1、BRITISH STANDARD BS 7023-3: 1988 ISO 8378-3: 1986 EN 28378-3: 1989 Incorporating Amendment 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, 3.8 tpmm (96 tpi) on both sides Part 3: Track
2、format B ISO title: Information processing Data interchange on 130 mm (5.25 in) flexible disk cartridges using modified frequency modulation recording at 7 958 ftprad, 3,8 tpmm (96 tpi), on both sides Part 3: Track format B This European Standard EN 28378-3:1989 has the status of a British Standard
3、UDC 681.327.634:.002.2:.004.14BS7023-3:1988 This British Standard, having been prepared under the directionof the Information Systems Technology Standards Committee, was published underthe authority of the BoardofBSI and comes into effect on 28February1989 BSI 12-1999 The following BSI references re
4、late to the work on this standard: Committee reference IST/4 Draft for comment 88/60282 DC ISBN 0 580 16916 2 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Information Systems Technology Standards Committee (IST/-) to Technical Committ
5、ee 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) HM Customs and Excis
6、e 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 Ltd. Post Office Amendm
7、ents issued since publication Amd. No. Date of issue Comments 6467 October 1991 Indicated by a sideline in the marginBS7023-3:1988 BSI 12-1999 i Contents Page Committees responsible Inside front cover National foreword ii Brief history 2 0 Introduction 3 1 Scope and field of application 3 2 Conforma
8、nce 3 3 References 3 4 Track format 3 5 Coded representation of data 6 Annex A EDC implementation 7 Annex B Procedure and equipment for measuring flux transition spacing 7 Annex C Data separators for decoding MFM recording 9 Figure 1 4 Figure 2 5 Figure 3 6 Figure 4 7 Figure 5 8 Table 1 5 Table 2 5
9、Publications referred to Inside back coverBS7023-3:1988 ii BSI 12-1999 National foreword This Part of BS7023, prepared under the direction of the Information Systems Technology Standards Committee, is identical with ISO8378-3:1986 “Information processing Data interchange on130mm (5.25in) flexible di
10、sk cartridges using modified frequency modulation recording at7958ftprad, 3,8tpmm (96tpi), on both sides Part3; Track format B” published by the International Organization for Standardization (ISO). In 1989 the European Committee for Standardization (CEN) accepted ISO8378-3 as European Standard EN28
11、378-3:1989. The purpose of this standard is to define 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 Intern
12、ational Standard does not accord with the recommendations for drafting product specifications given in the ISO Directives, or in BS0-3, 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 BS7023 has a
13、different title from the International Standard; it is 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 BS7023 should be made. Terminology
14、and conventions. The text of the International Standard 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 u
15、nits the comma has been used as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker. Wherever the words “part of ISO8378” and “ISO8378” appear, referring to this standard, they should be read as “Part of BS7023” and “BS7023” respect
16、ively. The Technical Committee has reviewed the provisions of ISO9293, to which reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. Cross-references International Standard Corresponding British Standard ISO 646:1983 BS 4730:1985 Specific
17、ation 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 6006:1987 Specification for structure and rules for implementati
18、on of United Kingdom 8-bit coded character set (Identical) BS 7023 Guide to construction and use of 130 mm (5.25 in) flexible disk cartridges for data interchange, using modified frequency modulation recording at7958ftprad, 3,8tpmm (96 tpi) on both sides ISO 8378-1:1986 Part 1:1988 Dimensional, phys
19、ical and magnetic characteristics (Identical) ISO 8378-2:1986 Part 2:1988 Track format A (Identical)BS7023-3:1988 BSI 12-1999 iii 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. Compl
20、iance 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 toiv, theENtitle page, pages2 to10, an inside back cover and a back cover. This standard has been updated (see copyright date
21、) 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 28378-3 March 1989 UDC 681.327.634 Key words: Data processing, information interchange, flexible disk cartridges, magnetic
22、recording, frequency modulation, track format English version Information processing Data interchange on 130 mm (5.25 in) flexible disk cartridges using modifiedfrequency modulation recording at 7 958 ftprad, 3.8 tpmm (96 tpi), on both sides Part 3: track format B (ISO 8378-3, 1st edition, 1986) Tra
23、itement de linformation Echange de donnes sur cartouches disquette de 130 mm (5,25 in) utilisant un enregistrement modulation de frquence modifie 7 958 ftprad, 3,8 tpmm (96 tpi), surdeux faces Partie 3: schma de piste B (ISO 8378-3, 1re dition, 1986) Informationsverarbeitung Datenaustausch auf130mm
24、(5.25in) Disketten mittels modifizierter Frequenzmodulationsaufzeichnung bei7958ftprad3,8tpmm (96tpi), auf beidenSeiten Teil3: Spurformat B (ISO8378-3, 1st edition, 1986) This European Standard was accepted by CEN on21December1988 and is identical to the ISO standard as referred to. CEN members are
25、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 any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on appli
26、cation 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 made by translation under the responsibility of a CEN member into its own language and notified to CEN Central Secretariat h
27、as the same status as the official versions. CEN members are the national standards organizations of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxemburg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee f
