1、Standard ECMA-236June 1996Standardizing 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-3 Format using125 m Length Tap
2、esStandard ECMA-236June 1996Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chMB - ECMA-236.DOC - 13.08.96 09,453,81 mm Wide Magnetic TapeCartridge for InformationInterchange - Helical ScanRecording
3、- DDS-3 Format using125 m Length TapesBrief HistoryECMA have produced a series of ECMA Standards for cassettes and cartridges containing magnetic tapes of different widthand characteristics. Of these, the following relate to helical scan recording.ECMA-139 (1990) 3,81 mm Wide Magnetic Tape Cartridge
4、 for Information Interchange - Helical Scan Recording- DDS formatECMA-145 (1990) 8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan RecordingECMA-146 (1990) 3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording- DATA/DAT FormatECMA-150 (1
5、991) 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 EditionECMA-169 (1992) 8 mm Wide Magnetic Tape Cartridge, Dual Azimuth Format for Information Interchange- HelicalScan RecordingECMA-170 (1992) 3,81 mm
6、Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording- DDS Format using 60 m and 90 m Length TapesECMA-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 TapesECMA-198 (1995)
7、3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording- DDS-2 Format using 120m Length TapesECMA-210 (1994) 12,65 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording- DATA-D3-1 FormatAll previously issued Standards for the family of
8、 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 ECMA-198, which offers an increase in datacapacity. The primary changes to the recorded format are a doubling of the
9、linear recording density and an increase in theproportion of a recorded track that is available for user data. Together, these provide three times the data capacity, comparedwith DDS-2, for a cartridge of a given tape length. The DDS-3 format, when recorded on a 3,81 mm wide tape the length ofwhich
10、is 125 metres, will provide a storage capacity of 12 Gigabytes of uncompressed user data or typically 24 to 36 Gigabytesof compressed user data.It is not a requirement for compliance to this ECMA Standard that a DDS-3 drive also reads and writes either the DDS format,the DDS-DC format or the DDS-2 f
11、ormat. Nor is it a requirement for compliance to this ECMA Standard that a drivecompresses data and records it in entities on the tape, or that a drive decompresses data contained within such entities.A recorded cartridge of the 3,81 mm wide magnetic tape family of cartridges has a single recorded f
12、ormat thereon, i.e. eitherDDS or DDS-DC or DDS-2 or DDS-3, and therefore a single track density and linear bit density. The tapes thickness, itsmagnetic coating and the recorded format are indicated by the combination of the states of the Recognition Holes on thecartridge case.This ECMA Standard has
13、 been adopted by the ECMA General Assembly of June 1996.- 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.
14、6 Average Signal 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) 34.15 End of Data (EOD) 34.16 Entity 34.17 Error Correcting Code (ECC) 34.18 flux transition position 34.19 flux transition spacin
15、g 34.20 Fragment 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 44.29 Physical Beginning of Tape (PBOT) 44.30
16、Physical End 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
17、44.41 Secondary Standard Reference Tape 44.42 Separator Mark 5- ii -4.43 Standard Reference Amplitude 54.44 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 Enviro
18、nment and safety 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 68 Dimensional and mechanical characteristics of the case 78.1 General 78.2 Overall dimensions 78.3 Loading grip 88.4
19、 Holding areas 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 108.8.4 Datum holes 128.8.5 Access room for tape gu
20、ides 128.8.6 Holes for accessing the hubs 128.8.7 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 148.10 Attachment of leader and trailer tapes 158.11 Interface b
21、etween the hubs 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 16- iii -Section 3 - Requirements for the unrecorded tape 289 Mechanical, physical and dimensional characteristics of the tape 289.1 Mate
22、rials 289.2 Tape length 289.2.1 Length of magnetic tape 289.2.2 Length of leader and trailer tapes 289.2.3 Length of splicing tapes 289.3 Tape width 289.3.1 Width of magnetic tape 289.3.2 Width of leader and trailer tapes 289.3.3 Width and position of splicing tape 289.3.4 Edge weave 289.4 Discontin
23、uities 299.5 Tape thickness 309.5.1 Thickness of magnetic tape 309.5.2 Thickness of leader and trailer tape 309.5.3 Thickness of splicing tape 309.6 Longitudinal curvature 309.7 Cupping 309.8 Coating adhesion 309.9 Layer-to-layer adhesion 319.10 Tensile strength 319.10.1 Breaking strength 319.10.2 Y
24、ield strength 319.11 Residual elongation 319.12 Flexural rigidity 329.13 Electrical resistance of coated surfaces 329.14 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 Resolut
25、ion 3510.4 Overwrite 3510.5 Ease of erasure 3510.6 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 3711.1 General 3711.2 Basic Groups 3711.2.1 Entity 3811.2.2 Group Info
26、rmation Table 3911.2.3 Block Access Table (BAT) 4111.3 Sub-Groups 44- iv -11.3.1 G1 Sub-Group 4411.3.2 G2 Sub-Group - randomizing 4411.3.3 G3 Sub-Group 4511.3.4 G4 Sub-Group 4611.3.5 Main Data Fragment 5011.3.6 Summary of the transformation of a Basic Group 5211.4 Sub code Information 5211.4.1 Pack
27、Item Number 0 5211.4.2 Pack Item Number 1 5211.4.3 Pack Item Number 2 5311.4.4 Pack Item Number 3 5311.4.5 Pack Item Number 4 5311.4.6 Pack Item Number 5 5411.4.7 Pack Item Number 6 5411.4.8 Pack Item Number 7 5511.4.9 Pack Item Number 8 5511.4.10 Pack Item Number 9 5611.4.11 Pack Item Number 10 561
28、1.4.12 Pack Item Number 11 5611.4.13 Pack Item Number 12 5711.4.14 Pack Item Number 13 5711.4.15 Pack Item Number 14 5811.4.16 Pack Item Number 15 5811.5 Sub code location 5811.5.1 Sub code Pack Items on a Single Data Space tape 5911.5.2 Sub code Pack Items on a partitioned tape 5912 Method of recor
29、ding 5912.1 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 6013 Track geometry 6013.1 Track configuration 6013.2 Average track pitch 6013.
