EN 28630-2:1992
(Main)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 2: Track format A for 77 tracks (ISO 8630-2:1987)
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 2: Track format A for 77 tracks (ISO 8630-2:1987)
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 2: Spurformat A für 77 Spuren (ISO 8630-2:1987)
Traitement de l'information - Echange de données sur cartouches à disquettes de 130 mm (5,25 in) utilisant un enregistrement à modulation de fréquence modifiée (MFM) à 13 262 ftprad sur 80 pistes sur chaque face - Partie 2: Schéma de piste A pour 77 pistes (ISO 8630-2:1987)
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 2: Track format A for 77 tracks (ISO 8630-2:1987)
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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 2: Track format A for 77 tracks (ISO 8630-2:1987)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 2: Spurformat A für 77 Spuren (ISO 8630-2:1987)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 2: Schéma de piste A pour 77 pistes (ISO 8630-2:1987)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 2: Track format A for 77 tracks (ISO 8630-2:1987)35.220.21Magnetni diskiMagnetic disksICS:Ta slovenski standard je istoveten z:EN 28630-2:1992SIST EN 28630-2:1997en01-december-1997SIST EN 28630-2:1997SLOVENSKI
STANDARD
SIST EN 28630-2:1997
SIST EN 28630-2:1997
SIST EN 28630-2:1997
INTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEXAYHAPOfiHAFl OPt-AHM3A~Mfl !10 CTAHJJAPTM3AL/MM 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 2: Track format A for 77 tracks ISO 8630-2 First edition 1987-06 15 Reference nurnber ISO 8630-2 : 1987 (E! SIST EN 28630-2:1997
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 8630-2 was prepared by Technical Committee ISO/TC 97, Information processing Systems. 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 28630-2:1997
ISO 8630-2 : 1987 (E) Contents Page 0 Introduction . 1 Scope and field of application . 2 Conformance . 3 References . 4 General requirements . 4.1 Modeofrecording . 4.2 Track location tolerante of the recorded flexible disk cartridge . 4.3 Recording offset angle . 4.4 Density of recording . 4.5 Flux transition spacing . 4.6 Average Signal Amplitude . 4.7 Byte . 4.8 Seetor . 4.9 Cylinder . 4.10 CylinderNumber . 4.11 Data capacityof a track . 4.12 Hexadecimal notation . 4.13 Error Detection Characters (EDC) . 5 Track layout after the first formatting for track 00, side 0 . 5.1 IndexGap. . 5.2 Seetor Identifier . 5.3 Identifier Gap . 5.4 DataBlock . 5.5 Data Block Gap . 5.6 TrackGap . 1 1 1 1 1 1 2 2 2 2 3 3 3 3 3 3 3 3 3 4 4 4 4 4 4 . . . 111 SIST EN 28630-2:1997
ISO 8630-2 : 1987 (E) 6 Track layout after the first formatting for all tracks excluding track 00, side 0 . . 5 6.1 IndexGap. . 5 6.2 Seetor Identifier . 5 6.3 Identifier Gap . 6 . 6.4 Data Block . 6 6.5 Data BlockGap . 6 6.6 TrackGap . 6 7 Track layout of a recorded flexible disk for data interchange . 6 7.1 Representation of characters . 6 7.2 Good and bad cylinders . 7 7.3 Requirements for cylinders. . 7 7.4 Layout of the tracks of a good cylinder . 7 7.5 Layout of the tracks of a bad cylinder . 8 Annexes A EDC implementation . 9 B Procedure and equipment for measuring flux transition spacing . IO C Data separators for dccoding MFM recording . 12 SIST EN 28630-2:1997
INTERNATIONAL STANDARD ISO 8630-2 : 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 2: Track format A for 77 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 8630-3 specifies an alternative track format for data inter- Change. ISO 8630-1 and ISO 8630-2, together with the labelling scheme specified in ISO 7665, provide for full data interchange between data processing Systems. 1 Scope and field of application This part of ISO 8630 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 2 of ISO 8630 and when it implements one of the three sector sizes specified in 4.11. Data interchange is possible only when the interchange Parties implement the same sector size. NOTE - ISO 7665 specifies a field in the volume label in which the implemented sector size is identified. 3 References ISO 646, Information processing - ISO 7-bit coded Character set for in forma tion in terchange. ISO 2022, Information processing - /SO 7-bit and g-bit coded Character sets - Code extension techniques. ISO 4873, Information processing - /SO g-bit Code for infor- mation in terchange - S truc ture and rules for implernen ta tion. ISO 6429, Information processing - ISO 7-bit and g-bit Character sets - Additional control functions for character- imaging devices. ISO 7065-2, Information processing - Data interchange on 200 mm (8 in) flexible disk cartridges using modified frequency modulation recording at 13 262 ftprad, 1,9 tpmm (48 tpi), on both sides - Part 2: Track formst. ISO 7665, Information processing - File structure and labelling o f flexible disk cartridges for in forma tion in terchange. 4 General requirements 4.1 Mode of recording 4.1.1 Track 00, side 0 The mode of recording shall be two-frequency where the Start of every bit cell is a clock flux transition. A ONE is represented by a data flux transition between two clock flux transitions. Exceptions to this are defined in 4.12. 4.1.2 All tracks excluding track 00, side 0 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. SIST EN 28630-2:1997
