1、BRITISH STANDARD BS 7024-3: 1988 ISO 7487-3: 1986 EN 27487-3: 1989 Incorporating Amendment Nos. 1, 2 and Corrigendum No.1 Guide to Construction and use of130 mm (5.25 in) flexible disk cartridges for data interchange using modified frequency modulation recording at 7958 ftprad, 1.9 tpmm (48 tpi) on
2、both sides Part 3: Track format B ISO title: Information processing Data interchange on 130 mm (5.25 in) flexible disk cartridges using modified frequency modulation recording at 7958 ftprad, 1,9 tpmm (48 tpi), on both sides Part 3: Track format B This European Standard EN 27487-3:1989 has the statu
3、s of a British Standard UDC 681.327.634:.002.2:.004.14BS7024-3:1988 This British Standard, having been prepared under the directionof the Information Systems Technology StandardsCommittee, was published under the authorityofthe Board of BSIandcomes into effect on 28February1989 BSI 12-1999 The follo
4、wing BSI references relate to the work on this standard: Committee reference IST/4 Draft for comment 88/60279 DC ISBN 0 580 16919 7 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Information Systems Technology Standards Committee (IST/-
5、) to Technical Committee IST/4, upon which the following bodies were represented: Association for Payment Clearing Services British Computer Society British Telecommunications plc Business Equipment and Information Technology Association Department of Trade and industry (National Physical Laboratory
6、) HM Customs and Excise HM Treasury (Central Computer and Telecommunications Agency) Institute of Administrative Management Institute of Quality Assurance Institution of Electrical Engineers Institution of Electronic and Radio Engineers Institution of Mechanical Engineers National Computing Centre L
7、td. Post Office Amendments issued since publication Amd. No. Date of issue Comments Corr.1 May 1991 6464 October 1991 8149 March 1994 Indicated by a sideline in the marginBS7024-3:1988 BSI 12-1999 i Contents Page Committees responsible Inside front cover National foreword ii Brief history 2 Foreword
8、 2 0 Introduction 3 1 Scope and field of application 3 2 Conformance 3 3 References 3 4 Track format 3 Annex A EDC implementation 6 Annex B Procedure and equipment for measuring flux transition spacing 6 Annex C Data separators for decoding MFM recording 8 Figure 1 4 Figure 2 5 Figure 3 6 Figure 4 7
9、 Table 1 5 Table 2 5 Publications referred to Inside back coverBS7024-3:1988 ii BSI 12-1999 National foreword This Part of BS 7024, prepared under the direction of the Information Systems Technology Standards Committee, is identical with ISO 7487-3:1986 “Information processing Data interchange on 13
10、0 mm (5.25 in) flexible disk cartridges using modified frequency modulation recording at7958 ftprad, 1,9 tpmm (48 tpi), on both sides Part 3: Track format B” including Technical Corrigendum 1:1991 published by the International Organization for Standardization (ISO). In 1989 the European Committee f
11、or Standardization (CEN) accepted ISO 7487-3:1986 as European Standard EN 27487-3:1989. In 1993 CEN accepted ISO Technical Corrigendum 1:1991 as Amendment 1:1993. NOTEThe EN title page and brief history denote ISO 7487-3:1986 incorrectly as ISO 7487-3:1987. The purpose of this standard is to define
12、those characteristics necessary for successful data interchange using flexible disk cartridges. The information contained is intended as a guide to writing complete specifications for manufacture, purchasing and/or testing. The text of the International Standard does not accord with the recommendati
13、ons for drafting product specifications given in the ISO Directives, or in BS 0-3, but the BSI Technical Committee considers the text is useful as a guide when cartridges are being described or specified. For this reason this Part of BS7024 has a different title from the International Standard; it i
14、s issued as a British Standard guide and it should only be used as such. It should not be used on its own as a British Standard product specification and, in particular, no claims of compliance with this Part of BS7024should be made. Terminology and conventions. The text of the International Standar
15、d has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. For metric units the comma has been used as a decimal marker. In B
16、ritish Standards it is current practice to use a full point on the baseline as the decimal marker. Wherever the words “part of ISO 7487” and “ISO 7487” appear, referring to this standard, they should be read as “Part of BS 7024” and “BS 7024” respectively. Cross-references International Standard Cor
