 mm 0,1 mm l 104 = 0,6 mm max. + 0,08 mm

d 4 = 10,00 mm - 0,00 mm

d 5 = 16,0 mm max. + 0,0 mm

d 6 = 18,0 mm - 0,1 mm + 0,0 mm

d 7 = 16,0 mm - 0,1 mm + 0,0 mm

d 8 = 45,1 mm - 0,5 mm + 0,0 mm

d 9 = 45,1 mm - 0,2 mm

There shall be a chamfer of the reel driving hole defined by l 105 = 2,4 mm 0,1 mm a 9 = 15 o 1 o There shall be a chamfer at the bottom of the reel on the outside edge defined by l 106 = 0,2 mm max. a 8 = 45 o 1 o The position and width of the slots to receive the reel drive spindle shall be defined by

- 15 -

+ 0,2 mm

l 107 = 2,4 mm - 0,0 mm

a 10 = 60 1 o o

The teeth in the reel driving hole shall have a radius r 5 = 0,2 mm max. The depth l 108 of the reel driving hole shall be effective to the diameter d 3 . l 108 = 9,4 mm min. + 0,08 mm

d 3 = 6,50 mm - 0,00 mm

When the tape is loaded in the drive, the position of the tape centre relative to Plane Z shall be l 109 = 7,05 mm 0,10 mm When the tape is loaded in the drive, the position of the reel relative to Plane Z shall be l 110 = 0,6 mm 0,2 mm The penetration of the reel drive spindle into the reel shall be defined by l 111 = 7,5 mm max. l 112 = 8,0 mm max. l 113 = 1,20 mm 0,05 mm l 114 = 1,40 mm 0,05 mm a 11 = 60 0 1 o When the cartridge is mounted in the drive and the Support areas are at a distance l 110 from Plane Z, the reel spring force F shall be 0,6 N 0,2 N in the direction shown in figure 23.

8.17

Light path (figures 10, 12, 20 and 21) A light path shall be provided for sensing the leader and trailer tapes. When the lid is open, an unobstructed light path shall exist from the d 10 diameter light path hole to the outside of the cartridge via square windows in the light path hole (see cross-section D-D in figure 12) and the light window in the cartridge lid. The centre of the light path hole shall be defined by l 82 and l 115 = 8,35 mm 0,10 mm The diameter of the light path hole shall be + 0,3 mm

d 10 = 6,5 mm - 0,0 mm

The light path hole shall have a chamfer defined by l 116 = 0,5 mm max. a 12 = 45 o 1 o The position and size of the square window on each side of the light path hole shall be l 117 = 6,05 mm 0,10 mm + 0,4 mm

l 118 = 2,5 mm - 0,0 mm

The hole shall be deep enough to allow penetration of a light emitter a distance of l 119 = 12,5 mm min.

- 16 -

The angle of the light path shall be a 13 = 5,50 o 0,25 o The position and size of the cartridge lid window shall be l 120 = 3,8 mm 0,1 mm + 0,4 mm

l 121 = 2,5 mm - 0,0 mm

l 122 = 6,05 mm 0,10 mm

8.18

Position of the tape in the case (figure 21) The tape shall run between two guide surfaces in a plane parallel to Plane X and l 123 from it. l 123 = 10,15 mm 0,10 mm The guide surfaces shall have a radius of r 6 and shall be tangential, as shown in figure 21, to lines tangential to the reel hubs that extend to points outside the case. r 6 = 3,0 mm 0,1 mm These points shall be defined by l 124 = 76,28 mm 0,30 mm l 125 = 27,15 mm 0,20 mm l 126 = 31,15 mm 0,20 mm l 127 = 9,67 mm 0,10 mm

8.19

Tape path zone When the cartridge is inserted into the drive, the tape is pulled outside the case by tape guides and is no longer in contact with the guide surfaces. The tape path zone (see figure 21) of the case is the zone in which the tape shall be able to move freely. This zone shall be maintained for both sides of the case and shall be defined by l 124 to l 127 and l 128 = 23,0 mm 0,1 mm l 129 = 0,3 mm min. l 130 = 46,2 mm 0,2 mm l 131 = 11,4 mm 0,1 mm The clearance between the tape and the guides shall be defined by l 132 = 0,3 mm min.

8.20

Tape access cavity (figure 10) When the cartridge is inserted into the drive, tape guides in the drive pull the tape into the drive tape path. The two radii r 7 are centred on Datum holes A and B. The shape and dimensions of the access cavity for these tape guides shall be defined by l 63 and l 64 , and the following r 7 = 2,3 mm 0,1 mm The two radii r 8 are centred on the centres of the reel access holes. r 8 = 24,15 mm 0,10 mm l 133 = 3,85 mm 0,10 mm

8.21

Tape access cavity clearance requirements (figure 24) The case design shall provide clearance for drive tape threading mechanisms and shall be defined by l 134 = 1,2 mm max.

- 17 -

+ 0,20 mm

l 135 = 1,15 mm - 0,00 mm + 0,0 mm

l 136 = 14,0 mm - 0,2 mm

l 137 = 66,8 mm min. l 138 = 10,0 mm min. l 139 = 14,8 mm 0,1 mm a 14 = 49 o max.

Figure 1 - Tape cartridge assembly top view, lid opened

- 18 -

Figure 2 - Tape cartridge assembly bottom view, lid closed

Figure 3 - Reference Planes X, Y, and Z

- 19 -

- 20 -

Figure 9 - Bottom side, Datum and Support areas

- 21 -

Figure 10 - Bottom side, lid removed

- 22 -

Figure 11 - Details of datum and recognition holes

- 23 -

Figure 12 - Cross-sections of light path holes, recognition holes and write-inhibit hole

- 24 -

Figure 13 - Lid

- 25 -

Figure 14 - Lid release insertion channel

Figure 15 - Lid release requirement

- 26 -

Figure 16 - Reel lock and release

- 27 -

Figure 17 - Direction of force needed to unlock the reel lock

Figure 18 - Direction of force needed to unlock the lid lock

Figure 19 - Direction of force needed to open the lid

- 28 -

Figure 20 - Light path and light window

- 29 -

Figure 21 - Internal tape path and light path

- 30 -

Figure 22 - Cartridge reel

- 31 -

Figure 23 - Interface with drive spindle

- 32 -

Figure 24 - Tape access cavity clearance

- 33 -

Section 3 - Requirements for the Unrecorded Tape 9

Mechanical, physical and dimensional characteristics of the tape

9.1

Materials The recordable area of the tape shall consist of polyethylene naphthalate film base material (or its equivalent) coated on one side with a strong yet flexible layer of ferromagnetic material. The back surface of the tape may be coated. There shall be a leader tape between the take-up hub and the PBOT. There shall be a trailer tape between PEOT and the supply hub. The leader and trailer tapes shall consist of a translucent length of polyethylene terephthalate film (or its equivalent) base material without the ferromagnetic coating and the back coating, if any. The leader and trailer tapes shall each be attached to the magnetic tape by means of a length of splicing tape which extends over each such joint. The splicing tape shall consist of polyethylene terephthalate (or its equivalent), coated on one side with an acrylic (or equivalent) adhesive material.

9.2

Tape length

9.2.1

Magnetic tape The length of tape between PBOT and PEOT shall be in the range 10 m to 163 m.

9.2.2

Leader and trailer tapes The length of the leader tape shall be in the range of 76 mm to 90 mm. The length of the trailer tape shall be in the range of 70 mm to 90 mm.

9.2.3

Splicing tape The splicing tape shall extend over the leader and trailer tapes for a distance in the range of 5,5 mm to 7,0 mm. Their extents over the magnetic tape shall be in the range of 4,0 mm to 10,0 mm.

9.3 9.3.1

Tape width Width of magnetic tape The width of the magnetic tape shall be 8,00 mm 0,01 mm. The difference between the largest and smallest width shall be no more than 6 m. The width shall be measured across the tape from edge to edge when the tape is under tension of 0,10 N 0,01 N and is lying flat between glass slides.

9.3.2

Width of leader and trailer tapes The width of the leader and trailer tapes shall be 8,00 mm 0,02 mm. The width shall be measured across the tape from edge to edge when the tape is under tension of 0,10 N 0,01 N and is lying flat between glass slides.

9.3.3

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 width of the splicing tape shall be + 0,02 mm

8,00 mm - 0,50 mm

Neither edge of the splicing tape shall extend beyond the edges of the leader, trailer and magnetic tapes.

9.4

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

9.5 9.5.1

Thickness Thickness of the magnetic tape The total thickness of the magnetic tape shall be 7,5 m 0,4 m.

- 34 -

9.5.2

Thickness of leader and trailer tape The thickness of the leader and trailer tape shall be between 13 µm and 17 µm.

9.5.3

Thickness of the splicing tape The thickness of the splicing tape shall be 27 m max.

9.6

Longitudinal curvature The radius of curvature of the edge of the tape shall not be less than 33 m. Procedure

Allow a 1 m length of tape to unroll and assume its natural curvature on a flat smooth surface. Measure the deviation from a 1 m chord. The deviation shall not be greater than 3,8 mm. This deviation corresponds to the minimum radius of curvature of 33 m if measured over an arc of a circle.

9.7

Cupping The departure across the width of tape from a flat surface shall not exceed 0,9 mm. Procedure

Cut a 1,0 m 0,1 m length of tape. Condition it for a minimum of 3 h in the test environment by hanging it so that the coated surface is freely exposed to the test environment. From the centre portion of the conditioned tape cut a test piece of length 25 mm approximately.

Stand the test piece on its end in a cylinder which is at least 25 mm high with a minimum inside diameter of 8 mm.

With the cylinder standing on an optical comparator measure the cupping by aligning the edges of the test piece to the reticle and determining the distance from the aligned edges to the corresponding surface of the test piece at its centre.

9.8

Coating adhesion The force required to peel any part of the coating from the tape base material shall not be less than 0,10 N (see figure 25). Procedure

Take a test piece of the tape approximately 380 mm long. Scribe a line through the coating across the width of the tape 125 mm from one end. Using a double-sided pressure sensitive tape, attach the test piece to a smooth metal plate, with the coated surface facing the plate.

Fold the test piece over 180 o adjacent to, and parallel with the scribed line. Attach the metal plate and the free end of the test piece to the jaws of a tensometer such that when the jaws are separated the tape is peeled.

Set the jaw separation rate to 254 mm/min. Note the force at which any part of the coating first separates from the base material. If this is less than 0,10 N, the tape has failed the test.

If the test piece peels away from the double-sided pressure sensitive tape before the force exceeds 0,10 N, an alternative type of double-sided pressure tape shall be used.

If the back surface of the tape is coated, repeat the above steps for the back coating.

- 35 -

Figure 25 - Measurement of coating adhesion

9.9

Layer-to-layer adhesion There shall be no tendency for the test piece to stick or for the coating to peel. Procedure

Attach one end of a test piece of magnetic tape of 1 m in length to the surface of a glass tube of 9.10

external diameter 36 mm. Wind the tape on to the tube at a tension of 1,1 N. Store the wound test piece in a temperature of 45 o C 3 o C and a relative humidity of 80 % for 4 h. Store for a further 24 h in the testing environment. Apply a force of 0,1 N to the free end of the test piece and allow it to unwind slowly.

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).

9.10.1

Breaking strength 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 shall not be less than 10,0 N.

9.10.2

Yield strength The yield strength is the force necessary to produce a 5 % elongation of the tape. The yield strength shall be greater than 4,9 N.

9.11

Residual elongation The residual elongation, stated in per cent of the original tape length, shall be less than 0,03 %. Procedure

Measure the initial length of a test piece of approximately 1 m with a maximum applied force of 0,20 N.

Apply an additional force per total cross-sectional area of 20,5 N/mm2 for a period of 10 min. Remove the additional force and measure the length after 10 min. 9.12

Electrical resistance of coated surfaces The electrical resistance of coated surfaces shall be within the ranges:

- 36 -

10 5 to 5 x 10 8 for non-back-coated tape 10 5 to 5 x 10 12 for back-coated tape The electrical resistance of any square area of the back-coating, if present, shall be less than 9 x 108 . Procedure

Condition a test piece of tape in the test environment for 24 h. Position the test piece over two 24-carat gold-plated, semicircular electrodes having a radius r = 10 mm and a finish of at least N4, so that the recording surface is in contact with each electrode. These electrodes shall be placed parallel to the ground and parallel to each other at a distance d = 8 mm between their centres.

Apply the force necessary to produce a tension of 5 N/mm2 to each end of the test piece. Apply a d.c. voltage of 100 V 10 V across the electrodes and measure the resulting current flow. From this value, determine the electrical resistance.

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 electrodes except that through the coating under test. Note Particular attention should be given to keeping the surfaces clean.

Figure 26 - Measurement of electrical resistance

9.13

Tape winding The magnetic recording surface of the tape shall face outward from the cartridge and reels.

9.14

Light transmittance of tape The light transmittance of the magnetic tape shall be 5 % max. The light transmittance of the leader and trailer tapes shall be 60 % min. The method for measuring light transmittance is given in annex A.