ISO 8630-2 : 1987 (E) 4.2 Track location tolerante of the recorded flexible disk cartridge The centrelines of the recorded tracks shall be within + 0,042 5 mm ( r$I 0.001 67 in) of the nominal positions, over the range of operating environment specified in ISO 8630-1. 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. It 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 for track 00, side 0 is 151 prad, and for all the other tracks it 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 Ifr 2,0 % of the nominai bit cell length. 4.4.3 The short-term average bit cell length, referred to a par- ticular bit celi, shall be the average of the lengths of the preceding eight bit cells. lt shall be within + 8 % of the long- term average bit cell length. 4.5 Flux transition spacing 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 (sec annexes 6 and C). 4.5.1 Flux transition spacing for track 00, side 0 (sec figure 1) 4.5.1.1 The spacing between two clock flux transitions sur- rounding a data flux transition or between two data flux transi- tions surrounding a clock flux transition shall be between 90 % and 140 % of the nominal bit cell length. 4.5.1.2 The spacing between two clock flux transitions not surrounding a data flux transition or between two data flux transitions surrounding a missing clock flux transition shall be between 60 % and 110 % of the nominal bit cell length. 4.5.1.3 The spacing between a data flux transition and the preceding clock flux transition (when not missing) or between a clock flux transition and the preceding data flux transition (when not missing) shall be between 45 % and 70 % of the nominal bit cell length. 4.5.2 Flux transition spacing for all tracks excluding track 00, side 0 (sec figure 2) 4.5.2.1 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. 1 I I 1 45% to 70% 45% to 70 O/o I 90 O/o to 140% 6()“/o to 110% Figure 1 I v 80% to 120°/o 1300/~ to 165 y. 130°/o to 165 ‘10 -- Figure 2 * Flux transitions per radian 2 SIST EN 28630-2:1997
ISO 8630-2 : 1987 (El 4.5.2.2 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 short-term average bit cell length. 4.5.2.3 The spacing between the two ONE flux transitions surrounding a ZERO bit cell 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 non- defective track (see ISO 8630-1) of the interchanged flexible disk cartridge shall be less than 160 % of SRAIfand more than 40 % of S.RAzf. 4.7 Byte A byte is a group of eight bit-positions, identified Bl to B8, with B8 most significant and recorded first. The bit in each Position is a ZERO or a ONE. 4.8 Seetor Track 00, side 0 and side 1 is divided into 26 sectors. All other tracks of the flexible disk cartridge shall have the same number of sectors, which tan be 8, 15 or 26. 4.9 Cylinder A pair of tracks, one on each side of the disk, having the same track number. 4.10 Cylinder Number The Cylinder Number shall be a two-digit number identical with the track number of the tracks of the cylinder. 4.11 Data capacity of a track The data capacity of track 00, side 0 shall be 3 328 bytes. The data capacity of track 00, side 1 shall be 6 656 bytes. The data capacity of all other tracks shall be as shown in table 1. Table 1 I Number of Number of data Data capacity sectors bytes in the sector -1 of a track 4.12 Hexadecimal notation Hexadecimal notation is used hereafter to denote the following bytes: (00) (01) (02) (03) (FF-1 FC)* FE) * (FB)” (F8)* (4E) FC) (FE) (FB) (F8) (Al 1” K2)” 4.13 for (B8 to BI) = 00000000 for (B8 to BI) = 00000001 for IB8 to Bl) = 00000010 for (B8 to Bl) = OOOOOO11 for (B8 to BI) = 11111111 for (B8 to Bl) = 11111100 where the clock transitions of B6 and B4 are missing for iB8 to BI) = 11111110 where the clock transitions of B6, 85 and B4 are missing for (B8 to Bl) = 11111011 where the clock transitions of B6, B5 and B4 are missing for (B8 to BI) = 11111000 where the clock transitions of B6, B5 and 84 are missing for (B8 to Bl) = 01001110 for (B8 to Bl) = 11111100 for (B8 to Bl) = 11111110 for (B8 to Bl) = 11111011 for (B8 to BI) = 11111000 for (B8 to BI) = 10100001 where the boundary transition between B3 and B4 is missing for (88 to BI) = 11000010 where the boundary transition between B4 and B5 is missing 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 a 16-bit shift register described by the generator polynomial : X’6 + X’2 + x5 + 1 (See also annex A.) 5 Track layout after the first formatting for track 00, side 0 After the first formatting there shall be 26 usable sectors on the track. The layout of the track shall be as shown in figure 3. INDEX GAP SECTOR IDENTIFIER IDENTIFIER 1 st sector Last sector Figure 3 3 SIST EN 28630-2:1997
ISO 8630-2 : 1987 (El 5.1 Index Gap This field shall comprise 73 bytes nominally. The content is not specified except that it shall not contain any (FE)*-bytes. -Writing the Index Gap is started when the index hole is detected. Any of the first 20 bytes may become ill-defined due to subsequent overwriting. 5.2 Seetor ldentifier This field shall be as given in table 2. Table 2 Identifier Mark Address Identifier Track Address S EDC 6 bytes 1 byte C Side 1 byte (00) (FE)” 1 byte 1 byte 1 byte (00) 2 bytes (00) (00) 5.2.2.4 EDC These two bytes shall be generated as defined in 4.13 using the bytes of the Seetor Identifier starting with the (FE)*-byte (sec 5.2.1) of the Identifier Mark and ending with the 4th byte (See 5.2.2.3) of the Seetor Address. 5.3 Identifier Gap This field shall comprise 11 initially recorded (FF)-bytes. 5.4 Data Block The layout of this field shall be as given in table 3. Table 3 Data Block I Data Mark 1 Data Field 1 EDC I I 6 bytes 1 byte (00) FB)” I 128 bytes 5.2.1 Identifier Mark 5.4.1 Data Mark This field shall comprise 7 bvtes: This field shall comprise 7 bytes: 6 (OOLbytes 1 (FE)*-byte 6 (OOLbytes 1 (FB)*-byte 5.2.2 Address Identifier 5.4.2 Data Field This field shall comprise 6 bytes. 5.2.2.1 Track Address This field shall comprise
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