1、 ANSI INCITS 121-1984 (R2001)(formerly ANSI X3.121-1984 (R2001)for Information SystemsTwo-Sided, Unformatted, 8-inch (200-mm),48-tpi, Double-Density, Flexible,Disk Cartridge General, Physical, and Magnetic Requirementsfor 13 262 ftpr Two-Headed ApplicationANSI X3.121-1984 American National Standard
2、for Information Systems - Two-Sided, Unformatted, 8-Inch (200-mm), 48-tpi, Double-Density, Flexible Disk Cartridge - General, Physical, and Magnetic Requirements for 13 262 ftpr Two-Headed Application Secretariat Computer and Business Equipment Manufacturers Association Approved August 16, 1984 Amer
3、ican National Standards Institute, Inc AmericanNationalStandardApproval of an American National 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
4、the ANSI Board of StandardsReview, substantial agreement has been reached by directly and materiallyaffected 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 effo
5、rt be made toward theirresolution.The use of American National Standards is completely voluntary; 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
6、to the standards.The American National Standards Institute does not develop standards and will 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 t
7、he American National StandardsInstitute. Requests for interpretations should be addressed to 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
8、 StandardsInstitute require that action be taken periodically to reaffirm, revise, or withdrawthis standard. Purchasers of American National Standards may receive currentinformation on all standards by calling or writing the American National StandardsInstitute.Published byAmerican National Standard
9、s Institute11 West 42nd Street, New York, New York 10036Copyright 1984 by Information Technology 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
10、 NW,Washington, DC 20005.Printed in the United States of AmericaForeword (This Foreword is not part of American National Standard X3 121-1984.) This standard presents, for the purpose of physical and magnetic interchange, a two-sided, double-density, unformatted, 8-inch (200-mm), 4%tracks-per-inch (
11、tpi), flexible disk cartridge (for 13 262 ftpr two-headed 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
12、 standard as a 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 Flexi
13、ble Disks, which 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 individ
14、ual efforts. Suggestions 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
15、Committee on Information 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.
16、Kachurik, Administrative Secretary Organization Represented Name of Representative American Library Association . . . . . . . . . . . . . . . . . . . . . . _ . .Paul Peters American Nuclear Society . . . . . . . . . . . . . . . . . . . . . . . . . . .Geraldine C. Main AMP Incorporated AMTELCO . Asso
17、ciation of American Railroads . . Association for Computing Machinery . Association of the Institute for Certification of Computer Professionals. . AT ANSI/IEEE 268-l 976 (and Toleranced Dimensions - Conversion from Inches into Millimetres and Vice Versa, IS0 370-1975) except as noted. For current c
18、onversions of toleranced dimensions, use Method A or Method B (as appropriate) as described in Ameri- can 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 standar
19、ds of IS0 member nations, additional rounding may be done to produce “preferred” values. These values should lie within or close to the original tolerance range. Except as previously indicated, interchange parties complying with the acceptable standards should be able to achieve compatibility withou
20、t 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 approved by the Am
21、erican National Standards Institute, Inc, the re- vision shall apply. 2.2 Other Standards. This standard is also intended for use in conjunction with the following standards: ASTM D 257-78, Test Methods for DC Resistance or Conductance of Insulating Materials Available from ASTM, 1916 Race Street, P
22、hiladelphia, PA 19103. AMERICAN NATIONAL STANDARD X3.121-1984 ASTM D 1922-67 (1978) Test Method for Propagation Tear Resistance of Plastic Film and Thin Sheeting by the Pendulum Method IS0 370-1975, Toleranced Dimensions - Conversion from Inches into Millimetres and Vice Versa incident upon the samp
