1、International Standard $ 6596/2 0 a 4 4! ,NTERNAT,ONAL ORGANIZATION FOR STANDARDIZATION*ME)AYAPOAHA OPrAHHJAUHR OCTAHAAPT!43AUkl!4.ORGANlSATlON INTERNATIONALE DE NORMALISATION Information processing - Data interchange on 130 mm (5.25 in) flexible disk cartridges using two-frequency recording at 7 95
2、8 ftprad, I,9 tpmm (48 tpi), on one side - Part 2 : Track format Traitement de Iinformation - e Descriptors : data processing, information interchange, data recording devices, magnetic disks, flexible disks, track formats, specifications. E Price based on 11 pages Adopted by INCITS (InterNational Co
3、mmittee for Information Technology Standards) as an American National Standard.Date of ANSI Approval: 1/30/98Published by American National Standards Institute,25 West 43rd Street, New York, New York 10036Copyright 2002 by Information Technology Industry Council (ITI).All rights reserved.These mater
4、ials are subject to copyright claims of International Standardization Organization (ISO), InternationalElectrotechnical Commission (IEC), American National Standards Institute (ANSI), and Information Technology Industry Council(ITI). Not for resale. No part of this publication may be reproduced in a
5、ny form, including an electronic retrieval system, withoutthe prior written permission of ITI. All requests pertaining to this standard should be submitted to ITI, 1250 Eye Street NW,Washington, DC 20005.Printed in the United States of AmericaForeword IS0 (the International Organization for Standard
6、ization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally 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
7、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 Internati
8、onal Standards by the IS0 Council. They are approved in accordance with IS0 procedures requiring at least 75 % approval by the member bodies voting. International Standard IS0 65!36/2 was prepared by Technical Committee ISO/TC 97, Information processing systems. 0 International Organization for Stan
9、dardization, 1985 0 Printed in Switzerland Contents Page 0 Introduction . 1 Scope and field of application 2 Conformance 3 References 4 General requirements . 5 Track layout after the first formatting for track 00 . 6 Track layout after the first formatting for tracks 01-34 7 Track layout of a recor
10、ded flexible disk for data interchange Annexes A Use of additional tracks. B EDCimplementation . C Prncedtrre and enuipment for measuring flux transition spacing. 8 9 10 INTERNATIONAL STANDARD IS0 6596/2-1985 (E) Information processing - Data interchange on 130 mm (5.25 in) flexible disk cartridges
11、using two-frequency recording at 7 958 ftprad, I,9 tpmm (48 tpi), on one side - Part 2: Track format 0 Introduction IS0 6596 specifies the characteristics of data interchange on 130 mm (5.25 in) flexible disk cartridges using two-frequency recording at 7 958 ftprad, 1,9 tpmm (46 tpi), on one side. I
12、S0 6596/l specifies the dimensional, physical, and magnetic characteristics of the cartridge so as to provide physical interchangeability between data processing systems. Together with the labelling scheme specified in IS0 7665, IS0 6596/l and IS0 6596/2 provide for full data interchange between dat
13、a processing systems. 1 Scope and field of application This part of IS0 6596 specifies the magnetic characteristics, the track layout, and a track format to be used on a 130 mm (5.25 in) flexible disk cartridge, recorded at 7 958 ftprad on one side using two-frequency recording at a track density of
14、 1,9 tracks per millimetre ftpmm) 48 tracks per inch itpi), which is intended for data interchange between data processing systems. NOTE - Numeric values in the SI and/or Imperial measurement system in this International Standard may have been rounded off and therefore are consistent with, but not e
15、xactly equal to, each other. Either system may be used, but the two should be neither intermixed nor re-converted. The original design for this part of IS0 6596 was made using SI units. 2 Conformance A flexible disk cartridge shall be in conformance with !SO 6596 when it meets all the requirements o
16、f parts 1 and 2 of IS0 6596. 3 References IS0 646, Information processing - IS0 7-bit coded character set for information interchange. IS0 2022, Information processing - IS0 Fbit and 8-bit coded character sets - Code extension techniques. IS0 4673, Information processing - IS0 8-bit code for informa
17、tion interchange - Structure and rules for im- plementation. IS0 659611, Information processing - Data interchange on 130 mm (5.25 in) flexible disk cartridges using two-frequency recording at 7 956 ftprad, 1,9 tpmm (48 tpi), on one side - Part 1 : Dimensional, physical and magnetic characteristics.