9.15

Media Recognition System (MRS) A pattern of opaque stripes shall exist on the leader tape close to PBOT. Each stripe shall extend across the entire width of the leader tape (see figure 27). The boundaries between adjacent stripes shall be perpendicular to the Tape Reference Edge to within 10 o . The length of each opaque stripe and of each clear stripe, measured parallel to the Tape Reference Edge,

- 37 -

shall be 3,0 mm 0,2 mm, including the effects of any deviation from parallelism between such boundaries. The light transmittance through the opaque stripes shall be less than, or equal to, 5 %. The light transmittance through the combination of the splicing tape and the leader tape shall be 55% minimum. The method for measuring light transmittance is given in annex A.

Figure 27 - Leader tape at PBOT

Magnetic recording characteristics The magnetic recording characteristics shall be defined by the testing requirements given below. When performing these tests, the output or resultant signal shall be measured on a read-while-write pass for both a tape calibrated to the Master Standard Reference Tape and the tape under test, on the same equipment. The following conditions shall apply to the testing of all magnetic recording characteristics, unless otherwise stated. tape condition

: a.c. erased to a level of less than 0,1 % of the Average Signal Amplitude at 914,5 ftpmm.

diameter of scanner

: 40,00 mm

+ 0,01 mm - 0,00 mm

rotational speed of scanner: 5 506,9 rpm 0,5 rpm tape speed

: 23,7 mm/s 0,5 mm/s

tape tension

: 0,10 N 0,02 N, measured at the input to the scanner

test tracks

: negative azimuth tracks (see 13.9 and figure 34)

write gap length

: 0,23 m 0,05 m

recording current

: Test Recording Current

recording waveform

: square wave

read track width

: in the range of 8 m to 16 m

write track width

: equal to, or greater than, the read track width but 24 m max.

- 38 -

read head setting of the

: during a read-while-write pass, all of the read head track is within the boundaries written track

read output level

: taken at the appropriate fundamental frequency only

10.1

Typical Field The Typical Field shall be between 89 % and 112 % of the Reference Field. Traceability to the Reference Field is provided by the calibration factor supplied with each Secondary Standard Reference Tape.

10.2

Signal amplitude The Average Signal Amplitude at the physical recording density of 3 658,1 ftpmm shall be between 89 % and 141 % of that for the Master Standard Reference Tape. Traceability to the Average Signal Amplitudes of the Master Standard Reference Tape is provided by the calibration factors supplied with each Secondary Standard Reference Tape.

10.3

Resolution The ratio of the Average Signal Amplitude at the physical recording density of 3 658,1 ftpmm to that at the physical recording density of 914,5 ftpmm shall be between 89 % and 112 % of the same ratio for the Master Standard Reference Tape. Traceability to the resolution for the Master Standard Reference Tape is provided by the calibration factors supplied with each Secondary Standard Reference Tape.

10.4

Overwrite Overwrite is the ratio of the Average Signal Amplitude of the residual of a low density recording after overwriting at a higher density to the Average Signal Amplitude of the original low density recording. Traceability to the overwrite ratios for the Master Standard Reference Tape is provided by the calibration factors supplied with each Secondary Standard Reference Tape. Procedure

a.c. erase the tape. Record at the physical density of 914,5 ftpmm and measure the Average Signal Amplitude. Overwrite at the physical recording density of 3 658,1 ftpmm and measure the Average Signal Amplitude of the residual 914,5 ftpmm signal.

Repeat for the Secondary Standard Reference Tape. Requirements Residual Average Signal Amplitude at 914,5 ftpmm after overwriting The ratio Average Signal Amplitude of the original recording at 914,5 ftpmm shall be less than 119 % of the same ratio for the Master Standard Reference Tape.

10.5

Ease of erasure When a tape has been recorded at 914,5 ftpmm with the Test Recording Current and then passed through a longitudinal steady erasing field of 240 000 A/m, any remaining signal shall not exceed 3 % of the SRA for that density. The erasing field shall be reasonably uniform, for example, the field in the middle of a solenoid. This measurement shall be made with a band pass filter passing at least the first three harmonics.

10.6 10.6.1

Tape quality Missing pulses A missing pulse is a loss of read signal amplitude. A missing pulse exists when the base-to-peak read signal is 50 %, or less, of half the Average Signal Amplitude for the recording density of 1 829,0 ftpmm on the same tape.

- 39 -

10.6.2

Missing pulse zone A missing pulse zone shall commence with a missing pulse and end when 5 consecutive flux transitions, which are not missing pulses, have been detected or when a length of 0,317 mm of track has been measured. If missing pulses continue for a distance exceeding 0,317 mm, a further missing pulse zone shall commence. A missing pulse zone does not continue from one track to the next. 5

The missing pulse zone rate shall be less than one in 2,3 x 10 flux transitions and applies to both positive and negative azimuth tracks.

10.7

Signal-to-Noise Ratio (SNR) The Signal-to-Noise Ratio is the average rms read signal amplitude divided by the average integrated rms noise amplitude, and expressed in decibels. Average rms read signal amplitude dB

SNR = 20 log Average integrated rms noise amplitude Requirement

The SNR for the tape under test (SNR tape) shall be better than -1 dB relative to the SNR for the Master Standard Reference Tape (SNR MSRT) when measured according to the procedure defined in annex B. Traceability to the (SNR MSRT) is provided by the calibration factor supplied with each Secondary Standard Reference Tape.

Section 4 - Requirements for an interchanged tape 11 11.1

Format General Data to be recorded is sent from a host computer to the tape sub-system. The tape sub-system combines this data with additional information before recording onto the tape. The additional information includes a definition of the relationship of the host data, in the form of Logical Records of variable length, to a Frame of fixed length and to a Information Block of fixed length. The host data, when recorded, is identified as being compressed or uncompressed by the tape sub-system. The host data with the additional information shall be recorded on helical tracks on a tape. A Frame is a pair of adjacent tracks with azimuths of opposite polarity, in which the track with the positive azimuth precedes that with the negative azimuth. Each track shall consist of a preamble zone, a data zone and a postamble zone. A data zone shall consist of eight Information Blocks. Each Information Block shall consist of 24 Sync Blocks (see figure 28). The data received from the host shall be allocated to an Information Matrix. The Information Matrix shall consist of host data with additional information and error detecting and correcting code bytes. The contents of one Information Matrix shall be divided into 24 Sync Blocks. Each Sync Block shall consist of a part of Information Matrix and additional header. The 24 Sync Blocks shall be a Information Block. In the following description, all operations on the data received from the host computer, including the use of error detecting and correcting codes, are described. The method of recording on the tape and the tape layout itself are also described. However, because of the inherent characteristics of this format, where required, advance reference to the tape layout will also be made in the course of the description of the operations on the data.

- 40 -

Figure 28 - Contents of a Frame

11.2

Information Matrix The data received from the host shall be allocated to a two dimensional array called an Information Matrix. The Information Matrix shall be a 56-column by 48-row array containing 2 688 cells. Each cell is identified by its column and row numbers and contains a byte. When complete, an Information Matrix shall contain: Search Information ID Information Data bytes CRC bytes C2 ECC bytes C1 ECC bytes

21 bytes 29 bytes 2 048 bytes 2 bytes 300 bytes 288 bytes

Total :

2 688 bytes

- 41 -

Figure 29 - Information Matrix 11.2.1

Loading the Information Matrix Cells are identified by column and row in the following form: 00/00 to 55/47. All additions in the calculations of CRC bytes and ECC bytes are Exclusive OR operations.

11.2.1.1

11.2.1.1.1

G1 Group A G1 group shall consist of 21 bytes of Search Information, 29 bytes of ID Information and 2 048 Data bytes. Search information Search Information shall contain 19 information bytes and two check bytes. Byte 0 to byte 20 of Search Information shall be entered into cells 00/00 to 20/00 sequentially. In this section, byte 0 corresponds to the content of cell 00/00, and byte n corresponds to the content of cell (00+n)/00. Search information contents are listed below and described in the clauses which follow.

Absolute Frame Address Logical Block Address Logical Record Address File Mark Address Set Mark Address Partition Identification CRC

bytes 00/00 to 02/00 bytes 03/00 to 06/00 bytes 07/00 to 10/00 bytes 11/00 to 14/00 bytes 15/00 to 17/00 byte 18/00 bytes 19/00 to 20/00

11.2.1.1.1.1 Absolute Frame Address The Absolute Frame Address is a count, starting with 0, that shall be incremented by 1 for each frame recorded on this tape. Bytes 0 to 2 shall express this 24-bit count in the Search information of all Information Blocks. Bit 0 of Byte 2 shall be the least significant bit of this 24-bit count. The Absolute Frame Address for the first Frame following the LBOT or the LBOP 0 (see 17.1.3.1) shall be 0. The Information Block types are:

Data Block ECC3 Block Long File Mark Block Short File Mark Block Set Mark Block

- 42 -

Gap Block End of Data Block Format Block Data Block in System Area

11.2.1.1.1.2 Logical Block Address The Logical Block Address is a count, starting with 0, that shall be incremented by 1 for each Data Block, Long File Mark, Short File Mark Block, Set Mark or End of Data recorded from LBOT or LBOP 0. Bytes 3 to 6 shall express this 32-bit count in the Search Information of a Data Block, ECC3 Block (if applicable), Long File Mark Block, Short File Mark Block, Set Mark Block, Gap Block or End of Data Block. Bytes 3 to 6 shall be set to ZEROs in the Search information of a Format Block or Data Block in the System Area. The content to be entered into the 4 bytes of Logical Block Address of all Block types are described in Table 1. Bit 0 of byte 6 shall be the least significant bit of this 32-bit count. This count shall not be incremented for, and shall not be changed in, a rewritten Data Block or a rewritten Short File Mark Block. Table 1 - Logical Block Address Information Block Type

Content

Data Block

Address of the Data Block

ECC3 Block

Address of the last Data Block that has been written prior to the ECC3 Block

Long File Mark Block

Address of the Long File Mark in which the Long File Mark Block is located

Short File Mark Block

Address of the Short File Mark Block.

Set Mark Block

Address of the Set Mark in which the Set Mark Block is located.

Gap Block

Address of the last Data Block, Long File Mark, Short File Mark or Set Mark that has been written prior to the Gap Block.

End of Data Block

Address of the End of Data in which the End of Data Block is located.

Format Block

ZEROs.

Data Block in System Area

ZEROs

11.2.1.1.1.3 Logical Record Address The Logical Record Address is a count, starting with 0, that shall be incremented by 1 for each Logical Record, Long File Mark, Short File Mark Block or Set Mark recorded from LBOT or LBOP 0. Bytes 7 to 10 shall express this 32-bit count in the Search information of a Data Block, ECC3 Block (if applicable), Long File Mark Block, Short File Mark Block, Set Mark Block, Gap Block or End of Data Block. Bytes 7 to 10 shall be set to ZEROs in the Search information of a Format Block or Data Block in System Area. The content to be entered into the 4 bytes of Logical Record Address of all Information Block types are described in table 2. Bit 0 of byte 10 shall be the least significant bit of this 32-bit count. This count shall not be incremented for, and shall not be changed in, a rewritten Logical Record or a rewritten Short File Mark Block.

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Table 2 - Logical Record Address Information Block Type

Content

Data Block

Address of the Logical Record to which the first Data Byte 00/01 of the Block belongs. Address of the last Logical Record that has been written prior to the ECC3 Block. Address of the Long File Mark in which the Long File Mark Block is located. Address of the Short File Mark Block. Address of the Set Mark in which the Set Mark Block is located. Address of the last Logical Record, Long File Mark, Short File Mark or Set Mark that has been written prior to the Gap Block. Address of the last Logical Record, Long File Mark, Short File Mark or Set Mark that has been written prior to the End of Data Block. ZEROs. ZEROs.

ECC3 Block Long File Mark Block Short File Mark Block Set Mark Block Gap Block

End of Data Block

Format Block Data Block in System Area

11.2.1.1.1.4 File Mark Address The File Mark Address is a count, starting with 0, that shall be incremented by 1 for each Short File Mark Block or Long File Mark recorded from LBOT or LBOP 0. Bytes 11 to 14 shall express this 32-bit count in the Search information of a Data block, ECC3 Block (if applicable), Long File Mark Block, Short File Mark Block, Set Mark Block, Gap Block or End of Data Block. Bytes 11 to 14 shall be set to ZEROs in the Search information of a Format Block or of a Data Block in System Area. The content to be entered into the 4 bytes of File Mark Address of all Information Block types are described in Table 3. Bit 0 of byte 14 shall be the least significant bit of this 32-bit count. This count shall not be incremented for, and shall not be changed in, a rewritten Short File Mark Block. Table 3 - File Mark Address Information Block Type

Content

Data Block

Address of the last Long File Mark or Short File Mark that has been written prior to the Data Block. Address of the last Long File Mark or Short File Mark that has been written prior to the ECC3 Block. Address of the Long File Mark in which the Long File Mark Block is located. Address of the Short File Mark Block. Address of the last Long File Mark or Short File Mark that has been written prior to the Set Mark Block. Address of the last Long File Mark or Short File Mark that has been written prior to the Gap Block. Address of the last Long File Mark or Short File Mark that has been written prior to the End of Data Block. ZEROs. ZEROs.

