1、Standard ECMA-3162nd Edition - December 2001Standardizing 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 VXA-1 Format.Standard
2、 ECMA-3162nd Edition - December 2001Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chMB Ecma-316.doc 04-01-02 10,118 mm Wide Magnetic TapeCartridge for InformationInterchange - Helical ScanRecording
3、 VXA-1 Format.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,
4、the following relate 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 Recording
5、ECMA-246 (1998): 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 Recording -ISO/IEC 15718 HH-1 FormatECMA-249 (1998): 8 mm Wide Magnetic Tap
6、e Cartridge Dual Azimuth 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 -ISO/IEC 18809 AIT-1withMICFormatECMA-292 (1999): 8 mm Wide Magnetic Tape Cartridge for
7、 Information Interchange - Helical Scan Recording -ISO/IEC 18810 AIT-2withMICFormatECMA-293 (1999): 8 mm Wide Magnetic Tape Cartridge for Information Interchange - Helical Scan Recording -ISO/IEC 18836 MammothTape-2 FormatThis Standard ECMA-316 describes a cartridge containing a magnetic tape 8 mm w
8、ide. With a tape length of 170 m, thisformat provides a native storage capacity of 33 Gbytes, or a compressed data capacity of typically 66 Gbytes. This ECMAStandard is the first in a family of VXA tape formats. It employs a R/S ECC-4 to ensure interchange of user data while beingless sensitive to u
9、ser alignment of the tracks recorded on the tape.This Standard has been adopted by ISO/IEC JTC 1 as International Standard ISO/IEC 20062.Adopted as an ECMA Standard by the General Assembly of December 2001.-i-Table of contentsSection 1 - General 11Scope 12 Conformance 12.1 Magnetic tape cartridges 1
10、2.2 Generating drive 12.3 Receiving drive 13 References 14 Definitions 14.1 ac erase 14.2 algorithm 14.3 Average Signal Amplitude 24.4 azimuth 24.5 back surface 24.6 Beginning of Data (BOD) 24.7 Beginning of Tape (BOT) 24.8 bit cell 24.9 byte 24.10 cartridge 24.11 Channel bit 24.12 Cyclic Redundancy
11、 Check (CRC) character 24.13 End of Data (EOD) 24.14 End of Partition (EOP) 24.15 End of Tape (EOT) 24.16 Error Correcting Code (ECC) 24.17 File Mark 24.18 Logical Block 24.19 magnetic tape 24.20 Master Standard Reference Tape 24.21 Partition 34.22 physical recording density 34.23 Reference Field 34
12、.24 Secondary Standard Reference Tape (SSRT) 34.25 Set Mark 34.26 Standard Reference Amplitude (SRA) 34.27 Standard Reference Current (Ir) 34.28 Tape Reference Edge 34.29 Test Recording Current (TRC) 34.30 Track 34.31 Typical Field 35 Conventions and Notations 35.1 Representation of numbers 35.2 Nam
13、es 46 Acronyms 47 Environment and Safety 47.1 Testing environment 47.2 Operating environment 4-ii-7.3 Storage environment 57.4 Transportation 57.5 Safety 57.6 Flammability 5Section 2 - Requirements for the case 58 Dimensional and mechanical characteristics of the case 58.1 General 58.2 Overall dimen
14、sion 68.3 Holding areas 68.4 Cartridge insertion 68.5 Window 78.6 Loading grips 78.7 Label areas 88.8 Datum areas and datum holes 88.9 Support areas 98.10 Recognition holes 108.11 Write-inhibit hole 118.12 Pre-positioning surfaces 118.13 Lid 118.14 Cartridge reel lock 138.15 Reel access holes 138.16
15、 Interface between the reels and the drive spindles 148.17 Light path 158.18 Position of the tape in the case 158.19 Tape path zone 168.20 Tape access cavity 168.21 Tape access cavity clearance requirements 16Section 3 - Requirements for the Unrecorded Tape 339 Mechanical, physical and dimensional c
16、haracteristics of the tape 339.1 Materials 339.2 Length 339.2.1 Length of the magnetic tape 339.2.2 Length of leader and trailer tapes 339.2.3 Length of the splicing tape 339.3 Width 339.3.1 Width of magnetic, leader and trailer tape 339.3.2 Width and position of the splicing tape 349.3.3 Edge weave
17、 349.4 Discontinuities 359.5 Thickness 359.5.1 Thickness of the magnetic tape 359.5.2 Thickness of leader and trailer tape 359.5.3 Thickness of the splice tape 359.6 Longitudinal curvature 369.7 Cupping 369.8 Coating adhesion 369.9 Layer-to-layer adhesion 369.10 Tensile strength 379.10.1 Breaking st
