1、Standard ECMA-1982nd Edition - June 1995Standardizing 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-2 Format using12
2、0 m Length Tapes.Standard ECMA-1982nd Edition - June 1995Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chMB - ECMA-198.DOC - 15.02.99 14:233,81 mm Wide Magnetic TapeCartridge for InformationInterch
3、ange - Helical ScanRecording - DDS-2 Format using120 m Length Tapes.Brief 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 m
4、m Wide Magnetic Tape Cartridge 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 Recordi
5、ng- DATA/DAT FormatECMA-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 EditionECMA-169 (1992) 8 mm Wide Magnetic Tape Cartridge, Dual Azimuth Format for Information Interchange- HelicalScan Rec
6、ordingECMA-170 (1992) 3,81 mm 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
7、m Length TapesDDS Standard ECMA-139 defines a specification for data interchange using 3,81 mm wide magnetic tape cartridges. Aderivative Standard ECMA-150 defines another data interchange specification for the same cartridges, but with a recordedformat, namely DDS-DC, which enables data to be compr
8、essed by the drive before being recorded.This ECMA Standard defines a specification, based on the features of both of these, which offers a further increase in datacapacity. The primary change to the recorded format is an increase in the track density by a factor of 1,5. This produces acorresponding
9、 increase in data capacity for a cartridge of a given tape length. Such a track density, when recorded on acartridge tape whose tape length is 125 metres, will provide a storage capacity of 4 Gigabytes of uncompressed user data andtypically 8 to 16 Gigabytes of compressed user data.The design philos
10、ophy is one of minimum change to the track format which is common to DDS and DDS-DC. This will aid thedevelopment of drives that support this DDS-2 format by derivation from existing products. It will also ease the development ofdrives that are able to support both previous formats as well as this f
11、ormat, thus providing the backwards compatibility whichthe market demands. However, it is not a requirement for compliance to this specification that a drive also reads and writeseither the DDS format or the DDS-DC format. Nor is it a requirement for compliance to this specification that a drivecomp
12、resses data and writes it in entities on the tape, or that a drive decompresses data contained within entities on the tape. Allthe recording on one cartridge will be at the same track density, either that of DDS and DDS-DC, or that of DDS-2. The mediacoating and the track density are indicated by th
13、e combination of the states of the Recognition Holes on the cartridge case.This ECMA Standard also includes the specifications of the Media Recognition System, namely a striped splicing tape.Adopted by the General Assembly of June 1995 as 2nd Edition of Standard ECMA-198.- i -Table of contentsPageSe
14、ction 1 - General 11 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 Automatic Track Finding (ATF) 24.7 Average Signal Amplitu
15、de 24.8 azimuth 24.9 back surface 24.10 byte 24.11 cartridge 34.12 Channel Bit 34.13 Codeword 34.14 Data Format ID 34.15 Early Warning Point (EWP) 34.16 End of Data (EOD) 34.17 Entity 34.18 Error Correcting Code (ECC) 34.19 flux transition position 34.20 flux transition spacing 34.21 Frame 34.22 Hou
16、sekeeping 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 44.28 Partition Boundary 44.29 Physical Beginning of Tape (PBOT) 44.30 Physical End of Tape (PEOT) 44.31 phys
17、ical 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 4- ii -4.40 Secondary Standard Amplitude Calibration Tape 44.41 Secondary Standard Referen
18、ce Tape 44.42 Separator Mark 54.43 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 Environment and safety 55.1 Testing environment 55.2 Operating environment 55.3 Stora
19、ge environment 65.4 Transportation 65.5 Safety 65.6 Flammability 6Section 2 - Requirements for the case 66 Dimensional and mechanical characteristics of the case 66.1 General 66.2 Overall dimensions 76.3 Loading grip 76.4 Holding areas 76.5 Notches of the lid 76.6 Lid dimensions 86.7 Optical detecti
20、on of the beginning and end of tape 86.8 Bottom side 96.8.1 Locking mechanism of the slider 96.8.2 Access holes 106.8.3 Recognition, sub-datums, and write-inhibit holes 106.8.4 Datum holes 116.8.5 Access room for tape guides 116.8.6 Holes for accessing the hubs 126.8.7 Internal structure of the lowe
21、r half 126.8.8 Light path 136.8.9 Support Areas 136.8.10 Datum Areas 136.8.11 Relationship between Support and Datum Areas and Reference Plane Z 146.9 Hubs 146.10 Attachment of leader and trailer tapes 146.11 Interface between the hubs and the drive spindles 146.12 Opening of the lid 146.13 Release
22、of the hub locking mechanism 156.14 Label areas 156.15 Requirement for autoloaders 15Section 3 - Requirements for the unrecorded tape 277 Mechanical, physical and dimensional characteristics of the tape 277.1 Materials 277.2 Tape length 28- iii -7.2.1 Length of magnetic tape 287.2.2 Length of leader
23、 and trailer tapes 287.2.3 Length of splicing tapes 287.3 Tape width 287.3.1 Width of magnetic, leader and trailer tapes 287.3.2 Width and position of splicing tape 287.4 Discontinuities 287.5 Tape thickness 287.5.1 Thickness of magnetic tape 287.5.2 Thickness of leader and trailer tape 287.5.3 Thic
24、kness of splicing tape 287.6 Longitudinal curvature 287.7 Cupping 297.8 Coating adhesion 297.9 Layer-to-layer adhesion 297.10 Tensile strength 307.10.1 Breaking strength 307.10.2 Yield strength 307.11 Residual elongation 307.12 Flexural rigidity 307.13 Electrical resistance of coated surfaces 307.14
