SIST EN 28630-3:1997

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Information processing - Data interchange on 130 mm (5.25 in) flexible disk cartridges using modified frequency modulation recording at 13 262 ftprad, on 80 tracks each side - Part 3: Track format B for 80 tracks (ISO 8630-3:1987)Informationsverarbeitung - Datenaustausch auf 130 mm (5,25 in) Disketten mit modifizierter Wechseltaktschrift bei zweiseitiger Aufzeichnung mit 13 262 Flußwechsel/rad und 80 Spuren auf jeder Seite - Teil 3: Spurformat B für 80 Spuren (ISO 8630-3:1987)Traitement de l'information - Echange de données sur cartouches a disquettes de 130 mm (5,25 in) utilisant un enregistrement a modulation de fréquence modifiée (MFM) a 13 262 ftprad sur 80 pistes sur chaque face - Partie 3: Schéma de piste B pour 80 pistes (ISO 8630-3:1987)Information processing - Data interchange on 130 mm (5.25 in) flexible disk cartridges using modified frequency modulation recording at 13 262 ftprad, on 80 tracks each side - Part 3: Track format B for 80 tracks (ISO 8630-3:1987)35.220.21Magnetni diskiMagnetic disksICS:Ta slovenski standard je istoveten z:EN 28630-3:1992SIST EN 28630-3:1997en01-december-1997SIST EN 28630-3:1997SLOVENSKI
STANDARD



SIST EN 28630-3:1997



SIST EN 28630-3:1997



SIST EN 28630-3:1997



INTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEXflYHAPO~HAfl OPrAHM3A~MR I-IO CTAH~APTM3A~MM Information processing - Data interchange on 138 mm (5.25 in) flexible disk cartridges using modified frequency modulation recording at 13 262 ftprad, on 80 tracks on each side - Part 3: Track format B for 80 tracks ISO 8630-3 First edition 19874645 Reference number SIST EN 28630-3:1997



Foreword ISO (the International Organization for Standardization) is a worldwide federation of national Standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Esch member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical committees %are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. They are approved in accordance with ISO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO 8630-3 was prepared by Technical Committee ISO/TC 97, Information prorcssing s ystems. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated. 0 International Organkation for Standardkation, 1987 Printed in Switzerland ii SIST EN 28630-3:1997



ISO 8630-3 : 1987 (EI Contents Page 0 introduction . 1 Scope and field of application . 2 Conformance . 3 References . 4 General requirements . 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 4.11 4.12 4.13 Mode of recording . Track location tolerante of the recorded flexible disk cartridge . Recording offset angle . Density of recording . Flux transition spacing . Average Signal Amplitude . Byte . Seetor . Cylinder . CylinderNumber . Data capacity of a track. . Hexadecimal notation . Error Detection Characters (EDC) . 5 Tracklayout . 5.1 IndexGap . 5.2 Seetor Identifier . 5.2.1 Identifier Mark. . 5.2.2 Address Identifier . 5.3 Identifier Gap . 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 4 . . . Ill SIST EN 28630-3:1997



ISO 8630-3 : 1987 (El 5.4 Data Block . 4 5.4.1 Data Mark . 4 5.4.2 Data Field . 4 5.4.3 EDC . 4 5.5 Data BlockGap . 4 5.6 TrackGap . 4 6 Coded representation of data . 4 6.1 Standards . 4 6.2 Coding methods . 4 Annexes A EDC implementation . 5 B Procedure and equipment for measuring flux transition spacing . 6 @ Data separators for decoding MFM recording . 8 iV SIST EN 28630-3:1997



