GB/T 15131.1-1994 130 mm floppy disks with a bit density of 13262 flux reversals/radian and 80 tracks per side for information processing data exchange Part 1: Dimensions, physical properties and magnetic properties
Some standard content:
National Standard of the People's Republic of China
Information processing - Data iaterchange on 130mmtlexible disk cartridges using modified frequency modulation recording at 13262 ftprad on 80 tracks on each side—Part 1: Dimensional physical and magnetic characteristicsGB/T 15131. 1—94
ISO 8630/1.-..1987
This standard is equivalent to the international standard ISO8630/1—1987≤Information processing - Data iaterchange on 130mmtlexible disk cartridges using modified frequency modulation recording at 13262 ftprad on 80 tracks on each side Part 1: Dimensional physical and magnetic characteristics
GB/T15131 specifies the performance of a 130rmm (5.25in) double-sided floppy disk with a bit density of 13262 flux reversals/radian and 80 tracks per side recorded using the modified frequency modulation system (MFM). B/T15131.2 and GB/T15131.3 respectively specify the quality of the recorded signal, track configuration and track format on a 130mm floppy disk, which is used for data exchange between data processing systems. The numbering system specified by GB/T 15131.1 and GB/T 15131.2 and GB/T 15134 provides conditions for all data exchanges between data processing systems.
The numbering system specified by GB/T15131.1 and GB/T15131.3 and GB/T13703 provides another method for all data exchanges between data processing systems.
1 Content and scope of application
This part of GB/T15131 specifies the size, physical properties and magnetic properties of floppy disks, thus providing the possibility of physical exchange between data processing systems.
2 Conformity
When a floppy disk meets all the requirements of this part of GB/T15131 and GB/T15131.2 or B/T15131.3, the floppy disk is consistent with GB/T15131.
3 Reference standards
GB1988
Information processing
Information processing
GB2311
GB5261
Information processing
Seven-bit coded character set for information interchange
Code extension technology for seven-bit and eight-bit coded character sets Supplementary control functions for text and symbol forming equipment Approved by the State Bureau of Technical Supervision on July 16, 1994 Implementation on 1995-D3-01
GB/T 15131. 1—94
B11383 Information processing Eight-bit code structure and coding rules for information interchange GB/T13703 Information processing Floppy disk volume and file structure for information interchange GB/T15134 Floppy disk file structure and numbering for information interchange in information processing systems 4 Terminology
This standard uses the following terminology.
4.1 Flexible disk
A flexible disk is a component that receives and holds magnetic signals on a specific single or double side. It is used for input/output and confirmation of information in information data processing and related systems.
4.2 Reference flexible disk A flexible disk with known characteristics selected for calibration. 4.3 Secondary reference flexible disk A flexible disk with known characteristics selected for routine calibration. Its characteristics are known, and the characteristics relative to the reference flexible disk are marked. 4.4 Signal amplitude reference flexible disk A reference flexible disk selected as a standard for recording magnetic field strength and signal amplitude. Note: Standards for signal amplitude, reference magnetic field strength, rewrite and resolution have been developed by Gürmary, F.R., Physikaliach-Techninche Bundesallee 100 in Braunschweig, Germany. Secondary reference diskettes RM8630 can be obtained from the PTB 1.41 laboratory, and secondary reference diskettes RM8530 can be obtained from the National Standards Institute (NRS) (NRS Office of Standard Reference Materials Room 311, Chemigtry Building, Gaithershbury, MD 20899, USA).
4.5 Typical magnetic field strength typicalfield
When recording at a specified track with a specified flux reversal density, the minimum magnetic field strength at which the average signal amplitude produced on the average signal amplitude versus recording magnetic field strength curve is equivalent to 95% of the maximum average signal amplitude is the typical magnetic field strength. 4.6 Reference magnetic field strength reference field The typical magnetic field strength of the reference floppy disk used as the reference for recording magnetic field strength and signal amplitude. There are two reference magnetic field strengths, one for each side. 4.7 Test recording current (for each side) When the test recording current is recorded at a frequency of 2500001ps on the 00 track, its magnitude is equivalent to a current that produces 145% to 155% of the current of the reference magnetic field strength.