18、 IS0 7665, Information processing - File structure and labelling of flexible disk cartridges for information interchange. 4 General requirements 4.1 Mode of recording 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
19、data flux transition between two clock flux transitions. Exceptions to this are defined in 4.10. 4.2 Track location tolerance of the recorded flexible disk cartridge The centrelines of the recorded tracks shall be within + 0,085 mm ( + 0.003 3 in) of the nominal positions over the range of operating
20、 environment specified in IS0 6596/l. This tolerance corresponds to twice the standard deviation. 4.3 Recording offset angle At the instant of writing or reading a magnetic transition, the transition may have an angle of O” + 18 with the radius. This tolerance corresponds to twice the standard devia
21、tion. 4.4 Density of recording 4.4.1 The nominal density of recording shall be 7 958 ftprad. The resulting nominal spacing between two clock flux tran- sitions, the nominal bit cell length, is 251 urad. 4.4.2 The long-term average bit cell length shall be the average bit cell length measured over a
22、sector. It shall be within + 3,5 % of the nominal bit cell length. 1 IS0 6596/2-1985 (El 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. It shall be within f 8 % of the long- term average bit cel
23、l length. 4.5 Flux transition spacing (see figure 1) The instantaneous spacing between flux transitions may be in- fluenced by the reading and writing process, the bit sequence recorded (pulse crowding effects), and other factors. The loca- tions of the transitions are defined as the locations of th
24、e peaks in the signal when reading. Tests should be carried out using a peak-sensing amplifier (see annex C). 4.5.1 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
25、 140 % of the nominal bit cell length. 4.5.2 The spacing between two clock flux transitions not sur- rounding a data flux transition or between two data flux tran- sitions surrounding a missing clock flux transition shall be between 60 % and 110 % of the nominal bit cell length. 4.5.3 The spacing be
26、tween 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. 4.6 Average signal amplitude The average signal amplitud
27、e on any non-defective track (see IS0 659611) of the interchanged flexible disk shall be less than 160 % of the stanclard reference amplitude for track 00 and more than 40 % of the standard reference amplitude for track 34. The bit in each position shall be a ZERO or a ONE. 4.8 Sector Track 00 is di
28、vided into 16 sectors. All other tracks are divided into 9 sectors. 4.9 Data capacity of a track The data capacity of track 00 shall be 2 048 bytes. The data capacity of all other tracks shall be 2 304 bytes. 4.10 Hexadecimal notation Hexadecimal notation shall be used to denote the following bytes
29、: (00) for (88 to Bll = 00000000 (01) for (88 to Bl) = OOOOOOOl (FF) for (88 to Bl) = 11111111 (FE)” for (88 to Bl) = 11111110 where the clock transitions of B6, B5 and 84 are missing (FBI” for (B8 to Bl) = 11111011 where the clock transitions of B6, B5 and 84 are missing (F8)* for (88 to Bl) = 1111
30、1000 where the clock transitions of B6, 85 and 84 are missing 4.11 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 1Sbit shift register described by the generator polynomial : 4.7
31、Byte Xa + X2 + X5 + 1 A byte is a group of eight bit-positions, identified Bl to 88, with 88 the most significant and recorded first. (See also annex B.) 1 c 1 c 1 c 0 c 45% to70A3 -a-8- 90%to 140Ac 90 % to 140% - 60% to 110% Figure 1 2 IS0 6596/2-1985 (E) 5 Track layout after the first formatting f
32、or track 00 5.2.2.3 Sector number (S) The 3rd byte shall specify in binary notation the sector number from 01 for the 1st sector to 16 for the last sector. After the first formatting, there shall be 16 usable sectors on the track. The track layout shall be as shown in figure 2. The 16 sectors shall
33、be recorded in the natural order 1, 2, 3, . . . . 15, 16 5.1 Index gap At nominal density, this field shall comprise 16 (FFI-bytes. Writing the index gap is started when the index window is detected. Any of the first 8 bytes may be ill-defined due to over- writing. 5.2.2.4 4th byte of the address id
34、entifier The 4th byte shall always be a UM)-byte. 5.2.2.5 EDC 5.2 Sector identifier These two bytes shall be generated as defined in 4.11 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 5.2.2.4) of the address
35、 identifier. This field shall be as given in table 1. Table 1 5.3 Identifier gap This field shall comprise 11 initially recorded fFF)-bytes. Identifier mark I Address identifier 6 bytes 1 byte T 1 byte S 1 byte EDC (00) (FE)” 1 byte (00) (00) 1 byte IOO) 2 bytes 5.4 Data block This field shall be as