18、rength 379.10.2 Yield strength 379.11 Residual elongation 37- iii -9.12 Electrical resistance of the recording surface 379.13 Tape winding 389.14 Light transmittance of tape 3810 Magnetic recording characteristics 3810.1 Test conditions 3810.2 Typical Recording Current 3810.3 Signal Amplitude 3910.4
19、 Resolution 3910.5 Signal-to-Noise Ratio 3910.6 Ease of erasure 3910.7 Tape quality 3910.7.1 Missing pulses 3910.7.2 Missing pulse zone 3910.7.3 Overwrite 39Section 4 - Requirements for an Interchanged Tape 4011 Track Format 4011.1 General 4011.2 Physical Logical Block Format 4111.2.1 Logical Block
20、Set (LBS) 4111.2.2 Logical Blocks 4211.2.3 Segment Packets 4211.2.4 Segment Overhead Packets 4211.2.5 Skipped Segment Packets 4611.2.6 Segment ECC packets 4611.2.7 Segment flush 4711.3 Track Packet format 4711.3.1 Virtual Packet Address 4811.3.2 Local Packet Address 4811.3.3 Packet data 5011.3.4 Pac
21、ket CRC 5011.3.5 Packet Reed-Solomon ECC 5011.4 Control packet format 5011.5 Packet framing sync 5412 Tape Format 5512.1 Track elements 5512.2 Data track format 5512.2.1 Order of packets in a data track 5612.2.2 Rewrite 5612.3 Gap tracks 5613 Method of recording 5713.1 Physical recording density 571
22、3.1.1 Long-term average bit cell length 5713.1.2 Short-term average bit cell length 5713.1.3 Rate of change 5713.2 Bit shift 5713.3 Amplitude of Data Signals 5714 Track geometry 57-iv-14.1 General 5714.2 Track pitch 5814.3 Average track pitch 5814.4 Track width 5814.5 Track angle 5814.6 Track length
23、 5814.7 Guard band 5914.8 Azimuth angles 5914.9 Track linearity 5915 Layout of a tape 5915.1 General 5915.2 Beginning of Partition 5915.3 Tape Header Record (THR) 5915.4 Data area 6015.5 Tape Directory Record 6015.6 End of Data 6115.7 End of Partition (EOP) 61Annex A - Measurement of Light Transmitt
24、ance of Tape and Leaders 63Annex B - Packet ECC 67Annex C - Segment ECC 69Annex D - Generation of the Segment Overhead CRCs 71Annex E - Generation of the Segment Data CRC 73Annex F - Generation of the Packet CRC 75Annex G - Representation of 8-bit bytes by 14-bit patterns 77Annex H - Measurement of
25、bit shift 85Annex J - Tape Count 87Annex K - Recommendations for transportation 89Section 1 - General1ScopeThis ECMA Standard specifies the physical and magnetic characteristics of an 8 mm wide magnetic tapecartridge to enable physical interchange of such cartridges between drives. It also specifies
26、 the quality of therecorded signals, the recording method and the recorded format called VXA-1, and thereby allowing datainterchange between drives by means of such magnetic tape cartridges.This ECMA Standard specifies three types depending on the length of magnetic tape contained in the case,referr
27、ed to as Type A, Type B and Type C.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.If compression is used w
28、ith this format, it shall be according to ECMA Standard ECMA-222.2 Conformance2.1 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
29、drive generating a magnetic tape cartridge for interchange shall be entitled 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 the registered compression al
30、gorithmspecified in ECMA-222 is implemented within the system to process data from the host prior to allocatingdata to segment data packets.2.3 Receiving driveA system receiving a magnetic tape cartridge for interchange shall be entitled to claim conformance withthis ECMA Standard if it is able to h
31、andle any recording on this tape according to this ECMA Standard. Areceiving drive shall be able to recognise the use of the data compression algorithm specified inECMA-222.3 ReferencesECMA-222 (1995) Adaptive Lossless Data Compression AlgorithmECMA-287 (1999) Safety of electronic equipmentISO 527-3
32、:1995 Plastics - Determination of tensile properties - Part 3: Test conditions for films andsheetsISO 1302:1992 Technical Drawings - Method of indicating surface texture on drawingsISO/IEC 11576:1994 Information technology - Procedure for the registration of algorithms for the losslesscompression of
33、 data4 DefinitionsFor the purpose of this ECMA Standard, the following definitions apply.4.1 ac eraseA process of erasure utilising alternating magnetic fields of decaying intensity.4.2 algorithmA set of rules for transforming the logical representation of data.-2-4.3 Average Signal AmplitudeThe ave