There are two test recording currents, one for each side. 4.8 Standard reference amplitude (SRA) standardrclerenueamplitude The average signal amplitude obtained on the signal amplitude reference floppy disk using the corresponding test recording current. There are four standard reference amplitudes, two for each side. SRAr is the average signal amplitude obtained when recording at 250000ftps on each 00 track, and SRA is the average signal amplitude obtained when recording at 500000ftps on 76 tracks on each side (see 9.1.4). 4.9Average signal amplitude avcragesignaiamplitudeThe arithmetic mean of the peak-to-peak output voltage measured over the entire track. 4.10Contact in-unaet
During operation, the magnetic surface of the disk is in actual contact with the head. 4.11Formatting
Writing the control information held on the surface of the floppy disk to determine the physical track and the address of the actual record. 4.12Initialization
The operation of writing any required information on the teaching disk before general processing, such as the error detection mark (ERMAP). 4.13Recording area
GB/T15131.1—94
The area where the head can contact each disk surface. 5General description
5.1General diagram
A typical floppy disk is shown in Figures 1 to 3: Figure 1 is a top view of a floppy disk, with the 0 side facing up. FIG2 is a cross-sectional view along the AA cross section of FIG1. FIG3 is a protective jacket with a floppy disk, with side 1 facing upward. Core
Multiple guides
FIG1 Floppy disk
FIG2A-A cross-sectional view
Main components
The main components of a floppy disk are:
Recording disk:
h. Liner,
Cover. The floppy disk is placed in the jacket.
3 Explanation
GB/T 15131. 1-- 94
FIG3 Protective jacket with soft magnetic strip
The cover is square. It has a core, an index window and a head window on both sides. The liner is fixed to the inner surface of the cover. It has two layers, with the disk located between them. The liner and the cover have corresponding windows. The disk has only one center hole and one index. 5.4 Optional external structure
The interchangeability of the floppy disk allows its structure to be varied as follows: the cover can have folded edges (three folded edges as shown in Figure 2, or no folded edges); a
notches on the base edge.
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: a.
Temperature: 23±2°C;
and relative humidity, 40%~60%;
. Acclimatization before testing, at least 21h.
The temperature and relative humidity should be measured in the surrounding air closest to the floppy disk. The stray magnetic field strength at any point on the disk surface, including the stray sensitive magnetic field strength caused by the magnetic collection effect of the recording head, should not exceed 4000A/m. 6.1.2 Use environment
Teaching disks for data exchange should be used under the following conditions: b.
Temperature: 10~51.5°C,
Relative humidity: 20%~80%,
Wet bulb temperature: below 29°C.
GB/T 15131. 1—94
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 20C/h. 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 1000A/m. 6.1.3 Storage environment
During storage, the floppy disk should be kept under the following conditions: a. Temperature, 4~51.5℃
h. Relative humidity: 8%~~80%.
Each floppy disk should be placed in a jacket and placed upright. No moisture should be attached to or inside the floppy disk. The surrounding stray magnetic field strength at any point on the disk surface should not exceed 4000A/m. Note: When the storage temperature and humidity of the floppy disk exceed the use environment, its performance may be reduced. This type of floppy disk should be treated for no less than 24 hours under the environmental conditions of use before use.
6. 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 latter should be free of dust and debris. The inner surface should be clean and dust-proof and moisture-proof. 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℃;
Maximum temperature change rate: 20℃/h,
Relative humidity: 8%~90%.
No moisture should adhere to the floppy disk or its inside. 6.1.5 Maintenance
The time for which the floppy disk is placed out of the jacket should be as short as possible. When using a floppy disk, the operator should not touch the magnetic surface of the disk and should avoid exposure to sunlight, moisture and dust. 6.2 Materials
6.2.1 Encapsulation
The enclosure can be made of any suitable material. 6.2.2 Lining
The lining material should be able to block dust without damaging the disk. 6.2.3 Disk
Material (such as CoYFc.O,) is made of magnetic slurry and coated on the surface of any suitable material (such as biaxially oriented polyethylene terephthalate).
6.2.4 Jacket
The jacket can be made of any suitable material (such as paper). 6.3 Direction of rotation
When looking from the 0 side, the disk should rotate counterclockwise. 7 Structural dimensions
The structural dimensions listed in the following items are shown in Figures 4 to 7. Figure 4 shows the enclosure dimensions.
CB/T 15131. 194
Figure 5 is a partial cross-sectional view of the cover, indicating the thickness of the floppy disk. Figure 6 is the size of the disk.
Figure 7 is a cross-sectional view of the disk, indicating the thickness of the disk. All dimensions are based on the standard of the floppy disk (see Figure 4). 7.1 Enclosure 7.1.1 Shape The enclosure shall be square with four corners of 90°±30 and a side length of t = j33.3±0.4 mm 7.1.2 Thickness 7.1.2.1 The enclosure wall and lining shall be within the area specified by r1 and r2, with the area r2-35 mm and r2=50 mm. A force of 1 N applied by a micro-point with a diameter of 15 mm shows that the thickness of the wall and lining is e — 0.45±0.15 mm. Figure 4 Enclosure dimensions 7.1.2.2 Floppy disks GB/T 15131.1.- 94
The total thickness of the floppy disk (see Figure 5 and 7.1.7) is: 1.2 mm12 < 2.1 mm
It should be measured according to Chapter A1 and A2 in Appendix A (Supplement). The floppy disk can pass freely in the narrow gap of the drop-through gauge. The width of the drop-through area is 2.6014 mm1. The depth is 150 mm, and the two walls are smooth and vertical.
