1、BRITISH STANDARD BS ISO/IEC 12248:1993 Implementation of ISO/IEC12248:1993 Information technology 3,81mm wide magnetic tape cartridge for information interchange Helical scan recording DATA/DAT-DC format using60m and90m length tapes UDC 681.327.636BSISO/IEC12248:1993 This British Standard, having be
2、en prepared under the directionof the Information Systems Technology Standards Policy Committee, was publishedunder the authority ofthe Standards Board and comesinto effect on 15 April 1994 BSI 05-2000 The following BSI references relate to the work on this standard: Committee reference IST/4 Draft
3、for comment 92/66916 DC ISBN 0 580 23308 1 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Information Systems Technology Standards Policy Committee (IST/-) to Technical Committee IST/4, upon which the following bodies were represented:
4、British Computer Society ICI Imagedata Institute of Quality Assurance Institution of Electrical Engineers International Computers Limited Kodak Limited Amendments issued since publication Amd. No. Date CommentsBSISO/IEC12248:1993 BSI 05-2000 i Contents Page Committees responsible Inside front cover
5、National foreword ii Foreword ix Text of ISO/IEC 12248 1BSISO/IEC12248:1993 ii BSI 05-2000 National foreword This British Standard reproduces verbatimISO/IEC12248:1993 and implements it as the UK national standard. This British Standard is published under the direction of the Information Systems Tec
6、hnology Standards Policy Committee whose Technical Committee IST/4 has the responsibility to: aid enquirers to understand the text; present to the responsible international committee any enquiries on interpretation, or proposals for change, and keep UK interests informed; monitor related internation
7、al and European developments and promulgate them in the UK. NOTEInternational and European Standards, as well as overseas standards, are available from Customer Services, Publications, BSI, Linford Wood, Milton Keynes, MK146LE. A British Standard does not purport to include all the necessary provisi
8、ons of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theISO/IECtitle page
9、, pages ii to x, pages1 to110 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.ISO/IEC12248:1993 (E) ii BSI 05-2000 Contents Page Foreword ix Introduction 1 Section
10、1. General 1 Scope 1 2 Conformance 1 2.1 Magnetic tape cartridge 1 2.2 Generating system 1 2.3 Receiving system 1 3 Normative references 2 4 Definitions 2 4.1 absolute frame number (AFN) 2 4.2 algorithm 2 4.3 area ID 2 4.4 automatic track finding (ATF) 2 4.5 average signal amplitude 2 4.6 azimuth 2
11、4.7 back surface 2 4.8 byte 2 4.9 cartridge 2 4.10 channel bit 2 4.11 codeword 3 4.12 data format ID 3 4.13 end of data (EOD) 3 4.14 end of information (EOI) 3 4.15 end of partition (EOP) 3 4.16 entity 3 4.17 error correcting code (ECC) 3 4.18 flux transition position 3 4.19 flux transition spacing
12、3 4.20 frame 3 4.21 group 3 4.22 logical beginning of tape (LBOT) 3 4.23 logical end of tape (LEOT) 3 4.24 magnetic tape 3 4.25 master reference 4 4.26 master standard amplitude calibration tape 4 4.27 master standard reference tape 4 4.28 optimum recording field 4 4.29 partition 4 4.30 partition re
13、ference 4 4.31 physical beginning of tape (PBOT) 4 4.32 physical end of tape (PEOT) 4 4.33 physical recording density 4 4.34 pre-recording condition 4 4.35 processed record 4 4.36 processed record sequence 4 4.37 processing 4 4.38 record 5 4.39 reference recording field 5 4.40 secondary standard amp
