1、Standard ECMA-291December 1999Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.ch8 mm Wide Magnetic TapeCartridge for InformationInterchange - Helical ScanRecording AIT-1 with MICFormat.Standard ECMA-
2、291December 1999Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chMB E-291.doc 12-01-00 11,488 mm Wide Magnetic TapeCartridge for InformationInterchange - Helical ScanRecording - AIT-1 With MICFormat
3、.Brief HistoryTechnical Committee ECMA TC17 has produced a series of ECMA Standards for magnetic tape cassettes andcartridges of different widths, e.g. 12,7 mm, 8 mm, 6,35 mm and 3,81 mm. In each series, the standards correspond tospecific types of application and user requirements. Enhanced and new
4、 media also correspond to advancements indrive technology. The series of helically recorded cartridges with a magnetic tape of 8 mm width comprises thefollowing standards.ECMA-145 (1990) 8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical RecordingISO/IEC 11319ECMA-169 (1992) 8 m
5、m Wide Magnetic Tape Cartridge - Dual Azimuth Format for Information Interchange -ISO/IEC 12246 Helical Scan RecordingECMA-246 (1996) 8 mm Wide Magnetic Tape Cartridges for Information Interchange - Helical Scan RecordingISO/IEC 15780 AIT-1 FormatECMA-247 (1996) 8 mm Wide Magnetic Tape Cartridges fo
6、r Information Interchange - Helical Scan RecordingISO/IEC 15718 HH-1 FormatECMA-249 (1996) 8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan RecordingISO/IEC 15757 DA-2 FormatECMA-292 (1999) 8 mm Wide Magnetic Tape Cartridges for Information Interchange - Helical Scan Reco
7、rdingISO/IEC yyyyy AIT-2 FormatECMA-293 (1999) 8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan RecordingISO/IEC xxxxx Mammoth Tape-2 FormatThe format of this ECMA Standard is based on, and compatible with, that of Standard ECMA-246. It specifies the useof a Memory In Car
8、tridge (MIC) chip. It provides for a storage capacity of 35 Gbytes uncompressed user data whenused with a tape of 230 m.This ECMA Standard has been contributed to ISO/IEC for adoption under the fast-track procedure as an InternationalStandard.This ECMA Standard has been adopted by the ECMA General A
9、ssembly of 16thDecember 1999.- i -Table of contentsSection 1 - General 11Scope 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 24.4 algorithm 24.5 Area ID 24.6 Automatic T
10、rack Finding (ATF) 24.7 Average Signal Amplitude 24.8 azimuth 24.9 back surface 24.10 byte 24.11 cartridge 24.12 Channel bit 34.13 Codeword 34.14 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 spac
11、ing 34.20 Frame 34.21 Housekeeping Frame 34.22 Logical Beginning of Tape (LBOT) 34.23 magnetic tape 34.24 Master Standard Amplitude Calibration Tape 34.25 Master Standard Reference Tape 34.26 Memory In Cartridge (MIC) 44.27 Partition Boundary 44.28 Physical Beginning of Tape (PBOT) 44.29 Physical En
12、d of Tape (PEOT) 44.30 physical recording density 44.31 pre-recording condition 44.32 processing 44.33 processed data 44.34 Processed Record 44.35 record 44.36 Reference Field 44.37 Secondary Standard Amplitude Calibration Tape 44.38 Secondary Standard Reference Tape 44.39 Separator Mark 54.40 Stand
13、ard Reference Amplitude (SRA) 54.41 Tape Reference Edge 5- ii -4.42 Typical Field 54.43 Standard Reference Current 54.44 Test Recording Current 54.45 track 54.46 unprocessed data 54.47 Unprocessed Record 55 Conventions and Notations 55.1 Representation of numbers 55.2 Names 56 Acronyms 57 Environmen
14、t and safety 67.1 Test environment 67.2 Operating environment 67.3 Storage environment 67.4 Transportation 67.5 Safety 77.6 Flammability 7Section 2 - Requirements for the case 78 Dimensional and mechanical characteristics of the case 78.1 General 78.2 Overall dimension 78.3 Holding areas 88.4 Cartri
15、dge insertion 88.5 Window 98.6 Loading grips 98.7 Label areas 98.8 Datum areas and Datum holes 108.9 Support areas 118.10 Recognition holes 118.11 Write-inhibit hole 118.12 Pre-positioning surfaces 128.13 Cartridge lid 128.14 Cartridge reel lock 148.15 Reel access holes 148.16 Interface between the
16、reels and the drive spindles 158.17 Light path 168.18 Position of the tape in the case 168.19 Tape path zone 178.20 Tape access cavity 178.21 Tape access cavity clearance 178.22 Requirements for the MIC 178.23 Recognition recesses 19Section 3 - Requirements for the unrecorded tape 399 Mechanical, ph
17、ysical and dimensional characteristics of the tape 399.1 Materials 399.2 Tape length 399.2.1 Length of the magnetic tape 39- iii -9.2.2 Length of the leader and trailer tapes 399.2.3 Length of the splicing tapes 399.3 Tape width 399.3.1 Width of the magnetic, leader and trailer tapes 399.3.2 Width a
