1、Standard ECMA-288June 1999Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.ch3,81 mm Wide Magnetic TapeCartridge for InformationInterchange - Helical ScanRecording - DDS-4 Format.Standard ECMA-288June
2、 1999Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chMB - ECMA-288.DOC - 27.07.99 10:113,81 mm Wide Magnetic TapeCartridge for InformationInterchange - Helical ScanRecording - DDS-4 Format.Brief Hi
3、storyTechnical Committee ECMA TC17 has produced a series of ECMA Standards for magnetic tapes and magnetic tape cartridgescontaining tapes of different widths, e.g. 12,7 mm, 8 mm, 6,35 mm and 3,81 mm, almost all of which have been adopted byISO/IEC under the fast-track procedure as International Sta
4、ndards. The series of such cartridges with a magnetic tape width of3,81 mm width and helical recorded tracks comprises the following DDS standards.ECMA-139 (1990) 3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan RecordingISO/IEC 10777 - DDS formatECMA-150 (1991) 3,81 m
5、m Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan RecordingISO/IEC 11557 - DDS-DC Format using 60 m and 90 m Length Tapes, 2nd EditionECMA-170 (1992) 3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan RecordingISO/IEC 12247 - DDS Format using 60 m
6、 and 90 m Length TapesECMA-198 (1995) 3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan RecordingISO/IEC 13923 - DDS-2 Format using 120m Length TapesECMA-236 (1996) 3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan RecordingISO/IEC 15521 -
7、DDS-3 Format using 125 m Length TapesAll previously issued Standards for the family of DDS cartridges have been adopted by ISO/IEC under the fast-track procedureas International Standards.This ECMA Standard specifies a magnetic tape cartridge, based on the features of Standard ECMA-236, which offers
8、 anincrease in data capacity. The primary changes from DDS-3 are a reduction in track width from 9,1 m m to 6,8 m m and anincrease in the tape length from 125 m to 155 m. The DDS-4 format, for a tape length of 155 m, will provide a storage capacityof 20 Gbytes of uncompressed user data or typically
9、40 Gbytes to 60 Gbytes of compressed user data.A recorded cartridge of the 3,81 mm wide magnetic tape family of cartridges has a single recorded format thereon, i.e. eitherDDS or DDS-DC or DDS-2, DDS-3 or DDS-4, and therefore a single track density and linear bit density.This Standard has been adopt
10、ed by the General Assembly of June 24, 1999.- i -Table of contents1 Scope 12 Conformance 12.1 Magnetic tape cartridge 12.2 Generating drive 12.3 Receiving drive 13 References 24 Definitions 24.1 Absolute Frame Number (AFN) 24.2 a.c. erase 24.3 Access Point 24.4 algorithm 24.5 Area ID 24.6 Average Si
11、gnal Amplitude 24.7 azimuth 24.8 back surface 24.9 byte 24.10 cartridge 24.11 Channel bit 24.12 Codeword 24.13 Data Format ID 24.14 Early Warning Point (EWP) 24.15 End of Data (EOD) 34.16 Entity 34.17 Error Correcting Code (ECC) 34.18 flux transition position 34.19 flux transition spacing 34.20 Frag
12、ment 34.21 Frame 34.22 Housekeeping Frame 34.23 Logical Beginning of Tape (LBOT) 34.24 magnetic tape 34.25 Master Standard Amplitude Calibration Tape 34.26 Master Standard Reference Tape 34.27 Optimum Recording Field 34.28 Partition Boundary 34.29 Physical Beginning of Tape (PBOT) 34.30 Physical End
13、 of Tape (PEOT) 44.31 physical recording density 44.32 pre-recording condition 44.33 processing 44.34 processed data 44.35 Processed Record 44.36 Processed Record Sequence 44.37 record 44.38 Reference Recording Field 44.39 reprocessing 44.40 Secondary Standard Amplitude Calibration Tape 44.41 Second
