ISO/IEC 13422:1994

Information technology - Data interchange on 90 mm Flexible Disk Cartridges 10 MByte capacity using sector servo tracking - ISO Type 304

Specifies the characteristics of 90 mm flexible disk cartridges of 10 MByte formatted capacity. Specifies the mechanical, physical and magnetic characteristics of the cartridge, so as to provide interchangeability between data processing systems. Also specifies the method of recording, the quality of the recorded signals, the track layout and the track format of data tracks and servo tracks.

Technologies de l'information — Échange de données sur cartouches pour disque souple de 90 mm de diamètre, de 10 Mbyte de capacité, utilisant le servo-pistage sur secteur — Type ISO 304

General Information

• Status: Withdrawn
• Publication Date: 12-Oct-1994
• Withdrawal Date: 12-Oct-1994
• ICS: 35.220.21 - Magnetic disks
• Technical Committee: ISO/IEC JTC 1/SC 23 - Digitally recorded media for information interchange and storage
• Drafting Committee: ISO/IEC JTC 1/SC 23 - Digitally recorded media for information interchange and storage
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 17-Nov-2021
• Completion Date: 30-Oct-2025

Standards Content (Sample)

INTERNATIONAL
ISO/IEC
STANDARD
First edition
1994-1 O-l 5
Information technology - Data
interchange on 90 mm Flexible Disk
Cartridges 10 MByte capacity using sector
servo tracking
- ISO Type 304
- fkhange de donnees SW cartouches
Technologies de I’information
pour disque souple de 90 mm de diametre, de 70 Mbyte de capacite,
utilisant Ie servo-pistage sur secteur - Type ISO 304

ISOIIEC 13422: 1994(E)
Contents
Foreword
Introduction
1 Scope
2 Conformance
2.1 Flexible Disk Cartridge
Generating Systems
2.2
Receiving sys tems
2.3
Normative references
Definitions
Average Signal Amplitude
4.1
4.2 case
4.3 data track
4.4 Error Detecting Code
4.5 Flexible Disk Cartridge
4.6 flux transition frequency
4.7 hub
4.8 liner
4.9 MFM recording mode
4.10 Master Standard Reference Flexible Disk Cartridge
4.11 peak value
4.12 primary identification hole
Reference Field
4s3
4.14 Secondary Standard Reference Flexible Disk Cartridge
4.15 secondary identification hole
4.16 sector servo
4.17 servo track
4.18 shutter
4.19 Standard Reference Ampli tude
4.20 Typical Field
4.21 write-inhibi t hole
5 Conventions and Notations
5.1 Representation of numbers
5.2 Acronyms
@ 1S0flEC 1994
All rights reserved. Unless otherwise spccifcd, no part of this publication may bg: reprducd
.or utilixd in any form or by any mcans, ekctronic or mcchanical, including phottxopying and
microfilm, without permission in writing from thc publisher.
ISO/IEC Copyright Office l Casc postrtlc: 56 l Cli- 1211 (kncvc 20 l Switzerland
Printcd in Switzerland
ii
ISOIIEC 13422:1994(E)
@ ISO/IEC
General description
Drawings
61 .
Main elements
62 .
Description
.
Marking of the Flexible Disk Cartridge
64 .
General requirements
Environment and transportation
7.1
7.1.1 Testing environment
7.1.2 Operating environmcnt
Storage environmcn t
7.1.3
Transportation
7.1.4
Materials
72 .
7.2.1 Case
Liner
7.2.2
7.2.3 Disk
7.2.4 Hub
Dimensional characteristics
. Case
Shape
8.1.1
Thickness
8.1.2
8.1.3 Hub access hole
8.1.4 Locating holes
8.1.5 Label area
8.1.6 Head windows
8.1.7 Write-inhibi t hole
8.1.8 Identification holes
8.1.9 Profile of the shuttcr edge of the case
8.1.10 Shutter
82 Liner
Disk
8:3
8.3.1 Diameter
8.3.2 Thickness
8.4 Hub
8.4.1 Dimensions
8.4.2 Hub orientation holcs
Optional handling notches
8:6 Interface betwecn cartridge and drive
8.7
Compliance
9 Physical characteristics
9.1 Flammabili ty
9.2 Cocfficicnt of lincnr thermal expansion of thc disk
. . .
Ill
@ ISO/IEC
ISO/IEC 13422: lW4( E)
Cmfficient of linear hygroscopic expansion of the disk
.