ECC3 Block Long File Mark Block Short File Mark Block Set Mark Block Gap Block End of Data Block Format Block Data Block in System Area

11.2.1.1.1.5 Set Mark Address The Set Mark Address is a count, starting with 0, that shall be incremented by 1 for each Set Mark recorded from LBOT or LBOP 0. Bytes 15 to 17 shall express this 24-bit count in the Search information of a Data block, ECC3 Block (if applicable), Long File Mark Block, Short File Mark Block, Set Mark Block, Gap Block or End of Data Block. Bytes 15 to 17 shall be set to ZEROs in the Search

- 44 -

information of a Format Block or of a Data Block in System Area. The content to be entered into the 3 bytes of Set Mark Address of all Information Block types are described in Table 4. Bit 0 of byte 17 shall be the least significant bit of this 24-bit count. Table 4 - Set Mark Address Information Block Type

Content

Data Block

Address of the last Set Mark that has been written prior to the Data Block. Address of the last Set Mark that has been written prior to the ECC3 Block. Address of the last Set Mark that has been written prior to the Long File Mark Block. Address of the last Set Mark that has been written prior to the Short File Mark Block. Address of the Set Mark in which the Set Mark Block is located. Address of the last Set Mark that has been written prior to the Gap Block. Address of the last Set Mark that has been written prior to the End of Data Block. ZEROs. ZEROs.

ECC3 Block Long File Mark Block Short File Mark Block Set Mark Block Gap Block End of Data Block Format Block Data Block in System Area

11.2.1.1.1.6 Partition Identification Byte 18 in the Search Information of all Information Block types shall express the Partition Identification. Bit 0 of byte 18 shall be set to ONE if the Information Block is in Partition 1. Bit 0 of byte 18 shall be set to ZERO if the Information Block is in Partition 0 or on Single Data Space tape. The other bits of this byte shall be set to ZERO. 11.2.1.1.1.7 CRC Bytes 19 and 20 in the Search Information of all Information Block types shall be CRC bytes. The two CRC bytes shall be computed over the 19 bytes of the Search Information and entered into cells 19/00 and 20/00. They are generated as follows: Dk is byte k of the Search Information where: k = 0 to 18 Dk,0, Dk,1,..., Dk,7 denote the 8 bits of Dk, where : Dk,7 is the high order bit. j=7

Dk ( x ) = ∑ Dk , j x j j=0

k =18

D( x ) = ∑ Dk ( x ) x 19 − k k =0

CH = D(x)mod(x+) where is from GF (28) generated by G(x) = x8 + x4 + x3 + x2 + 1

- 45 -

k =18

CL= CH +

∑D + x + x + x + x + x + x + x +1 7

k =0

where: CH0, CH1,..., CH7 are the bits of the byte 19, CH7 being the most significant bit. CL0, CL1,..., CL7 are the bits of the byte 20, CL7 being the most significant bit. 11.2.1.1.2

ID Information ID Information shall contain 29 information bytes for each block type. Byte 0 to byte 28 of ID Information shall be entered into cells 21/00 to 49/00 sequentially. In this section, Byte 0 corresponds to the contents of cell 21/00, and Byte n corresponds to the contents of cell (21+n)/00.

11.2.1.1.2.1 Data Block Byte 0: Bits 7 to 4

These bits shall be used for identifying the Information Block uniquely in a Frame (see 11.4.1).

Bit 3 to 0

These bits shall be set to ZERO.

Byte 1: Bit 7

This bit shall be set to ONE if a first Logical Record starts in the first data position, 00/01, in this Information Block, else it shall be set to ZERO.

Bits 6 to 0

These bits are undefined and shall be ignored in interchange.

Byte 2: Bits 7 to 0

These bits are undefined and shall be ignored in interchange.

Byte 3: This byte shall express the count of the number of times that the frame has been rewritten. Bit 0 shall be the least significant bit of this count. Bytes 4 and 5: Bit 7 of byte 4

This bit shall be set to ONE if a first Logical Record of this Information Block is compressed, else it shall be set to ZERO.

Bit 6 of byte 4

This bit shall be set to ONE if a first Logical Record is the last Logical Record of this Information Block, else it shall be set to ZERO. Further, if this Logical Record is the last Logical Record then bytes 9 to 28 are undefined and shall be ignored in interchange.

Bit 5 of byte 4

This bit shall be set to ONE if the last byte of a first Logical Record is in this Information Block, else it shall be set to ZERO.

Bits 4 and 3 of byte 4 These bits are undefined and shall be ignored in interchange. Bits 2 to 0 of byte 4 and bits 7 to 0 of byte 5 These bits shall express the 11-bit count of one less than the number of bytes within this Information Block of the first Logical Record. Bit 0 of Byte 5 shall be the least significant bit of this count. The count shall also includes CRC bytes (see Rule 1 of 11.2.1.1.3.1) if they are in this Information Block. Bytes 6 to 8: These bytes shall express the 24-bit count of the number of bytes of the first Logical Record before compression. Bit 0 of byte 8 shall be the least significant bit of this count. If this Logical Record is not compressed, these bits are undefined and shall be ignored in interchange.

- 46 -

Bytes 9 and 10: Bit 7 of byte 9

This bit shall be set to ONE if a second Logical Record of this Information Block is compressed, else it shall be set to ZERO.

Bit 6 of byte 9

This bit shall be set to ONE if a second Logical Record is the last Logical Record of this Information Block, else it shall be set to ZERO. Further, if this Logical Record is the last Logical Record then bytes 14 to 28 are undefined and shall be ignored in interchange.

Bit 5 of byte 9

This bit shall be set to ONE if the last Byte of a second Logical Record is in this Information Block, else it shall be set to ZERO.

Bits 4 and 3 of byte 9 These bits are not specified and shall be ignored in interchange. Bits 2 to 0 of byte 9 and bits 7 to 0 of byte 10 These bits shall express the 11-bit count of one less than the number of bytes within this Information Block of the second Logical Record. Bit 0 of Byte 10 shall be the least significant bit of this count. The count shall also includes CRC bytes (see Rule 1 of 11.2.1.1.3.1) if they are in this Information Block. Bytes 11 to 13: These bytes shall express the 24-bit count of the number of bytes of the second Logical Record before compression. Bit 0 of byte 13 shall be the least significant bit of this count. If this Logical Record is not compressed, these bits are undefined and shall be ignored in interchange. Bytes 14 and 15: Bit 7 of byte 14

This bit shall be set to ONE if a third Logical Record of this Information Block is compressed, else it shall be set to ZERO.

Bit 6 of byte 14

This bit shall be set to ONE if a third Logical Record is the last Logical Record of this Information Block, else it shall be set to ZERO. Further, if this Logical Record is the last Logical Record then bytes 19 to 28 are undefined and shall be ignored in interchange.

Bit 5 of byte 14

This bit shall be set to ONE if the last Byte of a third Logical Record is in this Information Block, else it shall be set to ZERO.

Bits 4 and 3 of byte 14 These bits are not specified and shall be ignored in interchange. Bits 2 to 0 of byte 14 and bits 7 to 0 of byte 15 These bits shall express the 11-bit count of one less than the number of bytes within this Information Block of the third Logical Record. Bit 0 of byte 15 shall be the least significant bit of this count. The count shall also includes CRC bytes (see Rule 1 of 11.2.1.1.3.1) if they are in this Information Block. Bytes 16 to 18: These bytes shall express the 24-bit count of the number of bytes of the third Logical Record before compression. Bit 0 of byte 18 shall be the least significant bit of this count. If this Logical Record is not compressed, these bits are undefined and shall be ignored in interchange. Bytes 19 and 20: Bit 7 of byte 19

This bit shall be set to ONE if a fourth Logical Record of this Information Block is compressed, else it shall be set to ZERO.

Bit 6 of byte 19

This bit shall be set to ONE if a fourth Logical Record is the last Logical Record of this Information Block, else it shall be set to ZERO. Further, if this Logical Record is the last Logical Record then bytes 24 to 28 are undefined and shall be ignored in interchange.

Bit 5 of byte 19

This bit shall be set to ONE if the last byte of a fourth Logical Record is in this Information Block, else it shall be set to ZERO.

- 47 -

Bits 4 and 3 of byte 19 These bits are not specified and shall be ignored in interchange. Bits 2 to 0 of byte 19 and bits 7 to 0 of byte 20 These bits shall express the 11-bit count of one less than the number of bytes within this Information Block of the fourth Logical Record. Bit 0 of byte 20 shall be the least significant bit of this count. The count shall also includes CRC bytes (see Rule 1 of 11.2.1.1.3.1) if they are in this Information Block. Bytes 21 to 23: These bytes shall express the 24-bit count of the number of bytes of the fourth Logical Record before compression. Bit 0 of byte 23 shall be the least significant bit of this count. If this Logical Record is not compressed, these bits are undefined and shall be ignored for interchange. Bytes 24 and 25: Bit 7 of byte 24

This bit shall be set to ONE if a fifth Logical Record of this Information Block is compressed, else it shall be set to ZERO.

Bit 6 of byte 24

This bit shall be set to ONE if a fifth Logical Record is the last Logical Record of this Information Block, else it shall be set to ZERO.

Bit 5 of byte 24

This bit shall be set to ONE if the last Byte of a fifth Logical Record is in this Information Block, else it shall be set to ZERO.

Bits 4 and 3 of byte 24 These bits are undefined and shall be ignored in interchange. Bits 2 to 0 of byte 24 and bits 7 to 0 of byte 25 These bits shall express the 11-bit count of one less than the number of bytes within this Information Block of the fifth Logical Record. Bit 0 of byte 25 shall be the least significant bit of this count. The count shall also includes CRC bytes (see Rule 1 of 11.2.1.1.3.1) if they are in this Information Block. Bytes 26 to 28: These bytes shall express the 24-bit count of the number of bytes of the fifth Logical Record before compression. Bit 0 of byte 28 shall be the least significant bit of this count. If this Logical Record is not compressed, these bits are undefined and shall be ignored in interchange. 11.2.1.1.2.2 ECC3 Block Byte 0: Bits 7 to 4

These bits shall be used for identifying the Information Block uniquely in a Frame (see 11.4.1).

Bits 3 to 1

These bits shall be set to ZERO.

Bit 0

This bit shall be set to ONE.

Bytes 1 and 2: These bytes are undefined and shall be ignored in interchange. Byte 3: This byte shall express the count of the number of times that the frame has been rewritten. Bit 0 shall be the least significant bit of this count. Bytes 4 to 28: These bytes are undefined and shall be ignored in interchange. 11.2.1.1.2.3 Long File Mark Block Byte 0: Bits 7 to 4

These bits shall be used for identifying the Information Block uniquely in a Frame (see 11.4.1).

Bit 3

This bit shall be set to ZERO.

- 48 -

Bit 2

This bit shall be set to ONE.

Bits 1 and 0

These bits shall be set to ZERO.

Byte 1 to Byte 28: These bytes are undefined and shall be ignored for interchange. 11.2.1.1.2.4 Short File Mark Block Byte 0: Bits 7 to 4

These bits shall be used for identifying the Information Block uniquely in a Frame (see 11.4.1).

Bit 3

This bit shall be set to ZERO.

Bit 2

This bit shall be set to ONE.

Bit 1

This bit shall be set to ZERO.

Bit 0

This bit shall be set to ONE.

These bits shall be used for identifying the Information Block uniquely in a Frame (see 11.4.1).

Bit 3

This bit shall be set to ZERO.

Bit 2

This bit shall be set to ONE.

Bit 1

This bit shall be set to ONE.

Bit 0

This bit shall be set to ZERO.

Byte 1 to Byte 28: These bytes are undefined and shall be ignored in interchange. 11.2.1.1.2.6 Gap Block Byte 0: Bits 7 to 4

These bits shall be used for identifying the Information Block uniquely in a Frame (see 11.4.1).

Bit 3

This bit shall be set to ONE.

Bits 2 to 0

These bits shall be set to ZERO.

- 49 -

Bytes 4 to 28: These bytes are undefined and shall be ignored in interchange. 11.2.1.1.2.7 End of Data Block Byte 0: Bits 7 to 4

These bits shall be used for identifying the Information Block uniquely in a Frame (see 11.4.1).

Bits 3 to 0

These bits shall be set to ONE.

Byte 1 to Byte 28: These bytes are undefined and shall be ignored in interchange. 11.2.1.1.2.8 Format Block Byte 0: Bits 7 to 4

These bits shall be used for identifying the Information Block uniquely in a Frame (see 11.4.1).

Bits 3 to 2

These bits shall be set to ZERO.

Bit 1

This bit shall be set to ONE.

Bit 0

This bit shall be set to ZERO.

Byte 1: Bit 7

This bit shall be set to ONE if the optional ECC3 is enabled in the partition, otherwise it shall be set to ZERO.

Bit 6

This bit shall be set to ZERO if updating of a System Log is enabled in the Partition, otherwise it shall be set to ONE.

Bit 5

This bit shall be set to ZERO if Rewrite is enabled in the Partition, otherwise it shall be set to ONE.

Bit 4

This bit shall be set to ZERO if Read Retry is enabled in the Partition, otherwise it shall be set to ONE.

Bits 3 to 0

These bits shall express the Data Format ID, which is an identifier specifying which data format is being used on the tape, and shall be set to ZEROs in this ECMA Standard.

Byte 2: This byte shall express the identification of the compression algorithm used in the Partition according to ISO/IEC 11576. Bytes 3 to 28 : These bytes are undefined and shall be ignored in interchange. 11.2.1.1.2.9 Data Block in System Area Byte 0: Bits 7 to 4

These bits shall be used for identifying the Information Block uniquely in a Frame (see 11.4.1).

