This standard specifies the dimensions, physical properties and magnetic properties of floppy disks to ensure practical interchangeability between data processing systems. GB/T 11384-1989 Information processing data exchange 200 mm modified frequency modulation recording bit density of 13262 flux reversals/radian, track density of 1.9 tracks/mm double-sided floppy disks Part 1: Dimensions, physical properties and magnetic properties GB/T11384-1989 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Information processing—Data interchange on 200 mm flexible disk cartridgesusing modified frequency modulatlon recordingat 13262 ftprad,1,9 tpmm ,on both sidesPart 1 : Dimensional,physical and magnetic characteristicsGB 11384—89
ISO 7065/1--1985
This standard is equivalent to the international standard ISO7065/1--1985 "200mm modified frequency modulation recording bit density 13262 flux reversals/radian, track density 1.9 tracks/mm double-sided floppy disks for information processing data exchange Part 1: Dimensions, physical properties and magnetic properties".
0 Reference
GB11384 specifies the performance of 200mm modified frequency modulation recording bit density 13262 flux reversals/radian, track density 1.9 tracks/mm double-sided floppy disks.
GB11385 specifies the quality of recorded signals, track configuration and track format on 200mm modified frequency modulation recording bit density 13262 flux reversals/radian, track density 1.9 tracks/mm double-sided floppy disks. It is used for data exchange between data processing systems. The labeling system specified in GB11384 and GB11385 and ISO7665 provides conditions for all data exchanges between data processing systems.
1 Subject content and scope of application
This standard specifies the dimensions, physical properties and magnetic properties of the above-mentioned floppy disks to ensure practical interchangeability between data processing systems. 2 Referenced standards
GB1988
Seven-bit coded character set for information processing exchange GB2311 Extension method for seven-bit coded character set for information processing exchange GB11383 Eight-bit code structure and encoding rules for information processing information exchange ISO7665 File structure and labeling of floppy disks for information processing exchange 3 Terminology
This standard uses the following terms:
3.1 Disk: A disk is a component that receives and holds magnetic signals on a specific single or double side, and is used for input/output and storage of information in information data processing and related systems. Approved by the State Administration of Technical Supervision on May 20, 1989 254
Implemented on January 1, 1990
GB 11384-89
3.2 Reference floppy disk: A floppy disk with known characteristics selected arbitrarily for calibration. 3.3 Secondary reference floppy disk: A floppy disk with known characteristics calibrated by the reference floppy disk and used for routine calibration. 3.4 Signal amplitude reference floppy disk: A reference floppy disk selected as a standard for recording magnetic field strength and signal amplitude. On the 0 side of the floppy disk, the 00 track with a radius of 91.754mm and the 76 track with a radius of 51.537mm are the reference tracks. In order to provide a standard for the 1 side as well, the disk in the cover is turned over to obtain the same side. In this case, the radius of the 00 track is 89.637mm and it is not a reference track. However, for this standard, it is closely related to the reference track with a radius of 91.754 mm, and the 72nd track with a radius of 51.537 mm is used as the reference track, not the 76th track. 3.5 Typical magnetic field strength: The minimum recording magnetic field strength when the signal output is equal to 95% of the maximum average signal amplitude when applied to a specified track of the floppy disk at a specified flux reversal frequency. 3.6 Reference magnetic field strength: The typical magnetic field strength of the signal amplitude reference floppy disk. 3.7 Test recording current: When recording at a frequency of 250,000 flux reversals/second on tracks 00 and 76 on side 0 and tracks 00 and 72 on side 1, four currents of magnitude are equivalent to 145% to 155% of the current producing the reference magnetic field strength. For each side, the first current is used to record tracks 00 to 43, and the second current is used to record tracks 44 to 76. 3.8 Standard reference amplitude: The average signal amplitude obtained from the reference track of the signal amplitude reference floppy disk. SRA,r is the average signal amplitude obtained when recording on a track with a radius of 91.754mm at a frequency of 250,000 flux reversals/second. SRA2s is the average signal amplitude obtained when recording on a track with a radius of 51.537mm at a frequency of 500,000 flux reversals/second. 3.9 Average signal amplitude: the arithmetic mean of the peak-to-peak output voltage measured on the entire track. 3.10 Contact recording: during operation, the magnetic surface of the disk and the head are in actual contact. 3.11 Formatting: writing unique control information on the disk surface, and determining the 77 actual cylinders and actual recorded addresses according to the control information. 3.12 Initialization: the operation of writing the volume label, error map label (ERMAP) and other required information on the floppy disk before general data processing and use.
3.13 Recording area: the area where the head can contact the disk surface. 4 General description
4.1 General diagram
A typical floppy disk is shown in Figures 1 to 3: a.
Figure 1 is a top view of a floppy disk, with side 0 facing upward. Figure 2 is a cross-sectional view along the A-A cross section of Figure 1. b.
Figure 3 is a protective jacket containing a floppy disk, with side 1 facing upward. c.