14、litude calibration tape 5ISO/IEC12248:1993 (E) BSI 05-2000 iii Page 4.41 secondary standard reference tape 5 4.42 separator mark 5 4.43 standard reference amplitude 5 4.44 tape noise amplitude 5 4.45 tape reference edge 5 4.46 track 5 5 Environment and safety 5 5.1 Testing environment 5 5.2 Operatin
15、g environment 6 5.3 Storage environment 6 5.4 Transportation 6 5.5 Safety 6 5.6 Flammability 6 Section 2. Requirements for the case 6 Dimensional and mechanical characteristics of the case 6 6.1 General 6 6.2 Overall dimensions 7 6.3 Loading grip 7 6.4 Holding areas 7 6.5 Notches of the lid 8 6.6 Li
16、d dimensions 8 6.7 Optical detection of the beginning and end of tape 8 6.8 Bottom side 9 6.8.1 Locking mechanism of the slider 9 6.8.2 Access holes 10 6.8.3 Recognition, sub-datum and write-inhibit holes 10 6.8.4 Datum holes 11 6.8.5 Access room for tape guides 11 6.8.6 Holes for accessing the hubs
17、 12 6.8.7 Internal structure of the lower half 12 6.8.8 Light path 13 6.8.9 Support areas 13 6.8.10 Datum areas 13 6.8.11 Relationship between support and datum areas and Reference Plane Z 13 6.9 Hubs 14 6.10 Leader and trailer attachment 14 6.11 Interface between the hubs and the drive spindles 14
18、6.12 Opening of the lid 14 6.13 Release of the hub locking mechanism 14 6.14 Label areas 15 Section 3. Requirements for the unrecorded tape 7 Mechanical, physical and dimensional characteristics of the tape 26 7.1 Materials 26 7.2 Tape length 26 7.2.1 Length of magnetic tape 26 7.2.2 Length of leade
19、r and trailer tapes 26ISO/IEC12248:1993 (E) iv BSI 05-2000 Page 7.3 Tape width 26 7.4 Discontinuities 26 7.5 Total thickness 26 7.6 Longitudinal curvature 26 7.7 Cupping 26 7.8 Coating adhesion 26 7.9 Layer-to-layer adhesion 27 7.10 Tensile Strength 27 7.10.1 Breaking Strength 27 7.10.2 Yield Streng
20、th 27 7.11 Residual elongation 27 7.12 Electrical resistance of coated surfaces 28 7.13 Light transmittance of tape 28 8 Magnetic recording characteristics 28 8.1 Optimum recording field 29 8.2 Signal amplitude 29 8.3 Resolution 29 8.4 Overwrite 29 8.4.1 Physical recording densities of750,6 and3002f
21、tpmm 29 8.4.2 Physical recording densities of83,4ftpmm and1001ftpmm 30 8.5 Ease of erasure 30 8.6 Tape quality 30 8.6.1 Missing pulses 30 8.6.2 Missing pulse zone 30 8.7 Signal-to-noise ratio (S/N) characteristic 30 Section 4. Format 9 DATA/DAT-DC format 31 9.1 General 31 9.2 Basic Groups 31 9.2.1 B
22、asic Groups for Group Format0 31 9.2.2 Basic Groups for Group Format1 32 9.3 Sub-groups 33 9.3.1 G1 Sub-group 33 9.3.2 G2 Sub-group 34 9.3.3 G3 Sub-group 34 9.3.4 G4 Sub-group 35 9.3.5 Main Data Block 39 9.4 Sub-Data area 40 9.4.1 Pack Item No. 1 41 9.4.2 Pack Item No. 2 41 9.4.3 Pack Item No. 3 43
23、9.4.4 Pack Item No. 4 43 9.4.5 Pack Item No. 5 44 9.4.6 Pack Item No. 6 44 9.4.7 Pack Item No. 7 45 9.4.8 Sub Data Block 45 9.5 Basic Group structure 47 9.5.1 User Data 47 9.5.2 System Data 49ISO/IEC12248:1993 (E) BSI 05-2000 v Page 9.5.3 Record ID list 51 9.5.4 Heuristic Recovery Data Area 55 10 Me
24、thod of recording 55 10.1 Physical recording density 55 10.2 Long-Term average bit cell length 55 10.3 Short-Term average bit cell length 55 10.4 Rate of change 55 10.5 Bit shift 55 10.6 Read signal amplitude 56 10.7 Maximum recorded levels 56 11 Track geometry 56 11.1 Track configuration 56 11.2 Av