Bits 3 to 0

These bits shall be set to ZERO.

Byte 1 to Byte 28 : These bits are undefined and shall be ignored for interchange.

- 50 -

11.2.1.1.3 Data bytes 11.2.1.1.3.1 Data Block Data bytes from the host shall be entered sequentially by row starting with 00/01 to 49/01, continuing until 47/41. This sequence shall be altered by the following 4 rules:

Rule 1: When a Logical Record ends in this Information Matrix, two CRC bytes shall be calculated for the User Data of the Logical Record and sequentially entered into the cells following the last byte of the Logical Record. As described in 11.2.1.1.1.3, the first Logical Record on the tape and the first Logical Record in a partition is Logical Record 0. The first byte of a Logical Record is Byte 0. The two CRC bytes are computed as follows: where: Dk

shall denote the kth byte of the Logical Record

Dk,j

shall denote the jth bit of the kth byte

shall denote the number of User Data bytes in the Logical Record

then j=7

∑D x

Dk ( x ) =

j=0

k,j

k = n −1

D( x ) =

∑ D ( x) x k =0

8 ( n +1− k )

GCRC (x) = x16 + x12 + x5 + 1 C(x) = D(x)mod GCRC(x) j =7

C ( x) + x

+ x + x + x + x +1=

∑ (CH x + CL x j

j=0

j +8

)

where CH0, CH1, ...., CH7 are the bits of the first CRC byte (CH) and CH7 is the most significant bit. Similarly CL0, CL1, ...., CL7 are the bits of the second CRC byte (CL) and CL7 is the most significant bit.

Rule 2: When the User Data bytes from the host comprise all or part of more than five Logical Records (including two CRC bytes described in Rule 1) in this Information Matrix, a five-byte group shall be entered into the five cells preceding the first User Data byte of each of the sixth and subsequent Logical Records of this Information Matrix. The contents of each five-byte group shall be related to the Logical Record which follows the five-byte group. Bytes 0 and 1: Bit 7 of byte 0: This bit shall be set to ONE if this Logical Record is compressed, else it shall be set to ZERO. Bit 6 of byte 0: This bit shall be set to ONE if this Logical Record is the last Logical Record in this Information Matrix, else it shall be set to ZERO. Bit 5 of byte 0: This bit shall be set to ONE if the last Byte of this Logical Record is in this Information Matrix, else it shall be set to ZERO. Bits 4 and 3 of byte 0: These bits are not specified by this ECMA Standard and shall be ignored in interchange. Bits 2 to 0 of byte 0 and bits 7 to 0 of byte 1 : These bits shall express the 11-bit count of the number of bytes within this Information Matrix of this Logical Record. Bit 0 of byte 1 shall be the least significant bit of this count. The count shall also include CRC bytes (see Rule 1) if they are in this Information Matrix.

- 51 -

Bytes 2 to 4: These bytes shall express the 24-bit count of the number of bytes of this Logical Record before compression. Bit 0 of byte 4 shall be the least significant bit of this count. If this Logical Record is not compressed, these bits are undefined by this ECMA Standard and shall be ignored in interchange.

Rule 3: If fifth or subsequent Logical Record (including two CRC bytes described in Rule 1) ends in this Information Matrix and a number of remaining Data bytes is less than six, next Logical Record shall start in next Information Matrix and the remaining Data bytes shall be padded with ZEROs.

Rule 4: When the number of Data bytes is less than 2,048 the remaining bytes are set to all ZEROs. 11.2.1.1.3.2 Optional ECC3 Block ECC3, if present, is applicable to Frames in the partition in which bit 7 of byte 1 of the ID Information of Format Blocks is ONE. In the Partition in which ECC3 is applicable, ECC3 bytes shall be entered into Data bytes of Information Blocks having the number 14 or 15 as the Information Block Number (described in 11.4.1) in Data Frames. ECC3 shall be a GF(28) Reed-Solomon Code (16, 14, 3). Calculation in a GF(28) shall be defined by: G(x) = x8 + x4 + x3 + x2 + 1 A primitive element in GF(28) is 00000010. The ECC3 bytes shall satisfy: HR V R = 0  1 1 1 HR =  15 14 13 α α α

...

... α

1 1  α 1

 Dn ,0    D  n ,1   Dn ,2      VR =  Dn ,12    Dn ,13    Rn ,14     Rn ,15  Dn,x and Rn,y is the byte in column c and row r in the Information Block which has x as the Information Block Number in a Frame, or the Information Block which has y as Information Block Number in a Frame where: n = 50 to 2 097 n = (c+50 r) c = 0 to 49 r = 1 to 41 x and y are the Information Block numbers described in 11.4.1 x = 0 to 13 y = 14 or 15 Rn,y is the ECC3 byte.

- 52 -

11.2.1.1.3.3 Long File Mark Block Data bytes in Long File Mark Block are undefined and shall be ignored in interchange. 11.2.1.1.3.4 Short File Mark Block Data bytes in Short File Mark Block are undefined and shall be ignored in interchange. 11.2.1.1.3.5 Set Mark Block Data bytes in Set Mark Block are undefined and shall be ignored in interchange. 11.2.1.1.3.6 Gap Block Data bytes in Gap Block are undefined and shall be ignored in interchange. 11.2.1.1.3.7 End of Data Block Data bytes in End of Data Block are undefined and shall be ignored in interchange. 11.2.1.1.3.8 Format Block Data bytes in Format Block are undefined and shall be ignored in interchange. 11.2.1.1.3.9 Data Block in the System Area Data bytes in a Data Block in the System Area are not specified by this ECMA Standard and shall be ignored in interchange. The data for this Block is generated by the tape system (see annex G). 11.2.1.2

G2 Group A G2 group shall consist of a G1 group with the addition of two CRC bytes. The two CRC bytes shall be computed over the 2 098 bytes of the G1 group and entered into cells 48/41 and 49/41. They are generated as follows: D k is the byte in column c and row r where: k = 0 to 2 097 k = (c + 50 r) c = 0 to 49 r = 0 to 41 D k,0 , D k,1 ...., D k,7 denote the 8 bits of D k , where D k,7 is the high order bit. j=7

Dk ( x ) =

∑D x j=0

k = 2 097

D( x) =

k,j

∑ D ( x) x k =0

8 ( 2 097 − k )

G CRC (x) = x 16 + x 12 + x 5 + 1 C(x) = D(x)mod G CRC (x) j =7

C( x) + x

+ x + x + x + x +1=

∑ (CH x j =0

j +8

+ CL j x )

where: CH 0 , CH 1 , ...., CH 7 are the bits of the cell 48/41, CH 7 being the most significant bit. CL 0 , CL 1 , ...., CL 7 are the bits of the cell 49/41, CL 7 being the most significant bit.

- 53 -

11.2.1.3

G3 Group A G3 group shall consist of a G2 group with the addition of the Error Correcting Code (ECC) bytes. The ECC bytes are obtained from two error detection and correction codes C1 and C2 computed over the bytes of a Group 2. The C2 ECC bytes shall be computed for the byte position with column numbers in the range 0 to 49 in each row having a row number in the range 42 to 47 from the bytes with the same column number in all the other rows. The C1 ECC bytes shall then be computed for byte positions with column numbers in the range 50 to 55 in all rows from all the other bytes in the same rows. In rows with a row number in the range 42 to 47, these C1 ECC bytes shall be computed from the C2 ECC bytes previously computed. These two computations yield the bytes for the byte positions indicated by the shaded portions of the array of figure 29.

C1 shall be a GF(2 8 ) Reed-Solomon Code (56, 50, 7) C2 shall be a GF(2 8 ) Reed-Solomon Code (48, 42, 7) Calculation in a GF(2 8 ) shall be defined by: G (x) = x 8 + x 4 + x 3 + x 2 + 1 A primitive element in GF(2 8 ) is 00000010. The C1 and C2 ECC bytes shall satisfy: HP VP = 0 HQ VQ = 0 The generator polynomials shall be: i =5

(

)

(

)

GP ( x) = ∏ x − α i =0 i =5

GQ ( x) = ∏ x − α i =0

 1  55 α  110 α H P =  165 α  220 α  α 20

...

... α 2 ... α 4

108

106

162

159

216

212

... α 6 ... α 8 ... α 10

1

  1  1  1 1 1

Note The last row of H P may be equivalently written as 275 270 265 … 10 5 1 . The identity 255 = 1 has been used to simplify the matrix elements. 1  1  α 47 α 46  94 92 α α H Q =  141 138 α α  188 184 α α α 235 α 230

135

180

225

... ... ... ... ... ...

1

  1 1  1 1 1

- 54 -

VP =

 D 0 ,k  D 1,k  D 2 ,k  D. 3. ,.k  ...  D 4 7 ,k  D 4 8 ,k  D 4 9 ,k 5 0 ,k P P  P5 1 , k  P55 23 ,,kk  P5 4 , k  P5 5 , k 

 D m ,0    D m ,1    D m ,2    .D. .m , 3    . . .   D m ,39    D m ,40    VQ =  D m , 4 1  m ,42  Q  Q  Q m ,43    Q mm ,, 44 45    Q m ,46    Q m ,47     

where D i,j = content of cell i / j P i,j = C1 ECC bytes Q i,j = C2 ECC bytes i = column number j = row number For C1: k = 0, 1, ..., 47 if k = 42, 43, ..., 47, then D i,j in V p is read as Q i,j For C2: m = 0, 1, ..., 55

11.3

Sync Block Sync Block Data shall be transformed into a 115-byte Sync Block by prefixing a 3-byte Sync Block Header (see figure 30).

11.3.1

Sync Block Data A Sync Block Data shall consist of 112 cells of consecutive 2 rows, even and odd, of Information Matrix, which are shown as figure 29 and 30.

11.3.2

Sync Block Header Sync Block Header shall be consist of 3 bytes as follows

Byte 0 : Sync Block ID W1 Byte 1 : Sync Block ID W2 Byte 2 : Sync Block ID Parity 11.3.2.1

Sync Block ID W1 These bits shall express in binary notation the Sync Block number described in 11.4.2. Bit 0 of this byte shall be the least significant bit.

11.3.2.2

Sync Block ID W2 Bits 7 to 4 : These bits shall express in binary notation the Absolute Frame Address mod 16. Bit 4 shall be the least significant bit. Bits 3 to 0 : These bits shall express an Area ID.

They shall be set to 0000 if the Sync Block is in a Data Area. They shall be set to 0010 if the Sync Block is in a Reference Area. They shall be set to 1100 if the Sync Block is in a System Area. They shall be set to 1111 if the Sync Block is in a End of Data Area.

- 55 -

11.3.2.3

Sync Block ID Parity Bit n of Sync Block ID Parity shall be Exclusive OR of Bit n of Sync Block ID W1 and Bit n of Sync Block ID W2 (n:0 to 7). Bit 7

ID W1 ID W2

Sync Block Number in the track Absolute Frame Address mod 16

Area ID

ID Parity

Exclusive OR of W1 and W2

Sync

Byte with column number 00 and even row number r Byte with column number 01 and even row number r … Byte with column number 54 and even row number r Byte with column number 55 and even row number r Byte with column number 00 and odd row number r+1 Byte with column number 01 and odd row number r+1 … Byte with column number 54 and odd row number r+1 Byte with column number 55 and odd row number r+1 Figure 30 - Sync Block

11.3.3

11.4

Sync Block Header in Preamble Zone The Preamble Zone in each track includes one Sync Block Header. Sync Block ID W1 of the Sync Block Header shall be set to (FF) in binary notation. Bit 0 of the byte shall be the least significant bit. Sync Block ID W2 shall be used in a manner identical with that of Sync Blocks in the Data Zone. The position of the recorded Sync Block Header in the Preamble Zone and the contents of Preamble Zone are described in clause 14.2.

Data Zone A Data Zone of a Track shall consist of eight Information Blocks. Each Information Block shall consist of 24 Sync Blocks into which an Information Matrix is divided. Each Information Block shall be uniquely identified in a Frame by bits 7 to 4 of byte 0 of ID Information of the Information Block. Each Sync Block shall be uniquely identified in a track by Sync Block ID W1.

11.4.1

Identification and arrangement of Information Blocks in the Data Zone of a Frame Bits 7 to 4 of byte 0 of the ID Information of an Information Block shall express in binary notation the Information Block Number in the Data Zone of a frame in the range of 0 to 15. Bit 4 of byte 0 is the least significant bit. In a frame, the Information Block having the smallest Logical Block Address shall have the smallest Information Block Number. An arrangement of Information Blocks in a Frame shall be as shown in figure 31 if the Frame is not a rewritten Frame or if the Frame has been rewritten an even number of times. The numbers in figure 31 express this Information Block number. An arrangement of Information Blocks in a Frame shall be as shown in figure 32 if the Frame has been rewritten an odd number of times. The numbers in figure 32 express this Information Block number.

11.4.2

Identification and arrangement of Sync Blocks in Data Zone of a Track Sync Block ID W1 of a Sync Block shall express the Sync Block number in a Track in binary notation in the range 0 to 191. Bit 0 is the least significant bit. Sync Block numbers are incremented sequentially starting with 0. An arrangement of Sync Blocks shall be as shown in figure 33. The numbers in figure 33 express this Sync Block number.

