1、Standard ECMA-315December 2000Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.ch12,65 mm Wide Magnetic TapeCassette for InformationInterchange - Helical ScanRecording - DTF-2.Standard ECMA-315Decembe
2、r 2000Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chMB - ECMA-315.DOC -14.03.2002 17:3412,65 mm Wide Magnetic TapeCassette for InformationInterchange - Helical ScanRecording - DTF-2.Brief History
3、ECMA has produced a series of Standards for cassettes and cartridges containing magnetic tapes of different widthsand characteristics.ECMA Standards for cartridges/cassettes recorded in a helical mode are:ECMA-139(1990): 3,81 mm Wide Magnetic Tape Cartridges - Helical Scan Recording - DDS FormatECMA
4、-146(1990): 3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical ScanRecording - DATA/DAT FormatECMA-150(1992): 3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical ScanRecording - DDS-DC FormatECMA-170(1992): 3,81 mm Wide Magnetic Tape Cartridge for Infor
5、mation Interchange - Helical ScanRecording-DDSFormatusing60mand90mLengthTapesECMA-171(1992): 3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical ScanRecording - DATA/DAT-DC Format using 60 m and 90 m Length TapesECMA-198(1995): 3,81 mm Wide Magnetic Tape Cartridge for Informat
6、ion Interchange - Helical ScanRecording - DDS-2 Format using 120 m Length TapesECMA-236(1996): 3,81 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical ScanRecording - DDS-3 Format using 125 m Length TapesECMA-288(1999): 3,81 mm Wide Magnetic Tape Cartridge for Information Intercha
7、nge - Helical ScanRecording - DDS-4 Format using 155 m Length TapesECMA-169(1992): 8 mm Wide Magnetic Tape Cartridge, Dual Azimuth for Information Interchange - HelicalScan RecordingECMA-246(1998): 8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording -AIT-1 FormatEC
8、MA-247(1998): 8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording -HH-1 FormatECMA-249(1998): 8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording -DA-2 FormatECMA-291(1999): 8 mm Wide Magnetic Tape Cartridge for Information Interc
9、hange - Helical Scan Recording -AIT-1with MIC FormatECMA-292(1999): 8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording -AIT-2with MIC FormatECMA-293(1999): 8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording -Mammoth Tape-2 Forma
10、tECMA-210(1995): 12,65 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical ScanRecording - DATA-D3-1 FormatECMA-248(1996): 12,65 mm Wide Magnetic Tape Cassette for Information Interchange - Helical ScanRecording-DTF-1FormatThis Standard ECMA-315 describes a cassette containing magn
11、etic tape 12,65 mm wide. The processing of data andmethod of recording employ technologies developed for recording digital television signals and thus provides highcapacity and data rate. Furthermore, the directory and file structure placeholders defined in this ECMA Standardprovide for fast search
12、and access to very large sets of data recorded on this magnetic tape as well as providing fordisaster recovery in the case of a lost or destroyed directory. The large and small cassettes have maximum capacitiesof 200 GB and 60 GB respectively.Adopted as an ECMA Standard by the General Assembly of 15
13、thDecember 2000.-i-Table of contentsSection 1 - General 11Scope 12 Conformance 12.1 Magnetic tape cassette 12.2 Generating system 12.3 Receiving system 13 References 14 Definitions 14.1 Absolute block number 24.2 a.c. erase 24.3 algorithm 24.4 Append file 24.5 Append volume 24.6 Average Signal Ampli
14、tude (ASA) 24.7 azimuth 24.8 back surface 24.9 bit cell 24.10 block 24.11 Block Management Table (BMT) 24.12 byte 24.13 cassette 24.14 compressed data 24.15 Control Track 24.16 flux transition position 24.17 flux transition spacing 24.18 Logical track set ID 24.19 Logical volume 24.20 magnetic tape
15、34.21 Master Standard Reference Tape (MSRT) 34.22 physical recording density 34.23 Reference Field (RF) 34.24 Secondary Standard Reference Tape (SSRT) 34.25 Standard Reference Amplitude (SRA) 34.26 Standard Reference Current (Ir) 34.27 Tape Reference Edge 34.28 Test Recording Current (TRC) 34.29 tra
16、ck 34.30 track angle 44.31 Track Set 44.32 Typical Field (TF) 44.33 word 45 Conventions and Notations 45.1 Representation of numbers 45.2 Names 46 Acronyms 4-ii-7 Environment and safety 57.1 Testing environment 57.2 Operating environment 57.3 Storage environment 57.4 Transportation 57.5 Safety 67.6
17、Flammability 6Section 2 - Requirements for the case 78 Dimensional and mechanical characteristics of the case 78.1 General 78.2 Type S cassette 78.2.1 Overall dimensions 78.2.2 Holding areas 88.2.3 Window 88.2.4 Label areas 88.2.5 Datum areas and datum holes 98.2.6 Support areas 98.2.7 Guiding groov
18、es 108.2.8 Recognition holes 118.2.9 Write-inhibit plug 128.2.10 Pre-positioning surface 138.2.11 Cassette lid 138.2.12 Cassette reel lock 148.2.13 Reel access holes 148.2.14 Reels 158.2.15 Position of the tape in the case 168.2.16 Tape path zone 168.2.17 Tape access cavity 168.3 Type L cassette 328