25、erage track pitch 57 11.3 Variations of the track pitch 57 11.4 Track width 57 11.5 Track angle 57 11.6 Track edge linearity 57 11.7 Track length 57 11.8 Ideal tape centreline 57 11.9 Azimuth angles 57 12 Recording of blocks on the tape 57 12.1 Recorded Main Data Block 57 12.2 Recorded Sub Data Bloc
26、k 57 12.3 Margin Blocks, Preamble Blocks and Postamble Blocks 57 12.4 Spacer Blocks 57 13 Format of a track 58 13.1 Track capacity 58 13.2 Positioning accuracy 58 13.3 Tracking scheme 58 14 Group Formats 61 14.1 Group Format 0 61 14.2 Group Format 1 61 14.3 Extended Gap Frames 62 14.3.1 Extended Lea
27、ding Gap Frames 62 14.3.2 Extended Trailing Gap Frames 62 14.4 Types of Groups 62 14.4.1 Normal Groups 62 14.4.2 Spare Groups 62 14.4.3 Amble Groups 63 14.4.4 Header Groups 63 15 Magnetic tape layout 63 15.1 Load/Unload Area 63 15.2 Lead-in Area 64 15.2.1 Preamble 64 15.2.2 Header 64 15.2.3 Format P
28、arameter Set 65 15.2.4 Master Reference 70 15.2.5 Postamble 75 15.3 Partition 75ISO/IEC12248:1993 (E) vi BSI 05-2000 Page 15.3.1 Partition Preamble 75 15.3.2 Partition Reference 75 15.3.3 Partition Postamble 86 15.3.4 Partition Data 86 15.3.5 End of Partition (EOP) 86 15.3.6 Unused Area 86 15.4 EOI
29、87 15.5 Repeated Groups 87 15.6 Repeated Frames within a Normal Group 87 15.7 Relocation of Defective Groups 87 15.8 Appending 88 15.8.1 Seamless appending 88 15.8.2 Non-seamless appending 89 15.9 Overwrite 90 15.9.1 Overlapped track width 91 15.9.2 Non-overlapped track width 91 15.9.3 Rules for ove
30、rwrite 91 Annex A (normative) Measurement of the light transmittance of the prisms 92 Annex B (informative) Recognition holes 93 Annex C (informative) Means for opening the lid 94 Annex D (normative) Measurement of light transmittance of tape and leaders 95 Annex E (normative) Measurement of Signal-
31、to-Noise Ratio 97 Annex F (normative) Method for determining the nominal and the maximum allowable recorded levels 97 Annex G (normative) Representation of8-bit bytes by10-bit pattern 98 Annex H (normative) Measurement of bit shift 104 Annex J (informative) Recommendations for transportation 106 Ann
32、ex K (normative) Method of measuring track edge linearity 106 Annex L (informative) Read-After-Write 107 Annex M (normative) Data allocation and C3 parity 107 Figure 1 Top view 15 Figure 2 Bottom view 15 Figure 3 Partial view of the rear side 16 Figure 4 Reference Planes X, Y, Z 16 Figure 5 Front si
33、de, lid closed 17 Figure 6 Top side, lid closed 17 Figure 7 Left side, lid closed 17 Figure 8 Top side, lid open 18 Figure 9 Left side, lid open 18 Figure 10 Bottom side, lid closed 19 Figure 11 Bottom side, lid open 20 Figure 12 Inside view of the lower half 21 Figure 13 Bottom side, lid and slider
34、 in open position 22 Figure 14 Left side, lid open 22 Figure 15 Top view of a hub 23 Figure 16 Side view of a hub 23 Figure 17 Interface with the drive spindle 23ISO/IEC12248:1993 (E) BSI 05-2000 vii Page Figure 18 Lid in completely open position 24 Figure 19 Extreme position of the lid for which th
35、e hubs are still locked 24 Figure 20 Minimum position of the lid for which the hubs are completely unlocked 25 Figure 21 Top side, label area 25 Figure 22 Rear side, label area 25 Figure 23 Setup for measuring coating adhesion 27 Figure 24 Setup for measuring the electrical resistance 28 Figure 25 D
36、ata allocation for Group Format 0 31 Figure 26 Sub-group allocation Group Format 0 32 Figure 27 Data allocation for Group Format 1 32 Figure 28 Sub-group allocation for Group Format1 33 Figure 29 G1 Sub-groups for Group Format 0 33 Figure 30 G1 Sub-groups for Group Format 1 34 Figure 31 G3 Sub-group