- 56 -

Figure 31 - Arrangement of Information Blocks in original or even times rewritten Frame

Figure 32 - Arrangement of Information Blocks in odd times rewritten Frame

Figure 33 - Arrangement of Sync Blocks in a Frame

Method of recording The method of recording shall be

a ONE is represented by a flux transition at the centre of a bit cell; a ZERO is represented by the absence of a flux transition in the bit cell. 12.1

Physical recording density The nominal maximum physical recording density is 3 658,1 ftpmm. The resulting nominal bit cell length is 0,273 36 m.

12.2

Long-term average bit cell length The long-term average bit cell length for each track shall be measured over its 192 recorded Sync Blocks in the Data Zone (see 14.1). It shall be within 0,2% of the nominal bit cell length.

- 57 -

12.3

Short-term average bit cell length The short-term average bit cell length, referred to a particular bit cell, shall be the average of the preceding 30 bit cells. It shall be within 0,35% of the long-term average bit cell length for the preceding track of the same azimuth.

12.4

Rate of change The short-term average bit cell length shall not change at a rate greater than 0,05% per bit cell.

12.5

Bit shift The maximum displacement of any ONEs zero crossing, exclusive of missing pulses, shall not deviate by more than 20% from the expected nominal position as defined by the short-term average bit cell length. See annex D for the method of measurement.

12.6

Read signal amplitude The Average Signal Amplitude at the physical recording density of 3 658,1 ftpmm of an interchange cartridge shall be between 89% and 141% of the Standard Reference Amplitude.

12.7

Recording current The recording current shall be between 94% and 106% of the Test Recording Current for recorded frequencies associated with a recording density of 914,5 ftpmm, 1 829,0 ftpmm and 3 658,1 ftpmm.

13 13.1

Track geometry Track configuration The helical track pattern is formed by the relationship between the direction of tape motion and the axis of rotation of a pair of heads, one of which has a positive azimuth angle and the other a negative azimuth angle. The direction of recording is away from the Tape Reference Edge. The track configuration is shown in figure 34.

- 58 -

A L P T R

: Tape width : Track length : Track pitch : Track width : Data Zone reference line : Track angle Figure 34 - Track configuration (view on recording surface)

13.2

Average track pitch The average track pitch, taken over any group of 30 consecutive tracks, shall be 11,00 m 0,25 m.

13.3

Variations of the track pitch The change of track pitch between successive track pitches shall not exceed 2,0 %, excluding the effect of an appending operation (see 16.5.5).

13.4

Track width The nominal track width is 11,000 m. The measured track width shall be 11,0 m 1,5 m.

13.5

Track angle The nominal angle of each track with respect to the Tape Reference Edge shall be 4 o 53'42,1".

13.6

Track edge linearity The linearity of the leading edge of each track shall be within 5 m, when measured according to annex E.

13.7

Track length The length of each track shall be 62,163 mm 0,124 mm.

- 59 -

13.8

Data Zone reference The nominal data zone reference point of the tape is 1,869 mm from the Tape Reference Edge.

13.9

Azimuth angles The positive azimuth angle shall be 20 o 00'36,1" 15'00,0". The negative azimuth angle shall be 9 o 59'23,9" 15'00,0".

Recording pattern Each 8-bit byte of the Sync Blocks shall be represented on the tape by a 10-bit pattern. Annex C specifies for each 8-bit byte the 10-bit pattern to be recorded. The bits of the 10-bit pattern are called Channel bits.

14.1

Recorded Sync Block A Recorded Sync Block shall consist of 1 160 Channel bits representing the 115 8-bit bytes of a Sync Block preceded by a Sync field of 10 Channel bits with one of the following patterns: a) 0100010001 b) 1100010001 Pattern a) shall be used for Q' = -1, DC = 0, Q = 1; pattern b) for Q' = 1, DC = 0, Q = 1 (see annex C). Either pattern may be used when there is no preceding pattern, and hence no value of Q'. See C.1 for the order of recording.

14.2

Preamble Zone A Preamble Zone shall be recorded with 372 10-bit patterns, which consist of 256 10-bit patterns of 1111111111, Sync field, Sync Block Header, and 112 10-bit patterns of 1111111111. See figure 35 for the structure of the Preamble Zone. Sequence of recording

2 560 Channel bits

10 Channel bits

30 Channel bits

1 120 Channel bits

11111…..11111

Sync field

Sync Block Header

11111…..11111

Figure 35 - Structure of Preamble Zone

14.3

Postamble Zone A Postamble zone shall be recorded with 96 instances of the 10-bit pattern of 1111111111.

Format of a track

15.1

Track capacity Each track shall consist of Preamble Zone, Data Zone and Postamble Zone, shown in table 5. Table 5 - Format of a track

Sequence of recording

15.2

Zone

Contents

Preamble Zone

Preamble pattern

Data Zone Postamble Zone

Number of 10-bit patterns 372

Recorded Sync Blocks

22 272

22 740

Postamble pattern

Positioning accuracy The positioning reference point is the start of the first Sync Block of a Data Zone, the Data Zone Reference. In the direction perpendicular to the Tape Reference Edge, the Data Zone Reference shall be 1,869 mm 0,018 mm. The position of the start of the first Sync Block is that of its first bit cell on the centreline of the track. This requirement shall not apply at an append point.

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15.3

Tracking scheme This format does not include any aids specifically designed to assist a reading drive in maintaining tracking. However, the specifications of clause 15.2 limit the extent of the conditions that it must handle correctly.

Layout of a Single Data Space tape (figure 36) A magnetic tape shall be recorded as a Single Data Space tape or as a Partitioned tape. The layout of a Single Data Space tape is specified in this clause, that of a Partitioned tape in clause 17. The layout of the Single Data Space tape consists of six areas:

16.1

the Device Area the Reference Area the System Area the Data Area the EOD Area the Post-EOD Area

Frame type There are eight types of Frames.

16.1.1

Data Frame A Data Frame shall include a minimum of one Data Block in a partition in which ECC3 is disabled or it shall include two ECC3 Blocks and a minimum of one Data Block in a partition in which ECC3 is enabled. A Data Frame may include Gap Blocks and/or Short File Mark Blocks.

16.1.2

Gap Frame All Information Blocks in a Gap Frame shall be Gap Blocks.

16.1.3

Long File Mark Frame All Information Blocks in a Long File Mark Frame shall be Long File Mark Blocks.

16.1.4

Short File Mark Frame A Short File Mark Frame shall include a minimum of one Short File Mark Block. The remaining Information Blocks shall be Gap Blocks.

16.1.5

Set Mark Frame All Information Blocks in a Set Mark Frame shall be Set Mark Blocks.

16.1.6

End of Data Frame All Information Blocks in a End of Data Frame shall be End of Data Blocks.

16.1.7

Format Frame All Information Blocks in a Format Frame shall be Format Blocks.

16.1.8

Data Frame in System Area All Information Blocks in a Data Frame in a System Area shall be Data Blocks in System Area.

16.2

Device Area This area shall be the first area on the magnetic tape and shall extend from PBOT to LBOT. It shall not be used for writing data for interchange. Its length, measured parallel to the Tape Reference Edge, from PBOT to the first bit of the first Information Block of the first recorded track of the Reference Area, shall be 735 mm 10 mm.

16.3

Reference Area This area shall consist of 600 Format Frames. The first Frame of the Reference Area starts at LBOT and has an Absolute Frame Address of 0. The Reference Area is used as a physical reference when updating the System Log.

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16.4

System Area This area shall consist of Guard Band No.1, the System Log Preamble, System Log, System Log Postamble, Guard Band No.2, and the Data Area Preamble.

16.4.1

Guard Band No.1 This band shall have a nominal length equivalent to 10 Frames, with a minimum length of five and a maximum length of 15 Frames. The Frames written in this band shall be Gap Frames. It is used to accommodate positioning tolerances when updating the System Log. Discontinuities or repetitions of the Absolute Frame Address may occur in this band. The recorded signals are not defined in this band and shall be ignored in interchange.

16.4.2

System Log Preamble The System Log Preamble shall consist of 100 Gap Frames, having the Absolute Frame Addresses 610 to 709.

16.4.3

System Log The System Log shall consist of 100 Data Frames in System Area, having the Absolute Frame Addresses 710 to 809. Note The history data in the System log cannot be relied upon to be always accurate, because drives cannot update the log if the Write-inhibit Hole is open. It may also be destroyed during initialization.

16.4.4

System Log Postamble The System Log Postamble shall consist of 30 Gap Frames, having the Absolute Frame Addresses 810 to 839. Note It is recommended that the continuum comprising the System log Preamble, System log and System log Postamble be written in a continuous motion when the System log is updated.

16.4.5

Guard Band No.2 This band shall have a nominal length equivalent to 60 Frames. Its actual length depends on the actual length of Guard Band No.1 and on the actual position of the first Frame of the Data Area Preamble, and hence may vary from 30 to 90 Frames. The Frames written in this band shall be Gap Frames. Discontinuities or repetitions of the Absolute Frame Address may occur in this band. The recorded signals are not defined in this band and shall be ignored in interchange.

16.4.6

Data Area Preamble The Data Area Preamble shall consist of 100 Gap Frames, having the Absolute Frame Addresses 900 to 999. The Data Area Preamble shall immediately precede the Data Area and be contiguous with it.

16.5

Data Area A Data Area must include at least one Data Frame. A Data Area may include a minimum of one Long File Mark and/or a minimum of one Short File Mark and/or a minimum of one Set Mark and/or a minimum of one Gap Frame.

16.5.1

Long File Mark A Long File Mark shall consist of one Gap Frame, one Long File Mark Frame and one Gap Frame. The Search Information and the ID Information shall be the same for all Information Blocks of the Long File Mark Frame of a Long File Mark.

16.5.2

Short File Mark A Short File Mark shall consist of one Short File Mark Block.

16.5.3

Set Mark A Set Mark shall consist of one Gap Frame, one Set Mark Frame and one Gap Frame.

- 62 -

The Search Information and the ID Information shall be the same for all Information Blocks of the Set Mark Frame of a Set Mark. 16.5.4

Write operation When data to be written is absent during the write operation as a result of a write command, a minimum of one Gap Frame shall be written subsequent to the last Data Frame. When the Write operation resulting from a Write command is completed, a minimum of one Gap Frame shall be written subsequent to the last Data Frame.

16.5.5

Append and overwrite operations When new data is appended to data previously recorded on the tape, or existing data is overwritten by new data, the append or overwrite operation shall start at the Frame following a Gap Frame previously written. The Gap Frame may be in the Data Area Preamble, in a Long File Mark, in an EOD Area or as described in clause 16.5.4. The first Frame written by the append or overwrite operation shall be a Gap Frame. No unrecorded space or Absolute Frame Address discontinuity or repetition is allowed at appending or overwriting point.

16.5.6

Rewritten Frames In the Data Area, a Data Frame, a Short File Mark Frame or a Gap Frame may be repeated by rewriting it further along the tape. The repeated Frame may be written after two other Frames have been written. Such sequence (i.e. the original or rewritten Frame and the two following Frames) can be repeated many times, e.g. to allow skipping over bad areas on the tape. The maximum number of instances of a sequence shall be 256, i.e. the original and up to 255 repetitions. The contents of each Information Block in a rewritten Frame is the same as that of the Information Block having the same Information Block Number of the original Frame, except for the Absolute Frame Address in Search Information, byte 3 of ID Information, Sync Block ID W1 and Sync Block ID W2.

16.6

EOD Area The Data Area shall be followed by an EOD Area. It shall consist of 10 Gap Frames and 1 000 EOD Frames, and shall start after the last Frame recorded in the Data Area. More than one EOD Area may exist on a tape. The EOD Area closest to LBOT shall be the only valid one for information interchange.

16.7

Post-EOD Area The EOD Area shall be followed by a Post-EOD Area which extends to PEOT. The contents of this PostEOD Area are not defined for interchange. Its length, measured parallel to the Tape Reference Edge, shall be 200 mm min.

- 63 -

Figure 36 - Layout of a Single Data Space tape

Layout of a partitioned tape (figure 37) A partitioned tape provides on one magnetic tape two independent partitions, each of which has a structure and properties similar to those of the recorded parts of a Single Data Space tape. With the exception of the differences described hereafter, all of the foregoing descriptions of the recorded format shall apply to each partition of a partitioned tape.

17.1

Overall magnetic tape layout The layout of a partitioned tape shall consist of the Device Area, Partition 1 and Partition 0, which shall be located in that order from PBOT to PEOT.

17.1.1

Device Area This area shall be identical with that of a Single Data Space tape.

17.1.2 Partition 1 17.1.2.1 Physical End of Partition 1 (PEOP 1) The PEOP 1 shall be a reference point at the Partition Boundary. This reference point is intended for use in a manner identical with that of PEOT on a Single Data Space tape, i.e. no recording shall occur within Partition 1 beyond PEOP 1, except during initialization. Note After overwriting commences in Partition 1, all data between the current recording point and PEOP1 is logically inaccessible. Data in Partition 0 is unaffected.

- 64 -

17.1.2.2

Partition 1 Post-EOD Area If the end of the EOD Area occurs before PEOP 1, it shall be followed by a Post-EOD Area which extends to PEOP 1. The contents of this Partition 1 Post-EOD Area are not defined for interchange.

