1、Standard ECMA-258June 1997Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chData Interchange on 12,7 mm128-Track Magnetic TapeCartridges - DLT 3-XT Format.Standard ECMA-258June 1997Standardizing Info
2、rmation and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chMB - Ecma-258.doc - 04.07.97 14:50Data Interchange on 12,7 mm128-Track Magnetic TapeCartridges - DLT 3-XT Format.Brief HistoryTechnical Committee ECMA TC17 has produce
3、d a series of ECMA Standards for magnetic tape cassettes and cartridges ofdifferent widths, e.g. 12,7 mm, 8 mm, 6,35 mm and 3,81 mm. In each series, the standards correspond to specific types ofapplication and different user requirements. Enhanced and new media correspond also to advancements in dri
4、ve technology.The series of such cartridges with a magnetic tape of 12,7 mm width and longitudinally recorded tracks comprises the followingstandards.ECMA-120 (1993) : Data Interchange on 12,7 mm 18-Track Magnetic Tape CartridgesISO 9661ECMA-152 (1993) : Data Interchange on 12,7 mm 18-Track Magnetic
5、 Tape Cartridges - Extended FormatISO/IEC 11559ECMA-182 (1992) : Data Interchange on 12,7 mm 48-Track Magnetic Tape Cartridges - DLT 1 Format -ISO/IEC 13421ECMA-196 (1993) : Data Interchange on 12,7 mm 36-Track Magnetic Tape CartridgesISO/IEC 14251ECMA-197 (1993) : Data Interchange on 12,7 mm 112-Tr
6、ack Magnetic Tape Cartridges - DLT 2 Format -ISO/IEC 13962ECMA-209 (1994) : Data Interchange on 12,7 mm 128-Track Magnetic Tape Cartridges - DLT 3 FormatISO/IEC 14833ECMA-231 (1995) : Data Interchange on 12,7 mm 128-Track Magnetic Tape Cartridges - DLT 4 FormatISO/IEC 15307ECMA-259 (1997) Data Inter
7、change on 12,7 mm 208-Track Magnetic Tape Cartridges - DLT 5 FormatStandards ECMA-182, ECMA-197, ECMA-209, ECMA-231 and ECMA-259 concern a cartridge of a type different from thatof Standards ECMA-120, ECMA-152 or ECMA-196. Whilst the magnetic tape is also 12,7 mm wide, these ECMA Standardsare charac
8、terized by the fact that the physical tracks are recorded and read in groups. These groups are recorded and readalternatively in forward and reverse direction. The capacity and performance of the DLT cartridges have been improved byraising the number of tracks from 48 in DLT 1 to 208 for DLT 5, and
9、by using an improved magnetic tape in DLT 4 andDLT 5.The present ECMA Standard for the DLT 3-XT cartridge specifies an improved version of the DLT 3 cartridge, in which ahigher capacity is achieved by using a thinner, thus longer tape.All published ECMA Standards listed above have been adopted by IS
10、O/IEC as International Standards. Standard ECMA-259and the present Standard ECMA-258 will also be contributed to ISO/IEC for adoption as International Standards under the fast-track procedure.Adopted as an ECMA Standard by the General Assembly of June 1997.ii.iTable of contentsPageSection 1 - Genera
11、l 11 Scope 12 Conformance 12.1 Magnetic tape cartridges 12.2 Generating systems 12.3 Receiving systems 13 References 14 Definitions 14.1 Average Signal Amplitude 14.2 azimuth 24.3 back surface 24.4 Beginning-Of-Tape markers (BOT 1 and BOT 2) 24.5 byte 24.6 cartridge 24.7 Cyclic Redundancy Check (CRC
12、) character 24.8 Early Warning (EW) 24.9 Error-Detecting Code (EDC) 24.10 End-Of-Tape marker (EOT) 24.11 Entity 24.12 Error-Correcting Code (ECC) 24.13 flux transition position 24.14 flux transition spacing 24.15 Logical Block 24.16 logical track 24.17 magnetic tape 24.18 Master Standard Reference T
13、ape 24.19 object 34.20 page 34.21 physical block 34.22 physical recording density 34.23 physical track 34.24 Record 34.25 Reference Edge 34.26 Reference Field 34.27 Secondary Standard Reference Tape 34.28 Standard Reference Amplitude (SRA) 34.29 Standard Reference Current 34.30 Test Recording Curren