37、 34 Figure 32 Twin arrays of a G4 Sub-group before C1 and C2 computation 36 Figure 33 W1 byte 39 Figure 34 W2 byte 39 Figure 35 Main data block 40 Figure 36 Area Codes 42 Figure 37 SW1 Byte 45 Figure 38 SW2 Byte 46 Figure 39 Sub Data Block 46 Figure 40 Pack Item location 47 Figure 41 Basic Group Lay
38、out 47 Figure 42 Record layout in User Data 47 Figure 43 Group Status Byte 50 Figure 44 Record ID Format 52 Figure 45 Control Byte for Data Records 52 Figure 46 Control Byte for Continuation Marks 53 Figure 47 Control Byte for Separators 1, 2 and 3 54 Figure 48 Control Byte for entities 54 Figure 49
39、 Track Configuration (view on the recording surface) 56 Figure 50 ATF Signals allocation 60 Figure 51 Group Format 0 61 Figure 52 Group Format 1 61 Figure 53 Tape Format 63 Figure 54 Load/Unload Area 64 Figure 55 Lead-in Area 64 Figure 56 Checksum procedure 69 Figure 57 Checksum summary 69 Figure 58
40、 Tape Protection Byte 71 Figure 59 Tape Flag 72 Figure 60 Partition Protection Byte 73 Figure 61 Partition Flags 74 Figure 62 Partition organization 75 Figure 63 Spare Group Sets and Normal Group Sets 78ISO/IEC12248:1993 (E) viii BSI 05-2000 Page Figure 64 Type A Group Entry 79 Figure 65 First Flag
41、Byte for Type A 79 Figure 66 Second Flag Byte for Type A 80 Figure 67 Type B Group Entry 80 Figure 68 First Flag Byte for Type B 81 Figure 69 Second Flag Byte for Type B 82 Figure 70 Consecutive Separator 2s Count 83 Figure 71 Type C Group Entry 84 Figure 72 First Flags Byte for Type C 84 Figure 73
42、Second Flag Byte for Type C 85 Figure 74 Seamless appending rules 88 Figure 75 Tolerance for seamless appending 89 Figure 76 Non-seamless appending 90 Figure 77 Track configuration after overwrite 90 Figure A.1 Reference prism 92 Figure A.2 Cartridge prism 92 Figure A.3 Perspective view of the refer
43、ence prism 93 Figure C.1 Bottom side of the case 94 Figure C.2 Intermediate position within the drive 94 Figure C.3 Final position within the drive 95 Figure D.1 Optical arrangement 96 Figure D.2 Measuring circuitry 97 Figure K.1 Track edge linearity 107 Table 1 Pack Item No. 1 41 Table 2 Pack Item
44、No. 2 41 Table 3 Pack Item No. 3 43 Table 4 Pack Item No. 4 43 Table 5 Pack Item No. 5 44 Table 6 Pack Item No. 6 44 Table 7 Pack Item No. 7 45 Table 8 Group ID 48 Table 9 Record length code 49 Table 10 New Group Number 50 Table 11 Record ID list 51 Table 12 Format of a Track 58 Table 13 Data of a H
45、eader Group 65 Table 14 Data of a Header Group Example 1 65 Table 15 Data of a Header Group Example2 65 Table 16 Format Parameter Set (first part) 66 Table 17 Information Data of the Master Reference Group 70 Table 18 Tape ID 70 Table 19 Partition Entry List 72 Table 20 Partition Entry 73 Table 21 P
46、artition Reference 75 Table 22 Partition ID 76 Table 23 Group Entry List Descriptor 77 Table 24 Record Type 77 Table 25 Group Entry List 78 Table B.1 Recognition holes 93ISO/IEC12248:1993 (E) BSI 05-2000 ix Foreword ISO (the International Organization for Standardization) and IEC (the International
47、Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of t
48、echnical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint te
49、chnical committee, ISO/IECJTC1. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least75% of the national bodies casting a vote. International Standard ISO/IEC12248 was prepared by the European Computer Ma
