1、INTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEXAYHAPOAHAR OPrAHM3AklR !-IO CTAHAAPTMSAWl Information processing - Data interchange on 130 mm (5.25 in) flexible disk cartridges using modified frequency modulation recording at 13 2
2、62 ftprad, on 80 tracks on each side - Part 2: Track format A for 77 tracks IS0 8630-2 First edition 1987-06-15 Reference number Adopted by INCITS (InterNational Committee for Information Technology Standards) as an American National Standard.Date of ANSI Approval: 1/30/98Published by American Natio
3、nal Standards Institute,25 West 43rd Street, New York, New York 10036Copyright 2002 by Information Technology Industry Council (ITI).All rights reserved.These materials are subject to copyright claims of InternationalStandardization Organization (ISO), International ElectrotechnicalCommission (IEC),
4、 American National Standards Institute (ANSI),and Information Technology Industry Council (ITI). Not for resale.No part of this publication may be reproduced in any form,including an electronic retrieval system, without the prior writtenpermission of ITI. All requests pertaining to this standard sho
5、uld besubmitted to ITI, 1250 Eye Street NW, Washington, DC 20005.Printed in the United States of AmericaForeword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is norma
6、lly carried out through IS0 technical committees. Each 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
7、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 IS0 Council. They are approved in accordance with IS0 procedures requiring at least 75 % approval by the member bodie
8、s voting. International Standard IS0 8S3g-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 e
9、dition, unless otherwise stated. 0 International Organization for Standardization, 1997 l Printed in Switzerland ii ISO 8630-2 : 1987 (I3 Contents 0 Introduction . 1 Scope and field of application 2 Conformance 3 References 4 General requirements . 4.1 Modeofrecording 4.2 Track location tolerance of
10、 the recorded flexible disk cartridge. 4.3 Recordingoffsetangle 4.4 Density of recording 4.5 Flux transition spacing 4.6 Average Signal Amplitude . 4.7 Byte 4.8 Sector 4.9 Cylinder . 4.10 CylinderNumber . 4.11 Data capacity of a track. . 4.12 Hexadecimal notation . 4.13 Error Detection Characters (E
11、DC) . 5 Track layout after the first formatting for track 00, side 0 . 5.1 IndexGap 5.2 Sectorldentifier . 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 iii IS0 8630-2 : 1987 (El 6 Track layout after the first formatting for
12、all tracks excluding track 00, side 0 6.1 IndexGap 6.2 Sectorldentifier . 6.3 Identifier Gap . 6.4 DataBlock . 6.5 Data Block Gap . 6.6 TrackGap 7 Track layout of a recorded flexible disk for data interchange 7.1 Representation of characters 7.2 Goodandbadcylinders 7.3 Requirements for cylinders. .
13、7.4 Layout of the tracks of a good cylinder. . 7.5 Layout of the tracks of a bad cylinder . Annexes A EDC implementation . B Procedure and equipment for measuring flux transition spacing . C Data separators for decoding MFM recording 5 5 . 5 6 6 6 6 . 6 6 . 7 7 7 . 8 9 . 10 . 12 iv INTERNATIONAL STA
14、NDARD IS0 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 IS0 8630 specifies the characteristics of
15、 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. IS0 8630-l specifies the dimensional, physical and magnetic characteristics of the cartridge, so as to provide physical inter- changeability between d
16、ata processing systems. IS0 8630-3 specifies an alternative track format for data inter- change. IS0 8636-l and IS0 8630-2, together with the labelling scheme specified in IS0 7665, provide for full data interchange between data processing systems. 1 Scope and field of application This part of IS0 8
17、630 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
18、 IS0 6630 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 reconverted. The original design was made using Imperial units and further developments were made using SI units. 2 Con
19、formance A flexible disk cartridge shall be in conformance with IS0 8630 when it meets all the requirements of parts 1 and 2 of IS0 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 si
20、ze. NOTE - IS0 7665 specifies a field in the volume label in which the implemented sector size is identified. 3 References IS0 646, Information processing - IS0 7-bit coded character set for information interchange. IS0 2022, Information processing - IS0 7-bit and 8-bit coded character sets - Code e
21、xtension techniques. IS0 4873, Information processing - IS0 B-bit code for infor- mation interchange - Structure and rules for implementation. IS0 6429, Information processing - IS0 7-bit and Shit character sets - Additional control functions for character- imaging devices. IS0 7065-2. Information p
22、rocessing - 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 format. IS0 7665, Information processing - File structure and labelling of flexible disk cartridges for information
23、interchange. 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 define