23、le. Transmittance is usually mul- tiplied by 100 and is called “percent transmittance” (%T). The maximum allowable transmittance shall be defined by the reading obtained with a neutral density filter with a known transmittance between 0.95% and 1.05%, calibrated at a wavelength of 940 nm when used i
24、n place of the sample. 3. Definitions 3.12 Jndex Hole Track. A concentric track on the disk at a radius of 1.5 in (38,l mm). 3.1 Disk. A circular device having a magnetic coating on both sides. 3.2 Jacket. An assembly of outer cover and liner. 3.3 Cartridge. An assembly of jacket and disk. 3.4 Prote
25、ctive Envelope. An envelope designed so as to protect all exposed areas of the disk. 3.5 Typical Magnetic Field. The minimum recording field that, when applied to a flexible disk cartridge, 3.13 Optic System. A system consisting of a light- emitting diode with a peak power point at 940 nm f 10 nm an
26、d a half-power bandwidth of 25 nm, maxi- mum, and a silicon photovoltaic cell with an appropri- ate aperture, operating in the short circuit mode, and spaced 0.16 in (4,l mm) apart with their optical axis parallel and contained in a suitable light tight cover. The disk shall be rotated. A possible t
27、est system is shown in Appendix A. - causes a signal output equal to 95% of the maximum 3.14 Peak Shift. The peak of each voltage pulse gen- average signal amplitude at the specified track and test erated at the read head defines the position of each recording frequency of that flexible disk cartrid
28、ge. magnetic flux transition. If two adjacent flux transi- 3.6 Reference Field. The typical field of the primary amplitude reference surface. 3.7 Test Recording Frequency (at the Recording Head). The number of flux transitions per unit of time, usually expressed as flux transition per second (ftps)
29、(1 Hz = 2 ftps). 3.8 Test Recording Currents. The four recording cur- rents between 145% and 155% of the current that pro- duce the reference field at 125 000 ftps on track 00 and track 76 respectively for both sides 0 and 1. For each side, the first of these currents shall be used for recording on
30、tracks 00 and 43 and the second of these currents shall be used for recording in tracks 44 to 76. tions are relatively far apart, then the two voltage signals (one positive and one negative) will not over- lap. As the distance between flux transitions decreases, the two voltage signals begin to over
31、lap and subtract from each other, causing a reduction in signal ampli- tude and a shift in position of the voltage signal peaks. This latter phenomenon is referred to as the “peak shift.” A universally acceptable test method for mea- suring that portion of the peak shift that is attributable to the
32、flexible disk cartridge is not presently available, but continues to be investigated by experts in the field. 4. General Requirements 3.9 Average Signal Amplitude. The arithmetically averaged value of the output voltages measured peak- to-peak, over an entire track. 3.10 Reference Amplitude. The ave
33、rage signal ampli- tudes derived from the primary or secondary ampli- tude reference surfaces at the density obtained when writing with 250 000 ftps on track 00 and with 500 000 ftps on track 76 using the appropriate test recording current for the track and side under test (see Section 7). 3.11 Tran
34、smittance. The radiant energy that passes through a sample divided by the radiant energy that is Available from the American National Standards Institute, 1430 Broadway, New York, NY 10018. 4.1 Environment 4.1.1 Operation and Storage. The disk shall with- stand operation and storage temperature at t
35、he surface of the disk cartridge in the range from 50F to 125F (10,O”C to 5 1,5”C) at a relative humidity of 8% to 80%. The wet bulb reading shall not exceed 85F (29,5(Z). Before a disk cartridge is placed into opera- tion, it shalI be conditioned for a minimum of 24 hours in the same environment in
36、 which the disk drive is operating. There shall be no moisture on or in the cartridge. Rate of temperature change shall not exceed 36F (20C) per hour. 4.1.2 Test. Unless otherwise stated, measurements shall be carried out at the ambient conditions of 73F + 5F (23,OC f 3C) and 40% to 60% relative hum