4.2 Main components
The main components of a floppy disk are:
Recording disk;
b. Liner;
c. Enclosure.
The floppy disk is placed in the jacket.
Index window
Center blind hole
GB 11384-89
Figure 1 Floppy disk
Figure 2 A-A cross-sectionwwW.bzxz.Net
Recording disk
Head-avoiding opening
4.3 Description
GB11384-89
Figure 3 Protective cover with floppy disk
The cover is square, with a center window, an index window and a head window on both sides. Label area
The liner is fixed to the inner surface of the cover. It has two layers, with the disk located between them. The liner has the same windows as the cover. The disk has two recording surfaces, but only a center window and an index window. 4.4 Optional appearance structure
The interchangeability of the floppy disk allows some changes in its structure. It may have a folded edge (three folded edges as shown in Figure 1, or no folded edge), or a notch on the reference edge. In some cases, a write-inhibiting notch may be used. See Appendix D (Supplement). 5 General requirements
5.1 Environment and transportation
5.1.1 Test environment
In order to verify whether the floppy disk meets the requirements of this standard, the test and measurement shall be carried out under the following conditions: a. Temperature: 23±2℃,
Relative humidity: 40%~60%,
Adaptation before testing, at least 24h.
The measurement of temperature and relative humidity shall be carried out in the surrounding air closest to the floppy disk. The stray magnetic field strength at any point on the disk surface, including the combined influence from the recording head, shall not exceed 4000A/m. 5.1.2 Usage Environment
Floppy disks for data exchange should be used under the following conditions: 257
Temperature: 10~51.5℃;
Relative humidity: 20%~80%;
c, wet bulb temperature: less than 29℃.
GB 11384--89
Temperature and relative humidity should be measured in the surrounding air closest to the floppy disk. It is recommended that the temperature change rate should not exceed 20℃/No moisture should be attached to or inside the floppy disk. The stray magnetic field strength at any point on the disk surface, including the combined influence from the recording head, should not exceed 4000A/m. 5.1.3 Storage Environment
During storage, floppy disks should be kept under the following conditions: Temperature: 4~～51.5℃;
b, relative humidity: 8%～80%.
Each floppy disk should be placed in a jacket and placed upright. The surrounding stray magnetic field strength should not exceed 4000A/m. Note: The storage temperature and humidity of the floppy disk exceed the use environment, but its performance may be reduced when it is within the storage environment. This floppy disk should be acclimatized in the use environment for no less than 24 hours before use. 5.1.4 Transportation
The consignor is responsible for taking measures to ensure that the floppy disk is not damaged during transportation. The floppy disk should be placed in the outer jacket and placed in a protective package together with the outer jacket. The packaging box should be free of dust and debris, the inner surface should be clean, and dust and water resistant. There should be enough space between the floppy disk and the outer surface of the outer packaging box to make the damage to the disk by various stray magnetic fields negligible. It is recommended not to exceed the following conditions:
Temperature: -40～51.5℃,
b. Maximum temperature change rate: 20℃/h; c. Relative humidity: 8%~90%.
No water droplets should condense inside or on the floppy disk. 5.1.5 Maintenance
The floppy disk should be placed out of the jacket for as short a time as possible. When using the floppy disk, the operator should not touch the magnetic surface of the disk and avoid direct exposure to sunlight, moisture and dust. 5.2 Materials
5.2.1 Enclosure
The enclosure can be made of any suitable material. 5.2.2 Lining
The material of the lining should be able to block dust without damaging the disk. 5.2.3 Disk
Material (such as -Fe2O) is made of magnetic slurry, which is coated on both sides of any suitable material (such as biaxially oriented polyethylene terephthalate).
5.2.4 Jacket
The jacket can be made of any suitable material (such as paper). 5.3 Direction of rotation
Looking at the ○ side of the enclosure, the disk should rotate counterclockwise. 6 Structural dimensions
The structural dimensions listed in the following items are shown in Figures 4 to 7. a. Figure 4 is the enclosure dimensions;
Figure 5 is a partial cross-sectional view of the enclosure;
Figure 6 is the disk dimensions;
Figure 7 is a cross-sectional view of the disk.
GB11384—89
All dimensions are based on the reference edge of the enclosure (see Figure 4). Figure 4 Enclosure dimensions
Reference edge
6.1 Enclosure
6.1.1 Shape
GB 11384—89
Figure 5 Thickness of floppy disk
Figure 6 Disk dimensions
Figure 7 Disk thickness
The enclosure is square, with four corners of 90°±30° and a side length of: li203.2±0.4mm
6.1.2 Thickness
6.1.2.1 The enclosure wall and lining
should be within the area specified by r and r2, where rr=60 mm
rz=85 mm
and a gauge with a diameter of 15 mm is applied to the floppy disk with a force of 1 N. When the force is applied, the thickness of the enclosure wall and lining is: er = 0.45 ± 0.15 mm || tt || 6.1.2.2 Floppy disk || tt || The total thickness of the floppy disk should be (also refer to 6.1.7): 1.2 mm
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