1、 ANSI INCITS 125-1985 (R2001)(formerly ANSI X3. 125-1985 (R2001)for Information Systems Two-Sided, Double-Density, Unformatted,5.25inch (130-mm), 48-tpi (1,9-tpmm),Flexible Disk Cartridge for 7958 bpr Use General, Physical, andMagnetic RequirementsAmericanNationalStandardApproval of an American Nati
2、onal Standard requires review by ANSI that therequirements for due process, consensus, and other criteria for approval havebeen met by the standards developer.Consensus is established when, in the judgment of the ANSI Board of StandardsReview, substantial agreement has been reached by directly and m
3、ateriallyaffected interests. Substantial agreement means much more than a simplemajority, but not necessarily unanimity. Consensus requires that all views andobjections be considered, and that a concerted effort be made toward theirresolution.The use of American National Standards is completely volu
4、ntary; their existencedoes not in any respect preclude anyone, whether he has approved the standardsor not, from manufacturing, marketing, purchasing, or using products, processes,or procedures not conforming to the standards.The American National Standards Institute does not develop standards and w
5、ill inno circumstances give an interpretation of any American National Standard.Moreover, no person shall have the right or authority to issue an interpretation ofan American National Standard in the name of the American National StandardsInstitute. Requests for interpretations should be addressed t
6、o the secretariat orsponsor whose name appears on the title page of this standard.CAUTION NOTICE: This American National Standard may be revised orwithdrawn at any time. The procedures of the American National StandardsInstitute require that action be taken periodically to reaffirm, revise, or withd
7、rawthis standard. Purchasers of American National Standards may receive currentinformation on all standards by calling or writing the American National StandardsInstitute.Published byAmerican National Standards Institute11 West 42nd Street, New York, New York 10036Copyright 1985 by Information Techn
8、ology Industry Council (ITI)All rights reserved.No part of this publication may be reproduced in anyform, in an electronic retrieval system or otherwise,without prior written permission of ITI, 1250 Eye Street NW,Washington, DC 20005.Printed in the United States of AmericaANSI X3.125-1985 American N
9、ational Standard for Information Systems - Two-Sided, Double-Density, Unformatted, 5.25Inch (130-mm), 48-tpi (1,9-tpmm), Flexible Disk Cartridge for 7958 bpr Use - General, Physical, and Magnetic Requirements Secretariat Computer and Business Equipment Manufacturers Association Approved November 2,
10、1994 American National Standards Institute, I nc Foreword (This Foreword is not part of American National Standard X3.125-1985.) This standard presents, for the purpose of physical and magnetic interchange, a two-sided, double-density, unformatted, 5.25-inch (130-mm), 48-tpi (1,9-tpmm), flexible dis
11、k cartridge (for 7958 bits-per-radian (bpr) use). Disk parameters are defined as required to achieve interchangeability between flexible disks, storage drives, and associated informa- tion processing systems. Subsequent related standards may contain specifications that differ from this standard as a
12、 result of the normal evolution of the product. Original source dimensions for this standard were in U.S. customary units, and reconversion from metric equivalents back to U.S. customary units should not be performed. This standard was developed by the X3B8 Technical Committee on Flexible Disks, whi
13、ch consists of a group of experienced and knowledgeable persons uniquely qualified with respect to the flexible disk cartridge and its performance requirements. Although most members are affiliated with industry or government organizations, this standard repre- sents the sum of individual efforts. S
14、uggestions for improvement of this standard will be welcome. They should be sent to the Computer and Business Equipment Manufacturers Association, 3 11 First Street, NW, Washington, DC 20001. This standard was processed and approved for submittal to ANSI by American National Standards Committee on I
15、nformation Processing Systems, X3. Committee approval of the standard does not necessarily imply that all members voted for its approval. At the time it approved this standard, the X3 committee had the following members: Edward Lohse, Chair William C. Rinehuls, Vice-Chair Catherine A. Kachurik, Admi
16、nistrative Secretary Organization Represented American Library Association. American Nuclear Society. AMP Incorporated . AMTELCO Association of American Railroads. . Association for Computing Machinery Association of the Institute for Certification of Computer Professionals . AT Version B uses 10 se
