This standard specifies the dimensions, physical properties and magnetic properties of floppy disks, thus providing the possibility of physical exchange between data processing systems. GB/T 15130.1-1994 Information processing data exchange 90 mm modified frequency modulation recording bit density of 15916 flux reversals/radian, 80 tracks per side floppy disks Part 1: Dimensions, physical properties and magnetic properties GB/T15130.1-1994 standard download decompression password: www.bzxz.net

GB/T15130.1--94
GB/T13703 Information processing and information exchange disk and file structure GB/T13719 Information processing and data exchange 90mm modified frequency modulation system recording bit density of 7958 flux reversals/radian, 80 tracks per side floppy disk Part 1: Dimensions, physical properties and magnetic properties 4 Terminology
This standard uses the following terms:
4.1 Recording disk
It is a component that receives and holds magnetic signals on a specific side or both sides, and is used for input/output and storage of information in information data processing and related systems.
4.2 Hub
It is a component installed in the center of the disk, driving the disk to rotate, and plays a role in center positioning and reference. It ensures that the center of the floppy disk is positioned on the drive shaft at a specific angle.
4.3 Shutter
It is a component that exposes the head window when the disk is inserted into the drive and automatically covers the head window when the disk is taken out. 4.4 Liner
A suitable material located between the cover and the disk to clean and prevent wear. 4.5 Case
It is a protective shell that includes the shutter mechanism and the write-inhibiting hole. 4.6 Master Standard Reference Flexible Disk Cartridge A reference disk selected as a reference for calibration of reference magnetic field, signal amplitude, resolution, peak shift and rewriting. Track 00 and track 79 on both sides are set as reference tracks.
The reference tracks are calibrated at a speed of 300 r/min. Note: The master standard was developed by the Physical Technical Institute (PTB), D-3300 Bendsalistraße 100, Braunschweig, Germany. 4.7 secondary standard reference flexible disk cartridge secondary standard reference flexible disk cartridge whose characteristics are known and marked relative to the primary reference flexible disk cartridge. Note: A secondary reference flexible disk cartridge numbered RM 9529 can be obtained from the PTB1.41 laboratory. It is used to further calibrate the tertiary reference flexible disk cartridge. 4.8 typical field strength typical field strength The minimum magnetic field strength at which the average signal output amplitude is equal to 95% of the maximum average signal amplitude on the curve of average signal amplitude versus recording magnetic field strength when recording at a specified track at a specified flux reversal density. 4.9 reference field strength reference field strength The typical magnetic field strength of the primary standard reference flexible disk cartridge. There are two reference magnetic fields, one for each side. 4.10 test recording current test recording current Current that is 148% to 152% of the current required to produce the reference magnetic field strength at a test frequency of 1f on the 00 track. There are two test recording currents, one for each side.
4.11 standard reference amplitude standard reference amplitude The average signal amplitude (SRA) obtained from the reference track of the primary standard reference flexible disk cartridge using the test recording current There are four SRAs, two on each side.
SRAu is the average signal amplitude obtained when recording on track 00 with test frequency 1f. SRA2t is the average signal amplitude obtained when recording on track 79 with test frequency 2f. 4.12 Average signal amplitudeaverage signal amplitudeThe arithmetic mean of the peak-to-peak output voltage measured over the entire track. 4.13In-contact
During operation, the disk surface and the head are in actual contact. 388
4.14Side
GB/T 15130.1--94
The side embedded in the spindle is side 0 and the other side is side 1. 4.15Direction of rotationThe direction of rotation should be counterclockwise when looking at side 0. 4.16
Indexindex
The point on the track that determines the start and end of the track. Access line
The straight line described by the center of the read/write head gap is actually a straight line from track 00 to track 79. 4.18 Formatting
Write unique control information on the surface of the floppy disk to determine the physical track and the address of the actual record. 4.19 Initialization
Write the initial required information on the floppy disk before general processing, such as the volume label. 5 General description
5.1 General drawing
Figure 10
The drawing contains:
Figure 1 is an enlarged sectional view of surface 0 and two positioning holes; Figure 2 is surface 1;
Figure 3 shows in detail the upper half of surface 0 after the shutter is removed;389
Figure 4 is a magnetic disk with a disk hub;
GB/T15130.1—94
Figure 5 is the contact surface between the floppy disk and the drive. Figure 21
Figure 30
5.2 Main components
Direction of rotation
The main components of a floppy disk are:
Recording disk;
GB/T 15130. 1--94
Figure 4 Disk with disk hub
Figure 5 Contact surface between disk and drive
Lining;
Wing shell.