94 . Torque
Starting torque
9.4.1
Running torque
9.4.2
Magnetit characteristics
Recording area
10.1
10.2 Track geometry
10.2.1 Number of tracks
10.2.2 Width of tracks
10.2.3 Track location
Track number
10.2.4
.
tes t ing
10.3 Func tional
10.3.1 Surface tests
10.3.2 Track quality tests
10.3.3 Rejection criteria
11 General requirements of the data track recording
11.1 Method of recording
11.2 Track location tolerancc of the recorded Flexible Disk Cartridge
11.3 Recording offset angle
11.4 Density of recording
11.5 Flux transition spacing
11.6 Average Signal Amplitude
1.1.7 Byte
11.8 secxor
11.9 Cylinder
11.10 Cylinder number
11.11 Data capacity of a track
11.12 Special MFM recording signals
11.13 Error Detecting Code
Defective sector
11.14
12 Data track layout
12.1
Index Gap
12.2 Seetor Idcntifier
12.2.1 Identifier Mark
12.2.2 Address Idcntifier
12.3 Identifier Gap
12.4 Data Block
12.4.1 Data Mark
12.4.2
Data Ficld
12.4.3 EDC
12.5 Data Block Gap
iv
@ ISO/IEC
13 General requirements of the servo track recording
13 1 General
13:2 Method of recording
Servo track
13.3
Number of tracks
13.3.1
Width of tracks
13.3.2
13.3.3 Track location
Track number
13.3.4
13.4 Average Signal Amplitude of Servo Data
13.5 Fluctuation of Signal amplitude of Servo Data
14 Servo track layout
14.1 Deviation between the data track and the servo track
Servo area timing
14.2
Servo Identifier
14.2.1
14.2.2 Servo Data
Annexes
A-
Test for compliance
B - Measurement of light transmittance
c - Method for measuring the effective track width
D- Procedure and equipment for measuring flux transition spacing
E - Data separators for decoding MFM recording
F - EDC implementation
G- Cartridge distortion test gauge
H- Method of measuring peak shift
J - Servo track recording condi tions
K- Method for measuring fluctuation of the Servo Data amplitude
L - Institute for the supply of Secondary Standard Reference Flexible Disk Cartridges

@ ISO/IEC
ISO/IEC 13422: 1994(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the Inter-
national Electrotechnical Commission) form the specialized System for worldwide
standardization. National bodies that are members of ISO or IEC participate in the
development of International Standards through technical committees established
by the respective organization to deal with particular fields of technical activity.
ISO and IEC technical committees collaborate in fields of mutual interest. Other
international organizations, governmental and non-governmental, in liaison with
ISO and IEC, also take part in the work.
In the field of information technology, ISO and IEC have established a joint
technical committee, ISO/IEC JTC 1. Draft International Standards adopted by the
joint technical committee are circulated to national bodies for voting. Publication
as an International Standard requires approval by at least 75 % of the national
bodies casting a vote.
International Standard ISO/IEC 13422 was prepared by the Japanese Industrial
Standards Committee (as JIS X 6227-1992) and was adopted, under a special
“fast-track procedure” by Joint Technical Committee ISO/IEC JTC 1, Information
technology, in parallel with its approval by national bodies of ISO and IEC.
Annexes A to D, G and H form an integral part of this International Standard.
Annexes E, F, J, K and L are for information only.

@ ISO/IEC
Introduction
This International Standard specifies the characteristics of 90 mm Flexible Disk
Cartridges recorded at 33 157 ftprad using modified frequency modulation recording,
on 255 tracks at 16,9 tpmm on each side using sector servo tracking.
This International Standard specifies the physical interchangeability of the
unrecorded disk and the format interchangeability of recorded data tracks and servo
tracks.
In referencc to ISO/IEC 9983, Flexible Disk Cartridges conforming to this
International Standard are designated as ISO Type 304.
vii
Jhis page intentionally left blank

INTERNATIONAL STANDARD 0 ISO/IEC
Information technology - Data interchange on 90 mm Flexible Disk
Cartridges 10 MByte capacity using sector servo tracking - ISO Type 304
1 Scope
This International Standard specifies the characteristics of 90 mm Flexible Disk Cartridges of 10 MByte formatted
capacity, recorded at 33 157 ftprad using modified frequency modulation recording and sector servo tracking on 255
data tracks on each side. Such Flexible Disk Cartridges are identified as ISO Type 304.
It specifies the mechanical, physical and magnetic characteristics of the cartridge, so as to provide physical
interchangeability between data processing Systems.