17、ctor holes in addition to the index hole; and Version C uses 16 sector holes in addition to the index hole. These configurations are further de- scribed in 5.1.3.3 and Figure 2. The existence and number of sector holes shall be specified by the user. 1.2 Purpose. This standard defines the requiremen
18、ts and supporting test methods necessary to ensure inter- change at acceptable performance levels. It is distinct from a specification in that it delineates a minimum of restrictions consistent with compatibility in inter- change transactions. 1.3 Application. The performance levels contained in thi
19、s standard represent the acceptable levels of perfor- mance for interchange purposes. They therefore repre- sent the performance levels that the interchange items should meet or surpass during their useful life. The per- formance levels in this standard are not intended to be employed as substitutes
20、 for purchase specifications. Wherever feasible, quantitative performance levels that must be met or exceeded in order to comply with this standard are given. In all cases including those in which quantitative limits for requirements falling with- in the scope of this standard are not stated but are
21、 left to agreement between interchange parties, standard test methods and measurement procedures shall be used to determine such quantities. U.S. engineering units were the original dimensions in this standard. Conversions of toleranced dimensions from customary U.S. engineering units (similar to Br
22、itish Imperial Units) to SI units have been done in this standard according to Method A of American Na- tional Standard Metric Practice, ANSI/ASTM E380-76. ANSI/IEEE 268.1976 (and Toleranced Dimensions - Conversion from Inches into Millimetres and Vice Versa, IS0 370.1975), except as noted. For curr
23、ent conversions of toleranced dimensions, use Method A or Method B (as appropriate) as described in American National Standard Metric Practice, ANSI/IEEE 268. 1982. Method A should be used for economy unless a requirement for absolute assurance of a fit justifies use of Method B. In the national sta
24、ndards of IS0 member nations, additional rounding may be done to produce “preferred” values. These values should lie within or close to the original tolerance ranges. Except as previously indicated, interchange parties complying with the acceptable standards should be able to achieve compatibility w
25、ithout need for addi- tional exchange of technical information. 2. Referenced Standards 2.1 American National Standard. This standard is in- tended for use in conjunction with American National Standard Metric Practice, ANSI/IEEE 268.1982. When this standard is superseded by a revision ap- proved by
26、 the American National Standards Institute, Inc, the revision shall apply. 5 AMERICAN NATIONAL STANDARD X3.125-1985 2.2 Other Standards. This standard is also intended for use in conjunction with the fi , I : : , / I , 1 L-J -1%. u, - El - * F1 e Figure 3 Loading Area for Running Torque Slde 5.3.1.2
27、 Requirement. The tensile yield force at 3% elongation shall be 14 lbf (62,3 N), minimum. 5.3.1.3 Procedure. Using a static-weighing, constant-rate-of-grip separation tester capable of indi- cating the load to an accuracy of ?2%, clamp a speci- men 0.498 in + 0.002 in (12,649 mm + 0,051 mm) wide and
28、 at least 6 in (152,4 mm) long with an initial separation of 4 in (101,6 mm), at a rate of 2 in/min (50,8 mm/min) a minimum elongation of 10% is reached. The force required to produce an elongation of 3% is the tensile yield force. 5.3.2 Tear Resistance. The tear resistance (Elmen- dorf tear strengt
29、h) shall be a minimum of 1.89 ozf (0,5 1 N) when measured in accordance with ASTM D 1922-67. S-3.3 Coefficients of Expansion 5.3.3.1 Thermal. The coefficient of linear thermal expansion shall be within a range from 0 to a maximum of 13.8 /.dn/in/” F (0 to a maximum of 25 X 1 O- 6 cm/cm/“C). / Slde 0
30、 Dimension Inch mm Cl 2.35 59,69 Dl 1.25 31,73 El 0.45 11,43 Ft 0.85 21,59 5.3.3.2 Hygroscopic. The maximum value for the coefficient of linear hygroscopic expansion shall be 15 fin/in/% RH (15 X 1 OA6 cm/cm/% RH) in all direc- tions. 5.3.4 Substrate Material. Biaxially oriented poly- ethylene terep
31、hthalate or an equivalent material that meets the physical requirements of this standard shall be used as the substrate material. 5.4 Disk Coating 5.4.1 Abrasivity. Abrasivity is defined as that char- acteristic of a disk that results in wear or abrasion of a read/write head. Disks shall not cause e
32、xcessive wear to the read/write head over the range of 1.23 to 2.46 in (31,24 to 62,48 mm) radius. The allowable limits of head wear and the procedures for measuring shall be negotiated between the concerned parties. See Ap- pendix C for a procedure that might be used to define the end-of-life. 5.4.
