1、ECMA I E UR O PEAN COMPUTER MAN U FACTURE RS ASS OC1 ATION STANDARD ECM1A-125 DATA INTERCHANGE ON 90 mm FLEXIBLE DISK CARTRIDGES USING MFM RECORDING AT 15916 ftprad ON 80 TRACKS ON EACH SIDE December 1987 BRIEF HISTORY Technical Committee TC19 of ECMA began work on the standardization of flexible di
2、sk cartridges in 1974. As a result ECMA has produced a set of standards for different types of flexible disk cartridges (FDC): 200 mm FDCs 130 mm FDCs ECMA-58 ECMA-59 ECMA-69 ECMA-66 ECMA-70 ECMA-78 ECM A-99 90 mm FDCs ECMA- 1 O0 Standards ECMA-70, ECMA-78 and ECMA-99 speciS, two different track for
3、mats, The first specifies FM recording in Cylinder 00 and is intended for use with the labelling system specified in Standard ECMA-91. The second track format, which is identical with that of Standard ECMA-100, specifies MFM recording on all cylinders and is in- tended for use with the volume and fi
4、le structure of Standard ECMA-107. Standard ECMA-100 was developed with a view to achieving a capacity of 1 Mbyte. The present Standard is a further development of the same medium providing a capa- city of 2 Mbytes. Work on this project started in ECMA in November 1985. Whilst some aspects may requi
5、re further investigation it has been decided to publish this Standard in its present form to meet the needs of users and industry; it is intended that these aspects shall be reviewed for the next editions. In particular, research is in progress on the ranges of operating environment within which rel
6、iable data interchange can take place, the tolerance on location of recorded tracks, the tolerance on the gener- ation of the Index pulse, and the upper limit for overwrite. In its present form this ECMA standard is technically identical with ISODIS 9529. This Standard has been accepted by the Gener
7、al Assembly of ECMA on 10th December 1987. -1- TABLE OF CONTENTS 1, SCOPE, FIELD OF APPLICATION AND CONFORMANCE 1.1 1.2 Conformance Scope and Field of Application 2. REFERENCES 3. GENERAL DESCRIPTION 3.1 Drawings 3.2 Main Elements 3.3 Description 4. DEFINITIONS 4.1 Recording Disk 4.2 Hub 4.3 Shutter
8、 4.4 Liner 4.5 Case 4.6 Master Standard Reference Flexible Disk Cartridge 4.7 Secondary Standard Reference Flexible Disk Cartridge 4.8 Typical Field 4.9 Reference Field 4.10 Test Recording Current 4.1 1 Standard Reference Amplitude 4.12 Average Signal Amplitude 4.13 In-Contact 4.14 Side 4.15 Directi
9、on of Rotation 4.16 Index 4.17 Line of Access 4.18 Formatting 4.19 Initialization 5. GENERAL REQUIREMENTS 5.1 Environment and Transportation 5.1.1 Testing environment 5.1.2 Operating environment 5.1.3 Storage environment 5.1.4 Transportation 5.2 Materials 5.2.1 Case 5.2.2 Liner 5.2.3 Disk 5.2.4 Hub
10、Page 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 6 6 6 6 9 9 9 9 9 10 10 10 10 10 10 ECMA ECMA*L25 87 831 3404573 0001495 4 W 6. DIMENSIONAL CHARACTERISTICS 6.1 Case 6.1.1 Shape (Fig. i) 6.1.2 Thickness 6.1.3 Hub access hole (Fig. 1) 6.1.4 Locating holes (Fig. 1 and 3) 6.1.5 Label area 6.1.6 Hea
11、d windows (Fig. 3) 6.1.7 Write-inhibit hole (Fig. 2) 6.1.8 Identification hole (Fig. 1 and 2) 6.1.9 Profile of the shutter edge of the case (Fig. 1 and 3) 6.1.10 Shutter (Fig. 2 and 3) 6.2 Liner 6.3 Disk (Fig. 4) 6.3.1 Diameter 6.3.2 Thickness 6.4 Hub (Fig. 4) 6.4.1 Dimensions 6.4.2 Hub orientation
12、holes (Fig. 4) 6.5 Optional Handling Notches (Fig. 1 and 2) 6.6 Interface between Cartridge and Drive 6.7 Compliance 7. PHYSICAL CHARACTERISTICS 7.1 Inflammability 7.2 7.3 7.4 Torque 7.4.1 Starting torque 7.4.2 Coefficient of Linear Thermal Expansion of the Disk Coefficient of Linear Hygroscopic Exp
13、ansion of the Disk Running torque without heads loaded 8. MAGNETIC CHARACTERISTICS 8.1 Recording Area 8.2 Track Geometry 8.2.1 Number of tracks 8.2.2 Width of tracks 8.2.3 Track location 8.2.4 Track number 8.3 Functional Testing 8.3.1 Surface tests 8.3.2 Track quality tests 8.3.3 Rejection criterion