It also specifies the method of recording, the quality of the recorded Signals, the track layout and the track format of
data tracks and sefvo tracks.
Together with a Standard for volume and file structure, for example International Standard ISO 9293, this
International Standard provides for full data interchange between data processing Systems.
Conformance
21 . Flexible Disk Cartridge
A 90 mm Flexible Disk Cartridge is in conformance with this International Standard if it meets all mandatory
requirements specified herein.
2.2 Generating systems
A System generating a Flexible Disk Cartridge for interchange shall be entitled to Claim conformance with this
International Standard if all recordings on the flexible disk meet the mandatory requirements of this International
Standard.
2.3 Receiving Systems
A System receiving a Flexible Disk Cartridge for interchange shall be entitled to Claim full conformance with this
International Standard if it is able to handle any recording made on the flexible disk according to this International
Standard.
3 Normative references
The following International Standards contain provisions which, through reference in this text, constitute provisions
of this International Standard. At the time of publication, the editions indicated were valid. All Standards are subject
to revision, and Parties to agreements based on this International Standard are encouraged to investigate the
possibility of applying the most rccent editions of the International Standards listed below. Members of IEC and ISO
maintain registers of currcntly valid International Standards.

@ ISO/IEC
ISOIIEC 13422:1994( E)
Part 13: Wrought stainless steels.
ISO 683~13:1986, Heat treatable steels, alloy steels andfree-cutting steels -
ISO 8860-1: 1987, Information Processing - Data interchange on 90 mm(3,5 in)flexible disk carfridges using modified
frequency mdulaion recording at 7 958fiprad on 80 tracks on each side - Part 1 :Dimnsional, physical and magnetic
characteristics.
Volume and file structure offlexible disk cartridges for informution
ISO 9293: 1987, Information processing -
interchange.
Data interchange on 90 tnm(3,5 in) flexible disk cartridges
ISO/IEC 9529-1: 1989, Information processing Systems -
using modified fiequency modulation recording at 15 916 ftprad, on 80 tracks on each side - Part 1 :Dimensional,
physical and magnetic characteristics.
Designation of unrecorded f ’lcxible disk cartridges.
ISO/IEC 9983; 1989, Information processing Systems -
ISO/lEC 109941992, Information technology - Data interchange on 90 mm flexible disk cartridges using modified
frequency modulation recording at 31 831 fiprad on 80 tracks on each side - ISO Type 303.
Definitions
For the purposes of this International Standard, the following definitions apply.
4.1 Average Signal Amplitude: The Average Signal Amplitude for a track is thc arithmetically averaged value of
the output voltages measured peak-to-peak over the whole track.
4.2 case: A protective enclosure including a shutter mechanism, identification holcs and a write-inhibit hole.
4.3 data track: A discrete concentric track on which data are recorded in the data sector areas.
4.4 Error Detecting Code: A mathematical computation yielding check bytes used for the detection of errors.
4.5
Flexible Disk Cartridge: A flexible information recording medium consisting of a case and a disk, which
accepts and retains information for data processing and associated Systems, on both rccording surfaces.
46 . flux transition frequency: The number of flux transitions per second (ftps) uscd for testing on the rotating disk
at a certain Speed.
4.7 hub: A centring and rcfcrencing devicc attachcd to the disk which allows corquc to be transmitted to the disk.
The hub is attached to the centre of thc disk. It cnsures centring of the disk on thc drivc shaft in a uniquc angular
position.
4.8 liner: Suitablc material positioned
bctwccn t-he casc and the disk to providc clcaning action and protcction from
abrasion.
4.9
MFM recording mode: A recording mode in which a flux transition shall bc writtcn at thc ccntrc of each bit cell
containing a ONE, and at cach ccll boundary bctween consccutivc bit cells containing ZEROS.
ISOhEC 13422:1!W4(E)
@ ISO/IEC
4.10 Master Standard Reference Flexible Disk Cartridge: A Referencc Flcxiblc Disk Cartridge selccted as the
Standard for Reference Fields, Signal amplitudes, resolution, peak shift, and ovcrwritc. Track Ooo and track 254 on both
sides are declared as reference tracks.
The reference tracks are calibrated at 360 rpm.
NOTE 1 - The Master Standard Reference Flexible Disk Cartridge has been established at the Reliability Centre for Elwtronic Components of
Japan (RCJ), 1-1-12 Hachiman-cho, IIigashikurume, Tokyo 203, Japan.
4.11 peak value: The crest value of read back output voltage, with 0 V as thc reference voltage.