Figure 5 Thickness of floppy disk
7.1.3 Center window
The diameter of the center window is:
t, = 39.7 ± 0.2 mm
The center position is determined by:
tz-66.65 ± 0.30 mm
7.1.4 Index window
7. 1.4. 1 Position
The position of the center of the index port is 1. Determine: Z: 42.10 ± 0.25 mm
14 -- 60. 00 ± 0. 251 m
7.1.4.2 Diameter
The diameter of the index window is:
dz 6. 35 ± 0. 20 mm
7. 1. 5 Head window
7.1.5. 1 Position
The position of the lowest point of the head window is determined by, t, = 3. 30 ± 0. 25 nitn
7.1.5.2 Dimensions
The width of the head window is:
t=12.7 ± 0. 2 mm
The nominal radius at both ends is:
r,-6. 35mm
Its length is:
t,=35. 00±0. 25mm
7.1.6 Reference edge contour:
In the area determined by 1, the reference edge contour should be a convex circle, for example, composed of one or more circles with a minimum radius of 0.3mm, where
tg=25mm
7.1.7 Structure of the closure
If the closure has a folded edge, its width should not exceed 1:. =12mr
GB/T15131.1—94
The total thickness e2 of the floppy disk and the folded edge shall meet the conditions of 7.1.2.2 [(See Appendix A (Supplement) 17.1.8 Groove
There may be two grooves along the reference edge. If there are grooves, they shall be within the following specified areas: tumn - 48.00mm
I.inw -- 58.0mm
12aun -- 75.0mm
l13ma—85.5mm
1* =2.0mm
7.1.9 Write-allowed groove
The position and size of the write-allowed groove are determined by the following: lig—96.5±0.2mm
t2, =6.35±0. 13mm
l-3.8+0.2mm
Writing is prohibited by covering the write-enable groove with a sufficiently hard and/or opaque material. 7.2 The lining shall cover the recording area (see 7.3.4). However, the amount of exposure to each window of the inner cover shall not exceed 0.5mm. 7.3 Disk
7.3.1 Diameter (see Figure 6)
The outer diameter of the disk should be:
d,=130. 2+ 0. 2mm
The inner diameter of the disk should be:
d,-28.575±0.025mm
Figure 6 Disk size
7. 3.2 Thickness (see Figure 7)
The thickness of the disk should be:
eg=0.080±0.010mm
Figure 7 Disk thickness
7. 3.3 Index hole
7. 3.3.1 Position
The position of the index hole is determined by:
r,=25. 4±0. 1mm
The diameter of the index hole should be:
d,=2.54±0.10mm
7.3.4 Recording area
GB/T 15131. 1.. 94
The recording area on both sides is determined by r, and -., where: r5m=31.3mm
rerin =62.5mm
For ease of explanation, two i are specified as 0[and 1. The two surfaces are shown in Figures 1 to 4 and Figure 8. Figure Pressure pad area
8 Physical properties
.8.1 Flammability
The material used to make the floppy disk should not continue to burn in a static carbon dioxide atmosphere if ignited by a match. B.2 Linear thermal expansion coefficient of the disk
The thermal expansion coefficient of the disk is (17±8)×10*/C8.3 Linear moisture expansion coefficient of the disk
The moisture expansion coefficient of the disk is (0～15)×10-*/%RH. B.4 Opacity
B.4.1 Opacity of the cover
When measured in accordance with Appendix B (Supplement), using a light-emitting diode with a nominal wavelength of 940nm as the radiation source, the light transmittance of the cover should be less than 1%. The write-in slot cover is placed in the cover to ensure opacity. 8.4.2 Opacity of knocking disk
When measured in accordance with Appendix B (Supplement), using a light emitting diode with a nominal wavelength of 940nm as the radiation source, the light transmittance of the disk shall be less than 2%.