28、or Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels CEN1989 Copyright reserved to all CEN members Ref. No. EN28378-3:1989EEN 28378-3:1989 BSI 12-1999 2 Brief history The Technical Board has decided to submit the In
29、ternational Standard ISO 8378-3, 1st edition1986 “Information processing; Data interchange on130mm (5.25in) flexible disk cartridges using modified frequencymodulation recording at7957ftprad, 3,8tpmm (96tpi) on both sides Part3: Track format B” to the formal vote. The result of this vote was positiv
30、e. For the time being, this document exists only in the English and the French versions. According to the CEN/CENELEC Common Rules, the following countries are bound to implement this standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxemburg, Netherlan
31、ds, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Statement The text of the International Standard ISO8378-3, 1stedition, 1986, was approved by CEN as a European Standard without any modification.EN 28378-3:1989 BSI 12-1999 3 0 Introduction ISO8378 specifies the characteristics of
32、130mm(5.25in) flexible disk cartridges recorded at7958ftprad, on80 tracks on each side, using modified frequency modulation (MFM) recording. ISO8378-1 specifies the dimensional, physical, and magnetic characteristics of the cartridge so as to provide physical interchangeability between data processi
33、ng systems. ISO8378-1 and ISO8378-3, together with the labelling scheme specified in ISO9293, provide for full data interchange between data processing systems. ISO8378-2 specifies an alternative track format for data interchange. 1 Scope and field of application This part of ISO8378 specifies the q
34、uality of recorded signals, the track layout, and a track format to be used on130mm (5.25in) flexible disk cartridges intended for data interchange between data processing systems. NOTENumeric values in the SI and/or Imperial measurement system in this part of ISO8378 may have been rounded off and t
35、herefore are consistent with, but not exactly equal to, each other. Either system may be used, but the two should be neither intermixed nor reconverted. The original design of this part of ISO8378 was made using SI units. 2 Conformance A flexible disk cartridge shall be in conformance with ISO8378 w
36、hen it meets all the requirements either of parts1 and2 or of parts1 and3 of ISO8378. 3 References ISO 646, Information processing ISO7-bit coded character set for information interchange. ISO 2022, Information processing ISO7-bit and8-bit coded character sets Code extension techniques. ISO 4873, In
37、formation processing ISO 8-bit code for information interchange Structure and rules for implementation. ISO 8378, Information processing Data interchange on130mm (5.25in) flexible disk cartridges using modified frequency modulation recording at7958ftprad, 3,8tpmm (96tpi), on both sides Part 1: Dimen
38、sional, physical and magnetic characteristics; Part 2: Track format A. ISO 9293, Information processing Volume and file structure of flexible disk cartridges for information interchange 1) . 4 Track format 4.1 General requirements 4.1.1 Mode of recording The mode of recording shall be Modified Frequ
39、ency 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 to this are defined in4.1.12. 4.1.2 Track l
40、ocation tolerance of the recorded flexible disk cartridge The centrelines of the recorded tracks shall be within 0,0425mm (0.0017in) of the nominal positions, over the range of operating environment specified in ISO8378-1. 4.1.3 Recording offset angle At the instant of writing or reading a magnetic
41、transition, the transition shall have an angle of0 18 with the radius. NOTEAs tracks may be written and overwritten at extremes of the tolerances given in4.1.2 and4.1.3, a band of old information may be left at one edge of the newly written data and would constitute unwanted noise when reading. It i
42、s, therefore, necessary to trim the edges of the tracks by erasure after writing. 4.1.4 Density of recording 4.1.4.1 The nominal density of recording shall be7958ftprad. 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 measur
43、ed 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 particular 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 Flu
44、x transition spacing (seeFigure 1) The instantaneous spacing between flux transitions may be influenced by the reading and writing process, the 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
45、when reading. Tests should be carried out using a peak-sensing amplifier. 1) At present at the stage of draft.EN 28378-3:1989 4 BSI 12-1999 4.1.5.1 The spacing between the flux transitions in a sequence of ONEs shall be between80% and120% of the short-term average bit cell length. 4.1.5.2 The spacin
46、g 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. 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 av
47、erage bit cell length. 4.1.6 Average signal amplitude For each side the average signal amplitude on any non-defective track (seeISO8378-1) of the interchanged flexible disk cartridge shall be less than160% of SRA 1fand more than40% of SRA 2f . 4.1.7 Byte A byte is a group of eight bit-positions, ide
48、ntified B1 to B8, with B8 the most significant and recorded first. The bit in each position is a ZERO or a ONE. 4.1.8 Sector All tracks are divided into9 sectors of512 bytes. 4.1.9 Cylinder A pair of tracks, one on each side, having the same track number. 4.1.10 Cylinder number The cylinder number s
49、hall be a two-digit number identical with the track number of the tracks of the cylinder. 4.1.11 Data capacity of a track The data capacity of a track shall be4608 bytes. 4.1.12 Hexadecimal notation Hexadecimal notation shall be used hereafter to denote the following bytes: 4.1.13 Error detection characters (EDC) The two EDC-bytes are hardware generated by shifting serially the relevant bits, specified later for each part of the track through a16-bit shift register described by X 16+ X 12+ X 5+ 1 (SeealsoAnnex