37、idity after 24 hours of acclimatization. 8 AMERICAN NATIONAL STANDARD X3.121-1984 4.1.3 Transportation. When the cartridges are packed for shipment, the allowable temperature range within the container shall be -40F to 125F (-40,O”C to 5 1 ,S”C) and the allowable relative humidity range shall be 8%
38、to 90%. No moisture shall condense in or on the cartridge. 4.2 Materials. Unless otherwise specified, the disk cartridge may be constructed from any suitable ma- terials so long as the general, physical, and magnetic requirements of this standard are maintained. 4.3 Disk Cartridge Assembly. The main
39、 elements of the disk cartridge assembly are identified in Figures 1 and 2. This cross-section view of the disk cartridge components does not imply a specific design, but is provided in the standard in order to identify the re- lated parameters relevant to interchange of the cartridge. 5. Physical R
40、equirements 5.1 Dimensions 5.1.1 Protective Envelope. The envelope shall pro- tect all exposed areas of the disk. 5.1.2 Jacket. The jacket shall comply with the di- mensions given in Figure 1 and detailed in 5.1.2.1 through 5.1.2.11. 5.1.2.1 Jacket Side. The jacket shall be a square with a side A =
41、8.000 in + 0.015 in (203,200 mm f 0,381 mm) and with square corners A, = 90” Z! 0” 30 5.1.2.2 Central Hole. The central hole shall be centered on the intersection of the axis located by B = 4.000 in f 0.010 in (101,600 mm f 0,254 mm) with a diameter of C = 2.300 in + 0.005 in (58,420 mm rt: 0,127 mm
42、) 5.1.2.3 Index Hole. The index hole shall have a diameter of II= 0.302 in + 0.005 in (7,671 mm f 0,127 mm) on both sides of the jacket; and positioned as shown in Figure 1, E = 0.650 in f 0.005 in (16,510 mm * 0,127 mm) from the centerline, and F = 5.352 in + 0.010 in (135,941 mm + 0,254 mm) from t
43、he reference edge of the jacket. 5.1.2.4 Head Windows. The head window open- ings (one on each side of jacket) sizes are Length, G = 2.07 1 in + 0.010 in (52,603 mm + 0,254 mm) Width, H = 0.500 in + 0.005 in (12,700 mm f 0,127 mm) and located by reference to the centerline I = 0.250 in + 0.005 in (6
44、,350 mm f 0,127 mm) and J = 0.145 in f 0.010 in (6,683 mm + 0,254 mm) The end of the head window shall be given a full radius K = 0.250 in (6,35 mm), nominal 5.1.2.5 Liner. The liner shall protect and separate the media from the outer cover. No liner fibers or com- ponents shall protrude by more tha
45、n 0.008 in (0,203 mm) into the head window and index hole openings in such a manner that they would interfere with the read-write function as described in Section 8. 5.1.2.6 Cartridge Thickness. The range for the nominal cartridge thickness is N = 0.055 to 0.067 in (1,397 to 1,702 mm) The cartridge
46、perimeter thickness is defined by 0 = 0.065 to 0.078 in (1,651 to 1,981 mm) When started from a zero velocity position and fully within the vertical gauge, the cartridge shall fall freely from a measurement gauge with an internal opening of 0.102 in, + 0.002 in, - 0.000 in (2,590 mm, +0,050 mm,- 0,0
47、00 mm), a width of 8.1 in (205,7 mm) and a depth of 8.5 in + 0.5 in (2 15,9 mm f 12,7 mm). A suggested design for this “drop-thru” test gauge is included in Appendix B. 5.1.2.7 Edges. The radius of the jacket edges is represented by: P = 0.020 in (0,5 1 mm) minimum. The reference edge shall have a c
48、onvex profile. 5.1.2.8 Measurement Reference. Thickness and edge radius measurements shall be made over length L = 1 .OO in (25,4 mm) 5.1.2.9 Light Transmittance of the Jacket. The light transmittance of the jacket measured with an optic system (as described in 3.13) shall not exceed 1 .O% at every
49、point contained within an annular band whose boundaries are tangent to the edges of the index hole D (see Figure 1). For the purpose of this measurement, two thick- nesses of jacket material and liner, as normally seen in a cartridge, shall be used. 9 AMERICAN NATIONAL STANDARD X3.121-1984 JACKET EDGE REF SEE DETAIL “B” P NOTE 1 DETAIL “A” DETAIL “C” OPTIONAL RELIEF NOTCH NOTES: (1) Effective for length of dimension L. (2) Hole in jacket - Both sides. SIDE 1 SIDE 0 / DETAIL “B” OPTIONAL WRITE INHIBIT NOTCH RADIUS) Figure 1 Cartridge Dimensions 10 AMERICAN NATIONAL ST