36、 given in table 2. Table 2 5.2.1 identifier mark This field shall comprise 7 bytes Data mark 6 bytes 1 byte vJo1 (FBI” Data field EDC 128 bytes 2 bytes 6 UIOLbytes 1 (FE)*-byte 5.2.2 Address identifier 5.4.1 Data mark This field shall comprise 6 bytes. This field shall comprise 5.2.2.1 Track address
37、 (T) 6 (OOI-bytes 1 (FBI*-byte The track address is the first byte of the address identifier. It shall always be a KM)-byte. 5.4.2 Data field 5.2.2.2 2nd byte of the address identifier This field shall comprise 128 bytes. No requirements are implied bevond the correct EDC for the content of this fie
38、ld (see also 7.3.2.4.2). The 2nd byte shall be always a fOOLbyte. INDEX GAP SECTOR IDENTIFIER IDENTIFIER I_- 1st Sector - -9th Sector-4 Figure 2 3 IS0 6596/2-1985 (E) 5.4.3 EDC 6.2.1 Identifier mark These two bytes shall be generated as defined in 4.11 using the bytes of the data block starting with
39、 the 7th byte of the data mark (see 5.4.1) and ending with the last byte of the data field (see 5.4.2). 5.5 Data block gap This field shall comprise 27 initially recorded (FFLbytes. It is recorded after each data block and it precedes the following sector identifier. After the last data block, it pr
40、ecedes the track gap. 5.6 Track gap This field shall follow the data block gap on the 16th sector. (FFLbytes are written until the index window is detected, unless it has been detected during writing of the last data block gap, in which case there shall be no track gap. At nominal den- sity it shall
41、 comprise 101 (FFLbytes, which may have become ill-defined due to the overwriting process. 6 Track layout after the first formatting for tracks 01-34 After the first formatting, there shall be 9 usable sectors on each track. The track layout shall be as shown in figure 3. 6.1 Index gap At nominal de
42、nsity, this field shall comprise 16 (FFI-bytes. Writing of the index gap is started when the index window is detected. Any of the first 8 bytes may be ill-defined due to over- writing. 6.2 Sector identifier This field shall be as given in table 3. Table 3 Identifier mark Address identifier 6 bytes 1
43、 byte T 1 byte S 1 byte EDC (00) (FE)” 1 byte (00) 1 byte 101) 2 bytes This field shall comprise 7 bytes 6 KMNbytes 1 (FE)*-byte 6.2.2 Address identifier This field shall comprise 6 bytes. 6.2.2.1 Track address (T) The track address is the first byte of the address identifier. It shall represent in
44、binary notation the track address from 01 for the outermost track to 32 for the innermost track. 6.2.2.2 2nd byte of the address identifier The 2nd byte shall always be a (OO)-byte. 6.2.2.3 Sector number (S) The 3rd byte shall specify in binary notation the sector number from 01 for the 1st sector t
45、o 09 for the last sector. The nine sectors shall be recorded in the natural order 1, 2, 3, . . . , 8, 9 6.2.2.4 4th byte of the address identifier The 4th byte shall always be a (OlI-byte. 6.2.2.5 EDC These two bytes shall be generated as defined in 4.11 using the bytes of the sector identifier star
46、ting with the (FE)*-byte (see 6.2.1) of the identifier mark and ending with the 4th byte (see 6.2.2.4) of the address identifier. 6.3 Identifier gap This field shall comprise 11 initially recorded (FF)-bytes. INDEX GAP SECTOR IDENTIFIER IDENTIFIER - 1st Sector - -16th Sector-4 Figure 3 IS0 6596/2-19
47、65 (E) 6.4 Data block This field shall be as given in table 4. Table 4 I Data mark I Data field 1 EDC 1 I 6 bytes 1 byte (00) (FB!* I 256 bytes I 2 bytes I 6.4.1 Data mark This field shall comprise 6 WI-bytes 1 (FE!)*-byte 6.4.2 Data field This field shall comprise 256 bytes. No requirements are imp
48、lied beyond the correct EDC for the content of this field (see also 7.3.2.4.2). 7 Track layout of a recorded flexible disk for data interchange 7.1 Representation of characters Characters shall be represented by means of the 7-bit coded character set (see IS0 6461 and, where required, by its 7-bit o
49、r 8-bit extensions (see IS0 2022) or by means of the 8-bit coded character set (see IS0 48731. Each 7-bit coded character shall be recorded in bit-positions 87 to Bl of a byte; bit position B8 shall be recorded with bit ZERO. The relationship shall be as shown in figure 4. Each 8-bit coded character shall be recorder in bit-positions B8 to Bl of a byte. The relationship shall be as shown in figure 5. 7.2 Good and bad tracks A good track is a track which has been formatted according to 7.3. 6.4.3 EDC A bad track is a track which has been handled according to 7.4. These two bytes s