18、nd position of the splicing tape 409.4 Discontinuities 409.5 Tape thickness 409.5.1 Thickness of the magnetic tape 409.5.2 Thickness of the leader and trailer tapes 409.5.3 Thickness of the splicing tape 409.6 Longitudinal curvature 409.7 Cupping 409.8 Coating adhesion 409.9 Layer-to-layer adhesion
19、419.10 Tensile strength 419.10.1 Breaking strength 419.10.2 Yield strength 419.11 Residual elongation 419.12 Electrical resistance of the recording surface 429.13 Tape winding 429.14 Light transmittance of the tape 4210 Magnetic recording characteristics 4210.1 Typical Field 4310.2 Signal Amplitude
20、4310.3 Resolution 4310.4 Overwrite 4310.5 Ease of erasure 4410.6 Tape quality 4410.6.1 Missing pulses 4410.6.2 Missing pulse zone 4410.7 Signal-to-Noise Ratio (SNR) characteristic 44Section 4 - Requirements for an interchanged tape 4411 Format 4411.1 General 4411.2 Basic Groups 4511.2.1 Entity 4611.
21、2.2 Group Information Table 4611.2.3 Block Access Table (BAT) 4911.3 Sub-Groups 5111.3.1 G1 Sub-Group 5111.3.2 G2 Sub-Group - Randomizing 5211.3.3 G3 Sub-Group 5311.4 Data Block 5411.4.1 ID information 5511.4.2 Recording of the ID Information in the Data Block Headers 5712 Method of recording 6312.1
22、 Physical recording density 6312.2 Long-term average bit cell length 63- iv -12.3 Short-term average bit cell length 6412.4 Rate of change 6412.5 Bit shift 6412.6 Read signal amplitude 6412.7 Maximum recorded levels 6413 Track geometry 6413.1 Track configuration 6413.2 Average track pitch 6513.3 Var
23、iations of the track pitch 6513.4 Track width 6513.5 Track angle 6513.6 Track edge straightness 6513.7 Track length 6513.8 Azimuth angles 6514 Recorded patterns 6514.1 Recorded Data Block 6514.2 Margin blocks 6515 Format of a track 6615.1 Track structure 6615.2 Positioning accuracy 6715.3 Tracking s
24、cheme 6716 Layout of the tape 6716.1 Device Area 6816.2 Reference Area 6916.3 Position Tolerance Band No. 1 6916.4 System Area 6916.4.1 System Preamble 6916.4.2 System Log 6916.4.3 System Postamble 7316.4.4 Position Tolerance Band No. 2 7316.4.5 Vendor Group Preamble 7316.5 Data Area 7316.5.1 Vendor
25、 Group 7316.5.2 Recorded Data Group 7416.5.3 ECC3 7416.5.4 Multiple Recorded Instances 7516.5.5 Repeated Frames 7516.5.6 Appending and overwriting 7616.6 EOD Area 7716.7 Optional Device Area 7816.8 Logical End Of Tape (LEOT) 7816.9 Logical Beginning of Tape (LBOT) 7816.10 Early Warning Point - EWP 7
26、816.11 Empty Partition 7816.12 Initialization 7917 Housekeeping Frames 7917.1 Amble Frames 7917.2 System Amble Frames 79- v -18 Content of the MIC 80Annex A - Measurement of light transmittance 81Annex B - Measurement of Signal-to-Noise Ratio 85Annex C - Method for determining the nominal and the ma
27、ximum allowable recorded levels 87Annex D - Representation of 8-bit bytes by 10-bit patterns 89Annex E - Measurement of bit shift 101Annex F - Method of measuring the straightness of track edges 103Annex G - ECC calculation 105Annex H - Recommendations for transportation 109Annex J - Read-After-Writ
28、e 111Annex K - Example of the content of a Basic Group No. 0 113Annex L - Examples of MIC chip 115- vi -.Section 1 - General1ScopeThis ECMA Standard specifies the physical and magnetic characteristics of an 8 mm wide magnetic tapecartridge containing a memory chip to enable physical interchange of s
29、uch cartridges between drives. It alsospecifies the quality of the recorded signals, the recording method and the recorded format - called AdvancedIntelligent Tape No. 1 with Memory In Cartridge (AIT-1 with MIC) - thereby allowing data interchangebetween drives by means of such magnetic tape cartrid
30、ges. The System Log is recorded in the MIC.This ECMA Standard specifies two types of cartridge depending on the thickness of the magnetic tapecontained in the case.Information interchange between systems also requires, at a minimum, agreement between the interchangeparties upon the interchange code(
31、s) and the specifications of the structure and labelling of the information onthe interchanged cartridge.2 Conformance2.1 Magnetic tape cartridgeA tape cartridge shall be in conformance with this ECMA Standard if it meets all the mandatoryrequirements specified herein. The tape requirements shall be
32、 satisfied throughout the extent of the tape.2.2 Generating driveA drive generating a magnetic tape cartridge for interchange shall be in conformance with this ECMAStandard if all recordings on the tape meet the mandatory requirements of this ECMA Standard, and ifeither or both methods of appending
33、and overwriting are implemented. In addition, such a drive shall beable to record the System Log in the MIC.A claim of conformance shall state which of the following optional features are implemented and which arenot the performing of a Read-After-Write check and the recording of any necessary repea