8.5 Torque
8.5.1 Starting torque
GB/T 15131. 1-94
When the head and pressure pad are not loaded on the disk, the starting torque shall not exceed 0.01N·m. 8.5.2 Running torque
When the floppy disk is tested at a rotational speed of 360+7 r/min, a force of 0.70±0.05N is applied to a pressure pad with a surface area of 280±10 mm2. The pressure pad is parallel to the head window and its position is determined by the following dimensions in Figure 8: 115=44mm
Tt. --55mtn
1,=7mm
tg-35mm
The torque causing the disk to rotate should not exceed 0.03N*m9 Magnetic properties
9.1 Geometric parameters of tracks
9. 1. 1 Number of tracks
For data exchange, there should be 80 separate concentric tracks in the recording area (see Section 7.3.4) on each side of the disk. 9.1.2 Track Width
The track width recorded on the disk surface shall be 0.155 ± 0.015 mm, and the area between tracks shall be erased. A method for measuring the effective track width is given in Appendix C (Supplement). 9.1.3 Track Position
9.1:3.1 Nominal Position
The nominal value of the radius of the center line of all tracks (mm) shall be calculated using the following formula; × 25.4mm
Where: For --- corresponding track number (see 9.1.4); For side 0: X = 57.150mm;
For side 1: X = 55.033mm.
Therefore, each track on side 1 is offset 2.117mm inward from the same track number on side 0. 9.1.3-2 Track position tolerance:
When measured under the test environment conditions (see 6.1.1), the tolerance of the recorded track center line relative to the nominal position shall be within ±0,025 mm.
9.1.4 Track number
The track number is indicated by a two-digit binary number (00 to 79 on each side). The numbering starts from the outermost track (00) and goes inwards. 9.1.5 Index
The index signal is used only for synchronization. The index is the point that determines the beginning and end of the track. At the moment when the leading edge of the index hole is detected, the index is just below the stop of the read-write gap.
9.2 Functional test
For the following tests, the same drive is used for both write and read operations. The contact working state shall be used. 9.2.1 Surface test
The magnetic properties of the two data surfaces are determined by the test requirements given below. The tests specified in 9.2.1.3 and 9.2.1.4 are completed on track 76 because they are the tracks tested by RM8630. 9.2.1.1 Test conditions
The disk shall be tested at a rotation speed of 360±7r/min. The test frequency (flux reversal/second (fups)) adopted shall be: If=250 000±250ftps:
2f-500 000±500flps.
GB/T 15131. 194
Each performance test uses the specified frequency. 9.2.1.2 Typical magnetic field strength
The typical magnetic field strength of the disk for each side tested shall be within ±20% of the reference magnetic field strength. It is tested using a frequency of 1f on track 00.
9.2.1.3 Average signal amplitude
When the disk under test is recorded with the test recording current, it is then read out and compared with the signal amplitude reference disk recorded under the same conditions and on the same system. Its average signal amplitude should be: when recorded with 1f on the 00 tracks of each side, it should be less than 130% of the standard reference amplitude SRA; when recorded with 2f on the 76 tracks of each side, it should be greater than 80% of the standard reference amplitude SRA2r. 9.2.1.4 Resolution
After recording with the specified test recording current on the 76 tracks of each side, its ratio: the average signal amplitude of 2f
the average signal amplitude of 1f
should be greater than 90% of the same ratio of the signal amplitude reference disk. 9.2.1.5 Overwrite
On track 00, first re-record with 1f using the specified test record, and then rewrite with 2f for one cycle. The ratio: 1f residual average signal amplitude after 2f rewrite and average signal amplitude after 1f start recording
should be less than 150% of the same ratio of the signal amplitude reference disk. The test should be carried out on both sides using a frequency-selective voltmeter with a bandwidth of 1~5kHz.
9.2.1.6 Modulation
The modulation should be:
Maximum mean value - minimum mean value,
×100%
Maximum mean value + minimum mean value
The maximum mean value is the average value of the AM output voltage of the part of the track with the maximum amplitude. The minimum mean value is the average value of the AM output voltage of the part of the track with the minimum amplitude. The output voltage should be measured peak-to-peak. The average value should be taken over approximately 2000 consecutive track reversals.
Record with 1f on track 00 and 2f on track 79 on both sides. The modulation should be less than 10%. 9.2.2 Track quality test
Test on all available tracks at specified positions on each side with the test recording current. 9.2.2.1 Leakage pulse
Write a track with 2f using the specified test recording current. When measuring the base-peak value, any read signal less than 40% of half of the arithmetic mean of the peak-to-peak output voltage of the entire track is a pulse. 9.2.2.2 Stomach pulse
Write a track with 2f using the specified test recording current. Wipe one cycle with a constant DC equivalent to the test recording current. When measuring the base-peak value, any read signal, including statistical noise and residual signals of the disk, exceeding 20% of half of the 2f average signal amplitude of the track under test is a leakage pulse.