17.1.3 Partition 0 17.1.3.1 Logical Beginning of Partition 0 (LBOP 0) The LBOP 0 is the Partition Boundary. The first Frame after LBOP 0 shall have the Absolute Frame Address of zero.

17.2

Partition Identification The least significant bit of byte 18 of Search Information (see 11.2.1.1.1.6) shall be set to ZERO for Partition 0 and to ONE for Partition 1.

- 65 -

Figure 37 - Layout of a partitioned tape

- 66 -

- 67 -

Annex A (normative)

Measurement of light transmittance of tape and leaders

A.1

Introduction The following description outlines the general principle of the measuring equipment and measuring method to be applied when measuring the light transmittance of tape. For the purpose of this ECMA Standard "light transmittance" is defined by convention as the relationship between the reading obtained from the measuring equipment with the test piece inserted and the reading obtained when no test piece is present. The transmittance value is expressed as the percentage ratio of the two readings.

A.2

Description of the measuring equipment The equipment shall consist of

A.2.1

the radiation source; the radiation receiver; the measuring mask; the optical path; the measuring circuitry.

Radiation source An infra-red light-emitting diode (LED) with the following parameters shall be used: wavelength at peak emission half-power bandwidth

A.2.2

: 850 nm 50 nm : 50 nm

Radiation receiver A flat silicon photo diode shall be used. It shall be operated in the short circuit mode.

A.2.3

Measuring mask The measuring mask shall have a thickness of 2 mm and a circular aperture of diameter d such that the area is 80 % to 100 % of the active area of the photo diode. The surface of the mask shall be matt black. The test piece shall be held firmly against the mask to cover the aperture and to ensure that no ambient light leaks past.

A.2.4

Optical path (figure A.1) The optical path shall be perpendicular to the mask. The distance from the emitting surface of the LED to the mask shall be L=

d 2 tan α

where d is in mm and is the angle where the relative intensity of the LED is equal to, or greater than, 95% of the maximum intensity of the optical axis.

A.2.5

Finish The whole assembly shall be enclosed in a matt black case.

- 68 -

A.2.6

Measuring circuitry (figure A.2) The components of the measuring circuitry are E R LED Di A R0, R1 S V

: regulated power supply with variable output voltage : current-limiting resistor : light-emitting diode : silicon photo diode : operational amplifier : feedback resistors : gain switch : voltmeter

The forward current of the LED, and consequently its radiation power, can be varied by means of the power supply E. Di is operating in the short circuit mode. The output voltage of the operational amplifier is given by V0 = Ik x Rf where: I k is the short-circuit current of Di. The output voltage is therefore a linear function of the light intensity. R f0 and R f1 shall be low temperature-drift resistors with an accuracy of 1%. The following ratio applies Rf 0 Rf 1

A.3

1 20

Measuring method Set switch S to position 0. With no test piece mounted vary the supply voltage of E until voltmeter V reads full scale (100 %). Mount a leader or trailer tape on the mask. The reading of the voltmeter shall be in the range 60 % to 100 %.

Mount a test piece of magnetic tape on the mask. Set switch S to position 1. Full deflection of the voltmeter now represents a light transmittance of 5 %.

- 69 -

Figure A.1 - Optical arrangement

Rf 0 R

0 1

Rf 1 LED Di

E V

9 3 -0 1 2 4 -A

Figure A.2 - Measuring circuitry

- 70 -

- 71 -

Annex B (normative)

Measurement of Signal-to-Noise Ratio The Signal-to-Noise Ratio shall be measured using a spectrum analyzer with a resolution bandwidth of 10 kHz. Unless otherwise stated, the test conditions are those defined in clause 10 of this ECMA Standard.

B.1

a.c. erase the tape to be tested.

B.2

Record the tape at 3 658,1 ftpmm. This recording frequency is denoted f1.

B.3

Measure the rms signal amplitude by gathering the sweep of the spectrum analyzer over a length of track that corresponds to a 160° ± 10° arc of scanner rotation. The centre of this arc shall be within 5° of the centre of the arc of the read head’ s contact with the tape. Each sweep yields one measured value. Compute the average of 8 measured values. This is Stape. During each of the same 8 sweeps, measure the total rms noise level at frequency 2 , where 2 is 2 MHz less than 1 . Each sweep yields one measured value. Compute the average of 8 measured values. This is Ntotal.

B.4

Measure the rms read channel noise level at frequency f2 over the same 160° arc, without a tape loaded but with the motors running. Each sweep yields one measured value. Compute the average of 8 measured values. This is N amp.

B.5

Compute the Signal-to-Noise Ratio for this pass, 20 log

S tape N tape

dB,

where N tape = N amp N tape

N total − N amp shall be less than 70%.

B.6

Repeat B.3 to B.5 for at least 64 passes. Take the average of the 64 Signal-to-Noise Ratios to determine the Signal-toNoise Ratio for the tape (SNRtape).

B.7

Repeat B.1 to B.6 for the Secondary Standard Reference Tape, to give SNRMSRT The Signal-to-Noise Ratio characteristic is SNRtape - SNR MSRT dB.

- 72 -

- 73 -

Annex C (normative)

Representation of 8-bit bytes by 10-bit patterns

C.1

The 8-bit bytes are represented with the most significant bit to the left and the least significant bit to the right. The 10-bit patterns are represented with the bit recorded first to the left and the bit recorded last to the right.

C.2

The magnetic recording system chosen requires that the d.c. level of the recorded signals be maintained near zero. All 10-bit patterns are either balanced to a d.c. level of zero or have a d.c. imbalance of 6:4 or 4:6. Each 10-bit pattern is accompanied by an indicator Q which instructs the translator which of the two alternative patterns should be selected for the next 10-bit pattern in order to maintain the lowest d.c. level.

C.3

is the d.c. information of the previous pattern.

is the d.c. information of the current pattern.

The left-hand column indicates the hexadecimal notation of the 8-bit byte for ease of search.

- 74 -

Q’ = - 1

8-bit byte

Q’ = 1

10-Channel bit pattern

(00) (01) (02) (03) (04) (05) (06) (07)

00000000 00000001 00000010 00000011 00000100 00000101 00000110 00000111

0101010101 0101010111 0101011101 0101011111 0101001001 0101001011 0101001110 0101011010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

0101010101 0101010111 0101011101 0101011111 0101001001 0101001011 0101001110 0101011010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

(08) (09) (0A) (0B) (0C) (0D) (0E) (0F)

00001000 00001001 00001010 00001011 00001100 00001101 00001110 00001111

0101110101 0101110111 0101111101 0101111111 0101101001 0101101011 0101101110 0101111010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

0101110101 0101110111 0101111101 0101111111 0101101001 0101101011 0101101110 0101111010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

(10) (11) (12) (13) (14) (15) (16) (17)

00010000 00010001 00010010 00010011 00010100 00010101 00010110 00010111

1101010010 0100010010 0101010010 0101110010 1101110001 1101110011 1101110110 1101110010

0 2 0 0 2 2 2 0

1 -1 -1 1 1 -1 -1 -1

1101010010 1100010010 0101010010 0101110010 0101110001 0101110011 0101110110 1101110010

0 -2 0 0 -2 -2 -2 0

-1 -1 1 -1 1 -1 -1 1

(18) (19) (1A) (1B) (1C) (1D) (1E) (1F)

00011000 00011001 00011010 00011011 00011100 00011101 00011110 00011111

0101100101 0101100111 0101101101 0101101111 0101111001 0101111011 0101111110 0101101010

2 2 2 2 2 2 2 2

-1 1 1 -1 1 -1 -1 -1

1101100101 1101100111 1101101101 1101101111 1101111001 1101111011 1101111110 1101101010

-2 -2 -2 -2 -2 -2 -2 -2

-1 1 1 -1 1 -1 -1 -1

(20) (21) (22) (23) (24) (25) (26) (27)

00100000 00100001 00100010 00100011 00100100 00100101 00100110 00100111

0111010101 0111010111 0111011101 0111011111 1111010001 1111010011 1111010110 0111011010

0 0 0 0 2 2 2 0

-1 1 1 -1 1 -1 -1 -1

0111010101 0111010111 0111011101 0111011111 0111010001 0111010011 0111010110 0111011010

0 0 0 0 -2 -2 -2 0

1 -1 -1 1 1 -1 -1 1

- 75 -

Q’ = - 1

Q’ = 1

8-bit byte

10-Channel bit pattern

(28) (29) (2A) (2B) (2C) (2D) (2E) (2F)

00101000 00101001 00101010 00101011 00101100 00101101 00101110 00101111

0111110101 0111110111 0111111101 0111111111 0111101001 0111101011 0111101110 0111111010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

0111110101 0111110111 0111111101 0111111111 0111101001 0111101011 0111101110 0111111010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

(30) (31) (32) (33) (34) (35) (36) (37)

00110000 00110001 00110010 00110011 00110100 00110101 00110110 00110111

0111010010 1110010010 1111010010 1111110010 0111110001 0111110011 0111110110 0111110010

0 2 0 0 2 2 2 0

1 -1 -1 1 1 -1 -1 -1

0111010010 0110010010 1111010010 1111110010 1111110001 1111110011 1111110110 0111110010

0 -2 0 0 -2 -2 -2 0

-1 -1 1 -1 1 -1 -1 1

(38) (39) (3A) (3B) (3C) (3D) (3E) (3F)

00111000 00111001 00111010 00111011 00111100 00111101 00111110 00111111

0111000101 0111000111 0111001101 0111001111 0111011001 0111011011 0111011110 0111001010

2 2 2 2 2 2 2 2

-1 1 1 -1 1 -1 -1 -1

1111000101 1111000111 1111001101 1111001111 1111011001 1111011011 1111011110 1111001010

-2 -2 -2 -2 -2 -2 -2 -2

-1 1 1 -1 1 -1 -1 -1

(40) (41) (42) (43) (44) (45) (46) (47)

01000000 01000001 01000010 01000011 01000100 01000101 01000110 01000111

0100010101 0100010111 0100011101 0100011111 0101010001 0101010011 0101010110 0100011010

2 2 2 2 2 2 2 2

1 -1 -1 1 1 -1 -1 1

1100010101 1100010111 1100011101 1100011111 1101010001 1101010011 1101010110 1100011010

-2 -2 -2 -2 -2 -2 -2 -2

1 -1 -1 1 1 -1 -1 1

(48) (49) (4A) (4B) (4C) (4D) (4E) (4F)

01001000 01001001 01001010 01001011 01001100 01001101 01001110 01001111

0100110101 0100110111 0100111101 0100111111 0100101001 0100101011 0100101110 0100111010

2 2 2 2 2 2 2 2

-1 1 1 -1 1 -1 -1 -1

1100110101 1100110111 1100111101 1100111111 1100101001 1100101011 1100101110 1100111010

-2 -2 -2 -2 -2 -2 -2 -2

-1 1 1 -1 1 -1 -1 -1

- 76 -

Q’ = - 1

Q’ = 1

8-bit byte

10-Channel bit pattern

(50) (51) (52) (53) (54) (55) (56) (57)

01010000 01010001 01010010 01010011 01010100 01010101 01010110 01010111

0100100101 0100100111 0100101101 0100101111 0100111001 0100111011 0100111110 0100101010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

0100100101 0100100111 0100101101 0100101111 0100111001 0100111011 0100111110 0100101010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

(58) (59) (5A) (5B) (5C) (5D) (5E) (5F)

01011000 01011001 01011010 01011011 01011100 01011101 01011110 01011111

0110100101 0110100111 0110101101 0110101111 0110111001 0110111011 0110111110 0110101010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

0110100101 0110100111 0110101101 0110101111 0110111001 0110111011 0110111110 0110101010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

(60) (61) (62) (63) (64) (65) (66) (67)

01100000 01100001 01100010 01100011 01100100 01100101 01100110 01100111

0010010101 0010010111 0010011101 0010011111 1010010001 1010010011 1010010110 0010011010

0 0 0 0 2 2 2 0

-1 1 1 -1 1 -1 -1 -1

0010010101 0010010111 0010011101 0010011111 0010010001 0010010011 0010010110 0010011010

0 0 0 0 -2 -2 -2 0

1 -1 -1 1 1 -1 -1 1

(68) (69) (6A) (6B) (6C) (6D) (6E) (6F)

01101000 01101001 01101010 01101011 01101100 01101101 01101110 01101111

0010110101 0010110111 0010111101 0010111111 0010101001 0010101011 0010101110 0010111010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

0010110101 0010110111 0010111101 0010111111 0010101001 0010101011 0010101110 0010111010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

(70) (71) (72) (73) (74) (75) (76) (77)

01110000 01110001 01110010 01110011 01110100 01110101 01110110 01110111

0010010010 1011010010 1010010010 1010110010 0010110001 0010110011 0010110110 0010110010

0 2 0 0 2 2 2 0

1 -1 -1 1 1 -1 -1 -1

0010010010 0011010010 1010010010 1010110010 1010110001 1010110011 1010110110 0010110010

0 -2 0 0 -2 -2 -2 0

-1 -1 1 -1 1 -1 -1 1

- 77 -

Q’ = - 1

Q’ = 1

8-bit byte

10-Channel bit pattern

(78) (79) (7A) (7B) (7C) (7D) (7E) (7F)