5.3 Description
GB/T 15130.194
The cover is basically square. There is a center hole on one side and a head window, a write-inhibit hole and an identification hole on each of the two sides. The lining is fixed between the cover and the disk. It has two layers, with the disk located between them. The disk has a center hole with a metal hub. 6 General requirements
6.1 Environment and transportation
6.1.1 Test environment
To verify whether the floppy disk meets the requirements of this standard, the test and measurement should be carried out under the following conditions: Temperature: 23±2℃;
Relative humidity: 40%~60%; Www.bzxZ.net
Adaptation before test: at least 24h.
For the tests specified in Article 9.3, the temperature and relative humidity measurements should be made in the surrounding air closest to the floppy disk drive. For all other tests, the temperature and relative humidity measurements should be made in the surrounding air closest to the floppy disk. The stray magnetic field strength at any point on the disk surface, including the stray magnetic field strength caused by the magnetic collection effect of the recording head, should not exceed 4000A/m.
6.1.2 Use environment
Floppy disks for data exchange should be used under the following conditions: Temperature: 10~51.5℃;
b. Relative humidity: 20% to 80%;
Wet bulb temperature: below 29°C.
The 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°C/h, and the temperature and relative humidity conditions during reading should not exceed the environmental conditions during recording. 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 stray magnetic field strength caused by the magnetic collection effect of the recording head, should not exceed 4000A/m.
6.1.3 Storage environment
During storage, the floppy disk should be maintained in the following conditions: b. Temperature: 4 to 53°C;
b. Relative humidity: 8% to 90%.
No moisture should be attached to or inside the floppy disk. The surrounding stray magnetic field strength should not exceed 4000A/m. Note: When the temperature and humidity of the floppy disk are stored beyond the use environment, its performance may be reduced. 6.1.4 Transportation
The consignor shall be responsible for taking measures to ensure that the floppy disk is not damaged during transportation. The floppy disk should be placed in a protective package to avoid the intrusion of dust and foreign matter. It is recommended that 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: -40～60℃;
Maximum temperature change rate: 20℃/h;
Relative humidity: 8%~90%.
GB/T 15130.1-—94
No moisture shall adhere to or inside the floppy disk. 6.2 Materials
6.2.1 Cover
The cover can be made of any suitable material and shall meet the requirements of Appendix A (Supplement). 6.2.2 Lining
The lining material should be able to block dust or debris without damaging the disk. 6.2.3 Disk
The disk can be made of any suitable material (such as biaxially oriented polyethylene terephthalate) with a magnetic material coated on the surface. 6.2.4 Hub
The hub can be made of any suitable material (such as type 8 stainless steel in accordance with ISO683-13). 7 Structural dimensions
The dimensions of the floppy disk are based on the X-axis and the Y-axis, which are two straight lines that intersect at right angles at the center of the first positioning hole. The plane they define is the reference plane XY of the floppy disk.
7.1 Cover
7.1.1 Shape (see Figure 1)
The cover is rectangular with a side length of:
t=94.0±0.3mm
2= 90. 0+:1mm
The radii of three of its four corners should be:
r=2.0±1.0mm
The angle of the fourth angle should be:
w45°±2°
7.1.2 Thickness (see Figure 2)
Within the range of 8.5mm extending inward from both sides shown in Figure 2, the thickness of the cover should be:e13.3±0.2mm
When the floppy disk is inserted into the detection block gauge in accordance with the provisions of Appendix D (Supplement), a force not exceeding 0.2N should be applied to the opposite sides to enable the floppy disk to pass through the block gauge.