9.2.3 Rejection criteria
9.2.3.1 Defective tracks
GB/T15131.1-94
When continuous testing is performed, if one or more pain pulses and/or spurious pulses are detected at the same position of the track, the track is considered a defective track. The number of continuous testing shall be determined by both the supplier and the buyer.
9.2.3.2 Requirements for tracks
The first floppy disk received from the supplier shall not have defective tracks. 9.2.3.3 Rejection criteria
The floppy disk that does not meet the requirements of 9.2.3.2 shall be rejected.1 Starting torque
GB/T 15131. 1-94
When the head and pressure pad are not loaded on the disk, the starting torque shall not exceed 0.01N·m. 8.5.2 Running torque
When the floppy disk is tested at a rotational speed of 360+7 r/min, a force of 0.70±0.05N is applied to a pressure pad with a surface area of 280±10 mm2. The pressure pad is parallel to the head window and its position is determined by the following dimensions in Figure 8: 115=44mm
Tt. --55mtn
1,=7mm
tg-35mm
The torque causing the disk to rotate should not exceed 0.03N*m9 Magnetic properties
9.1 Geometric parameters of tracks
9. 1. 1 Number of tracks
For data exchange, there should be 80 separate concentric tracks in the recording area (see Section 7.3.4) on each side of the disk. 9.1.2 Track Width
The track width recorded on the disk surface shall be 0.155 ± 0.015 mm, and the area between tracks shall be erased. A method for measuring the effective track width is given in Appendix C (Supplement). 9.1.3 Track Position
9.1:3.1 Nominal Position
The nominal value of the radius of the center line of all tracks (mm) shall be calculated using the following formula; × 25.4mm
Where: For --- corresponding track number (see 9.1.4); For side 0: X = 57.150mm;wwW.bzxz.Net
For side 1: X = 55.033mm.
Therefore, each track on side 1 is offset 2.117mm inward from the same track number on side 0. 9.1.3-2 Track position tolerance:
When measured under the test environment conditions (see 6.1.1), the tolerance of the recorded track center line relative to the nominal position shall be within ±0,025 mm.
9.1.4 Track number
The track number is indicated by a two-digit binary number (00 to 79 on each side). The numbering starts from the outermost track (00) and goes inwards. 9.1.5 Index
The index signal is used only for synchronization. The index is the point that determines the beginning and end of the track. At the moment when the leading edge of the index hole is detected, the index is just below the stop of the read-write gap.
9.2 Functional test
For the following tests, the same drive is used for both write and read operations. The contact working state shall be used. 9.2.1 Surface test
The magnetic properties of the two data surfaces are determined by the test requirements given below. The tests specified in 9.2.1.3 and 9.2.1.4 are completed on track 76 because they are the tracks tested by RM8630. 9.2.1.1 Test conditions
The disk shall be tested at a rotation speed of 360±7r/min. The test frequency (flux reversal/second (fups)) adopted shall be: If=250 000±250ftps:
2f-500 000±500flps.
GB/T 15131. 194
Each performance test uses the specified frequency. 9.2.1.2 Typical magnetic field strength
The typical magnetic field strength of the disk for each side tested shall be within ±20% of the reference magnetic field strength. It is tested using a frequency of 1f on track 00.
9.2.1.3 Average signal amplitude
When the disk under test is recorded with the test recording current, it is then read out and compared with the signal amplitude reference disk recorded under the same conditions and on the same system. Its average signal amplitude should be: when recorded with 1f on the 00 tracks of each side, it should be less than 130% of the standard reference amplitude SRA; when recorded with 2f on the 76 tracks of each side, it should be greater than 80% of the standard reference amplitude SRA2r. 9.2.1.4 Resolution
After recording with the specified test recording current on the 76 tracks of each side, its ratio: the average signal amplitude of 2f
the average signal amplitude of 1f
should be greater than 90% of the same ratio of the signal amplitude reference disk. 9.2.1.5 Overwrite
On track 00, first re-record with 1f using the specified test record, and then rewrite with 2f for one cycle. The ratio: 1f residual average signal amplitude after 2f rewrite and average signal amplitude after 1f start recording
should be less than 150% of the same ratio of the signal amplitude reference disk. The test should be carried out on both sides using a frequency-selective voltmeter with a bandwidth of 1~5kHz.
9.2.1.6 Modulation
The modulation should be:
Maximum mean value - minimum mean value,
×100%
Maximum mean value + minimum mean value
The maximum mean value is the average value of the AM output voltage of the part of the track with the maximum amplitude. The minimum mean value is the average value of the AM output voltage of the part of the track with the minimum amplitude. The output voltage should be measured peak-to-peak. The average value should be taken over approximately 2000 consecutive track reversals.
