1、Standard ECMA-293December 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 MammothTape-2Format.Standard ECMA-2
2、93December 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-293.DOC 13-01-00 15,498 mm Wide Magnetic TapeCartridge for InformationInterchange - Helical ScanRecording MammothTape-2Format.
3、Brief HistoryECMA has produced a series of Standards for cassettes and cartridges containing magnetic 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 by ISO/IEC under the fast-trackprocedure as International Standards. Of these, the following r
4、elate to 8 mm helical scan recording.ECMA-145 (1990): 8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan RecordingISO 11319ECMA-169 (1992): 8 mm Wide Magnetic Tape Cartridge Dual Azimuth Format for Information Interchange ISO/IEC 12246 Helical Scan RecordingECMA-246 (1998):
5、 8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording -ISO/IEC 15780 AIT-1 FormatECMA-247 (1998): 8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan RecordingISO/IEC 15718 HH-1 FormatECMA-249 (1998): 8 mm Wide Magnetic Tape Cartridge Dual A
6、zimuth Format for Information Interchange -ISO/IEC 15757 Helical Scan Recording DA-2 FormatECMA-291 (1999): 8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording -AIT-1 with MIC FormatECMA-292 (1999): 8 mm Wide Magnetic Tape Cartridge for Information Interchange - He
7、lical Scan Recording -AIT-2 with MIC FormatThis ECMA Standard describes a cartridge containing cleaning tape and magnetic tape 8 mm wide. With a tape of 225 m, thisformat provides a native storage capacity of 60 Gbytes, or a compressed data capacity of typically 150 Gbytes. This formattriples the fo
8、rmat capacity of Standard ECMA-249 by increasing the bit density, increasing the track density, improving theformat efficiency, and increasing tape length. In addition, a third level of Error Correction Code was added to improve datareliability.This ECMA Standard has been contributed to ISO/IEC for
9、adoption under the fast-track procedure as an InternationalStandard.Adopted as an ECMA Standard by the General Assembly of 16thDecember 1999.- i -Table of contentsSection 1 - General 11Scope 12 Conformance 12.1 Magnetic tape cartridges 12.2 Generating drive 12.3 Receiving drive 13 References 14 Defi
10、nitions 14.1 a.c. erase 14.2 algorithm 14.3 Average Signal Amplitude 14.4 azimuth 24.5 back surface 24.6 bit cell 24.7 byte 24.8 cartridge 24.9 Channel bit 24.10 Cyclic Redundancy Check (CRC) character 24.11 Error Correcting Code (ECC) 24.12 File Mark 24.13 Logical Beginning of Partition (LBOP) 24.1
11、4 Logical Block 24.15 magnetic tape 24.16 Master Standard Reference Tape 24.17 Partition 24.18 Physical Beginning of Partition (PBOP) 24.19 Physical Beginning of Tape (PBOT) 24.20 Physical End of Partition (PEOP) 24.21 Physical End of Tape (PEOT) 24.22 physical recording density 34.23 Read Back Chec
12、k (RBC) 34.24 Reference Field 34.25 Secondary Standard Reference Tape (SSRT) 34.26 Set Mark 34.27 Standard Reference Amplitude (SRA) 34.28 Standard Reference Current (Ir) 34.29 Tape Reference Edge 34.30 Test Recording Current (TRC) 34.31 Track 34.32 Typical Field 35 Conventions and Notations 35.1 Re
13、presentation of numbers 35.2 Names 46 Acronyms 47 Environment and Safety 47.1 Testing environment 4- ii -7.2 Operating environment 47.3 Storage environment 57.4 Transportation 57.5 Safety 57.6 Flammability 5Section 2 - Requirements for the case 68 Dimensional and mechanical characteristics of the ca
14、se 68.1 General 68.2 Overall dimension 68.3 Holding areas 78.4 Cartridge insertion 78.5 Window 88.6 Loading grips 88.7 Label areas 88.8 Datum areas and datum holes 98.9 Support areas 108.10 Recognition holes 108.11 Write-inhibit hole 118.12 Pre-positioning surfaces 118.13 Cartridge lid 118.14 Cartri
15、dge reel lock 138.15 Reel access holes 138.16 Interface between the reels and the drive spindles 148.17 Light path 158.18 Position of the tape in the case 168.19 Tape path zone 168.20 Tape access cavity 168.21 Tape access cavity clearance requirements 16Section 3 - Requirements for the Unrecorded Ta
16、pe 339 Mechanical, physical and dimensional characteristics of the tape 339.1 Materials 339.2 Tape length 339.2.1 Length of the magnetic tape 339.2.2 Length of leader and trailer tapes 339.2.3 Length of the cleaning tape 339.2.4 Length of the splicing tape 339.3 Width 349.3.1 Width of magnetic, clea
17、ning, leader and trailer tape 349.3.2 Width and position of the splicing tape 349.3.3 Edge weave 349.4 Discontinuities 359.5 Thickness 359.5.1 Thickness of the magnetic tape 359.5.2 Thickness of the cleaning tape 359.5.3 Thickness of leader and trailer tape 359.5.4 Thickness of the splice tape 369.6