33、2 Wear Resistance. Wear resistance of the disk 11 AMERICANNATIONALSTANDARDX3.125-1985 shall be determined on the outermost track with speed and loading conditions given in 5:2.1. A dual-head assembly whose configuration is agreed upon between the interchange parties shall be used with the heads load
34、ed on the disk. The test shall be performed at 73” f 5F (23,O” f 3C) with a relative humidity of 40 to 60%. The end of the test shall be determined when the 250 000 ftps signal amplitude of any track on either side of the disk has decreased 25% from its average value at the start of the test. The mi
35、nimum number of wear revolutions shall be negotiated be- tween the concerned parties. 5.4.3 Light Resistance. The index hole track of the disk shall have a light transmittance, measured with an optic system as described in 3.13, of not more than 1% at every point except the index hole and sec- tor h
36、oles (see Appendix A). 5.5 Magnetic Coating Resistivity. The surface resistiv- ity of the magnetic disk coating shall be less than 5 X IO9 ohms per square. This measurement shall be made in accordance with ASTM D 257-78. 5.6 Flammability. The disk cartridge shall be self- extinguishing in a still ca
37、rbon dioxide atmosphere. 5.7 Toxicity. The disk cartridge should not cause bodily harm by contact during normal use. 6. Test Track Requirements (Track and Recording Information) 6.1 Number. There shall be 40 discrete concentric tracks in the recording area on each side of the disk. 6.2 Width. The re
38、corded track width on the disk sur- face shall be 0.0118 in + 0.0010 in (0,2997 mm * 0,0254 mm). The area between the tracks shah be erased. 6.3 Location 6.3.1 Nominal Locations. The nominal radius R of the centerline of all tracks shall be calculated by using the formula: N. RN =X- 2u-r (RN=X-$X25.
39、4-) where X = 2.2500 in for side 0 2.1667 in for side 1 N = 00 to 39 (the track number) 6.3.2 Tolerance. The centerline of the recorded tracks in the test environment (4.1.2) shall be within *O.OOl in (?0,025 mm) 07 nominal positions. 6.3.3 Recording Offset Angle. At the instant of writing or readin
40、g a magnetic transition, the transition shall have an angle of 0” t 12 with the radius. 6.4 Physical Identification. Track identification shah be a two-digit decimal number that identifies the tracks consecutively, starting at the outermost track (00). 6.5 Index. The index is the point that determin
41、es the beginning and the end of a track. At the instant of hav- ing detected the leading edge of the index hole, the index is under the read-write gap. 7. Standard Reference Surfaces 7.1 General. The magnetic properties shall be uniform between the radii shown in the following table and as specified
42、 in other sections of this standard. Radii Side 1.437 - 2.260 in (36,499 - 57,404 mm) 0 1.354 - 2.180 in (34,392 - 55,372 mm) 1 7.2 Primary Standard Amplitude Reference Surfaces. The primary standard amplitude reference surface is the disk or disks held by NBS or other approved stan- dards organizat
43、ions as the amplitude reference surface by which all secondary standard amplitude reference surfaces shah be calibrated. 7.3 Secondary Standard Amplitude Reference Sur- faces. A secondary standard amplitude reference sur- face is a disk that has been measured (calibrated) rela- tive to the primary s
44、tandard amplitude reference sur- face on the NBS or other approved measurement system. 8. Magnetic Characteristics 8.1 Data Surfaces. For correlation purposes, the mag- netic properties of the data surfaces are defined by the testing requirements given in 8.1 .l through 8.1.6 for both surfaces (side
45、 00 and side 1). 81.1 Test Conditions. The disk shall be tested at 300 r/mm + 7 r/min. The test recording frequency is either 125 000 ftps or 250 000 ftps. The test recording current for the appropriate side shall be used for all recording frequencies. 12 AMERICAN NATIONAL STANDARD X3.125-1985 8.1.2
46、 Typical Magnetic Field Tolerance. The typical field of the disk under test shall be within 520% of the reference field. It will be tested at 125 000 ftps on track 00. 8.1.3 Average Signal Amplitude. When a disk has been recorded with the test recording currents, then read back on a system that has
47、been calibrated by means of a secondary standard amplitude reference sur- face, recorded under the same conditions, the average signal amplitude of the disk under test shall be (1) At track 00, using 125 000 ftps, not more than 130% of the standard reference amplitude (2) At track 39, using 250 000
48、ftps, not less than 80% of the standard reference amplitude 8.1.4 Resolution. On track 39, the ratio average signal amplitude at 250 000 ftps average signal amplitude at 125 000 ftps shall be greater than 90% and less than 120% of the value of the same ratio for the primary standard ampli- tude refe
49、rence surface. The recording current shall be the test recording current for track 00. 8.1.5 Overwrite. On track 00, after recording with the appropriate test recording current, first using 125 000 ftps (1 F) and then overwriting with 250 000 ftps (2F) for one revolution, the ratio residual average signal amplitude at 1 F after overwrite using 2F average signal amplitude after first recording using 1 F shall be less than 100% of the same ratio for the stan- dard amplitude flexible disk cartridge. This test shall be performed using a frequency-selective voltmeter. 8.1.6 M
