1、BRITISH STANDARD BS ISO/IEC 1863:1990 Implementation of ISO/IEC 1863:1990 Information processing 9-track, 12,7 mm (0,5 in) wide magnetic tape for information interchange using NRZI at 32 ftpmm (800 ftpi) 32 cpmm (800 cpi) UDC 681.327.636BSISO/IEC1863:1990 This British Standard, having been prepared
2、under the directionof the Information Systems Technology StandardsPolicy Committee,waspublished underthe authorityof the Standards Boardand comesintoeffect on 15November1992 BSI 01-2000 The following BSI references relate to the work on this standard: Committee reference IST/4 Draft for comment 92/6
3、3549 DC ISBN 0 580 21404 4 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: British Computer
4、 Society ICI Imagedata Institution of Electrical Engineers International Computers Limited Kodak Limited Co-opted UK Expert Future Technology Amendments issued since publication Amd. No. Date CommentsBSISO/IEC1863:1990 BSI 01-2000 i Contents Page Committees responsible Inside front cover National fo
5、reword ii Foreword iii Text of ISO/IEC 1863 1BSISO/IEC1863:1990 ii BSI 01-2000 National foreword This British Standard reproduces verbatim ISO/IEC1863:1990 and implements it as the UK national standard. This British Standard is published under the direction of the Information Systems Technology Stan
6、dards 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 international and Europ
7、ean developments and promulgate them in the UK. NOTEInternational and European Standards, as well as overseas standards, are available from BSI Sales Department, BSI, Linford Wood, Milton Keynes, MK146LE. A British Standard does not purport to include all the necessary provisions of a contract. User
8、s 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/IEC title page, pagesii toiv, pages1
9、 to7 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/IEC1863:1990 (E) ii BSI 01-2000 Contents Page Foreword iii 1 Scope 1 2 Normative references 1 3 Definitions
10、 1 4 General requirements 2 5 Recording 2 6 Track configuration 3 7 Data representation 3 8 Format of the tape 4 9 Quality of recording for data interchange 4 10 Erasure of ID bursts 4 Annex A (normative) CRC register 6 Annex B (informative) Determination of the erase magnetic field direction 6 Anne
11、x C (informative) Storage and transportation 7 Figure 1 Track layout 5 Descriptors: Data processing, information interchange, data recording devices, magnetic tapes, 9-tracks, half-inch magnetic tapes, specifications, dimensions, track formats.ISO/IEC1863:1990(E) BSI 01-2000 iii Foreword ISO (the In
12、ternational Organization for Standardization) and IEC (the International 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 estab
13、lished by the respective organization to deal with particular fields of technical 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
14、 field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC1. 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
15、the national bodies casting a vote. International Standard ISO/IEC1863 was prepared by Joint Technical Committee ISO/IEC JTC1, Information technology. This second edition cancels and replaces the first edition (ISO1863:1976), which has been technically revised. Annex A forms an integral part of this
16、 International Standard. Annex B andAnnex C are for information only.iv blankISO/IEC1863:1990(E) BSI 01-2000 1 1 Scope This International Standard specifies a format and recording standard for9-track, 12,7mm (0,5in) magnetic tape to be used for data interchange between information processing systems
17、, communication systems, and associated equipment utilizing the7-bit coded character set (seeISO646), its extension in ISO2022 where required, and the8-bit coded character set (seeISO4873). Magnetic labelling for use on magnetic tape is the subject of ISO1001. The magnetic tape and reel to be used s
18、hall conform to ISO1864 and/or ISO8064. NOTENumeric values in the SI and/or Imperial measurement system in this International Standard may have been rounded off and therefore are consistent with, but not exactly equal to, each other. Either system may be used, but the two should be neither intermixe
19、d nor reconverted. The original design was made using the Imperial measurement system. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated wer
20、e valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid Internation