30、3 Variations of the track pitch 6113.4 Track width 6113.5 Track angle 6113.6 Track edge linearity 6113.7 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 o
31、f a track 6115.2 Positioning accuracy 62- v -15.3 Tracking scheme 6216 Layout of a Single Data Space tape 6216.1 Device Area 6316.2 Reference Area 6316.3 Position Tolerance Band No. 1 6316.4 System Area 6316.4.1 System Preamble 6416.4.2 System Log 6416.4.3 System Postamble 6416.4.4 Position Toleranc
32、e Band No. 2 6416.4.5 Vendor Group Preamble 6416.5 Data Area 6416.5.1 Vendor Group 6416.5.2 Recorded Data Group 6416.5.3 ECC3 6516.5.4 Repeated Frames 6516.5.5 Appending and overwriting 6616.6 EOD Area 6716.7 Post-EOD Area 6716.8 Early Warning Point - (EWP) 6816.9 Initialization 6817 Layout of a par
33、titioned tape 6817.1 Overall magnetic tape layout 6917.1.1 Device Area 6917.1.2 Partition 1 6917.1.3 Partition 0 7017.2 Area ID 7117.3 System Area Pack Items No. 3 and No. 4 7117.4 Empty partitions 7117.4.1 Empty partition 1 7117.4.2 Empty partition 0 7117.5 Initialization of partitioned tapes 7118
34、Housekeeping Frames 7118.1 Amble Frames 7118.2 System Log Frames 7218.3 Tape Management Frames 72AnnexesA - 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 no
35、minal and the maximum allowable recorded levels 81E - Representation of 8-bit bytes by 10-bit patterns 85F - Measurement of bit shift 95G - Measurement of track edge linearity 97H - Recognition Holes 99- vi -J - Means to open the lid 101K - Recommendations for transportation 103L - Read-After-Write.
36、 105M - Example of the content of a Basic Group No. 0. 107N - Generating and Receiving Drives. 1091ScopeThis ECMA Standard specifies the physical and magnetic characteristics of a 3,81 mm wide magnetic tape cartridge toenable physical interchangeability of such cartridges between drives. It also spe
37、cifies the quality of the recordedsignals, the recording method and the recorded format - called Digital Data Storage (DDS) - thereby allowing datainterchange between drives by means of such magnetic tape cartridges.Information interchange between systems also requires, at a minimum, agreement betwe
38、en the interchange parties uponthe interchange code(s) and the specifications of the structure and labelling of the information on the interchangedcartridge.Under information interchange circumstances in which a processing algorithm, e.g. for lossless data compression asspecified in ECMA-151, is app
39、lied 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 parties is alsorequired.2 Conformance2.1 Magnetic tape cartridgeA tape cartridge shall be in conformance with this E
40、CMA 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 algorithm for lossless data compression used for processing the data therein shall havebeen registered, and according to IS
41、O/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 shall be in conformance with this ECMA Standard ifall recordings on the tape meet the mandatory requirements of this
42、 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 which are not the performing of a Read-After-Write check and the recording of any necessary repeated frames; the g
43、eneration 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 processdata received from the host prior to collecting the data into Basic Groups, and the algorithm registration identificat
44、ion 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 itis able to handle any recording made on the tape according to this ECMA Standard. In particular it shall be able to recogn
45、ize 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 not capable of using ECC3 check bytes in aprocess of error correction; be able to recognize processed data within an Entity
46、, 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 conformance shall state whether or not the system is capable of using ECC3 check bytes in a process of error correction; whether
47、 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; the algorithm registration number(s) of the processing algorithm(s) for which a complementary reprocessingalgorithm is impleme
48、nted.- 2 -3 ReferencesISO/R 527:1966 Plastics - Determination of tensile properties.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 losslesscompression of data.ECMA-12
49、9 (1994) Information Technology Equipment - Safety4 DefinitionsFor the purposes of this ECMA Standard the following definitions apply.4.1 Absolute Frame Number (AFN)A sequence number, encoded 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 interest in a retrieval operation starts at that point orat a subsequent point.4.4 algorithmA set of rul