19、.3.1 Overall dimensions 328.3.2 Holding areas 328.3.3 Window 338.3.4 Label areas 338.3.5 Datum areas and datum holes 338.3.6 Support areas 348.3.7 Guiding grooves 348.3.8 Recognition holes 358.3.9 Write-inhibit plug 368.3.10 Pre-positioning surface 378.3.11 Cassette lid 378.3.12 Cassette reel lock 3
20、88.3.13 Reel access holes 398.3.14 Reels 398.3.15 Position of the tape in the case 408.3.16 Tape path zone 418.3.17 Tape access cavity 418.3.18 Cavity for compatibility with Type S cassette 42Section 3 - Requirements for the unrecorded tape 589 Mechanical, physical and dimensional characteristics of
21、 the tape 589.1 Materials 589.2 Tape length 58- iii -9.3 Tape width 589.4 Width and position of splicing tape 589.5 Discontinuity 589.6 Tape thickness 589.7 Longitudinal curvature 599.8 Out-of-plane distortions 599.9 Coating adhesion 599.10 Layer-to-layer adhesion 609.11 Tensile strength 609.11.1 Br
22、eaking strength 609.11.2 Yield strength 609.11.3 Strength of Splice 609.12 Residual elongation 609.13 Electrical resistance of the coated surfaces 609.14 Tape wind 6110 Magnetic recording characteristics 6110.1 Typical Field (TF1) 6210.2 Average Signal Amplitude(ASA) 6210.3 Resolution 6210.4 Signal-
23、to-noise ratio (S/N) 6210.5 Ease of erasure 6210.6 Tape quality 6210.6.1 Missing pulses 6210.6.2 Missing pulse zone 6210.7 Inhibitor tape 63Section 4 - Requirements for an interchanged tape 6411 Format for helical tracks 6411.1 General description of the write data path 6411.2 Formation of a Logical
24、 Track Set 6411.2.1 Types of information track sets 6411.2.2 Generation of a Logical Track Set 6611.2.3 Subcode data field 6611.2.4 Block Management Table (BMT) 7011.2.5 Data and information field defintions 7011.3 Track Set information 7411.3.1 Loading the Product Code Arrays 7511.4 Product code ar
25、ray processing 7711.4.1 Error correction method 7711.4.2 Error correction coding for C1 Parity 7711.5 Track assignments 7811.5.1 Segments/Sectors 7811.5.2 Sync Blocks 7911.5.3 Track interleave 8011.5.4 Byte interleave across Sync Blocks 8211.5.5 Randomization 8311.6 Formation of the contents of a he
26、lical track 8311.6.1 Segment/Sector details 8311.6.2 Channel bit coding 8411.6.3 Interleaved-NRZ1 8411.6.4 Tracking Pilot Signals (TPS) 85-iv-12 Track geometry 8512.1 General 8512.2 Helically recorded tracks 8512.2.1 Location of the tracks 8512.2.2 Track width 8612.2.3 Track angle 8612.2.4 Track pit
27、ch 8612.2.5 Location of elements in the helical track 8712.2.6 Location of the Data Area Reference Point 8812.2.7 Straightness of tracks 8812.2.8 Azimuth angles 8812.2.9 Tracking Pilot Signals (TPS) 8812.2.10 Amplitude of servo signals 8812.3 Longitudinal tracks geometry 8812.3.1 Control Track 8812.
28、3.2 Time Code Track signals recording position 8813 Method of recording helical tracks 8813.1 Physical recording density 8913.2 Record current optimization 8913.3 Efficiency of erasure 8914 Method of recording longitudinal tracks 8914.1 Overview 8914.2 Control Track 8914.2.1 Signal 8914.2.2 Polarity
29、 of magnetisation 8914.2.3 Alignment 8914.2.4 Read signal amplitude 9014.2.5 Quality of the Control Track 9014.3 Time Code Track 9014.3.1 Method of recording the Time Code Track 9014.3.2 Physical recording density 9014.3.3 Bit shift 9014.3.4 Read signal amplitude 9114.3.5 Quality of the Time Code Tr
30、ack 9114.4 Format for the Time Code Track 9114.4.1 Count bits 9114.4.2 Phase bit 9114.4.3 Synchronizing pattern 9114.4.4 Supplemental Data 9114.4.5 Extent of Time Code 91Section 5 - Requirements for recorded information 9215 Recorded information 9215.1 Recording area 9215.2 Magnetic tape layout 9215
31、.2.1 Valid data areas 9215.2.2 Invalid data areas 9215.3 Physical TSID 9215.3.1 Structure surrounding the VSIT area 9415.3.2 Structure of the DIT area 94-v-15.3.3 Structure of the User Data Area 95Section 6 - Write operations 9616 Write retry sequence 9617 Append file operation 9617.1 Append volume
32、9617.2 Append write 9717.3 Overwrite 9717.4 File extension (figure 62) 98Annex A - Measurement of Signal-to-Noise Ratio 101Annex B - Representation 8/9 coding patterns 103Annex C - Recommendations for Transportation 110Annex D - Inhibitor Tape 112Section 1 - General1ScopeThis ECMA Standard specifies
33、 the physical and magnetic characteristics of magnetic tape cassettes, usingmagnetic tape 12,65 mm wide so as to provide physical interchange of such cassettes between drives. It alsospecifies the quality of the recorded signals, the recording method and the recorded format, called DigitalTape Forma
34、t-2 (DTF-2), thereby allowing data interchange between drives by means of such cassettes. Theformat supports variable length Logical Records, high-speed search, and the use of a registered algorithm fordata compression.This ECMA Standard specifies two sizes of cassette. For the purposes of this ECMA