18、 Longitudinal curvature 369.7 Cupping 369.8 Coating adhesion 369.9 Layer-to-layer adhesion 379.10 Tensile strength 37- iii -9.10.1 Breaking strength 379.10.2 Yield strength 379.11 Residual elongation 379.12 Electrical resistance of the recording surface 379.13 Tape winding 389.14 Light transmittance
19、 of tape 389.15 Abrasivity 3810 Magnetic recording characteristics 3810.1 Test conditions 3810.2 Typical Field 3910.3 Signal Amplitude 3910.4 Resolution 3910.5 Signal-to-Noise Ratio 3910.6 Ease of erasure 4010.7 Tape quality 4010.7.1 Missing pulses 4010.7.2 Missing pulse zone 4010.7.3 Overwrite 40Se
20、ction 4 - Requirements for an Interchanged Tape 4111 Track Format 4111.1 General 4111.2 Physical block format 4211.2.1 Logical Transfer Segment (LTS) 4211.2.2 Compression Unit 4311.2.3 Physical block 4411.2.3.1 Physical Block header 4611.2.4 Information Matrix 5111.2.5 Recorded patterns 5211.3 Searc
21、h field format 5211.3.1 Search field data 5211.3.2 Search field CRC and ECC 5411.3.3 Search field recording patterns 5411.4 Servo area 5411.5 Track layout 5512 Method of recording 5712.1 Physical Recording Density 5712.1.1 Long Term Average Bit Cell Length 5712.1.2 Short Term Average Bit Cell Length
22、 5712.1.3 Rate of Change 5712.2 Bit Shift 5812.3 Amplitude of Data Signals 5813 Track geometry 5813.1 General 5813.2 Track pitch 5813.3 Average track pitch 5813.4 Track width 5813.5 Track angle 5913.6 Track length 5913.7 Guard band 59- iv -13.8 Azimuth angles 5913.9 Track linearity 5914 Layout of a
23、tape 5914.1 General 5914.2 Tape History Log (THL) 5914.3 Physical Beginning of Partition 6014.4 Logical Beginning of Partition 6014.5 Data area 6014.5.1 General 6014.5.2 Short File Mark 6014.5.3 Long File Mark 6014.5.4 Set Mark 6014.6 End of Data 6014.7 Physical End of Partition (PEOP) 60Annex A - M
24、easurement of Light Transmittance of Tape and Leaders 61Annex B - Tape abrasivity measurement procedure 65Annex C - Generation of the Logical Block CRC 67Annex D - ECC3 Check Bytes 69Annex E - Generation of the Data Area CRC 71Annex F - Generation of the ECC 73Annex G - Pre-coder 75Annex H - Represe
25、ntation of 8-bit bytes by 10-bit patterns 77Annex J - Randomisation 85Annex K - Generation of the Search Field CRC 87Annex L - The Search Field ECC 89Annex M - Measurement of bit shift 91Annex N - Recommendations for transportation 93.Section 1 - General1ScopeThis ECMA Standard specifies the physica
26、l and magnetic characteristics of an 8 mm wide magnetic tapecartridge to enable physical interchange of such cartridges between drives. It also specifies the quality of therecorded signals, the recording method and the recorded format called MammothTape-2, and thereby allowingdata interchange betwee
27、n drives by means of such magnetic tape cartridges.Information interchange between systems also requires, at a minimum, agreement between the interchangeparties upon the interchange code(s) and the specifications of the structure and labelling of the information onthe interchanged cartridge.2 Confor
28、mance2.1 Magnetic tape cartridgesA magnetic tape cartridge shall be in conformance with this ECMA Standard if it satisfies all mandatoryrequirements of this ECMA Standard throughout the extent of the tape.2.2 Generating driveA drive generating a magnetic tape cartridge for interchange shall be entit
29、led to claim conformance withthis ECMA Standard if all the recordings that it makes on a tape meet the mandatory requirements of thisECMA Standard. A claim of conformance shall state whether or not one or more registered compressionalgorithm(s) are implemented within the system to process data from
30、the host prior to allocating data tophysical blocks.2.3 Receiving driveA system receiving a magnetic tape cartridge for interchange shall be entitled to claim conformance withthe ECMA Standard if it is able to handle any recording on this tape according to this ECMA Standard. Areceiving drive shall
31、be able to recognise the use of a data compression algorithm and make the algorithmregistration number available to the host.3 ReferencesECMA-287 (1999) Safety of electronic equipmentECMA-222 (1995) Adaptive Lossless Data Compression AlgorithmISO 527-1:1993 Plastics - Determination of tensile proper
32、ties - Part 1: General principles.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.4 DefinitionsFor the purpose of this ECMA Standard, the f
33、ollowing definitions apply.4.1 a.c. eraseA process of erasure utilising alternating magnetic fields of decaying intensity.4.2 algorithmA set of rules for transforming the logical representation of data.4.3 Average Signal AmplitudeThe average peak-to-peak value of the output signal from the read head
34、 at a density of 3 704 ftpmmmeasured over a distance of 3000 mm, exclusive of missing pulses.- 2 -4.4 azimuthThe angular deviation, in degrees of arc, of the recorded flux transitions on a track from a line normal to thetrack centreline.4.5 back surfaceThe surface of the tape opposite to the magneti