14、 10 10 10 11 11 11 12 12 13 13 13 14 14 14 14 14 15 15 15 16 16 16 17 17 17 17 17 17 21 21 21 21 21 21 21 21 22 23 23 .17 - - iij - 9. GENERAL REQUIREMENTS 27 9.1 Mode of Recording 27 9.2 Track Location Tolerance of the Recorded Flexible Disk Cartridge 9.3 Recording Offset Angle 9.4 Density of Recor
15、ding 9.5 Flux Transition Spacing 9.6 Average Signal Amplitude 9.7 Byte 9.8 Sector 9.9 Cylinder 9.10 Cylinder Number 9.11 Data Capacity of a Track 9.12 Hexadecimal Notation 9.13 Error Detection Characters (EDC) 27 27 27 28 28 29 29 29 29 29 29 29 10. TRACK LAYOUT 29 10.1 Index Gap 10.2 Sector Identif
16、ier 30 30 10.2.1 Identifier Mark 10.2.2 Address Identifier 30 30 10.3 Identifier Gap 10.4 Data Block 31 31 10.4.1 Data Mark 10.4.2 Data Field 10.4.3 EDC 31 32 32 10.5 Data Block Gap 10.6 Track Gap 32 32 11. CODED REPRESENTATION OF DATA 32 11.1 Standards 11.2 Coding Methods 32 32 APPENDIX A - TEST FO
17、R COMPLIANCE 45 APPENDIX B - MEASUREMENT OF LIGHT TRANSMITTANCE 47 APPENDIX C - METHOD FOR MEASURING THE EFFECTIVE TRACK WIDTH 51 APPENDIX D - PROCEDURE AND EQUIPMENT FOR MEASURING FLUX TRANSITION SPACING 53 APPENDIX E - DATA SEPARATORS FOR DECODING MFM RECORDING 57 - iv - APPENDIX F - EDC IMPLEMENT
18、ATION APPENDIX G - CARTRIDGE DISTORTION TEST GAUGE APPENDIX H - METHOD FOR MEASURING PEAK SHIFT 59 61 63 -1- SECTION I SCOPE FIELD OF APPLICATION CONFORMANCE GENERAL DESCRIPTION DEFINITIONS ECMA ECMA*125 87 W 3404593 0001499 I = . 1. 1.1 Scope and Field of Application This ECMA Standard specifies th
19、e characteristics of 90 mm flexible disk car- tridges recorded at 1591 6 ftprad using modified frequency modulation recording, on 80 tracks on each side. It specifies the mechanical, physical and magnetic characteristics of the cartridge, so as to provide physical interchangeability between data pro
20、cessing systems. It also specifies the method of recording, the quality of the recorded signals, the track layout and the track format. Together with the labelling scheme of Standard ECMA-107, this Standard provides for full data interchange between data processing systems. SCOPE, FIELD OF APPLICATI
21、ON AND CONFORMANCE 1.2 Conformance A 90 mm flexible disk cartridge is in conformance with this Standard if it meets all mandatory requirements specified herein. 2. REFERENCES ECMA-6 ECMA-35 : Code Extension Techniques ECMA-43 ECMA-9 1 ECMA-107 IS0 683/13 : 7-Bit Coded Character Set : 8-Bit Coded Cha
22、racter Set - Structure and Rules : File Structure and Labelling of Flexible Disk Cartridges for In- formation Interchange : Volume and File Structure of Flexible Disk Cartridges for Infor- mation Interchange. : Wrought Stainless Steels 3. GENERAL DESCRIPTION 3.1 Drawings In the enclosed drawings: Fi
23、g. 1 Fig. 2 shows Side 1, Fig. 3 Fig. 4 Fig. 5 shows Side O and enlarged cross-sections through the location holes, shows at a larger scale the upper part of Side O without shutter, shows the disk with hub, and shows the interface between the cartridge and the drive. 3.2 Main Elements The main eleme
24、nts of the flexible disk cartridge are: - the recording disk, Previous page is blank ECMA ECMA*125 87 E 3404573 0001500 4 -4- - the liner, - the case. 3.3 Description The cartridge is of a substantially square form. It includes a central hole on one side, a head window on both sides, an identificati
25、on hole and a write-inhibit hole. The liner is provided between the case and the disk. It comprises two layers of material between which the disk lies. The disk has a centrai hole with a metal hub attached. 4.1 4.2 4.3 4.4 4.5 4.6 4. DEFINITIONS For the purpose of this Standard the following definit