INTERNATIONAL STANDARD ISO 8630-3 : 1987 (E) Information processing - Data interchange on 130 mm (5.25 in) flexible disk cartridges using modified frequency modulation recording at 13 262 ftprad, on 80 tracks on each side - Part 3: Track format B for 80 tracks 0 Introduction ISO 8630 specifies the characteristics of 130 mm (5.25 in) flexible disk cartridges recorded at 13 262 ftprad, using modified frequency modulation (MFM) recording, on 80 tracks on each side. ISO 8630-1 specifies the dimensional, physical and magnetic characteristics of the cartridge, so as to provide physical inter- changeability between data processing Systems. ISO 8630-2 specifies an alternative track format for data inter- Change. ISO 8630-1 and ISO 8630-3, together with the labelling scheme specified in ISO 9293, provide for full data interchange between data processing Systems. 1 Scope and field of application This part of ISO 8636 specifies the quality of recorded Signals, the track layout, and a track format to be used on 130 mm (5.25 in), 13 262 ftprad flexible disk cartridges intended for data interchange between data processing Systems. _ NOTE - Numeric values in the SI and/or Imperial measurement System in this part of ISO 8630 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 was made using Imperial units and further developments were made using SI units. 2 Conformance A flexible disk cartridge shall be in conformance with ISO 8630 when it meets all the requirements of Parts 1 and 3 of ISO 8630. NOTE - ISO 9293 specifies a field in the volume label. 3 References ISO 646, Information processing - ISO 7-bit coded Character set for in forma tion in terchange. ISO 2022, Information processing - ISO 7-bit and 8-bit coded Character sets - Code extension technigues. ISO 4373, Information processing - ISO 8-bit Code for infor- mation interchange - Structure and rules for implernen tation. ISO 6429, Information processing - ISO 7-bit and 8-bit Character sets - Additional control functions for character- imaging devices. ISO 9293, Information processing - Volume and file structure o f flexible disk cartridges for in forma tion in terchange. 4 General requirements 4.1 Mode of recording The mode of recording shall be Modified Frequency Modula- tion (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 in 4.12. 4.2 Track location tolerante of the recorded flexible disk cartridge The centrelines of the recorded tracks shall be within -t 0,642 5 mm ( z!~ 0.001 67 in) of the nominal positions, over the range of operating environment specified in ISO 8630-1. 1 SIST EN 28630-3:1997



ISO 8630-3 : 1987 (E) 4.3 Recording offset angle At the instant of writing or reading a magnetic transition, the transition shall have an angle of O” + 18’ with the radius. NOTE - As tracks may be written and overwritten at extremes of the tolerantes given in 4.2 and 4.3, a band of old information may be left at one edge of the newly written data and would constitute unwanted noise when reading. lt is therefore necessary to trim the edges of the tracks by erasure after writing. 4.4 Density of recording 4.4.1 The nominal density of recording shall be 13 262 ftprad”. The resulting nominal bit cell length is 75,5 prad. 4.4.2 The long-term average bit cell length shall be the average bit cell length measured over a sector. lt shall be within -f: 3,0 % of the nominal bit cell length. 4.4.3 The short-term average bit cell length, referred to a par- ticular bit cell, shall be the average of the lengths of the preceding eight bit cells. lt shall be within $I 8 % of the long- term average bit cell length. 4.5 Flux transition spacing (sec figure 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 when reading. Tests should be carried out using a peak-sensing read amplifier (see annexes B and CL 4.5.1 The spacing between the flux transitions in a sequence of ONEs shall be between 80 % and 120 % of the short-term average bit cell length. 4.5.2 The spacing between the flux transition for a ONE and that between two ZEROS preceding or following it shall be between 130 % and 165 % of the shot-t-term average bit cell length. 4.5.3 The spacing between the flux transitions of two ONEs surrounding a ZERO shall lie between 185 % and 225 % of the short-term average bit cell length. 4.6 Average Signal Amplitude , For each side the Average Signal Amplitude on any track (see ISO 8630-1) of the interchanged flexible disk cartridge shall be less than 160 % of SRA,fand more than 40 % of SRAzJ. 4.7 Byte A byte is a group of eight bit-positions, identified BI to B8. The bit in each Position is a ZERO or a ONE. 4.8 Seetor
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