Record with 1f on track 00 and 2f on track 79 on both sides. The modulation should be less than 10%. 9.2.2 Track quality test
Test on all available tracks at specified positions on each side with the test recording current. 9.2.2.1 Leakage pulse
Write a track with 2f using the specified test recording current. When measuring the base-peak value, any read signal less than 40% of half of the arithmetic mean of the peak-to-peak output voltage of the entire track is a pulse. 9.2.2.2 Stomach pulse
Write a track with 2f using the specified test recording current. Wipe one cycle with a constant DC equivalent to the test recording current. When measuring the base-peak value, any read signal, including statistical noise and residual signals of the disk, exceeding 20% of half of the 2f average signal amplitude of the track under test is a leakage pulse.
9.2.3 Rejection criteria
9.2.3.1 Defective tracks
GB/T15131.1-94
When continuous testing is performed, if one or more pain pulses and/or spurious pulses are detected at the same position of the track, the track is considered a defective track. The number of continuous testing shall be determined by both the supplier and the buyer.
9.2.3.2 Requirements for tracks
The first floppy disk received from the supplier shall not have defective tracks. 9.2.3.3 Rejection criteria
The floppy disk that does not meet the requirements of 9.2.3.2 shall be rejected.1 Starting torque
GB/T 15131. 1-94
When the head and pressure pad are not loaded on the disk, the starting torque shall not exceed 0.01N·m. 8.5.2 Running torque
When the floppy disk is tested at a rotational speed of 360+7 r/min, a force of 0.70±0.05N is applied to a pressure pad with a surface area of 280±10 mm2. The pressure pad is parallel to the head window and its position is determined by the following dimensions in Figure 8: 115=44mm
Tt. --55mtn
1,=7mm
tg-35mm
The torque causing the disk to rotate should not exceed 0.03N*m9 Magnetic properties
9.1 Geometric parameters of tracks
9. 1. 1 Number of tracks
For data exchange, there should be 80 separate concentric tracks in the recording area (see Section 7.3.4) on each side of the disk. 9.1.2 Track Width
The track width recorded on the disk surface shall be 0.155 ± 0.015 mm, and the area between tracks shall be erased. A method for measuring the effective track width is given in Appendix C (Supplement). 9.1.3 Track Position
9.1:3.1 Nominal Position
The nominal value of the radius of the center line of all tracks (mm) shall be calculated using the following formula; × 25.4mm
Where: For --- corresponding track number (see 9.1.4); For side 0: X = 57.150mm;
For side 1: X = 55.033mm.
Therefore, each track on side 1 is offset 2.117mm inward from the same track number on side 0. 9.1.3-2 Track position tolerance:
When measured under the test environment conditions (see 6.1.1), the tolerance of the recorded track center line relative to the nominal position shall be within ±0,025 mm.
9.1.4 Track number
The track number is indicated by a two-digit binary number (00 to 79 on each side). The numbering starts from the outermost track (00) and goes inwards. 9.1.5 Index
The index signal is used only for synchronization. The index is the point that determines the beginning and end of the track. At the moment when the leading edge of the index hole is detected, the index is just below the stop of the read-write gap.
9.2 Functional test
For the following tests, the same drive is used for both write and read operations. The contact working state shall be used. 9.2.1 Surface test
The magnetic properties of the two data surfaces are determined by the test requirements given below. The tests specified in 9.2.1.3 and 9.2.1.4 are completed on track 76 because they are the tracks tested by RM8630. 9.2.1.1 Test conditions
The disk shall be tested at a rotation speed of 360±7r/min. The test frequency (flux reversal/second (fups)) adopted shall be: If=250 000±250ftps:
2f-500 000±500flps.
GB/T 15131. 194
Each performance test uses the specified frequency. 9.2.1.2 Typical magnetic field strength
The typical magnetic field strength of the disk for each side tested shall be within ±20% of the reference magnetic field strength. It is tested using a frequency of 1f on track 00.
9.2.1.3 Average signal amplitude
When the disk under test is recorded with the test recording current, it is then read out and compared with the signal amplitude reference disk recorded under the same conditions and on the same system. Its average signal amplitude should be: when recorded with 1f on the 00 tracks of each side, it should be less than 130% of the standard reference amplitude SRA; when recorded with 2f on the 76 tracks of each side, it should be greater than 80% of the standard reference amplitude SRA2r. 9.2.1.4 Resolution
After recording with the specified test recording current on the 76 tracks of each side, its ratio: the average signal amplitude of 2f
the average signal amplitude of 1f
should be greater than 90% of the same ratio of the signal amplitude reference disk. 9.2.1.5 Overwrite
On track 00, first re-record with 1f using the specified test record, and then rewrite with 2f for one cycle. The ratio: 1f residual average signal amplitude after 2f rewrite and average signal amplitude after 1f start recording
should be less than 150% of the same ratio of the signal amplitude reference disk. The test should be carried out on both sides using a frequency-selective voltmeter with a bandwidth of 1~5kHz.