35、 Standard the largercassette is referred to as Type L, and the smaller as Type S.Together with a standard for volume and file structure, e.g. Standard ECMA-13, this ECMA Standardprovides for full data interchange between data processing systems.2 Conformance2.1 Magnetic tape cassetteA claim of confo
36、rmance with this ECMA Standard shall specify the Type of cassette. It shall be inconformance with this ECMA Standard if: the case and unrecorded tape meet all the requirements of clause 8 to 10 for that Type the recording on the tape meets the requirements of clauses 11 to 172.2 Generating systemA c
37、laim of conformance with this ECMA Standard shall specify which Type(s) of cassette is (are)supported. A system generating a magnetic tape cassette for interchange shall be in conformance with thisECMA Standard if all the recordings that it makes, meet the mandatory requirements of this ECMAStandard
38、. A claim of conformance with this ECMA Standard shall state whether or not one, or more,registered algorithm(s) is (are) implemented and, if so, the registered number(s) of (all) the implementedalgorithm(s).2.3 Receiving systemA claim of conformance with this ECMA Standard shall specify which Type(
39、s) of cassette is (are)supported. A system receiving a magnetic tape cassette for interchange shall be in conformance with thisECMA Standard if it is able to handle any recording made on the tape according to this ECMA Standard,and a claim of conformance shall state whether or not one, or more, regi
40、stered algorithm(s) is (are)implemented and, if so, the registered number(s) of (all) the implemented algorithm(s).3 ReferencesECMA-13: 1985 File Structure and Labelling of Magnetic Tapes for Information InterchangeECMA-287: 1999 Safety of Electronic EquipmentISO/527-1:1993 Plastics Determination of
41、 tensile properties.ISO/IEC 11576:1994 Information Technology - Procedure for the Registration of Algorithms for theLossless Compression of DataSMPTE timecode: C98.12 : time and control code for video and audio tape for 525/60 television systemJIS-B-7502 Characteristics of plastic goods4 Definitions
42、For the purpose of this ECMA Standard, the following definitions apply.-2-4.1 Absolute block numberA number N allocated to each block, indicating that the block is the Nth block from the beginning of theLogical volume containing it. The first block is number one.4.2 a.c. eraseA process of erasure ut
43、ilizing alternating magnetic fields of decaying intensity.4.3 algorithmA set of rules for transforming the logical representation of data.4.4 Append fileA new file added from the End of Data (EOD) of a Logical volume.4.5 Append volumeA Logical volume added after the last Logical volume recorded on t
44、he cassette.4.6 Average Signal Amplitude (ASA)The average peak-to-peak value of the signal output of a read head measured over a minimum of 1,40 mmof track, exclusive of missing pulses.4.7 azimuthThe angular deviation, in degrees of arc, of the recorded flux transitions on a track from the line norm
45、al tothe track centreline.4.8 back surfaceThe surface of the tape opposite to the magnetic coating used to record data.4.9 bit cellA distance along the track allocated for the recording of a Channel bit.4.10 blockA unit of data which is sent to the tape controller when a single write command is exec
46、uted.4.11 Block Management Table (BMT)A table included in each Track Set to manage blocks contained in that Track Set.4.12 byteAn ordered set of bits acted upon as a unit.4.13 cassetteA case containing magnetic tape stored on twin reels.4.14 compressed dataA representation of host-transmitted data a
47、fter transformation by a data compression algorithm.4.15 Control TrackA track used for recording the servo control signals.4.16 flux transition positionThat point along a track on the magnetic tape that exhibits the maximum free-space flux density normal tothe tape surface.4.17 flux transition spaci
48、ngThe distance along a track between successive flux transitions.4.18 Logical track set IDThe track set ID assigned to each track set containing data received from the host.4.19 Logical volumeA data entity received by the generating system from the host.-3-4.20 magnetic tapeA tape which will accept
49、and retain the magnetic signals intended for input, output, and storage purposes.4.21 Master Standard Reference Tape (MSRT)A tape selected as the standard for Signal Amplitude, Reference Field, Resolution and Signal to NoiseRatio (S/N).NOTEThe Master Standard Reference Tape has been established at SONY Corporation.4.22 physical recording densityThe number of recorded flux transitions per unit length of track, specified as flux transitions per millimetre(ftpmm).4.23 Reference Field (RF)The Typical Field of the MSRT. There are two Reference Fields:RF1 is that for a helically recorded track