4.12 primary identification hole: A through-hole provided on the casc to identify the Flexible Disk Canridge
specified by this International Standard.
4.13 Reference Field: The Typical Field of the Master Standard Reference Flexible Disk Cartridge. There arc two
Reference Field, one for each side.
4.14 Secondary Standard Reference Flexible Disk Cartridge: A Flexible Disk Cartridge the performancc of
which is known and stated in relation to that of the Master Standard Referencc Flexible Disk Cartridge.
NOTE 2 - Secondary Standard Reference Flexible Disk Cartridges tan be ordered under Part Nurnbcr JRM 6227 from the Reliability Centre
for Electronie Components of Japan (RCJ), l-l-12 Hachiman-cho, Higashikurume, Tokyo 203, Japan, until the year 2004 (sec annex L).
It is intended that these be used for calibrating tertiary reference disks for use in routine calibration.
4.15 secondary identification hole: An identification hole provided on the casc to identify the Flexible Disk
Cartridge specified by this International Standard.
4.16 nfonnation is rccorded bctwccn scctors, in
sector servo: A method of position control, where head positioning i
which data are writtcn and rcad.
4.17
servo track: A discrete concentric track on which servo data are recordcd pcrmanently in the servo scctor arcas.
4.18 shutter: A device
which uncovcrs the head windows upon insertion of the cartridge into a drivc, and
automatically covcrs them
upon rcmoval from the drive.
4.19 Standard Reference Amplitude: Tbc Standard Rcference Amplitudcs (SRAs) arc thc Avcragc Signal
Amplitudcs dcrivcd from thc rcfcrcncc tracks of thc Master Standard Rcfcrcncc Flcxiblc Disk Cartridgc using thc Test
Rccording Currcnt.
Therc arc four SRAs, two for cach sidc:
SRA-f, is thc Avcragc Signal Amplitudc from a rccording writtcn usingf, at tr;tck 000.
SRA-f, is thc Avcragc Signal Amplirudc from a recording writtcn usingf, at tr;t& 54.
4.20 Typical Field: Tbc minimuni rccording ficld which, whcn applicd 10 ;i Flcxiblc Disk Cartridgc, causcs an
Avcrage Signal Amplitudc cqual to 95 % of thc maximum Avcragc Signal Amplitutic whcn takcn as a function of thc
recording ficld at thc specific.d track and Ilux transition dcnsity.
4.21 write-inhibit hole: A through-holt with a sliding covcr, providcd on thc‘ cw 10 inhibit writing on thc disk whcn
thc hole is uncovcrcd.
@ ISO/IEC
ISO/IEC 13422: 1994(E)
5 Conventions and Notations
5.1 Representation of numbers
A measured value is rounded off to the least significant digit of the corresponding specified value.
It implies that a specified value of 40,OO with a positive tolerante of +0,15, and a negative tolerante -0,lS
allows a range of measured values from 39,845 to 40,155.
Letters A to F and digits in parentheses represent numbers in hexadecimal notation.
The setting of a bit is denoted by ZERO or ONE.
Numbers in binary notation and bit combinations are represented by strings of ZEROS and ONEs.
Numbers in binary notation and bit combinations are shown with the most significant bit to the left.
Negative value of numbers in binary notation are given in TWO ’s complement.
In each field the data is recorded so that the most significant byte (byte 0) is recorded first. Within each byte
the least significant bit is numbered 1 and is recorded last, the most significant bit (numbered 8 in an 8-bit
byte) is recorded first.
This Order of recording applies also to the data input of the Error Detection circuits and to their output.
5.2 Acronyms
ASA Average Signal Amplitude
EDC Error Detecting Code
FDC Flexible Disk Cartridge
Fast Fourier Transform
ftprad flux transition per radian
ftps flux transition per second
MFM Modified Frequency Modulation
SRA
Standard Reference Amplitude
SVDT
Servo Data
SVID Servo Identifier
@ ISO/IEC
General descrip tion
61 . Drawings
In the enclosed drawings:
Figure 13 Shows Side 0 and enlarged cross-sections through the bcation and secondary identification hola;
Figure 14 Shows Side 1;
Figure 15 Shows at a larger scale the top part of Side 0 without shutter;
Figure 16 Shows the disk with hub;
Figure 17 Shows the interface between the cartridge and the drive.
62 . Main elements
The main elements of the Flexible Disk Cartridge are
the disk,
the liner,
the case.