9.2.1.6 Modulation
The modulation should be:
Maximum mean value - minimum mean value,
×100%
Maximum mean value + minimum mean value
The maximum mean value is the average value of the AM output voltage of the part of the track with the maximum amplitude. The minimum mean value is the average value of the AM output voltage of the part of the track with the minimum amplitude. The output voltage should be measured peak-to-peak. The average value should be taken over approximately 2000 consecutive track reversals.
Record with 1f on track 00 and 2f on track 79 on both sides. The modulation should be less than 10%. 9.2.2 Track quality test
Test on all available tracks at specified positions on each side with the test recording current. 9.2.2.1 Leakage pulse
Write a track with 2f using the specified test recording current. When measuring the base-peak value, any read signal less than 40% of half of the arithmetic mean of the peak-to-peak output voltage of the entire track is a pulse. 9.2.2.2 Stomach pulse
Write a track with 2f using the specified test recording current. Wipe one cycle with a constant DC equivalent to the test recording current. When measuring the base-peak value, any read signal, including statistical noise and residual signals of the disk, exceeding 20% of half of the 2f average signal amplitude of the track under test is a leakage pulse.
9.2.3 Rejection criteria
9.2.3.1 Defective tracks
GB/T15131.1-94
When continuous testing is performed, if one or more pain pulses and/or spurious pulses are detected at the same position of the track, the track is considered a defective track. The number of continuous testing shall be determined by both the supplier and the buyer.
9.2.3.2 Requirements for tracks
The first floppy disk received from the supplier shall not have defective tracks. 9.2.3.3 Rejection criteria
The floppy disk that does not meet the requirements of 9.2.3.2 shall be rejected.2 Functional tests
For the following tests, the same drive is used for both write and read operations. Contact operation should be used. 9.2.1 Surface tests
The magnetic properties of the two data surfaces are determined by the test requirements given below. The tests specified in 9.2.1.3 and 9.2.1.4 are completed on 76 tracks because they are the tracks tested by RM8630. 9.2.1.1 Test conditions
The disk should be tested at a rotation speed of 360±7r/min. The test frequency (flux reversal/second (fups)) used should be: If=250 000±250ftps:
2f-500 000±500flps.
GB/T 15131. 194
Each performance test uses the specified frequency. 9.2.1.2 Typical magnetic field strength
The typical magnetic field strength of the disk when tested on each side shall be within ±20% of the reference magnetic field strength. It is measured using a frequency of 1f on the 00 track.
9.2.1.3 Average signal amplitude
When the disk under test is recorded with the test recording current, it is then read out and compared with the signal amplitude reference floppy disk recorded under the same conditions and on the same system. Its average signal amplitude shall be: when recorded with 1f on the 00 track of each side, it shall be less than 130% of the standard reference amplitude SRA; when recorded with 2f on the 76 tracks of each side, it shall be greater than 80% of the standard reference amplitude SRA2r. 9.2.1.4 Resolution
After recording with the specified test recording current on the 76 tracks of each side, its ratio: the average signal amplitude of 2f
the average signal amplitude of 1f
shall be greater than 90% of the same ratio of the signal amplitude reference floppy disk. 9.2.1.5 Overwrite
On track 00, first re-record with 1f using the specified test record, and then rewrite with 2f for one cycle. The ratio: 1f residual average signal amplitude after 2f rewrite and average signal amplitude after 1f start recording
should be less than 150% of the same ratio of the signal amplitude reference disk. The test should be carried out on both sides using a frequency-selective voltmeter with a bandwidth of 1~5kHz.
9.2.1.6 Modulation
The modulation should be:
Maximum mean value - minimum mean value,
×100%
Maximum mean value + minimum mean value
The maximum mean value is the average value of the AM output voltage of the part of the track with the maximum amplitude. The minimum mean value is the average value of the AM output voltage of the part of the track with the minimum amplitude. The output voltage should be measured peak-to-peak. The average value should be taken over approximately 2000 consecutive track reversals.