26、ions apply. Recording Disk A flexible disk which accepts and retains, on the specified side or sides, magnetic signals in tended for inputloutput and storage purposes. Hub A centring and referencing device attached to the disk which allows torque to be transmitted to the disk. The hub is attached to
27、 the centre of the disk. It ensures centring of the disk on the drive shaft in a unique angular position. Shut ter A device which uncovers the head windows upon insertion, and automatically covers them upon removal from the drive. Liner Suitable material positioned between the case and the disk to p
28、rovide cleaning action and protection from abrasion. Case A protective enclosure including a shutter mechanism, identification hole and a write-inhibit hole. Master Standard Reference Flexible Disk Cartridge Az reference flexible disk cartridge selected as the standard for reference fields, signal a
29、mplitudes, resolution, peak shift and overwrite. Track O0 and Track 79 on both sides are declared as reference tracks. The reference tracks are calibrated at 300 rpm. Note I This Master Standard has been established by the Physikalisch- Technische Bundesanstalt (PTB), Bundesallee 100, 0-3300 Braunsc
30、hweig, Germany. I 4.7 4.8 4.9 4.10 4.11 4.12 4.13 4.14 4.15 -5- Secondary Standard Reference Flexible Disk Cartridge A flexible disk cartridge the performance of which is known and stated in rela- tion to that of the Master Standard Reference Flexible Disk Cartridge. Note 2 Secondary Standard Refere
31、nce Flexible Disk Cartridges can be ordered until I998 from PTB, Lab. 1.41, under Part Number RM 9529. li is intended tha these be wed for calibrating tertiary cartridges for use in routine calibration. Typical Field The minimum recording field which, when applied to a flexible disk cartridge, cause
32、s an average signal amplitude equal to 95% of the maximum Average Signal Amplitude when taken as a function of the recording field at the specified track and flux transition density. Reference Field The Reference Field is the Typical Field of the Master Standard Reference Flexible Disk Cartridge. Th
33、ere are two Reference Fields, one for each side. Test Recording Current The Test Recording Current is the current between 148% and 152% of the cur- rent which produces the Reference Field at If on Track OO. There are two Test Recording Currents, one for each side. Standard Reference Amplitude The St
34、andard Reference Amplitudes (SRAs) are the Average Signal Amplitudes derived from the reference tracks of the Master Standard Reference Flexible Disk Cartridge using the Test Recording Current. There are four SRAs, two for each side: SRA-lf is the Average Signal Amplitude from a recording written us
35、ing If at Track OO. SRA-2f is the Average Signal Amplitude from a Recording written using 2f at Track 79, Average Signal Amplitude The Average Signal Amplitude for a track is the arithmetically averaged value of the output voltages measured peak-to-peak over the whole track. In-Contact An operating
36、condition in which the magnetic surface of the disk is in physical contact with the magnetic heads. Side Side O is the side engaged by the spindle. Side 1 is the opposite side. Direction of Rotation The direction of rotation shall be counter-clockwise when looking at Side O. ECMA ECMA*L25 87 m 34045
37、93 -6- 4.16 Index The signal generated in the index transducer of the drive by the drive spindle once per revolution. 4.17 Line of Access The straight line described by the centre of the gap of the read/write head as it is positioned from Track O0 to Track 79. 4.18 Formatting Writing the proper cont