25、 Light transmittance of the tape 317.15 Media Recognition System (MRS) 318 Magnetic recording characteristics 328.1 Optimum Recording Field 338.2 Signal Amplitude 338.3 Resolution 338.4 Overwrite 338.4.1 Physical recording densities of 750,0 ftpmm and 2 999,9 ftpmm 338.4.2 Physical recording densiti
26、es of 83,3 ftpmm and 1 000,0 ftpmm 338.5 Ease of erasure 338.6 Tape quality 348.6.1 Missing pulses 348.6.2 Missing pulse zone 348.7 Signal-to-Noise Ratio (S/N) characteristic 34Section 4 - Requirements for an interchanged tape 349 Format 349.1 General 349.2 Basic Groups 359.2.1 Entity 359.2.2 Group
27、Information Table 379.2.3 Block Access Table (BAT) 389.3 Sub-Groups 419.3.1 G1 Sub-Group 419.3.2 G2 Sub-Group - randomizing 429.3.3 G3 Sub-Group 429.3.4 G4 Sub-Group 449.3.5 Main Data Block 48- iv -9.4 Sub-Data Area 499.4.1 Pack Item Number 1 509.4.2 Pack Item Number 2 519.4.3 Pack Item Number 3 519
28、.4.4 Pack Item Number 4 529.4.5 Pack Item Number 5 549.4.6 Pack Item Number 6 549.4.7 Pack Item Number 7 559.4.8 Pack Item Number 8 569.4.9 Sub Data Block 5610 Method of recording 5910.1 Physical recording density 5910.2 Long-term average bit cell length 6010.3 Short-term average bit cell length 601
29、0.4 Rate of change 6010.5 Bit shift 6010.6 Read signal amplitude 6010.7 Maximum recorded levels 6011 Track geometry 6011.1 Track configuration 6011.2 Average track pitch 6111.3 Variations of the track pitch 6111.4 Track width 6111.5 Track angle 6111.6 Track edge linearity 6111.7 Track length 6211.8
30、Ideal tape centreline 6211.9 Azimuth angles 6212 Recording of Blocks on the tape 6212.1 Recorded Main Data Block 6212.2 Recorded Sub Data Block 6212.3 Margin Blocks, Preamble Blocks and Postamble Blocks 6212.4 Spacer Blocks 6213 Format of a track 6213.1 Track capacity 6213.2 Positioning accuracy 631
31、3.3 Tracking scheme 6314 Layout of a Single Data Space tape 6414.1 Device Area 6514.2 Reference Area 6514.3 Position Tolerance Band No. 1 6514.4 System Area 6514.4.1 System Preamble 6614.4.2 System Log 6614.4.3 System Postamble 6614.4.4 Position Tolerance Band No. 2 6614.4.5 Vendor Group Preamble 66
32、14.5 Data Area 66- v -14.5.1 Vendor Group 6614.5.2 Recorded Data Group 6614.5.3 ECC3 6714.5.4 Multiple Recorded Instances 6714.5.5 Repeated Frames 6714.5.6 Appending and overwriting 6814.6 EOD Area 7014.7 Post-EOD Area 7014.8 Early Warning Point - EWP 7014.9 Initialization 7015 Layout of partitioned
33、 tape 7015.1 Overall magnetic tape layout 7115.1.1 Device Area 7115.1.2 Partition 1 7115.1.3 Partition 0 7215.2 Area ID 7315.3 System Area Pack Items No. 3 and No. 4 7315.4 Empty partitions 7315.4.1 Empty partition 1 7315.4.2 Empty partition 0 7315.5 Initialization of partitioned tapes 7316 Housekee
34、ping Frames 7316.1 Amble Frames 7316.2 System Log Frames 7416.3 Tape Management Frames 74AnnexesAnnex A - Measurement of the light transmittance of the prisms 75Annex B - Recognition Holes 81Annex C - Means to open the lid 79Annex D - Measurement of light transmittance of tape and leaders 81Annex E
35、- Measurement of Signal to Noise Ratio 85Annex F - Method for determining the nominal and the maximum allowable recorded levels 87Annex G - Representation of 8-bit bytes by 10-bit patterns 89Annex H - Measurement of bit shift 97Annex J - Recommendations for transportation 99Annex K - Method of measu
36、ring track edge linearity 101Annex L - Read-After-Write 107Annex M - Example of the content of a Basic Group No. 0 109- vi -.Section 1 - General1ScopeThis ECMA Standard specifies the physical and magnetic characteristics of a 3,81 mm wide magnetic tape cartridge toenable interchangeability of such c
37、artridges between drives. It also specifies the quality of the recorded signals, therecording method and the recorded format, thereby allowing data interchange between drives by means of suchmagnetic 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 used for processing the data therein shall have been registered, and theregistration identification shall be incl
41、uded, when appropriate, in Byte No. 3 of the Entity Header.A recorded tape shall be either a Single Data Space Tape or a Partitioned Tape.2.2 Generating driveA drive generating a magnetic tape cartridge for interchange shall be entitled to claim conformance with this ECMAStandard if all recordings o
42、n the tape meet the mandatory requirements of this ECMA Standard, and if either or bothmethods of appending 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 th
43、e recording of any necessary repeated frames;- the recording of multiple representations of the same Basic Group;- 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 proc
44、essdata 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 entitled to claim conformance with this ECMA
45、Standard if it is able to handle any recording made on the tape according to this ECMA Standard. In particular itshall- 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 multiple representations of the
46、 same Basic Group, and to make available to the host, dataand Separator Marks from only one of these representations;- 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 update the System Log(s) if the
47、 Write-inhibit Hole state so permits;- 2 - 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 conformance shall state- whether
48、 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;- the algorithm registration
49、number(s) of the processing algorithm(s) for which a complementary reprocessingalgorithm is implemented.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-129 (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 F