63 . Description
The case includes a central hole on one side, head windows covered with a shutter on both sides, identification holes
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 central hole with a metal hub attached.
64 . Marking of the Flexible Disk Cartridge
The case of the flexible disk shall be clearly marked with the following information:
Type of flexible disk, type (both sides), mode of recording and number of tracks, ISO Type number
Year and month of manufacture or mark thereof
Manufacturer ’s name or mark
@ ISO/IEC
7 General requirements
7.1 Environment and transportation
7.1.1 Testing environment
Tests and measurements made on the cartridge to check the requirements of this International Standard shall be
operated under the following conditions,
23 ’C t 2 ’C
temperature:
relative humidity: 4o%to60%
conditioning before testing: 24 h min.
For the tests specified in 10.3 the temperature and relative humidity shall be measured in the air immediately
surrounding the cartridge drive. For all other tests the temperature and the relative humidity shall be measured in the
air immediately surrounding the cartridge.
The stray magnetic field at any point on the disk surface, including that resulting from the concentrating effect of the
magnetic head, shall not exceed 4 000 A/m.
7.1.2 Operating environment
Cartridges used for data interchange shall be capable of operating under the following conditions
1o ’c to Sl,S%
temperature:
relative humidity: 20 % to 80 %
wet bulb temperature: less than 29 ’C
The temperature and the relative humidity shall be measured in the air irnmediately surrounding the cartridge. It is
recommended that the rate of Change of the temperature should not exceed 2O ’C per hour.
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 concentrating effect of the
magnetic head, shall not exceed 4 000 A/m.
7.1.3 Storage environment
During storage the cartridges shall be kept within the following conditions
temperature: 4t to 53Oc
relative humidity: 8 % to 90 %
The ambient stray magnetic field shall not exceed 4 000 A/m. There shall be no dcposit sf moisturc on or in thc
cartridge.
NOTE 3 - Cartridges which have been stored at temperatures and humidities exceeding the operating conditions may exhibit degraded
performante characteristics. Such cartridges should be subjected to a conditioning period of not less than 24 h within the operating
environment prior to use.
7.1.4
Transportation
Responsibility for ensuring that adcquate precautions are taken during the transportation shall bc with thc Sender.
The cartridge shall be in a protective package free from dust or extraneous matter. It is recommcnded that a
sufficient space exists between cartridge and outer surface of the final containcr, so that risk of crasure due to stray
magnetic fields will be negligiblc.

ISO/IEC 13422:1W4(E)
@ ISO/IEC
It is recommended that the following conditions are not exceeded
-4oOc to 6o ”c
temperature:
20°C per hour
maximum rate of temperature Change:
relative humidity: 8 % to 90 %
There should be no deposit of moisture on or in the cartridge.
7.2 Materials
7.2.1 Gase
The case may be constructed from any suitable material such that it meets the rcquirements of 8.7.
7.2.2 Liner
The material of the liner shall be able to retain dust or debris without darnage to the disk.
7.2.3 Disk
The disk may be constructed from any suitable material (e.g. bi-axially oriented polyethylene terephthalate) coated
on both sides with a flexible layer of magnetic material (e.g. metal iron particlcs).
7.2.4 Hub
The hub shall be made of any suitable material (e.g. stainless steel alloy in accordance with ISO 683-13, type 8).
8 Dimensional characteristics
The dimensions of the cartridge are referred to two Reference Axes X and Y. Thcy are two lines in space
intersecting at right angles. The plane they define is the Reference Plane XY 01’ the cartridge.
81 . Case
8.1.1 Shape (figure 13)
The case has a rectangular form, its sides shall be
L, = 94,0 mm t 0,3 mm
L,= 90,O mm +Ov4 mm
-01 9
The radius of three of its comcrs shall be
R,=Z,Omm * 1,Omm
The angle of its fourth corncr shall be
w =45* t 2*
8.1.2
Thickness (figure 14)
In the area extending 8,5 mm from each of thc two cdgcs as shown in figurt 13, thc thickncss of thc casc shall be
E, = 3,3 mm -t 0,2 mm
When the cartridgc is inscrtcd in thc tcst gaugc spccified in anncx G, a forte of’ 02 N maximum, applicd to thc
centre of thc back edgc shall causc thc cartridge to pass through thc gauge.
Tbc edge radius shall be
R, = 0,40 mm k 0,25 mm
@ ISO/IEC
8.1.3 Hub access hole (figure 13)
On Side 0 there shall be a hub access hole the diameter of which shall be
D, = 26,SO mm min.