The radius of the corners should be:
rz=0.40±0.25mm
7.1.3 Hub inlet and outlet hole (see Figure 1)
There should be a hub inlet and outlet hole on the 0 surface, and its diameter should be: dimin =26.50mm
The center position of the inlet and outlet hole is determined by and l:
13=40.00±0.15mm
l.=31.00±0.15mm
7.1.4 Positioning hole (see Figures 1 and 3)
7.1.4.1 First positioning hole
The center of the first positioning hole should be on the intersection of the reference axes X and Y, and its diameter should be: d2-3.6±0.1mm
The cross-section (see Figure 1A-A cross-section) size should be: d3min = 1. 5mm
l: 0.2±0. 1mm
Igmin =1. Omm
l1omin =- 2. 5mm
7.1.4.2 Second locating hole
GB/T 15130.1--94
The center of the second locating hole should be on the reference axis X, and the distance from the reference axis Y should be: l,-80.0±0.2mm
The second locating hole is basically rectangular, and its short axis should be (see Figure 1B-B section): l,=3.6±0.1mm
The long axis should be: l,=4.4±0.2mm
The cross-sectional dimensions d3, g, lg, of the second locating hole are determined in 7.1.4.1. 7.1.5 Label area
7.1.5.10 surface (see Figure 1)
0 surface label area position and size should be:
lmin3.5mm
Z12max = 76. 5mm
l14min =60, 0mm
7.1.5.21 surface (see Figure 2)
1 surface label area position and size should be:
l1imin - 3. 5mm
l12mx=76.5mm
l13min =20. 0mm
7.1.6 Head window (see Figure 3)
The position and size of the two head windows are determined by the same set of dimensions. 7.1.6.1 Position
The position of the head window is determined by 115, 116 and 11: t15min =12.3mm
Tisin -11.5mm
l,=35.5±0.2mm
7.1.6.2 Size
The width of the head window should be:
l1s=9.00±0.20mm
The radius of its corner should be:
r:=0.5±0.1mm
The radius of its upper side should be:
ramin = 8.85mm
7.1.7 Write-inhibited hole (see Figure 2)
7.1.7.1 Position
The center of the write-inhibit hole should be on the reference axis Y, and the distance from the reference axis X should be: lyg = 67.75±0.25mm
7.1.7.2 Size
The size of the write-inhibit hole should be:
120min = 3.5mm
121min = 4.0mm
7.1.7.3 Use
GB/T 15130.1-94
The write-inhibit hole is used in conjunction with the mechanical switch or light detector of the drive. Writing on the disk can only be done when this hole is covered. When the block is covered, it cannot exceed the reference plane; under the action of 3N force, it cannot be lower than 0.3mm below the reference plane of the cover. And when the write-inhibit hole is covered, the light transmittance of the write-inhibit hole area should not exceed 1% when measured by the optical system described in Appendix B (Supplement). 7.1.8 Identification hole (see Figures 1 and 2)
The identification hole is used to distinguish the floppy disks specified in GB/T15130.1 and GB/T13719. Note: Since the requirements for the opacity of the cover are not specified in GB/T13719, it is recommended to use mechanical methods for identification. 7.1.8.1 Position
The center position of the identification hole is determined by 15 and 1. 7.1.8.2 Dimensions
The dimensions of the identification hole should be:
l49min =3.5mm
150min = 4.0mm
7.1.9 Dimensions of the shutter side of the housing (see Figures 1 and 3) The shape of the side of the housing where the shutter is placed should be determined according to the following dimensions: 122=80.0±0.2mm
t23 ==76.0±0.3mm
124=68.0±0.3mm
I2s =64.50±0.35mm
26=57.00±0.35mm
t2=55.5±0.6mm
128min=3.5mm
tzg=17.5±0.2mm
1go=17.00±0.15mm
13=15.50±0.25mm
145=12.50±0.25mm
α=45°±2°
β=135°±2°
w=45°±2°
7110 shutter (see Figures 2 and 3)
When the floppy disk is inserted into the drive, the shutter should slide to expose the head window, and when the floppy disk is taken out, it will automatically cover the head window. The maximum resistance in the fully open position should be 1N, and the minimum resistance in the fully closed position should be 0.2N. The shutter sliding length is determined by 125 and 12g. When the shutter is in the open position, the distance from its leading edge to the reference axis Y should be: 132 = 53.75 ± 1.25mm
The width of the shutter window should be:
133 = 12.0 ± 0.2mm
Note: The drive is required to have a mechanical device that allows the shutter to slide to expose the head window when the floppy disk is accurately inserted into the drive. 7.2 Lining
The amount of lining exposed to the head window cannot exceed 0.2mm. 7.3 Magnetic disk (see Figure 4)
7.3.1 Diameter
The diameter of the magnetic disk should be:
d,=85.8±0.2mm
7.3.2 Thickness
The thickness of the magnetic disk should be:
e2=0.080±0.008mm