34、ted 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 tocompress data received from the host prior to collecting the data into Basic Groups, and the registered ident
35、ification number(s) of the implemented compression algorithm(s).2.3 Receiving driveA drive receiving a magnetic tape cartridge for interchange shall be in conformance with this ECMAStandard if it is able to handle any recording made on the tape according to this ECMA Standard. Inparticular it shall
36、be able to read the System Log recorded in the MIC, be able to recognise repeated frames, and to make available to the host, data and Separator Marks fromonly one of these frames; be able to recognise multiple representations of the same Basic Group, and to make available to thehost, data and Separa
37、tor Marks from only one of these representations; be able to recognise an ECC3 frame, and ignore it if the system is not capable of using ECC3 checkbytes in a process of error correction; be able to recognise processed data within an Entity, identify the algorithm used, and make itsregistered identi
38、fication number available to the host;- 2 - 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 or not one or more de-compression algorithm(s) are
39、implemented within the system, and areable to be applied to compressed data prior to making such data available to the host; the registered identification number(s) of the compression algorithm(s) for which a complementary de-compression algorithm is implemented.3 ReferencesECMA-287 (1999) Safety of
40、 electronic equipmentISO/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 thelossless compression of data.4 Defini
41、tionsFor the purposes of this ECMA Standard the following definitions apply.4.1 Absolute Frame Number (AFN)A sequence number encoded in a Frame.4.2 a.c. eraseA process of erasure utilizing magnetic fields of decaying intensity.4.3 AccessA read or write pass over a partition.4.4 algorithmA set of rul
42、es 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 Automatic Track Finding (ATF)The method by which tracking is achieved.4.7 Average Signal AmplitudeThe average peak-to-peak value of the output s
43、ignal from the read head at the fundamental frequency of thespecified physical recording density over a minimum of 20,0 mm of track, exclusive of missing pulses.4.8 azimuthThe angular deviation made by the mean flux transition line with a line normal to the centreline of therecorded track.4.9 back s
44、urfaceThe surface of the tape opposite to the magnetic coating which is used to record data.4.10 byteAn ordered set of bits acted upon as a unit.4.11 cartridgeA case containing magnetic tape stored on twin hubs.- 3 -4.12 Channel bitA bit after 8-10 transformation.4.13 CodewordA word generated by a c
45、ompression algorithm. The number of bits in a Codeword is variable, and is notspecified by this ECMA Standard.4.14 Early Warning Point (EWP)A point along the length of the tape at which warning is given of the approach, in the forward direction ofthe tape motion, of the Partition Boundary or of the
46、Physical End of Tape.4.15 End of Data (EOD)The point on the tape at the end of the group which contains the last user data.4.16 EntityA unit of recorded data, comprising an Entity Header and a Record sequence.4.17 Error Correcting Code (ECC)A mathematical computation yielding check bytes used for th
47、e detection and correction of errors.4.18 flux transition positionThat point which exhibits maximum free-space flux density normal to the tape surface.4.19 flux transition spacingThe distance along a track between successive flux transitions.4.20 FrameA pair of adjacent tracks with azimuths of oppos
48、ite polarity, in which the track with the positive azimuthprecedes that with the negative azimuth.4.21 Housekeeping FrameA Frame which contains no user data and which is identified as such by the setting of the Data Fieldstherein.4.22 Logical Beginning of Tape (LBOT)The point along the length of the
49、 tape where a recording of data for interchange commences.4.23 magnetic tapeA tape which will accept and retain the magnetic signals intended for input, output and storage purposes oncomputers and associated equipment.4.24 Master Standard Amplitude Calibration TapeA pre-recorded tape on which the standard signal amplitudes have been recorded in the tracks of positiveand negative azimuth recorded at a track pitch of 11,0 m, on an a.c. erased tape.Note 1The tape includes recording at 1 428,6 ftpmm, 1 904,8 ftpmm, 2 857,1 ftpmm and 3 809,5 ftpmm.Note 2The Master Standard Ampl