01111000 01111001 01111010 01111011 01111100 01111101 01111110 01111111

0011100101 0011100111 0011101101 0011101111 0011111001 0011111011 0011111110 0011101010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

0011100101 0011100111 0011101101 0011101111 0011111001 0011111011 0011111110 0011101010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

(80) (81) (82) (83) (84) (85) (86) (87)

10000000 10000001 10000010 10000011 10000100 10000101 10000110 10000111

1010010101 1010010111 1010011101 1010011111 1010001001 1010001011 1010001110 1010011010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

1010010101 1010010111 1010011101 1010011111 1010001001 1010001011 1010001110 1010011010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

(88) (89) (8A) (8B) (8C) (8D) (8E) (8F)

10001000 10001001 10001010 10001011 10001100 10001101 10001110 10001111

1010110101 1010110111 1010111101 1010111111 1010101001 1010101011 1010101110 1010111010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

1010110101 1010110111 1010111101 1010111111 1010101001 1010101011 1010101110 1010111010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

(90) (91) (92) (93) (94) (95) (96) (97)

10010000 10010001 10010010 10010011 10010100 10010101 10010110 10010111

1100100101 1100100111 1100101101 1100101111 1100111001 1100111011 1100111110 1100101010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

1100100101 1100100111 1100101101 1100101111 1100111001 1100111011 1100111110 1100101010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

(98) (99) (9A) (9B) (9C) (9D) (9E) (9F)

10011000 10011001 10011010 10011011 10011100 10011101 10011110 10011111

1010100101 1010100111 1010101101 1010101111 1010111001 1010111011 1010111110 1010101010

2 2 2 2 2 2 2 2

-1 1 1 -1 1 -1 -1 -1

0010100101 0010100111 0010101101 0010101111 0010111001 0010111011 0010111110 0010101010

-2 -2 -2 -2 -2 -2 -2 -2

-1 1 1 -1 1 -1 -1 -1

- 78 -

Q’ = - 1

Q’ = 1

8-bit byte

10-Channel bit pattern

(A0) (A1) (A2) (A3) (A4) (A5) (A6) (A7)

10100000 10100001 10100010 10100011 10100100 10100101 10100110 10100111

1011010101 1011010111 1011011101 1011011111 1011001001 1011001011 1011001110 1011011010

2 2 2 2 2 2 2 2

1 -1 -1 1 -1 1 1 1

0011010101 0011010111 0011011101 0011011111 0011001001 0011001011 0011001110 0011011010

-2 -2 -2 -2 -2 -2 -2 -2

1 -1 -1 1 -1 1 1 1

(A8) (A9) (AA) (AB) (AC) (AD) (AE) (AF)

10101000 10101001 10101010 10101011 10101100 10101101 10101110 10101111

1011110101 1011110111 1011111101 1011111111 1011101001 1011101011 1011101110 1011111010

2 2 2 2 2 2 2 2

-1 1 1 -1 1 -1 -1 -1

0011110101 0011110111 0011111101 0011111111 0011101001 0011101011 0011101110 0011111010

-2 -2 -2 -2 -2 -2 -2 -2

-1 1 1 -1 1 -1 -1 -1

(B0) (B1) (B2) (B3) (B4) (B5) (B6) (B7)

10110000 10110001 10110010 10110011 10110100 10110101 10110110 10110111

1101110101 1101110111 1101111101 1101111111 1101101001 1101101011 1101101110 1101111010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

1101110101 1101110111 1101111101 1101111111 1101101001 1101101011 1101101110 1101111010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

(B8) (B9) (BA) (BB) (BC) (BD) (BE) (BF)

10111000 10111001 10111010 10111011 10111100 10111101 10111110 10111111

1011100101 1011100111 1011101101 1011101111 1011111001 1011111011 1011111110 1011101010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

1011100101 1011100111 1011101101 1011101111 1011111001 1011111011 1011111110 1011101010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

(C0) (C1) (C2) (C3) (C4) (C5) (C6) (C7)

11000000 11000001 11000010 11000011 11000100 11000101 11000110 11000111

1110010101 1110010111 1110011101 1110011111 1110001001 1110001011 1110001110 1110011010

2 2 2 2 2 2 2 2

1 -1 -1 1 -1 1 1 1

0110010101 0110010111 0110011101 0110011111 0110001001 0110001011 0110001110 0110011010

-2 -2 -2 -2 -2 -2 -2 -2

1 -1 -1 1 -1 1 1 1

- 79 -

Q’ = - 1

Q’ = 1

8-bit byte

10-Channel bit pattern

(C8) (C9) (CA) (CB) (CC) (CD) (CE) (CF) (D0) (D1) (D2) (D3) (D4) (D5) (D6) (D7)

11001000 11001001 11001010 11001011 11001100 11001101 11001110 11001111 11010000 11010001 11010010 11010011 11010100 11010101 11010110 11010111

1110110101 1110110111 1110111101 1110111111 1110101001 1110101011 1110101110 1110111010 1101000101 1101000111 1101001101 1101001111 1101011001 1101011011 1101011110 1101001010

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

-1 1 1 -1 1 -1 -1 -1 -1 1 1 -1 1 -1 -1 -1

0110110101 0110110111 0110111101 0110111111 0110101001 0110101011 0110101110 0110111010 0101000101 0101000111 0101001101 0101001111 0101011001 0101011011 0101011110 0101001010

-2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2

-1 1 1 -1 1 -1 -1 -1 -1 1 1 -1 1 -1 -1 -1

(D8) (D9) (DA) (DB) (DC) (DD) (DE) (DF)

11011000 11011001 11011010 11011011 11011100 11011101 11011110 11011111

1110100101 1110100111 1110101101 1110101111 1110111001 1110111011 1110111110 1110101010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

1110100101 1110100111 1110101101 1110101111 1110111001 1110111011 1110111110 1110101010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

(E0) (E1) (E2) (E3) (E4) (E5) (E6) (E7)

11100000 11100001 11100010 11100011 11100100 11100101 11100110 11100111

1111010101 1111010111 1111011101 1111011111 1111001001 1111001011 1111001110 1111011010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

1111010101 1111010111 1111011101 1111011111 1111001001 1111001011 1111001110 1111011010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

(E8) (E9) (EA) (EB) (EC) (ED) (EE) (EF)

11101000 11101001 11101010 11101011 11101100 11101101 11101110 11101111

1111110101 1111110111 1111111101 1111111111 1111101001 1111101011 1111101110 1111111010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

1111110101 1111110111 1111111101 1111111111 1111101001 1111101011 1111101110 1111111010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

- 80 -

Q’ = - 1

Q’ = 1

8-bit byte

10-Channel bit pattern

(F0) (F1) (F2) (F3) (F4) (F5) (F6) (F7)

11110000 11110001 11110010 11110011 11110100 11110101 11110110 11110111

1101010101 1101010111 1101011101 1101011111 1101001001 1101001011 1101001110 1101011010

0 0 0 0 0 0 0 0

-1 1 1 -1 1 -1 -1 -1

1101010101 1101010111 1101011101 1101011111 1101001001 1101001011 1101001110 1101011010

0 0 0 0 0 0 0 0

1 -1 -1 1 -1 1 1 1

(F8) (F9) (FA) (FB) (FC) (FD) (FE) (FF)

11111000 11111001 11111010 11111011 11111100 11111101 11111110 11111111

1111100101 1111100111 1111101101 1111101111 1111111001 1111111011 1111111110 1111101010

2 2 2 2 2 2 2 2

-1 1 1 -1 1 -1 -1 -1

0111100101 0111100111 0111101101 0111101111 0111111001 0111111011 0111111110 0111101010

-2 -2 -2 -2 -2 -2 -2 -2

-1 1 1 -1 1 -1 -1 -1

- 81 -

Annex D (normative)

Measurement of bit shift

The tape to be measured shall have been written by the tape drive used for data interchange. The tape shall have been written in any mode compatible with system operation.

D.1

Reading equipment Reading equipment shall comprise a read head, a pre-amplifier, a rotary transformer and an integrator.

D.1.1

Read head There are no absolute requirements for the output voltage of the read head. However, the read head, the pre-amplifier, the rotary transformer and the integrator shall be chosen so as to avoid problems due to a low signal-to-noise ratio. gap length

0,19 m 0,05 m

track width

14,5 m 1,5 m

angle of the head gap

The gap in the head of the positive azimuth shall make an angle of +20o 00’ 15’ with the axis of the scanner. The gap in the head of the negative azimuth shall make an angle of -10 o 00’ 15’ with the axis of the scanner.

D.1.2

Pre-amplifier and rotary transformer The overall frequency response of the read head, the pre-amplifier and the rotary transformer shall have the following characteristics.

from 1/100 of the ONEs frequency to 1,2 times the ONEs frequency the response shall be within 1 dB in amplitude response and within 5 o in phase response.

At 1/200 of the ONEs frequency shall be -3 dB relative to the response at 1/2 of the ONEs frequency. Below 1/200 of the ONEs frequency the response shall fall at a rate of 6 dB per octave. At 1,5 times the ONEs frequency the response shall be -3 dB relative to the response at 1/2 of the ONEs frequency.

Above 1,5 times the ONEs frequency the response shall fall at a rate of 12 dB per octave. The damping coefficient of the input impedance of pre-amplifier on the read head shall be more than 0,7.

D.1.3

Integrator The amplitude response of the integrator shall be within 1 dB of a line rising by 6 dB per octave from the ONEs frequency to 1/100 of the ONEs frequency.

D.2 D.2.1

Measurement Test Pattern Measurement shall be made over sections of helical tracks which display the sequence of flux transitions shown in figure D.1.

- 82 -

The first Reference Zero Crossing ZEROs.

(RZC1) is a ONE zero crossing followed by two ONEs and two

The second Reference Zero Crossing (RZC2) occurs 11 bit cells after RZC1. The first Test Zero Crossing (TZC1) occurs 5 bit cells after RZC1. The second Test Zero Crossing (TZC2) occurs 1 bit cell after TZC1.

Figure D.1 - Test Pattern

D.2.2

Measurement of the average bit cell length The average bit cell length shall be L=

D.2.3

d 4 − d1 11

Calculation of bit shift Bit shift at TZC1 shall be TZC1 =

(

5L − d 2 − d 1

)

× 100%

Bit shift at TZC2 shall be

(

d −d

TZC2 =

)

− 6L × 100%

To ensure that the asymmetrical effect of d.c. components are included, the measurements shall be repeated for the following inverted waveform. The average bit cell length shall be L=

d8 − d5 11

- 83 -

Bit shift at TZC3 shall be TZC3 =

(

5L − d 6 − d 5

)

× 100%

Bit shift at TZC4 shall be TZC4 =

(d − d ) − 6L 7

× 100%

The requirements of clause 12.5 shall be met for all measurements.

- 84 -

- 85 -

Annex E (normative)

Measurement of track edge linearity tolerance

E.1

Condition The test piece shall be secured under a longitudinal tension 0,10 N 0,02 N.

E.2

Procedure (figure E.1) The following procedure shall be used:

Place a line L0 in contact with the track leading edge on the left side, with its longitudinal axis at an angle = 4 o53’ 42,1” with the Tape Reference Edge. Place a line L1 parallel to L0 in contact with the track leading edge on the right side. Measure the distance d between L0 and L1 .

E.3

Requirement The value d shall be within 5 m.

Figure E.1 - Track edge linearity

- 86 -

- 87 -

Annex F (informative)

Recommendations for transportation

F.1

Environment It is recommended that during transportation the cartridges are kept within the following conditions: temperature relative humidity wet bulb temperature

: -40 o C to 45 o C : 5% to 80% : 26 o C max.

There shall be no condensation in or on the cartridge.

F.2

Hazards Transportation of recorded cartridges involves three basic potential hazards.

F.2.1

Impact loads and vibrations The following recommendations should minimize damage during transportation. a) Avoid mechanical loads that would distort the cartridge shape. b) Avoid dropping the cartridge more than 1m. c) Cartridges should be fitted into a rigid box containing adequate shock-absorbent material. d) The final box must have a clean interior and a construction that provides sealing to prevent the ingress of dirt and water. e) The orientation of the cartridges within the final box should be such that the axis of the tape reels are horizontal. f) The final box should be clearly marked to indicate its correct orientation.

F.2.2

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

F.2.3

Effects of stray magnetic fields A nominal spacing of not less than 80 mm should exist between the cartridges and the outer surface of the shipping container. This should minimize the risk of corruption.

- 88 -

- 89 -

Annex G (informative)

Example of the content of a Data Block in the System Area

Table G.1 shows an example of the content of a Data Block in the System Area. In table G.1, byte 0 to byte 2 047 means data bytes in the Data Block in the System Area. In a Partitioned tape, the content of a Data Block in the System Area is related to the Partition in which the block is located.

Table G.1 - An example of the content of a Data Block in the System Area

Byte Positions

Length in Bytes

Description of contents

0 to 7

The number of positive azimuth tracks written on the tape between the 7th previous update of the System Log and the 6th previous update.

8 to 15

The number of negative azimuth tracks written on the tape between the 7th previous update of the System Log and the 6th previous update.

16 to 23

The number of positive azimuth tracks read from the tape between the 7th previous update of the System Log and the 6th previous update.

24 to 31

The number of negative azimuth tracks read from the tape between the 7th previous update of the System Log and the 6th previous update.