21、al Standards. ISO 646:1983, Information processing ISO7-bit coded character set for information interchange. ISO 1001:1986, Information processing File structure and labelling of magnetic tapes for information interchange. ISO 1864:1985, Information processing Unrecorded12,7mm (0,5 in) wide magnetic
22、 tape for information interchange 32ftpmm (800 ftpi) NRZ1, 126 ftpmm (3200 ftpi) phase encoded and356ftpmm (9042 ftpi), NRZ1. ISO 2022:1986, Information processing ISO 7-bit and 8-bit coded character sets Coded extension techniques. ISO 4873:1986, Information processing ISO8-bit code for information
23、 interchange Structure and rules for implementation. ISO 8064:1985, Information processing Reels for12,7mm (0,5in) wide magnetic tapes Sizes16, 18 and 22. 3 Definitions For the purpose of this International Standard, the following definitions apply. 3.1 magnetic tape a tape which will accept and ret
24、ain magnetic signals intended for input, output and storage purposes on computers and associated equipment 3.2 reference tape a tape which has been selected for given properties for use in calibration 3.3 master standard reference tape a reference tape selected as a standard for signal amplitude NOT
25、EA Master Standard Reference Tape has been established by the US National Institute for Standards and Technology (NIST). 3.4 secondary standard reference tape a tape the performance of which is known and stated in relation to that of the Master Standard Reference Tape NOTESecondary Standard Referenc
26、e Tapes are available from NIST (Office of Standard Reference Materials, Room B311, Chemistry Building, NIST, Gaithersburg, Md20899, USA) under part number SRM3200. it is intended that these be used for calibration of tertiary tapes for use in routine calibration 3.5 typical field in the plot of Ave
27、rage Signal Amplitude against recording field at the specified flux transition density, the Typical Field is the minimum field that causes an average Signal Amplitude equal to95% of the Maximum Average Signal Amplitude 3.6 reference field the Typical Field of the Master Standard Reference Tape at th
28、e specified recording density 3.7 standard reference amplitude the average peak-to-peak signal amplitude derived from the Master Standard Reference Tape on the NIST measurement system under the recording conditions specified in5.6.1ISO/IEC1863:1990(E) 2 BSI 01-2000 3.8 reference edge the edge furthe
29、r from an observer when a tape is lying flat with the magnetic surface uppermost and the direction of movement for recording is from left to right 3.9 in contact an operating condition in which the magnetic surface of a tape is in contact with a magnetic head 3.10 track a longitudinal area on the ta
30、pe along which a series of magnetic signals may be recorded 3.11 row nine transversely related locations (one in each track) in which bits are recorded 3.12 physical recording density the number of recorded flux transitions per unit length of track ftpmm (ftpi) 3.13 data density the number of data c
31、haracters stored per unit length of tape cpmm (cpi) 3.14 skew within a row, the maximum displacement of any location from any other location measured as the distance between two perpendiculars to the reference edge through said locations 4 General requirements 4.1 Operating environment Tapes used fo
32、r data interchange shall be operated under the following conditions: temperature: 16 C to32 C (60 F to90 F); relative humidity: 20% to80%; wet bulb temperature: not greater than25 C (78 F). Conditioning before operating: If a tape has been exposed during storage and/or transportation to conditions o
33、utside the above values, it should be conditioned for a period of2h to12h depending upon the extent of exposure. 4.2 Storage and transportation The recommendations for storage and transportation environment are specified inAnnex C. Responsibility for ensuring that adequate precautions against damage
34、 are taken during shipment shall be with the sender (seeAnnex C). 4.3 Wind tension For interchange, the tape winding tension shall be between2,0N and3,6N (7ozf to13ozf). 5 Recording 5.1 Method of recording The “non return to zero change-on-ones recording” (NRZ1) method of recording shall be used whe
35、re a ONE is represented by a change of direction of longitudinal magnetization. 5.2 Density of recording The nominal density shall be designated by32ftpmm (800ftpi). The actual density shall be31,5ftpmm (800ftpi). The resulting nominal flux transition spacing is31,754m (12504in). 5.3 Average flux tr