7.4 Hub (see Figure 4)
GB/T 15130. 1--94
The center part of the hub should be a raised circular disk. 7.4.1 Dimensions
The diameter of the central part shall be:
d,=25. 00±8: 9mm
The diameter of the hub shall be:
dsm =31. 15mm
When measured at radius r, the distance from the surface of the central part of the hub to the surface of the disk surface 0 shall be: l34 = 1.36±0.10mm
r7nom =14mm
7.4.2 Hub Orientation Holes (see Figure 4)
The hub has two orientation holes, the first in the center of the hub and the second away from the center. 7.4.2.1 First Orientation Hole
The first orientation hole is square and is determined by 1s: 135min =4.00mm
When measured from both sides of the hole, the center of rotation of the disk is determined by 136: 13s = 1.9955mm
This center of rotation should be within 0.5mm of the geometric center of the disk. The radius of the four internal corners of the hole should be:
rs = 1.0 ± 0.3mm
7.4.2.2 Second Orientation Hole
The second orientation hole is rectangular, and the position and size of each side are determined by mutually perpendicular radial lines A and B. The position of A and B is determined by y: 15° ± 3°
The side length of the hole should be:
13z8.0 ± 0.3mm
138min = 4.5mm
Each side should be parallel to line A and line B respectively, and the distance between them is: l3g-2.0±0.2mm
laa-10.00±0.15mm
The radius of one inner angle of the hole should be:
r.-2.0±0.1mm
The radius of the other three inner angles should be:
rs=1.0±0.3mm
7.5 Optional assembly groove (see Figure 1 and Figure 2) The cover is allowed to have two assembly grooves. If there are two grooves, the following requirements should be met: The centers of the two grooves should be parallel to the reference axis X and on a line above the X axis. The distance between this line and the X axis is: lu=7.50±0.15mm
The dimensions of the two should be:
lazmin - 3. Omm
143=4.2±0.2mm
The depth of both below the reference plane should be: 144min =2. Omm
GB/T 15130.1--94
7.6 Contact surface between floppy disk and drive (see Figure 5) When the floppy disk is inserted into the drive, the main shaft of the drive is embedded in the floppy disk, as shown in Figure 5. The disk hub is tightly attached to the main shaft of the drive by magnetic attraction. When in this position, the distance between the surface of the disk hub on the 0 plane and the XY plane should be: l46nom = 0. 3mm
Except for the annular area determined by 1s and 14s, the dimensions of the inside of the cover 1 surface should be: e31.3±0.1mm
l4z=22.6mm
1421.7±0.2mm
dmin=7.0mm
The thickness of the annular area should be:
4max—2.5mm
To ensure that the circumference of the disk does not touch the inner side of the cover, lA should be large enough. The value of 14 specified above is a recommended value, so it is without tolerance.
7.7—Conformity
When the floppy disk is tested by the method specified in Appendix A (Supplement), the floppy disk should be in contact with posts P1 to P4. 8 Physical properties
8.1 Flammability
The material used to make the lining and cover of the floppy disk should not continue to burn in the static carbon dioxide and ammonia if it is ignited by a match. 8.2 Linear thermal expansion coefficient of the disk
The thermal expansion coefficient of the disk should be (17±8)×10-\/℃. 8.3 Linear moisture expansion coefficient of the disk
The moisture expansion coefficient of the disk should be (0～15))×10-6/%RH. 8.4 Torque
8.4.1 Starting torque
When the head is not loaded on the disk, the starting torque should not exceed 0.006Nm. 8.4.2 Running torque when there is no head loading When the floppy disk is running at a speed of 300±3r/min, the torque required to rotate the disk should be in the range of 0.0005～0.0025N·m. 9 Magnetic properties
9.1 Recording area
On each side, the specified magnetic properties shall be the same within the recording area defined by the two radii of 42.0 mmmin and 20.6 mmmax.
9.2 Track geometry
9.2.1 Number of tracks
There shall be 80 separate concentric circular tracks in the recording area on each side of the disk. The distance between the center lines of adjacent tracks shall be 0.1875 mm. 9.2.2 Track width
The recording track width shall be: 0.115 ± 0.008 mm. The method for measuring the effective track width is given in Appendix C (Supplement). 397
9.2.3 Track position
9.2.3.1 Nominal position
GB/T 15130.1-94
The nominal value of the centerline radius R of all tracks (mm) shall be calculated using the following formula: R.=x—0.1875n
Where: n——is the track number, n=00～79; for face 0: x=39.5000mm;
for face 1: z=38.0000mm.