38、rol information establishing the physical cylinders and the addresses of physical records on the surfaces of the flexible disk. 4.19 Initialization Writing any information initially required to be on the flexible disk cartridge, e.g. the Volume Label, prior to the commencement of general processing
39、use. -7- SECTION II GENERAL REQUIREMENTS MECHANICAL AND PHYSICAL CHARACTERISTICS -9- 5, GENERAL REQUIREMENTS 5.1 Environment and Transportation 5.1.1 Testing environment Tests and measurements made on the cartridge to check the requirements of this Standard shall be carried out under the following c
40、onditions: Temperature RH : 40% to 60% Conditioning before test i ng : 24 hours minimum For the tests specified in 8.3 the temperature and the RH shall be measured in the air immediately surrounding the cartridge drive. For all other tests the temperature and the RH shall be measured in the air imme
41、diately surrounding the cartridge. The stray magnetic field at any point on the disk surface, including that resulting from the concentrating effect of the recording head, shall not exceed 4000 Nm. : 23 “C k 2 “C 5.1.2 Operating environment Cartridges used for data interchange shall be operated unde
42、r the following conditions: Temperature RH : 8% to 80% Wet bulb temperature The temperature and the RH shall be measured in the air immediately sur- rounding the cartridge. It is recommended that the rate of change of the tem- perature should not exceed 20 “C per hour. It is also recommended that th
43、e temperature and the RH conditions when reading a cartridge are not at the opposite extremes to the conditions when it was recorded. There shall be no deposit of moisture on or in the cartridge. The stray magnetic field at any point on the disk surface, including that resulting from the concentrati
44、ng effect of the recording head, shall not exceed 4000 Am. : 10 “C to 60 “C : less than 29 “C 5.1.3 Storage environment During storage the cartridges shall be kept within the following conditions: : 4 OC to 53 “C Tem peratu re RH : 8% to 90% The ambient stray magnetic field shall not exceed 4000 Am.
45、 There shall be no deposit of moisture on or in the cartridge. Previous page is blank ECMA ECMA*125 87 = 3404593 0001505 3 W - 10- Note 3 Cartridges which have been stored at temperatures and humidities exceeding the operating conditions may exhibit degraded performance characteristics. Such cartrid
46、ges should be subjected to a conditioning period of not less than 24 hours within the operating environment prior to use. 5.1.4 Transport at ion Responsibility for ensuring that adequate precautions are taken during the transportation shall be with the sender. The cartridge shall be in a protective
47、package free from dust or extraneous matter. It is recommended that a suffi- cient space exists between cartridge and outer surface of the final container, so that risk of erasure due to stray magnetic fields will be negligible. It is recommended that the following conditions are not exceeded: Tempe
48、rature : -40 OC to 60 “C Maximum rate of temperature change RH : 8% to 90% There should be no deposit of moisture on or in the cartridge. : 20 OC per hour 5.2 Materials 5.2.1 Case The case may be constructed from any suitable material such that it meets the requirements of 6.7. 5.2.2 Liner The mater
49、ial of the liner shall be able to retain dust or debris without damage to the disk. 5.2.3 Disk The disk may be constructed from any suitable material (e.g. bi-axially ori- ented polyethylene terephthalate) coated on both sides with a flexible layer of magnetic material. 5.2.4 Hub The hub shall be made of any suitable material (e.g. stainless steel alloy according to IS0 683/13, type 8). 6. DIMENSIONAL CHARACTERISTICS The dimensions of the cartridge are referred to two Reference Axes X and Y. They are two lines in space intersecting at right angles. The plane they define is the Reference P