36、ansition spacing The average flux transition spacing shall be within 3% of31,754m (12504in). This average shall be measured over a minimum of1,2 10 5successive flux transitions, at the extremes of operating conditions, by reading a tape that has been continuously and evenly recorded at31,5ftpmm (800
37、ftpi) in phase in all tracks. 5.4 Instantaneous flux transition spacing The instantaneous spacing between flux transitions may be influenced by the reading and writing processes, the pattern recorded (pulse crowding effects) and other factors. Measurements are taken from leading edge to leading edge
38、 of flux transitions. The following conditions shall all be met. a) The spacing between the first detected bitsofsuccessive rows shall be greater than22,94m (9004in); b) The spacing between the first detected bit and the last detected bit of a row shall be less than10,84m (4254in); c) There shall be
39、 a minimum apparent spacingbetween any bits of successive rows of11,24m (4404in). 5.5 Static skew The static skew shall be less than3,814m (1504in). This condition is required to be satisfied for both flux transition polarities.ISO/IEC1863:1990(E) BSI 01-2000 3 5.6 Signal amplitude 5.6.1 Standard Re
40、ference Amplitude The Standard Reference Amplitude is the averagepeak-to-peak signal amplitude derived from the Master Standard Reference Tape on the qualified measurement system at the density of32ftpmm (800ftpi) and the recording current I rof2,1 I f . The signal amplitude shall be averaged over40
41、00 flux transitions, and shall be measured on the read-while-write pass. The reference currentI fis the minimum current which produces the Reference Field. 5.6.2 Average signal amplitude The average peak-to-peak output signal amplitude of an interchanged tape at32ftpmm (800ftpi) shall be between70%
42、and115% of the Standard Reference Amplitude. Averaging shall be done over a minimum of4000 flux transitions which, for the interchange tape, may be segmented into blocks. Averaging shall be done on the first read pass after interchange. 5.6.3 Maximum signal amplitude An interchanged tape shall conta
43、in no flux transition the base-to-peak signal amplitude of which exceeds120% of one-half the Standard Reference Amplitude on the first read pass after interchange. 5.6.4 Minimum signal amplitude An interchanged tape shall contain no flux transition the base-to-peak signal amplitude of which is less
44、than35% of one-half the Standard Reference Amplitude on the first read pass after interchange. 5.7 Erasure 5.7.1 Erase direction When erased, the rim end of the erased area of the tape shall be magnetized so that it is a North-seeking pole and the hub end of the erased area is a South-seeking pole (
45、seeAnnex B). 5.7.2 Erase width The full width of the tape shall be d.c.-erased in the direction specified in5.7.1. 5.7.3 Residual signal The tape shall be erased so that any residual signals, including NRZ1 at32ftpmm (800ftpi) and356ftpmm (9042ftpi) and phase encoding at126ftpmm (3200ftpi) are less
46、than4% of the Standard Reference Amplitude at32ftpmm (800ftpi). 6 Track configuration 6.1 Number of tracks There shall be nine tracks. 6.2 Track identification Tracks shall be numbered consecutively beginning at the reference edge with track1 (seeFigure 1). 6.3 Track positions The distance from the
47、centrelines of the tracks to the reference edge shall be Track 1:0,74 mm (0,029 in) Track 2:2,13 mm (0,084 in) Track 3:3,53 mm (0,139 in) Track 4:4,93 mm (0,194 in) Track 5:6,32 mm (0,249 in) Track 6:7,72 mm (0,304 in) Track 7:9,12 mm (0,359 in) Track 8: 10,52 mm (0,414 in) Track 9: 11,91 mm (0,469
48、in) The tolerance shall be 0,08mm (0,003in) for all tracks. 6.4 Track width The width of a written track shall be 1,09mm min. (0,043in min.) 7 Data representation 7.1 Coded representation of characters Characters shall be represented by means of the7-bit coded character set (seeISO646), the8-bit cod
49、ed character set (seeISO4873) or, where required, of an extension of the7-bit coded character set (seeISO2022). The bit-to-track allocation shall be as follows: 7.1.1 7-bit coded characters Track7 shall always be recorded with bit ZERO. BitP in track4 shall be the parity bit. The parity shall be odd. 7.1.2 8-bit coded characters Bit P in track4 shall be the parity bit. The parity shall be odd. Binary weight 2 0 2 1 2 2 2 3 2 4 2 5 2 6 Bit designation b 1 b 2 b 3 b 4 b 5 b 6 b 7 P Track 2 8 1 9 3 5 6 7 4 Binary weight 2 0