32 to 39

The number of write error blocks with positive azimuth tracks written on the tape between the 7th previous update of the System Log and the 6th previous update.

40 to 47

The number of write error blocks with negative azimuth tracks written on the tape between the 7th previous update of the System Log and the 6th previous update.

48 to 55

The number of read error blocks with positive azimuth tracks read from the tape between the 7th previous update of the System Log and the 6th previous update.

56 to 63

The number of read error blocks with negative azimuth tracks read from the tape between the 7th previous update of the System Log and the 6th previous update.

64 to 71

The number of read error blocks with positive azimuth tracks read from the System Log area on the tape between the 7th previous update of the System Log and the 6th previous update.

72 to 79

The number of read error blocks with negative azimuth tracks read from the System Log area on the tape between the 7th previous update of the System Log and the 6th previous update.

80 to 87

The number of positive azimuth tracks written on the tape between the 6th previous update of the System Log and the 5th previous update.

- 90 -

88 to 95

The number of negative azimuth tracks written on the tape between the 6th previous update of the System Log and the 5th previous update.

96 to 103

The number of positive azimuth tracks read from the tape between the 6th previous update of the System Log and the 5th previous update.

104 to 111

The number of negative azimuth tracks read from the tape between the 6th previous update of the System Log and the 5th previous update.

112 to 119

The number of write error blocks with positive azimuth tracks written on the tape between the 6th previous update of the System Log and the 5th previous update.

120 to 127

The number of write error blocks with negative azimuth tracks written on the tape between the 6th previous update of the System Log and the 5th previous update.

128 to 135

The number of read error blocks with positive azimuth tracks read from the tape between the 6th previous update of the System Log and the 5th previous update.

136 to 143

The number of read error blocks with negative azimuth tracks read from the tape between the 6th previous update of the System Log and the 5th previous update.

144 to 151

The number of read error blocks with positive azimuth tracks read from the System Log area on the tape between the 6th previous update of the System Log and the 5th previous update.

152 to 159

The number of read error blocks with negative azimuth tracks read from the System Log area on the tape between the 6th previous update of the System Log and the 5th previous update.

160 to 167

The number of positive azimuth tracks written on the tape between the 5th previous update of the System Log and the 4th previous update.

168 to 175

The number of negative azimuth tracks written on the tape between the 5th previous update of the System Log and the 4th previous update.

176 to 183

The number of positive azimuth tracks read from the tape between the 5th previous update of the System Log and the 4th previous update.

184 to 191

The number of negative azimuth tracks read from the tape between the 5th previous update of the System Log and the 4th previous update.

192 to 199

The number of write error blocks with positive azimuth tracks written on the tape between the 5th previous update of the System Log and the 4th previous update.

- 91 -

200 to 207

The number of write error blocks with negative azimuth tracks written on the tape between the 5th previous update of the System Log and the 4th previous update.

208 to 215

The number of read error blocks with positive azimuth tracks read from the tape between the 5th previous update of the System Log and the 4th previous update.

216 to 223

The number of read error blocks with negative azimuth tracks read from the tape between the 5th previous update of the System Log and the 4th previous update.

224 to 231

The number of read error blocks with positive azimuth tracks read from the System Log area on the tape between the 5th previous update of the System Log and the 4th previous update.

232 to 239

The number of read error blocks with negative azimuth tracks read from the System Log area on the tape between the 5th previous update of the System Log and the 4th previous update.

240 to 247

The number of positive azimuth tracks written on the tape between the 4th previous update of the System Log and the 3rd previous update.

248 to 255

The number of negative azimuth tracks written on the tape between the 4th previous update of the System Log and the 3rd previous update.

256 to 263

The number of positive azimuth tracks read from the tape between the 4th previous update of the System Log and the 3rd previous update.

264 to 271

The number of negative azimuth tracks read from the tape between the 4th previous update of the System Log and the 3rd previous update.

272 to 279

The number of write error blocks with positive azimuth tracks written on the tape between the 4th previous update of the System Log and the 3rd previous update.

280 to 287

The number of write error blocks with negative azimuth tracks written on the tape between the 4th previous update of the System Log and the 3rd previous update.

288 to 295

The number of read error blocks with positive azimuth tracks read from the tape between the 4th previous update of the System Log and the 3rd previous update.

296 to 303

The number of read error blocks with negative azimuth tracks read from the tape between the 4th previous update of the System Log and the 3rd previous update.

304 to 311

The number of read error blocks with positive azimuth tracks read from the System Log area on the tape between the 4th previous update of the System Log and the 3rd previous update.

- 92 -

312 to 319

The number of read error blocks with negative azimuth tracks read from the System Log area on the tape between the 4th previous update of the System Log and the 3rd previous update.

320 to 327

The number of positive azimuth tracks written on the tape between the 3rd previous update of the System Log and the 2nd previous update.

328 to 335

The number of negative azimuth tracks written on the tape between the 3rd previous update of the System Log and the 2nd previous update.

336 to 343

The number of positive azimuth tracks read from the tape between the 3rd previous update of the System Log and the 2nd previous update.

344 to 351

The number of negative azimuth tracks read from the tape between the 3rd previous update of the System Log and the 2nd previous update.

352 to 359

The number of write error blocks with positive azimuth tracks written on the tape between the 3rd previous update of the System Log and the 2nd previous update.

360 to 367

The number of write error blocks with negative azimuth tracks written on the tape between the 3rd previous update of the System Log and the 2nd previous update.

368 to 375

The number of read error blocks with positive azimuth tracks read from the tape between the 3rd previous update of the System Log and the 2nd previous update.

376 to 383

The number of read error blocks with negative azimuth tracks read from the tape between the 3rd previous update of the System Log and the 2nd previous update.

384 to 391

The number of read error blocks with positive azimuth tracks read from the System Log area on the tape between the 3rd previous update of the System Log and the 2nd previous update.

392 to 399

The number of read error blocks with negative azimuth tracks read from the System Log area on the tape between the 3rd previous update of the System Log and the 2nd previous update.

400 to 407

The number of positive azimuth tracks written on the tape between the 2nd previous update of the System Log and the last previous update.

408 to 415

The number of negative azimuth tracks written on the tape between the 2nd previous update of the System Log and the last previous update.

416 to 423

The number of positive azimuth tracks read from the tape between the 2nd previous update of the System Log and the last previous update.

424 to 431

The number of negative azimuth tracks read from the tape between the 2nd previous update of the System Log and the last previous update.

- 93 -

432 to 439

The number of write error blocks with positive azimuth tracks written on the tape between the 2nd previous update of the System Log and the last previous update.

440 to 447

The number of write error blocks with negative azimuth tracks written on the tape between the 2nd previous update of the System Log and the last previous update.

448 to 455

The number of read error blocks with positive azimuth tracks read from the tape between the 2nd previous update of the System Log and the last previous update.

456 to 463

The number of read error blocks with negative azimuth tracks read from the tape between the 2nd previous update of the System Log and the last previous update.

464 to 471

The number of read error blocks with positive azimuth tracks read from the System Log area on the tape between the 2nd previous update of the System Log and the last previous update.

472 to 479

The number of read error blocks with negative azimuth tracks read from the System Log area on the tape between the 2nd previous update of the System Log and the last previous update.

480 to 487

The number of positive azimuth tracks written on the tape since the last previous update.

488 to 495

The number of negative azimuth tracks written on the tape since the last previous update.

496 to 503

The number of positive azimuth tracks read from the tape since the last previous update.

504 to 511

The number of negative azimuth tracks read from the tape since the last previous update.

512 to 519

The number of write error blocks with positive azimuth tracks written on the tape since the last previous update.

520 to 527

The number of write error blocks with negative azimuth tracks written on the tape since the last previous update.

528 to 535

The number of read error blocks with positive azimuth tracks read from the tape since the last previous update.

536 to 543

The number of read error blocks with negative azimuth tracks read from the tape since the last previous update.

544 to 551

The number of read error blocks with positive azimuth tracks read from the System Log area on the tape since the last previous update.

552 to 559

The number of read error blocks with negative azimuth tracks read from the System Log area on the tape since the last previous update.

560 to 567

The number of total written frames.

568 to 575

The number of total read frames.

576 to 583

The number of total write error blocks.

584 to 591

The number of total read error blocks.

592 to 599

The number of total read error blocks read from the System Log area on the tape.

- 94 -

600 to 607

The position of the EOD frame.

608 to 615

The Logical Record Address of the last Logical Record.

616 to 623

The number of frames that can be written on the tape.

624 to 655

Name of the manufacturer of the drive that updated the System Log the sixth previous time.

656 to 687

Model number or identifier of the drive that updated the System Log the sixth previous time.

688 to 719

Serial number assigned to the drive that updated the System Log the sixth previous time.

720 to 735

Revision number of the drive software that updated the System Log the sixth previous time.

736 to 751

Revision number of the drive hardware that updated the System Log the sixth previous time.

752 to 767

Date and time that the System Log was updated the sixth previous time.

768 to 799

Name of the manufacturer of the drive that updated the System Log the fifth previous time.

800 to 831

Model number or identifier of the drive that updated the System Log the fifth previous time.

832 to 863

Serial number assigned to the drive that updated the System Log the fifth previous time.

864 to 879

Revision number of the drive software that updated the System Log the fifth previous time.

880 to 895

Revision number of the drive hardware that updated the System Log the fifth previous time.

896 to 911

Date and time that the System Log was updated the fifth previous time.

912 to 943

Name of the manufacturer of the drive that updated the System Log the fourth previous time.

944 to 975

Model number or identifier of the drive that updated the System Log the fourth previous time.

976 to 1 007

Serial number assigned to the drive that updated the System Log the fourth previous time.

1 008 to 1 023

Revision number of the drive software that updated the System Log the fourth previous time.

1 024 to 1 039

Revision number of the drive hardware that updated the System Log the fourth previous time.

1 040 to 1 055

Date and time that the System Log was updated the fourth previous time.

1 056 to 1 087

Name of the manufacturer of the drive that updated the System Log the third previous time.

1 088 to 1 119

Model number or identifier of the drive that updated the System Log the third previous time.

1 120 to 1 151

Serial number assigned to the drive that updated the System Log the third previous time.

1 152 to 1 167

Revision number of the drive software that updated the System Log the third previous time.

- 95 -

1 168 to 1 183

Revision number of the drive hardware that updated the System Log the third previous time.

1 184 to 1 199

Date and time that the System Log was updated the third previous time.

1 200 to 1 231

Name of the manufacturer of the drive that updated the System Log the second previous time.

1 232 to 1 263

Model number or identifier of the drive that updated the System Log the second previous time.

1 264 to 1 295

Serial number assigned to the drive that updated the System Log the second previous time.

1 296 to 1 311

Revision number of the drive software that updated the System Log the second previous time.

1 312 to 1 327

Revision number of the drive hardware that updated the System Log the second previous time.

1 328 to 1 343

Date and time that the System Log was updated the second previous time.

1 344 to 1 375

Name of the manufacturer of the drive that updated the System Log the last previous time.

1 376 to 1 407

Model number or identifier of the drive that updated the System Log the last previous time.

1 408 to 1 439

Serial number assigned to the drive that updated the System Log the last previous time.

1 440 to 1 455

Revision number of the drive software that updated the System Log the last previous time.

1 456 to 1 471

Revision number of the drive hardware that updated the System Log the last previous time.

1 472 to 1 487

Date and time that the System Log was updated the last previous time.

1 488 to 1 519

Name of the manufacturer of the drive that is currently updating the System Log.

1 520 to 1 551

Model number or identifier of the drive that is currently updating the System Log.

1 552 to 1 583

Serial number assigned to the drive that is currently updating the System Log.

1 584 to 1 599

Revision number of the drive software that is currently updating the System Log.

1 600 to 1 615

Revision number of the drive hardware that is currently updating the System Log.

1 616 to 1 631

Date and time that is currently updating the System Log..

1 632 to 1 663

Name of the manufacturer of the drive that initialized the tape.

1 664 to 1 695

Model number or identifier of the drive that initialized the tape.

- 96 -

1 696 to 1 727

Serial number assigned to the drive that initialized the tape.

1 728 to 1 743

Revision number of the drive software that initialized the tape.

1 744 to 1 759

Revision number of the drive hardware that initialized the tape.

1 760 to 1 775

Date and time that the tape was initialized.

1 776 to 1 783

The number of times the tape has been loaded.

1 784 to 1 785

All bytes set to ZERO.

1 786 to 2047

262

Manufacturer’s data.

Printed copies can be ordered from: ECMA 114 Rue du Rhône CH-1204 Geneva Switzerland Fax: Internet:

+41 22 849.60.01 [email protected]

Files can be downloaded from our FTP site, ftp.ecma.ch. This Standard is available from library ECMA-ST as a compacted, self-expanding file in MSWord 6.0 format (file E247-DOC.EXE) and as an Acrobat PDF file (file E247PDF.PDF). File E247-EXP.TXT gives a short presentation of the Standard. Our web site, http://www.ecma.ch, gives full information on ECMA, ECMA activities, ECMA Standards and Technical Reports.

ECMA 114 Rue du Rhône CH-1204 Geneva Switzerland This Standard ECMA-247 is available free of charge in printed form and as a file. See inside cover page for instructions.

ECMA-247 — 8 mm wide magnetic tape cartridge for information interchange - Helical scan recording - HH-1 format (June 1998)

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