Record with 1f on track 00 and 2f on track 79 on both sides. The modulation should be less than 10%. 9.2.2 Track quality test
Test on all available tracks at specified positions on each side with the test recording current. 9.2.2.1 Leakage pulse
Write a track with 2f using the specified test recording current. When measuring the base-peak value, any read signal less than 40% of half of the arithmetic mean of the peak-to-peak output voltage of the entire track is a pulse. 9.2.2.2 Stomach pulse
Write a track with 2f using the specified test recording current. Wipe one cycle with a constant DC equivalent to the test recording current. When measuring the base-peak value, any read signal, including statistical noise and residual signals of the disk, exceeding 20% of half of the 2f average signal amplitude of the track under test is a leakage pulse.
9.2.3 Rejection criteria
9.2.3.1 Defective tracks
GB/T15131.1-94
When continuous testing is performed, if one or more pain pulses and/or spurious pulses are detected at the same position of the track, the track is considered a defective track. The number of continuous testing shall be determined by both the supplier and the buyer.
9.2.3.2 Requirements for tracks
The first floppy disk received from the supplier shall not have defective tracks. 9.2.3.3 Rejection criteria
The floppy disk that does not meet the requirements of 9.2.3.2 shall be rejected.2 Functional tests
For the following tests, the same drive is used for both write and read operations. Contact operation should be used. 9.2.1 Surface tests
The magnetic properties of the two data surfaces are determined by the test requirements given below. The tests specified in 9.2.1.3 and 9.2.1.4 are completed on 76 tracks because they are the tracks tested by RM8630. 9.2.1.1 Test conditions
The disk should be tested at a rotation speed of 360±7r/min. The test frequency (flux reversal/second (fups)) used should be: If=250 000±250ftps:
2f-500 000±500flps.
GB/T 15131. 194
Each performance test uses the specified frequency. 9.2.1.2 Typical magnetic field strength
The typical magnetic field strength of the disk when tested on each side shall be within ±20% of the reference magnetic field strength. It is measured using a frequency of 1f on the 00 track.
9.2.1.3 Average signal amplitude
When the disk under test is recorded with the test recording current, it is then read out and compared with the signal amplitude reference floppy disk recorded under the same conditions and on the same system. Its average signal amplitude shall be: when recorded with 1f on the 00 track of each side, it shall be less than 130% of the standard reference amplitude SRA; when recorded with 2f on the 76 tracks of each side, it shall be greater than 80% of the standard reference amplitude SRA2r. 9.2.1.4 Resolution
After recording with the specified test recording current on the 76 tracks of each side, its ratio: the average signal amplitude of 2f
the average signal amplitude of 1f
shall be greater than 90% of the same ratio of the signal amplitude reference floppy disk. 9.2.1.5 Overwrite
On track 00, first re-record with 1f using the specified test record, and then rewrite with 2f for one cycle. The ratio: 1f residual average signal amplitude after 2f rewrite and average signal amplitude after 1f start recording
should be less than 150% of the same ratio of the signal amplitude reference disk. The test should be carried out on both sides using a frequency-selective voltmeter with a bandwidth of 1~5kHz.
9.2.1.6 Modulation
The modulation should be:
Maximum mean value - minimum mean value,
×100%
Maximum mean value + minimum mean value
The maximum mean value is the average value of the AM output voltage of the part of the track with the maximum amplitude. The minimum mean value is the average value of the AM output voltage of the part of the track with the minimum amplitude. The output voltage should be measured peak-to-peak. The average value should be taken over approximately 2000 consecutive track reversals.
Record with 1f on track 00 and 2f on track 79 on both sides. The modulation should be less than 10%. 9.2.2 Track quality test
Test on all available tracks at specified positions on each side with the test recording current. 9.2.2.1 Leakage pulse
Write a track with 2f using the specified test recording current. When measuring the base-peak value, any read signal less than 40% of half of the arithmetic mean of the peak-to-peak output voltage of the entire track is a pulse. 9.2.2.2 Stomach pulse
Write a track with 2f using the specified test recording current. Wipe one cycle with a constant DC equivalent to the test recording current. When measuring the base-peak value, any read signal, including statistical noise and residual signals of the disk, exceeding 20% of half of the 2f average signal amplitude of the track under test is a leakage pulse.
9.2.3 Rejection criteria
9.2.3.1 Defective tracks
GB/T15131.1-94
When continuous testing is performed, if one or more pain pulses and/or spurious pulses are detected at the same position of the track, the track is considered a defective track. The number of continuous testing shall be determined by both the supplier and the buyer.
9.2.3.2 Requirements for tracks
The first floppy disk received from the supplier shall not have defective tracks. 9.2.3.3 Rejection criteria
The floppy disk that does not meet the requirements of 9.2.3.2 shall be rejected.
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