24、d 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
25、between consecutive bit cells containing ZEROS. Exceptions to this are defined in 4.12. IS0 8630-2 : 1987 (El 4.2 Track location tolerance of the recorded flexible disk cartridge The centrelines of the recorded tracks shall be within + 0,042 5 mm ( IL 0.001 67 in) of the nominal positions, over the
26、range of operating environment specified in IS0 8630-l. 4.3 Recording offset angle At the instant of writing or reading a magnetic transition, the transition shall have an angle of O” f 18 with the radius. NOTE - As tracks may be written and overwritten at extremes of the tolerances given in 4.2 and
27、 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 ftpr
28、ad”. The resulting nominal bit cell length for track 00, side 0 is 151 urad, and for all the other tracks it is 75,5 prad. 4.4.2 The long-term average bit ceil length shall be the average bit cell length measured over a sector. It shall be within + 2,0 % of the nominal oit cell length. 4.4.3 The sho
29、rt-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. It shall be within f 8 % of the long- term average bit cell length. C G 9oxto 140% J 4.5 Flux transition spacing The instantaneous spacing between flux transiti
30、ons 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
31、annexes B and C). 4.5.1 Flux transition spacing for track 00, side 0 (see figure I) 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 bi
32、t 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 date flux transi
33、tion 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 80, side 0 (see fig
34、ure 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. C 45% to70% 90 %to 140% 6Oo/o to 110% Figure 1 130% to 165% 130%to 165% 185% to 225% m hf Figure 2 l Flux transitions per radian 2 IS0 8530-2 : 198
35、7 (E) 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
36、% 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 IS0 8630-I) 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
37、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 Sector 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
38、 can 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
39、 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 Number of 1 Number of data 1 Data capacity 1 sectors bytes in the sector 26 256 15 512 a 1 024 of a track 6 656 bytes 7 680 bytes
40、8 192 bytes 4.12 Hexadecimal notation Hexadecimal notation is used hereafter to denote the following bytes: (00) (01) (02) (03) (FF) (FC)” (FE)” (FBI” (F8)” (4E) (FC) (FE) (FBI IF81 (Al 1” (C2)” for (B8 to Bl) = 00000000 for (B8 to Bl) = OOOOOOOI for (88 to Bl) = 00000010 for (88 to Bl) = 06000611 f
41、or (88 to Bl) = 11111111 for (88 to Bl) = 11111100 where the clock transitions of B6 and 84 are missing for iB8 to Bl) = 11111110 where the clock transitions of B6, 85 and 84 are missing for (B8 to Bl) = 11111011 where the clock transitions of B6, B5 and 84 are missing for (88 to Bl) = 11111000 wher
42、e the clock transitions of B6, 85 and 84 are missing for (88 to Bl) = 01001110 for (88 to Bl) = 11111100 for (88 to 81) = 11111110 for (88 to Bl) = 11111011 for (88 to Bl) = 11111000 for (88 to Bl) = 10100001 where the boundary transition between 83 and 84 is missing for (88 to Bl) = 11OWOlO where t
43、he boundary transition between B4 and B5 is missing 4.13 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 a 16-bit shift register described by the generator polynomial : x16 + x12 + x
44、5 + I (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 IS0 8630
45、-2 : 1987 (E) 5.1 Index Gap 5.2.2.4 EDC 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 o
46、verwriting. These two bytes shall be generated as defined in 4.13 using the bytes of the Sector Identifier starting with the (FE)*-byte (see 5.2.1) of the Identifier Mark and ending with the 4th byte (see 5.2.2.3) of the Sector Address. 5.3 Identifier Gap This field shall comprise 11 initially recor
47、ded (FFI-bytes. 5.2 Sector Identifier 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 bvte 1 bvte 1 bvte (ool 2 bytes 5.2.1 Identifier Mark This field shall comprise 7 bvtes: 6 fOOLbytes 1 (FE)*-byte 5.
48、2.2 Address Identifier This field shall comprise 6 bytes. 5.2.2.1 Track Address This field shall comprise 2 bytes: a) Cylinder Address (C) This field shall specify in binary notation the Cylinder Address. It shall be (00) for all sectors. b) Side Number (Side) This field shall specify the side of th
49、e disk. It shall be (00) for all sectors. 5.2.2.2 Sector Number (S) The 3rd byte shall specify in binary notation the Sector Number from 01 for the first sector to 26 for the last sector. The 26 sectors shall be recorded in the natural order: 1, 2, 3, . . ., 25, 26 5.2.2.3 4th byte of the Sector Address The 4th byte shall be always a fOOLbyte. 5.4 Data Block The layout of this field shall be as given in table 3. Table 3 Data Mark Data Block Data Field EDC I 6 bytes 1 byte (OOI (FB)” I 128 bytes 2 bytes I 5.4.1 Data Mark This field shall comprise 7 bytes: 6 KU)-bytes 1 (FBI*-byte 5.4.2 Data