The position of the centre of this hole shall be defined by
L3 = 40,OO mm t 0,15 mm
L4 = 31,00 mm t 0,15 mm
8.1.4 Locating holes (figures 13 and 15)
8.1.4.1 Primary locating hole
The centre of the primary locating hole shall be at the intersection of Reference Axes X and Y.
Its diameter shall be
D, = 3,6 mm k 0,l mm
The dimensions of its section (see Cross-section A-A in figure 13) shall be
= 1,5mmmin.
D3
= 0,2 mm t 0,l mm
L8
= 1,Ommmin.
L9
= 2,5 mm min.
L,,
8.1.4.2 Secondary locating hole
The centre of the secondary Iocating hole shall be on Reference Axis X, its distance from Reference Axis Y shall be
L, = 80,O mm k 0,2 mm
It shall have a substantially rectangular shape. Its short axis shall be (see Cross-section B-B in figure 13)
Lh= 3,6mm 2 0,l mm
Its long axis shall be
L, = 4.4 mm t 0,2 mm
The dimensions D,, L,, L, and L,, of the Cross-section of the secondary locating hole are as specified in 8.1.4.1.
8.1.5 Label area
8.1.5.1 Side 0 (figure 13)
The locations and dimensions of the label area of Side 0 shall be defined by
= 3,5 mm min.
L,,
= 76,5 mm max.
L,2
L ,4 = 60,O mm min.
8.1.5.2
Side 1 (figure 14)
The locations and dimensions of thc label area of Sidc 1 shall bc defincd by
= 3,5 mm min.
L,,
= 76,5 mm max,
L,*
= 20,O mm min.
LU
8.1.6 Head windows (figure 15)
The locations and dimensions sf thc two head windows arc specified by thc same set of dimcnsions.
@ ISO/IEC
8.1.6.1 Location
The location of the head windows shall be defined by
12,3 mm min.
L15 =
L 16= 11,5 mmmin.
35,5 mm t 0,2 mm
L,7 =
8.1.6.2 Dimensions
The width of the head windows shall be
9,00 mm -t 0,20 mm
L,8 =
The radius of their comers shall be
R, = 0,5 mm t 0,l mm
R,=0,5mmfOJ mm
8.1,7 Write-inhibit hole (figures 13 and 14)
8.1.7.1 Location
The centre of the write-inhibit hole shall be specified by L, and
67,75 mm z& 0,25 mm
L,9 =
8.1.7.2 Dimensions
The dimensions of the write-inhibit hole shall be
L
49 = 3,5 mm min.
= 4,0 mm min.
L50
8.1.7.3
USi?
The write-inhibit hole is intended for use either with a mechanical switch or with an optical detector so that only
when the hole is covered is writing on the disk possible. When covered, the closure device shall not extend outside
the Reference Plane XY nor shall it deflect by more than 0.3 mm from the Reference Plane XY inside the case under
the action of a forte of 3 N.
Also when covered, the light transmittance of the write-inhibit hole area shall not exceed 1 %, when measured with
an Optical System such as described in annex B.
8.1.8 Identification holes (figures 13,14 and 15)
The identification holes arc provided to distinguish between the Flexible Disk Cartridge by this International
Standard from those specificd by ISO 8860-1, ISO/IEC 9529-1, and ISO/IEC 10994.
NOTE 4 - As the secondary identification hole is not a through-hole, it is recommended that the identification holes arc detectd by mcchanical
means.
8.1.8.1
Primary iden tification hole
The Position of the centre of the primary identification hole shall be on Reference Axis Y. Its distance from
Reference Axis X shall be specified by Llg.
The dimensions of the primary identification hole shall be
= 3,5 mm min.
Lm
= 4,O mm min.
L2,
0 ISO/IEC
8.1.8.2 Secondary identification hole
The Position of the centre of the secondary identification hole shall be
L, = 7,50 mm t 0,15 mm
L,, =74,Omm t 0,2 mm
Its diameter shall be
= 3,5 mm min.
D,o
The dimensions of its section (see Cross-section C-C in figurc 13) shall be specified by L, and
L
62 = 2,5 mm min.
8.1.9 Profile of the shutter edge of the case (figure 15)
The edge on which the shutter is mounted shall have a Profile defined by the following dimensions:
Lu= 80,O mm t 0,2 mm
L, =
76,0 mm I!I 0,3 mm
L, = 68,0 mm t 0,3 mm
L, = 64,50 mm + 0,35 mm
L, = 57,00 mm k 0,35 mm
L
2, = 55,5 mm k 0,6 mm
= 3.5 mm min.