14、t 34.31 Typical Field 35 Conventions and notations 45.1 Representation of numbers 45.2 Dimensions 45.3 Names 45.4 Acronyms 4ii6 Environment and safety 46.1 Cartridge and tape testing environment. 46.2 Cartridge operating environment 46.3 Cartridge storage environment 56.4 Safety 56.4.1 Safeness 56.4
15、.2 Flammability 56.5 Transportation 5Section 2 - Requirements for the unrecorded tape 57 Mechanical and electrical requirements 57.1 Material 57.2 Tape length 57.3 Width 57.4 Total thickness 57.5 Discontinuity 57.6 Longitudinal curvature 57.6.1 Requirement 67.6.2 Procedure 67.7 Out-of-Plane distorti
16、ons 67.8 Cupping 67.9 Roughness of the coating surfaces 67.9.1 Roughness of the back coating surface 67.9.2 Roughness of the magnetic coating surface 67.10 Coating adhesion 67.11 Layer-to-layer adhesion 77.11.1 Requirements 77.11.2 Procedure 77.12 Modulus of elasticity 87.12.1 Requirement 87.12.2 Pr
17、ocedure 87.13 Flexural rigidity 87.13.1 Requirement 87.13.2 Procedure 87.14 Tensile yield force 97.14.1 Procedure 97.15 Electrical resistance 97.16.1 Requirement 97.15.2 Procedure 97.16 Inhibitor tape 97.17 Abrasivity 97.17.1 Requirement 107.17.2 Procedure 107.18 Light transmittance of the tape and
18、the leader 107.19 Coefficient of dynamic friction 107.22.1 Requirements 107.19.2 Procedure for the measurement of the friction between the magnetic surface and the back surface 107.19.3 Procedure for the measurement of the friction between the magnetic surface or the back surface andcalcium titanate
19、 ceramic 11iii8 Magnetic recording characteristics 118.1 Typical Field 118.2 Signal amplitude 128.3 Resolution 128.4 Overwrite 128.4.1 Requirement 128.5 Peak shift 128.5.1 Requirement 128.5.2 Procedure 129 Tape quality 139.1 Missing pulses 139.1.1 Requirement 139.2 Missing pulse zone 139.2.1 Require
20、ment 139.3 Tape durability 13Section 3 - Mechanical specifications of the tape cartridge 1310 General 1310.1 Bottom side and right side 1410.2 Back side and left side 1510.3 Tape reel 1510.4 Tape leader and markers 1610.5 Front side 1710.6 Operation of the cartridge 1710.7 Tape winding 1810.8 Moment
21、 of inertia 1810.9 Material 19Section 4 - Requirements for an interchanged tape 2811 Method of recording 2811.1 Physical recording density 2811.2 Channel bit cell length 2811.2.1 Average Channel bit cell length 2811.2.2 Long-term average Channel bit cell length 2811.2.3 Short-term average Channel bi
22、t cell length 2811.3 Flux transition spacing 2811.4 Read signal amplitude 2811.5 Azimuth 2911.6 Channel skew 2912 Tape format 2912.1 Reference Edge 2912.2 Direction of recording 2912.3 Tape layout 2912.4 Calibration and Directory Area 2912.4.1 Scratch Area 3012.4.2 Guard Area G1 3012.4.3 Calibration
23、 Tracks Area 3012.4.4 Guard Area G2 3112.4.5 Directory Area 31iv12.4.6 Guard Area G3 3112.5 Data Area 3112.5.1 Physical tracks 3212.5.2 Width of the physical tracks 3212.5.3 Logical tracks 3212.5.4 Locations of the physical tracks 3212.5.5 Layout of tracks in the Data Area 3313 Data format 3413.1 Da
24、ta Bytes 3413.2 Logical Blocks 3413.3 Data Blocks 3413.4 Types of Logical Blocks 3513.5 Entities 3513.6 Logical Block format 3513.6.1 Preamble 3613.6.2 Sync 3613.6.3 Data Field 3613.6.4 EDC 3713.6.5 Control Field 1 (CF1) 3813.6.6 Control Field 2 (CF2) 3913.6.7 CRC 4013.6.8 Postamble 4014 Use of Logi
25、cal Blocks 4014.1 Data Blocks 4014.2 Filler Blocks 4014.3 End of Track Blocks (EOTR) 4114.4 End of Data Blocks (EOD) 4114.5 ECC Blocks 4115 Format of Entities 4116 Error handling 41Annex A - Measurement of light transmittance 43Annex B - Generation of the Data Block CRCs 47Annex C - ECC generation 4