14、ary Standard Reference Tape 44.42 Separator Mark 54.43 Standard Reference Amplitude 5- ii -4.44 Tape Reference Edge 54.45 Test Recording Current 54.46 track 54.47 unprocessed data 54.48 Unprocessed Record 54.49 Virtual End of Tape (VEOT) 55 Conventions and Notations 56 Acronyms 57 Environment and sa
15、fety 67.1 Testing environment 67.2 Operating environment 67.3 Storage environment 67.4 Transportation 67.5 Safety 67.6 Flammability 6Section 2 - Requirements for the case 78 Dimensional and mechanical characteristics of the case 78.1 General 78.2 Overall dimensions 78.3 Loading grip 88.4 Holding are
16、as 88.5 Notches of the lid 88.6 Lid dimensions 88.7 Optical detection of the beginning and end of tape 98.8 Bottom side 98.8.1 Locking mechanism of the slider 108.8.2 Access holes 108.8.3 Recognition, sub-datums, and write-inhibit holes 118.8.4 Datum holes 128.8.5 Access room for tape guides 128.8.6
17、 Holes for accessing the hubs 138.8.7 Internal structure of the lower half 138.8.8 Light path 148.8.9 Support Areas 148.8.10 Datum Areas 148.8.11 Relationship between Support and Datum Areas and Reference Plane Z 148.9 Hubs 158.10 Attachment of leader and trailer tapes 158.11 Interface between the h
18、ubs and the drive spindles 158.12 Opening of the lid 158.13 Release of the hub locking mechanism 158.14 Label areas 168.15 Requirement for autoloaders 16Section 3 - Requirements for the unrecorded tape 299 Mechanical, physical and dimensional characteristics of the tape 299.1 Materials 299.2 Tape le
19、ngth 29- iii -9.2.1 Length of magnetic tape 299.2.2 Length of leader and trailer tapes 299.2.3 Length of splicing tapes 299.3 Tape width 299.3.1 Width of magnetic tape 299.3.2 Width of leader and trailer tapes 299.3.3 Width and position of splicing tape 299.3.4 Edge weave 299.4 Discontinuities 309.5
20、 Tape thickness 309.5.1 Thickness of magnetic tape 309.5.2 Thickness of leader and trailer tape 319.5.3 Thickness of splicing tape 319.6 Longitudinal curvature 319.7 Cupping 319.8 Coating adhesion 319.9 Layer-to-layer adhesion 319.10 Tensile strength 329.10.1 Breaking strength 329.10.2 Yield strengt
21、h 329.11 Residual elongation 329.12 Flexural rigidity 329.13 Electrical resistance of coated surfaces 339.14 Light transmittance of the tape 339.15 Media Recognition System (MRS) 3310 Magnetic recording characteristics 3410.1 Optimum Recording Field 3510.2 Signal Amplitude 3510.3 Resolution 3510.4 O
22、verwrite 3510.5 Ease of erasure 3610.6 Tape quality 3610.6.1 Missing pulses 3610.6.2 Missing pulse zone 3610.7 Signal-to-Noise Ratio (SNR) characteristic 36Section 4 - Requirements for an interchanged tape 3611 Format 3611.1 General 3611.2 Basic Groups 3711.2.1 Entity 3711.2.2 Group Information Tabl
23、e 3811.2.3 Block Access Table (BAT) 4011.3 Sub-Groups 4311.3.1 G1 Sub-Group 4311.3.2 G2 Sub-Group - randomizing 4311.3.3 G3 Sub-Group 4411.3.4 G4 Sub-Group 4511.3.5 Main Data Fragment 4911.3.6 Summary of the transformation of a Basic Group 5111.4 Sub code Information 51- iv -11.4.1 Pack Item Number
24、0 5111.4.2 Pack Item Number 1 5111.4.3 Pack Item Number 2 5211.4.4 Pack Item Number 3 5211.4.5 Pack Item Number 4 5211.4.6 Pack Item Number 5 5311.4.7 Pack Item Number 6 5411.4.8 Pack Item Number 7 5411.4.9 Pack Item Number 8 5511.4.10 Pack Item Number 9 5511.4.11 Pack Item Number 10 5511.4.12 Pack
25、Item Number 11 5611.4.13 Pack Item Number 12 5611.4.14 Pack Item Number 13 5711.4.15 Pack Item Number 14 5711.4.16 Pack Item Number 15 5811.5 Sub code location 5811.5.1 Sub code Pack Items on a Single Data Space tape 5811.5.2 Sub code Pack Items on a partitioned tape 5812 Method of recording 5912.1