17、responding British Standard ISO 646:1983 BS 4730:1985 Specification for UK 7-bit coded character set (Identical, exercising national options) ISO 2022:1986 BS 6856:1987 Specification for code extension techniques for United Kingdom 7-bit and 8-bit coded character sets (Identical) ISO 4873:1986 BS 60
18、06:1987 Specification for structure and rules for implementation of United Kingdom 8-bit coded character set (Identical) BS 7024 Guide to construction and use of130mm(5.25in) flexible disk cartridges for data interchange, using modified frequency modulation recording at 7958 ftprad, 1.9 tpmm (48 tpi
19、) on both sides ISO 7487-1:1985 Part 1:1988 Dimensional, physical and magnetic characteristics (Identical)BS7024-3:1988 BSI 12-1999 iii The Technical Committee has reviewed the provisions of ISO 9293, to which reference is made in the text, and has decided that they are acceptable for use in conjunc
20、tion with this standard. A British Standard does not purport to include all the necessary provisions 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. International St
21、andard Corresponding British Standard ISO 7487-2:1985 Part 2:1988 Track format A (Identical) Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, the EN title page, pages 2 to 8, an inside back cover and a back cover. This standard has been updated (see copyr
22、ight date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.iv blankEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 27487-3 March 1989 + A1 September 1993 UDC 681.327.634 Key words: Data processing, information interchange, flexib
23、le disk cartridges, magnetic recording, frequency modulation, track format English version Information processing Data interchange on130mm(5.25 in) flexible disk cartridges using modified frequency modulation recording at 7958 ftprad, 1.9 tpmm (48 tpi), on both sides Part 3: track format B (includes
24、 amendment A1:1993) (ISO 7487-3, 1st edition, 1987) Traitement de l information Echange de donnes sur cartouches disquette de 130 mm (5,25 in) utilisant un enregistrement modulation de frquence modifie 7958 ftprad, 1,9 tpmm (48 tpi), sur deux faces Partie 3: schma de piste B (ISO 7487-3, 1re dition,
25、 1987) (inclut lamendement A1:1993) Informationsverarbeitung Datenaustausch auf 130 mm (5,25 in) Disketten mittels modifizierter Frequenzmodulationsaufzeichnung bei 7 958 ftprad, 1,9 tpmm (48 tpi), auf zwei Seiten Teil 3: Spurformat B (ISO 7487-3, 1 Ausgabe, 1987) (enthlt nderungen A1:1993) This Eur
26、opean Standard was accepted by CEN on 21 December 1988 and is identical to the ISO standard as referred to. CEN members are bound to comply with the requirements of the CEN/CENELEC Common Rules which stipulate the conditions for giving this European Standard the status of a national standard without
27、 any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language
28、made by translation under the responsibility of a CEN member into its own language and notified to CEN Central Secretariat has the same status as the official versions. CEN members are the national standards organizations of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Irela
29、nd, Italy, Luxemburg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels CEN 1989. Copyright reserved to all CE
30、N members Ref. No. EN 27487-3:1989 + A1:1993 EEN27487-3:1989 BSI 12-1999 2 Brief history The Technical Board has decided to submit the International Standard ISO 7487-3, 1st edition, 1987 Information processing; Data interchange on 130 mm (5.25 in) flexible disk cartridges using modified frequencymo
31、dulation recording at 7 958 ftprad, 1,9 tpmm (48 tpi), on both sides; Part 3: Track format B to the formal vote. The result of this vote was positive. For the time being, this document exists only in the English and the French versions. According to the CEN/CENELEC Common Rules, the following countr
32、ies are bound to implement this standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxemburg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Statement The text of the International Standard ISO 7487-3, 1st edition, 1987, was
33、 approved by CEN as a European Standard without any modification. Foreword On the proposal of the CEN Central Secretariat, the Technical Board has decided to submit this draft Amendment Information processing Data interchange on130mm (5,25 in) flexible disk cartridges using modified frequency modula