L,
L
29 = 17,5 mm + 0,2 mm
L,= 17,00 mm t 0,15 mm
15,50 mm -b 0,25 mm
L31 =
L 45 = 12,50 mm & 0,25 mm
a = 45O t 2O
p = 135O t 2.
8.1.10 Shutter (figures 14 and 15)
The shutter shall slide upon insertion of the cartridge into the drive so as to uncover the head windows, and close
automatically upon removal. The maximum resistance forte at the fully open position shall be 1 N, and the
minimum resistance forte at the fully closed position shall be 0,2 N.
The path along which the shuttcr tan slide is defined by L, and L,.
In the open Position of the shuttcr, the distance from its leading edge to the Referencc Axis Y shall be
L 32 = 53,75 mm I!I 1,25 mm
The width of the windows of thc shutter shall be
L 33 = 12,O mm t 0,2 mm
NOTE 5 - It is a requirement that the drivc shall provide
a mechanism whereby correct insertion of the cartridgt: into the drive C~USCS thc
shutter to slide so as to uncover the he4 windows.
8.2 Liner
NO part of the liner shall protrude by more than 0,2 nm into thc head access windows.
83 . Disk (figure 16)
8.3.1 Diameter
Tbc diamctcr of thc disk shall bc
D, = 85,8 mm Z!I 0,2 mm
ISOIIEC 13422:1994(E)
@ ISO/IEC
Thickness
8.3.2
The thickness of the disk shall be
E, = 0,067 mm & 0,008 mm
8.4 Hub (figure 16)
The hub shall have a central part and a flange.
8.4.1 Dimensions
The diameter of the central part shall be
0,~
D,=25,OOmm -015 mm
The diameter of the flange shall be
D, = 29,50 mm max.
The distance from the surface of the central part sf the hub to the surface of Side 0 of the disk shall be
L,= 1,36 mm & 0,lO mm
when measured at a radius R,
R, = 14 mm nominal
8.4.2 Hub orientation holes (figure 16)
The hub shall have two orientation holes. The first one at its centre, the second off centre.
8.4.2.1 First orientation hole
The first orientation hole shall have a Square form defmed by
L 35 = 4,0 mm min.
The position of the centre of rotation of the disk is defined by
=1,9955mm
L36
measured from two sides of the hole. The centre of rotation shall be within 0.5 mm of the geometric centre of the
disk.
The radius of the four comers of this hole shall be
R,= 1,Omm I!Z 0,3 mm
The angles of two sides of the hole which is in contact with the spindle shaft (sec Cross-sections D-D and E-E in
figure 16) shall be
+1°
6 =90° oo
8.4.2.2
Second orientation hole
The position and dimensions of the sides of the rectangular sccond oricntation hole arc rcfcrred to two radial
Reference Lines A and B that arc perpendicular to each other. Their positions shall bc specified by
= 15O t 3O
Y
The lcngth of the sidcs of this hole shall be
L 3, = 8,O mm k 0,3 mm
L 38 = 43 mm min.
@ ISOPEC
These sides shall be parallel to Reference Lines A and B, respectively, at a distmce;
L
39 = 2,0 mm + 0,2 mm
La = 10,OO mm t 0,15 mm
I
The radius of one comer of this hole shall be
R, = 2,0 mm Z!Z 0,l mm
The radius of t.he three other comers shall be
R,= 1,Omm Z!Z 0,3 mm
8.5 Optional handling notches (figures 13 and 14)
Two handling notches are permitted. If present they shall satisfy the following requirements. Their centres shall be
on a line parallel to, and lying above, Reference Axis X at a distance;
Ld1 = 7,50 mm t 0,15 mm
Their dimensions shall be
L 42 = 3,0 mm min.
L,, = 4,2 mm t 0,2 mm
Their depth below the Referencc Plane XY shaI1 be
Lu = 2,0 mm min.
8.6 Interface between cartridge and drive (figure 17)
When the cartridge is inserted into the drive, the drive spindle engages the cartridge as shown in figure 17. The hub
is held against the drive spindle by means of a magnetic attraction forte. When in this position the distance betwecn
the hub surface on Side 0 and plane XY shall be
= 0,3 mm nominal
L46
The inside dimensions of the case with the centre plate on Sidc 1 shall be
D, = 7,0 mm min.
E,= 1,3mm + 0,l mm
with the exception of the annular zone defmed by Ld, and La where the thickness shall be
E, = 2,5 mm max.