26、Physical recording density 5912.2 Long-term average bit cell length 5912.3 Short-term average bit cell length 5912.4 Rate of change 5912.5 Bit shift 5912.6 Read signal amplitude 5912.7 Maximum recorded levels 5913 Track geometry 5913.1 Track configuration 5913.2 Average track pitch 6013.3 Variations
27、 of the track pitch 6013.4 Track width 6013.5 Track angle 6013.6 Track edge linearity 6013.7 Track length 6113.8 Ideal tape centreline 6113.9 Azimuth angles 6114 Recorded patterns 6114.1 Recorded Main Data Fragment 6114.2 Preamble Zone, Margin Zones 6115 Format of a track 6115.1 Format of a track 61
28、15.2 Positioning accuracy 6115.3 Tracking scheme 6216 Layout of a Single Data Space tape 6216.1 Device Area 6216.2 Reference Area 6316.3 Position Tolerance Band No. 1 6316.4 System Area 6316.4.1 System Preamble 63- v -16.4.2 System Log 6316.4.3 System Postamble 6316.4.4 Position Tolerance Band No. 2
29、 6316.4.5 Vendor Group Preamble 6316.5 Data Area 6316.5.1 Vendor Group 6416.5.2 Recorded Data Group 6416.5.3 ECC3 6416.5.4 Repeated Frames 6516.5.5 Appending and overwriting 6516.6 EOD Area 6716.7 Post-EOD Area 6716.8 Early Warning Point - (EWP) 6716.9 Initialization 6717 Layout of a partitioned tap
30、e 6717.1 Overall magnetic tape layout 6817.1.1 Device Area 6817.1.2 Partition 1 6817.1.3 Partition 0 6917.2 Area ID 7017.3 System Area Pack Items No. 3 and No. 4 7017.4 Empty partitions 7017.4.1 Empty partition 1 7017.4.2 Empty partition 0 7017.5 Initialization of partitioned tapes 7018 Housekeeping
31、 Frames 7018.1 Amble Frames 7018.2 System Log Frames 7118.3 Tape Management Frames 71AnnexesA - Measurement of the light transmittance of the prisms 73B - Measurement of light transmittance of tape and leaders 75C - Measurement of Signal-to-Noise Ratio 79D - Method for determining the nominal and th
32、e maximum allowable recorded levels 81E - Representation of 8-bit bytes by 10-bit patterns 83F - Measurement of bit shift 95G - Measurement of track edge linearity 97H - Tape abrasivity measurement procedure 99J - Method for measurement of written track error, using pre-written tape. 101K - Recognit
33、ion Holes 103L - Means to open the lid 105M - Recommendations for transportation 107N - Read-After-Write. 109O - Example of the content of a Basic Group No. 0. 111P - Generating and Receiving Drives. 113- vi -1ScopeThis ECMA Standard specifies the physical and magnetic characteristics of a 3,81 mm w
34、ide magnetic tape cartridge toenable physical interchangeability of such cartridges between drives. It also specifies the quality of the recordedsignals, the recording method and the recorded format - called Digital Data Storage 4 (DDS-4) - thereby allowing datainterchange between drives by means of
35、 such magnetic tape cartridges.Information interchange between systems also requires, at a minimum, agreement between the interchange parties uponthe interchange code(s) and the specifications of the structure and labelling of the information on the interchangedcartridge.Under information interchang
36、e circumstances in which a processing algorithm, e.g. for lossless data compression asspecified in ECMA-151, is applied to the host data prior to recording on the tape and a complementary reprocessingalgorithm is applied after the data is read from the tape, agreement upon these by the interchange p
37、arties is alsorequired.2 Conformance2.1 Magnetic tape cartridgeA tape cartridge shall be in conformance with this ECMA Standard if it meets all the mandatory requirementsspecified herein. The tape requirements shall be satisfied throughout the extent of the tape.For each recorded Entity any algorith
38、m for lossless data compression used for processing the data therein shall havebeen registered, and according to ISO/IEC 11576 the corresponding numerical identifier shall be recorded in ByteNo. 3 of the Entity Header.2.2 Generating driveA drive generating a magnetic tape cartridge for interchange s