34、tion recording at7958ftprad,1,9tpmm (48 tpi), on both sides Part 3: Track format B (ISO 7487-3:1986, Technical Corrigendum 1:1991) to the Unique Acceptance Procedure (UAP). The result of the Unique Acceptance Procedure was positive. For the time being, this document exists only in English and in Fre
35、nch. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 1994, and conflicting national standards shall be withdrawn at the latest by March 1994. In accordance with the CEN/CENELEC Internal Regu
36、lations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EN27487-3:1989 BSI 12-1999 3 0 Introduction I
37、SO7487specifies the characteristics of130mm (5.25 in) flexible disk cartridges recorded at7958 ftprad, on40tracks on each side, using modified frequency modulation (MFM) recording. ISO 7487-1 specifies the dimensional, physical, and magnetic characteristics of the cartridge so as to provide physical
38、 interchangeability between data processing systems. ISO7487-1and ISO 7487-3, together with the labelling scheme specified in ISO 9293, provide for full data interchange between data processing systems. ISO 7487-2 specifies an alternative track format for data interchange. 1 Scope and field of appli
39、cation This part of ISO7487specifies the quality of recorded signals, the track layout, and a track format to be used on130mm (5.25 in) flexible disk cartridges intended for data interchange between data processing systems. NOTENumeric values in the SI and/or Imperial measurement system in this Inte
40、rnational 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 intermixed nor re-converted. The original design of this part of ISO7487was made using SI units. 2 Conformance A flexible dis
41、k cartridge shall be in conformance with ISO7487when it meets all the requirements either of parts1and2or of parts1and3of ISO 7487. 3 References ISO 7487, Information processing Data interchange on 130 mm (5.25 in) flexible disk cartridges using modified frequency modulation recording at 7 958 ftpra
42、d, 1,9 tpmm (48 tpi), on two sides Part 1: Dimensional, physical and magnetic characteristics; Part 2: Track format A. ISO 9293, Information processing Volume and file structure of flexible disk cartridges for information interchange. 4 Track format 4.1 General requirements 4.1.1 Mode of recording T
43、he mode of recording shall be Modified Frequency Modulation (MFM) for which the conditions are a) a flux transition shall be written at the centre of each bit cell containing a ONE; b) a flux transition shall be written at each cell boundary between consecutive bit cells containing ZEROs. Exceptions
44、 to this are defined in 4.1.12. 4.1.2 Track location tolerance of the recorded flexible disk cartridge The centrelines of the recorded tracks shall be within 0,085mm (0.003 3 in) of the nominal positions, over the range of operating environment specified in ISO 7487-1. This tolerance corresponds to
45、twice the standard deviation. 4.1.3 Recording offset angle At the instant of writing or reading a magnetic transition, the transition shall have an angle of0 18 with the radius. This tolerance corresponds to twice the standard deviation. 4.1.4 Density of recording 4.1.4.1 The nominal density of reco
46、rding shall be7958 ftprad. The nominal bit cell length is125,74rad. 4.1.4.2 The long-term average bit cell length shall be the average bit cell length measured over a sector. It shall be within 3,5% of the nominal bit cell length. 4.1.4.3 The short-term average bit cell length, referred to a particu
47、lar bit cell, shall be the average of the lengths of the preceding eight bit cells. It shall be within 8% of the long-term average bit cell length. 4.1.5 Flux transition spacing (see Figure 1) The instantaneous spacing between flux transitions may be influenced by the reading and writing process, th
48、e bit sequence recorded (pulse crowding effects), and other factors. The locations of the transitions are defined as the locations of the peaks in the signal when reading. Tests should be carried out using a peak-sensing amplifier. 4.1.5.1 The spacing between the flux transitions in a sequence of ON
49、Es shall be between80% and120% of the short-term average bit cell length. 4.1.5.2 The spacing between the flux transition for a ONE and that between two ZEROs preceding or following it shall be between130% and165% of the short-term average bit cell length.EN27487-3:1989 4 BSI 12-1999 4.1.5.3 The spacing between the two ONE flux transitions surrounding a ZERO bit cell shall lie between185% and225% of the short-term average bit cell length. 4.1.6 Average signal amplitude For each side the average signal amplitud