35、c coating used to record data.4.6 bit cellA distance along the track allocated for the recording of a Channel bit.4.7 byteAn ordered set of bits acted upon as a unit.4.8 cartridgeA case containing magnetic tape stored on twin reels.4.9 Channel bitA bit after 8-10 transformation.4.10 Cyclic Redundanc
36、y Check (CRC) characterA character derived from information contained in data bytes that is used for error detection.4.11 Error Correcting Code (ECC)A mathematical procedure yielding bytes used for the detection and correction of errors.4.12 File MarkA mark recorded on the tape at the request of the
37、 host system to separate files or to provide an appendpoint. This format provides for Long or Short File Marks.4.13 Logical Beginning of Partition (LBOP)The point in a partition where a recording of data for interchange commences.4.14 Logical BlockInformation (data, file marks, or set marks) sent to
38、 the tape drive to be recorded.4.15 magnetic tapeA tape that accepts and retains magnetic signals intended for input, output, and storage of data forinformation processing.4.16 Master Standard Reference TapeA tape selected as the standard for Signal Amplitude, Typical Field, Overwrite and Resolution
39、.NOTEThe Master Standard Reference Tape has been established by Pericomp Corporation.4.17 PartitionA formatted length of tape used to record data.4.18 Physical Beginning of Partition (PBOP)The point along the length of tape at which a partition begins.4.19 Physical Beginning of Tape (PBOT)The transi
40、tion from the tape leader to an opaque area of the splice by which a translucent leader tape isjoined to the magnetic tape.4.20 Physical End of Partition (PEOP)The point along the length of tape at which a partition ends.4.21 Physical End of Tape (PEOT)The transition from an opaque area of the splic
41、e to a translucent trailer tape.- 3 -4.22 physical recording densityThe number of recorded flux transitions per unit length of track, expressed in flux transitions per millimetre(ftpmm).4.23 Read Back Check (RBC)A Read Back Check occurs when, while writing, the data is read by trailing heads and che
42、cked for errors.4.24 Reference FieldThe Typical Field of the Master Standard Reference Tape.4.25 Secondary Standard Reference Tape (SSRT)A tape the performance of which is known and stated in relation to that of the Master Standard ReferenceTape.NOTESecondary Standard Reference Tapes can be ordered
43、under the Part Number SSRT/M.AME/PC97, fromPericomp Corporation, 14 Huron Drive, Natick, MA 01760, USA.In principle, such tapes will be available for a period of 10 years from the publication of the first edition ofthis ECMA Standard. However, by agreement between ECMA and Pericomp, this period may
44、be shortenedor extended to take account of demand for such tapes.It is intended that these be used for calibrating Tertiary Reference Tapes for use in routine calibration.4.26 Set MarkA mark recorded on the tape at the request of the host system to separate a set of data or to provide anappend point
45、.4.27 Standard Reference Amplitude (SRA)The Average Signal Amplitude derived from the Master Standard Reference Tape, using the Test RecordingCurrent at 3 704 ftpmm.4.28 Standard Reference Current (Ir)The current that produces the Reference Field.4.29 Tape Reference EdgeThe lower edge of tape as see
46、n when viewing the recording surface of the tape with the supply reel to theobservers right.4.30 Test Recording Current (TRC)The current used to record the SRA. The TRC is 1,5 times the Standard Reference Current.4.31 TrackA diagonally positioned area on the tape along which a series of magnetic tra
47、nsitions may be recorded.4.32 Typical FieldIn the plot of the Average Signal Amplitude against the recording field at the physical recording density of3 704 ftpmm, the minimum field that causes an Average Signal Amplitude equal to 90% of the maximumAverage Signal Amplitude.5 Conventions and Notation
48、s5.1 Representation of numbersA measured value is rounded off to the least significant digit of the corresponding specified value. Itimplies that a specific value of 1,26 with a positive tolerance of +0,01, and a negative tolerance of -0,02allows a range of measured values from 1,235 to 1,275. Lette
49、rs and digits in parentheses represent numbers in hexadecimal notation. The setting of a bit is denoted by ZERO or ONE.- 4 - Numbers in binary notation and bit combinations are represented by strings of digits 0 and 1. Numbers in binary notation and bit combinations are shown with the most significant byte to the left,and with the most significant bit in each byte to the left. Negative values of numbers in binary notation are given in Twos complement. In each field the data is processed so that the most significant byte (byte 0) is processed first. Withineach byte the mo