39、hall be in conformance with this ECMA Standard if allrecordings on the tape meet the mandatory requirements of this ECMA Standard, and if either or both methods ofappending and overwriting are implemented.A claim of conformance shall state which of the following optional features are implemented and
40、 which are not- the performing of a Read-After-Write check and the recording of any necessary repeated frames;- the generation of ECC3 Frames.In addition a claim of conformance shall state- whether or not one, or more, registered algorithm(s) are implemented within the system and are able to process
41、data received from the host prior to collecting the data into Basic Groups, and- the algorithm registration identification number(s) of the implemented algorithm(s).2.3 Receiving driveA drive receiving a magnetic tape cartridge for interchange shall be in conformance with this ECMA Standard if it is
42、able to handle any recording made on the tape according to this ECMA Standard. In particular it shall- be able to recognize repeated frames and to make available to the host, data and Separator Marks from only oneof these frames;- be able to recognize an ECC3 frame, and ignore it if the system is no
43、t capable of using ECC3 check bytes in aprocess of error correction;- be able to recognize processed data within an Entity, identify the algorithm used, and make the algorithmregistration number available to the host;- be able to make processed data available to the host.In addition a claim of confo
44、rmance 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 reprocessing algorithm(s) are implemented within the system, and are able to beapplied to processed data prior to making such data available to the host;-
45、the algorithm registration number(s) of the processing algorithm(s) for which a complementary reprocessingalgorithm is implemented.- 2 -3 ReferencesISO/R 527:1966 Plastics - Determination of tensile properties.ISO 1302:1992 Technical Drawings - Method of indicating surface texture on drawings.ISO/IE
46、C 11576:1994 Information technology - Procedure for the registration of algorithms for the losslesscompression of data.ECMA-287 (1999) Safety of electronic equipment4 DefinitionsFor the purposes of this ECMA Standard the following definitions apply.4.1 Absolute Frame Number (AFN)A sequence number, e
47、ncoded in the Frame.4.2 a.c. eraseA process of erasure utilising magnetic fields of decaying intensity.4.3 Access PointA point, at the start of a Processed Record Sequence, at which the presentation of Codewords to a reprocessingalgorithm is required to start, regardless of whether the data of inter
48、est in a retrieval operation starts at that point orat a subsequent point.4.4 algorithmA set of rules for transforming the logical representation of data.4.5 Area IDAn identifier defining the area of the tape and specifying the types of Frame written.4.6 Average Signal AmplitudeThe average peak-to-p
49、eak value of the output signal from the read head at the fundamental frequency of thespecified physical recording density over a minimum of 7,8 mm of track, exclusive of missing pulses.4.7 azimuthThe angle, in degrees, minutes and seconds of arc, made by the mean flux transition line with a line normal to thecentreline of the recorded track.4.8 back surfaceThe surface of the tape opposite to the magnetic coating which is used to record data.4.9 byteAn ordered set of bits acted upon as a unit.4.10 cartridgeA case containing a magnetic tape wound on twin hubs.4.11 Channel bitA bit after 8-
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