26、9Annex D - Generation of page CRCs 53Annex E - Format of MAP entries 55Annex F - Format of Control Field 1 57Annex G - Format of Control Field 2 59Annex H - Recommendations for transportation 61Annex J - Inhibitor tape 63Annex K - Recommendations on tape durability 65Annex L - Handing guidelines 67S
27、ection 1 - General1 ScopeThis ECMA Standard specifies the physical and magnetic characteristics of a 12,7 mm wide, 128-track magnetic tapecartridge, to enable physical interchangeability of such cartridges between drives. It also specifies the quality of therecorded signals, a format - called Digita
28、l Linear Tape 3 Extended (DLT 3-XT) - and a recording method, therebyallowing data interchange between drives. Together with a labelling standard, for instance Standard ECMA-13 forMagnetic Tape Labelling, it allows full data interchange by means of such magnetic tape cartridges.2 Conformance2.1 Magn
29、etic tape cartridgesA magnetic tape cartridge shall be in conformance with this ECMA Standard if it satisfies all mandatoryrequirements of this ECMA Standard. The tape requirements shall be satisfied throughout the extent of the tape.2.2 Generating systemsA system generating a magnetic tape cartridg
30、e for interchange shall be entitled to claim conformance with thisECMA Standard if all the recordings that it makes on a tape according to 2.1 meet the mandatory requirements ofthis ECMA Standard.In addition a claim of conformance shall state whether or not one, or more registered algorithm(s) are i
31、mplemented witin the system, and are able to compressdata received from the host prior to collecting data into blocks, and the registered identification number(s) of the implemented algorithm(s)In addition a claim of conformance shall state2.3 Receiving systemsA system receiving a magnetic tape cart
32、ridge for interchange shall be entitled to claim conformance with this ECMAStandard if it is able to handle any recording made on a tape according to 2.1.In addition a claim of conformance shall state whether or not one, or more de-compression algorithm(s) are implemented witin the system, and are a
33、ble to beapplied to de-compress data prior to making such data available to the host, and the registered identification number(s) of the implemented algorithm(s)3 ReferencesECMA-13 (1985) File Structure and Labelling of Magnetic Tapes for Information InterchangeISO 1302:1992 Technical drawings - Met
34、hod of indicating surface texture on drawings.ISO/IEC 11576:1994 Information Technology - Procedure for the registration of algorithms for the losslesscompression of data4 DefinitionsFor the purpose of this ECMA Standard, the following definitions apply.4.1 Average Signal AmplitudeThe average peak-t
35、o-peak value of the output signal from the read head at the physical recording density of 1 640ftpmm measured over a minimum length of track of 25,4 mm, exclusive of missing pulses.- 2 -4.2 azimuthThe angular deviation, in degrees of arc, of the mean flux transition line of the recording made on a t
36、rack from theline normal to the Reference Edge.4.3 back surfaceThe surface of the tape opposite the magnetic coating which is used to record data.4.4 Beginning-Of-Tape markers (BOT 1 and BOT 2)Two holes punched on the centreline of the tape towards the end nearest to the leader.4.5 byteAn ordered se
37、t of bits acted upon as a unit.NOTEIn this ECMA Standard, all bytes are 8-bit bytes.4.6 cartridgeA case containing a single supply reel of 12,7 mm wide magnetic tape with a leader attached at the outer end.4.7 Cyclic Redundancy Check (CRC) characterA 64-bit character, generated by a mathematical com
38、putation, used for error detection.4.8 Early Warning (EW)A signal generated by the drive indicating the approaching end of the recording area.4.9 Error-Detecting Code (EDC)A mathematical computation yielding check bytes used for error detection.4.10 End-Of-Tape marker (EOT)A hole punched on the cent