9.2.3.2 Track position tolerance
When measured under the test environment (see 6.1.1), the recorded track centerline shall be within ±0.020mm of the nominal position. 9.2.3.3 Access lines of read/write heads
Access lines of read/write heads are parallel to radial lines and 0.35 mm apart from them (see 4.3 of GB/T15130.2). 9.2.4 Track numbers
Track numbers are two-digit decimal numbers (00 to 79 on each side), numbered sequentially from the outermost track 00 to the inner side. 9.3 Functional test
9.3.1 Test conditions
Drive unit: For the tested double-sided floppy disk and RM9529 (or the third-level reference floppy disk, see 4.7), the same drive shall be used for read and write operations.
Speed: 300±3r/min
Test frequency: 1f=250000±250ftps; 2f=500000±500ftps.
Each property is tested using the specified frequency. Recording current: Test recording current of the surface to be tested. Recording and reading conditions: Contact type.
Test range: Performed on both sides of the disk. Correction factor: The value obtained by the test with RM9529 is corrected with the calibration factor provided by RM9529 (if a three-level reference floppy disk is used for testing, it is corrected with the calibration factor of the disk). 9.3.2 Surface test
Magnetic properties are determined by the test requirements given below. 9.3.2.1 Typical magnetic field strength
The typical magnetic field strength of the disk during the test should be within ±20% of the reference magnetic field strength. Measured using a frequency of 1f on the 00 track.
9.3.2.2 Average signal amplitude
Record with 1f on the 00 track and with 2f on the 79 track, then read out and compare with RM9529 recorded under the same conditions.
On track 00, the average signal amplitude should be less than 130% of the standard reference amplitude SRA1f; on track 79, the average signal amplitude should be greater than 80% of the standard reference amplitude SRA2f. 9.3.2.3 Resolution
After recording on track 79, the ratio:
2f average signal amplitude
if average signal amplitude
should be greater than 80% of the same ratio of the main standard reference floppy disk. 398
9.3.2.4 Peak drift
GB/T 15130.1-94
During the test, the average peak drift measured on the floppy disk using the method specified in Appendix E (Supplement) should be within the range of 63% to 137% of the main standard reference floppy disk. Peak drift test is carried out on track 79. 9.3.2.5 Overwrite
When measured according to the method of Appendix F (Supplement), the ratio: 1f residual average signal amplitude after 2f overwrite and the average signal amplitude after 1f start recording
shall be less than 125% of the same ratio of the master standard reference disk. 9.3.2.6 Modulation
The modulation shall be:
Maximum average value - minimum average value,
Maximum average value + minimum average value
The maximum average value is the average value of the AM output voltage of the part of the track with the maximum amplitude, and the minimum average value is the average value of the AM output voltage of the part of the track with the minimum amplitude. The output voltage shall be measured peak-to-peak. The average value shall be taken over approximately 2000 consecutive flux reversals,
recorded with 1f on track 00 and 2f on track 79, and the modulation shall be less than 10%. 9.3.3 Track Quality Test
Perform this test on all 80 tracks at the specified positions. 9.3.3.1 Leakage Pulse
Write a track at 2f and measure the average signal amplitude. When measuring the base-to-peak value, any read signal that is less than 45% of half the average signal amplitude measured on the track is a leakage pulse. 9.3.3.2 Spurious Pulse
Write a track at 2f and measure the average signal amplitude. Wipe one cycle with a constant DC equivalent to the test recording current. When measuring the base-to-peak value, any read signal that exceeds 20% of half the average signal amplitude of the track under test at 2f is a spurious pulse. 9.3.4 Rejection criteria
9.3.4.1 Defective tracks
When continuous testing is performed, if one or more missing pulses and/or emitting pulses are detected at the same position of the track, the track is considered a defective track. The number of continuous tests shall be determined by both the supplier and the buyer. 9.3.4.2 Requirements for tracks
The floppy disk initially received from the supplier shall be free of defective tracks. 9.3.4.3 Rejection criteria
The floppy disk that does not meet the requirements of 9.3.4.2 shall be rejected. 399
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