34、rage peak-to-peak value of the output signal from the read head at a density of 2 740 ftpmmmeasured over a minimum distance of 100 mm, exclusive of missing pulses.4.4 azimuthThe angular deviation, in degrees of arc, of the recorded flux transitions on a track from a line normal to thetrack centrelin
35、e.4.5 back surfaceThe surface of the tape opposite to the magnetic coating used to record data.4.6 Beginning of Data (BOD)The point in a partition after which a recording of data for interchange commences.4.7 Beginning of Tape (BOT)The transition from the tape leader to an opaque area of the splice
36、by which a translucent leader tape isjoined to the magnetic tape.4.8 bit cellA distance along the track allocated for the recording of a Channel bit.4.9 byteAn ordered set of bits acted upon as a unit.4.10 cartridgeA case containing magnetic tape stored on twin reels.4.11 Channel bitA bit after 8-14
37、 transformation.4.12 Cyclic Redundancy Check (CRC) characterA character derived from information contained in data bytes that is used for error detection.4.13 End of Data (EOD)The point in a partition before which a recording of data for interchange ends.4.14 End of Partition (EOP)The virtual point
38、along the length of tape at which a partition ends.4.15 End of Tape (EOT)The transition from an opaque area of the splice to a translucent trailer tape.4.16 Error Correcting Code (ECC)A mathematical procedure yielding bytes used for the detection and correction of errors.4.17 File MarkA mark recorde
39、d on the tape at the request of the host system to separate files or to provide an appendpoint. This format provides for Long and Short File Marks.4.18 Logical BlockInformation (data) sent to the tape drive to be recorded.4.19 magnetic tapeA tape that accepts and retains magnetic signals intended fo
40、r input, output, and storage of data forinformation processing.4.20 Master Standard Reference TapeA tape selected as the standard for Signal Amplitude, Typical Recording Current, Overwrite andResolution.-3-NOTEThe Master Standard Reference Tape has been established by Ecrix Corporation.4.21 Partitio
41、nA formatted length of tape used to record data.4.22 physical recording densityThe number of recorded flux transitions per unit length of track, expressed in flux transitions per millimetre(ftpmm).4.23 Reference FieldThe Typical Field of the Master Standard Reference Tape.4.24 Secondary Standard Ref
42、erence 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 under the Part Number 111.00124 from EcrixCorporation, 5525 Central Avenue, Boulder, Co. 80301, USA.In principle, such
43、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 Ecrix Corporation, this period may beshortened or extended to take account of demand for such tapes.It is intended that these be used for calibratin
44、g Tertiary Reference Tapes for use in routine calibration.4.25 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.4.26 Standard Reference Amplitude (SRA)The Average Signal Amplitude derived from the Master Standard Reference T
45、ape, using the Test RecordingCurrent at 2 740 ftpmm.4.27 Standard Reference Current (Ir)The current that produces the Reference Field.4.28 Tape Reference EdgeThe lower edge of tape as seen when viewing the recording surface of the tape with the supply reel to theobservers right.4.29 Test Recording C
46、urrent (TRC)The current used to record the SRA. The TRC is 1,4 times the Standard Reference Current.4.30 TrackA diagonally positioned area on the tape along which a series of magnetic transitions may be recorded.4.31 Typical FieldIn the plot of the Average Signal Amplitude against the recording fiel
47、d at the physical recording density of2 740 ftpmm, the minimum field that causes an Average Signal Amplitude equal to 90 % of the maximumAverage Signal Amplitude.5 Conventions and Notations5.1 Representation of numbersA measured value is rounded off to the least significant digit of the correspondin
48、g 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.-4- Letters and digits in parentheses represent numbers in hexadecimal notation. The setting of a bit is denoted by ZE
49、RO or ONE. 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 most significant bit (numbered 7 in an 8-bit byte) is processed first, least significant bit isnumbered 0 and is process
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