39、reline of the tape towards the end farthest from the leader.4.11 EntityA group of twenty physical blocks treated as a logical unit and recorded on a logical track.4.12 Error-Correcting Code (ECC)A mathematical computation yielding check bytes used for the correction of errors detected by the CRC and
40、 theEDC.4.13 flux transition positionThe point which exhibits the maximum free-space flux density normal to the tape surface.4.14 flux transition spacingThe distance on the magnetic tape between successive flux transitions.4.15 Logical BlockThe two physical blocks simultaneously written on, or read
41、from, the two physical tracks of a logical track.4.16 logical trackA pair of physical tracks that are written or read simultaneously.4.17 magnetic tapeA tape that accepts and retains magnetic signals intended for input, output, and storage purposes on computers andassociated equipment.4.18 Master St
42、andard Reference TapeA tape selected as the standard for reference field, signal amplitude, resolution, peakshift, and overwritecharacteristics.- 3 -NOTEThe Master Standard Reference Tape is maintained by the Quantum Corporation.4.19 objectA Record or a Tape Mark Block.4.20 pageA logical division of
43、 a physical block.4.21 physical blockA set of contiguous bytes recorded on a physical track and considered as a unit.4.22 physical recording densityThe number of recorded flux transitions per unit length of track, expressed in flux transitions per millimetre(ftpmm).4.23 physical trackA longitudinal
44、area on the tape along which a series of magnetic signals can be recorded.4.24 RecordA collection of User Bytes, the number of which is determined by the host.4.25 Reference EdgeThe bottom edge of the tape when viewing the magnetic coating of the tape with the BOT holes to the left and theEOT hole t
45、o the right of the observer.4.26 Reference FieldThe Typical Field of the Master Standard Reference Tape.4.27 Secondary Standard Reference TapeA tape the characteristics of which are known and stated in relation to those of the Master Standard Reference Tape.NOTESecondary Standard Reference Tapes can
46、 be ordered under Reference “SSRT/DLT3XT“ until the year 2003 fromQuantum Corporation, 333 South Street, Shrewsbury, Mass. 01545-4195, USA. It is intended that these be used forcalibrating tertiary reference tapes for routine calibration.In principle, these Secondary Standard Reference Tapes will be
47、 available for a period of 10 years from thepublication of the first version of this ECMA Standard. However, by agreement between ECMA and QuantumCorporation, this period may be changed to take into account the demand for such Secondary Standard ReferenceTapes.4.28 Standard Reference Amplitude (SRA)
48、The Average Signal Amplitude from the Master Standard Reference Tape when it is recorded with the TestRecording Current at 1 640 ftpmm.4.29 Standard Reference CurrentThe current that produces the Reference Field.4.30 Test Recording CurrentThe current that is 1,1 times the Standard Reference Current.
49、4.31 Typical FieldIn the plot of the Average Signal Amplitude against the recording field at the physical recording density of1 640 ftpmm, the minimum field that causes an Average Signal Amplitude equal to 95 % of the maximum AverageSignal Amplitude.- 4 -5 Conventions and notations5.1 Representation of numbersThe following conventions and notations apply in this ECMA Standard, unless otherwise stated. In each block and in each field the bytes shall be arranged with Byte 1, the least significant, first. Within eachbyte the bits shall be arranged with Bit 1, the least significant, first