Ld, shall be sufficiently large to cnsure that the circumference of the disk shall not tauch the inside edges of the casc.
The value of Lh, specified below is a recommended value, therefore it is stated without tolerante.
L 47 = 22,6 mm
La = 21,7 mm t 0,2 mm
8.7
Compliance
When the cartridge is constraincd in the manner described in annex A, thc cartridgc shall be in contact with posts P,
to P,.
Physical characteristics
9.1 Flammability
The disk, case and liner componcnts shall be made from matcrials that, if ignitcd from a match flamc, do not
continuc to bum in a still carbon dioxide atmosphcrc.
@ ISO/IEC
9.2 Coefflcient of linear thermal expansion of the disk
The coefficient of thermal expansion of the disk shall be
(17 t 8) X 10-6per “C.
The range from maximum value to minimuni value on the disk surface shall bc
8 X 10-6 per “C max.
Coefflcient of linear hygroscopic expansion of the disk
93 .
The coefficient of hygroscopic expansion of the disk shall be
(0 to 15) X 10-6 per % of relative humidity.
The range from maximum value to minimum value on the disk surface shall bc
5 X 10-6 per % of relative humidity max.
9.4 Torque
9.4s Starting torque
The starting torque, without the heads loaded, shall not excecd 0,006 N ‘m.
Running torque
9.4.2
The torque necessary to turn the disk, without the heads loaded, shall be in thc r~gc 0,000 5 N ~rn to 0,002 5 N em
when the cartridge is in Operation at a Speed of 360,O rpm $- 3,O rpm.
10 Magnetit characteristics
10.1 Recording area
On each side the magnetic properties specified shall be uniform in the recording arca, which shall be the area limited
by two radii:
20,6 mm max.
42,0 mm min.
10.2 Track geometry
10.2.1 Number of tracks
In the recording arca there shall be 255 discretc conccntric tracks on each sidc 01’ disk.
10.2.2
Width of tracks
Tbc width of a recordcd track shall bc
0,044 mm t 0,003 mm
Tbc method of mcasuring cl ‘l’cctivc track width is givcn in anncx C.
10.2.3 Track location
10.2.3.1 Nominal locat ions
Tbc nominal radius (R ) of’ ttw ccntrclirw 01’ all mcks du11 bc calculatctl ty uw~! tl
n
R non~. = x - 0,osc) 12
n
@ ISO/IEC
ISO/IEC 13422: 1994(E)
where
n is the track number, n = 000 to 254
x = 39,500 mm for Side 0, x = 38,000 mm for Side 1
10.2.3.2 Track location tolerante
For testing purposes the centrelines of the recorded tracks shall be within t 0,020 mm of the nominal positions,
when measured in the testing environment (7.1.1).
10.2.3.3 Line of access of the heads
‘I’he line of access of the heads shall be a line parallel to a radial line and spaced 0,35 mm from it (see 11.3).
10.2.4 Track number
The track number shall be a three-digit decimal number (from 000 to 254) for each side. It identifies the tracks
consecutively, starting at the outermost track (Ooo).
10.3 Functional testing
For the purpose of the following tests the same drive unit shall be used for writing and reading operations, both for
the disk under test and for the Secondary Standard Reference Flexible Disk Cartridge.
The in-contact condition shall be used.
10.3.1 Surface tests
The magnetic properties of both surfaces arc defined by the testing requirements given below.
10.3.1.1
Test conditions
Traceability to the Typical Field, SR&, resolution, peak shift and overwrite of the Master Standard Reference
Flexible Disk Cartridge arc provided by the calibration factors supplied with each Secondary Standard Refcrencc
Flexible Disk Cartridge.
10.3.1.1.1 Flux transition frequency
The disk shall be tested at 360.0 rpmt 3.6 rpm. The test frequencies, expressed in flux transitions per second (ftps),
shall be
fl= 625 000 ftps t 625 ftps
fz= 1 250 000 ftps t l 250 ftps
The frequency(ies) to be used is(arc) specified for each test.
10.3.1.1.2 Test Recording Kurrent
The Test Recording Currcnt for track 000 to track 119 shall bc (200 I!I 2) a/c of t.hc currcnt which produccs thc
Reference Field atf, on track 254. The Test Recording Current for track 120 to track 254 shall tX: (1 SO I!I 2) 5% of
the current which produccs thc Rcference Field at fi on track 254.
10.3.1.2 Typical Field
The Typical Ficld of the disk undcr tcst shall bc (100 I!I 20) c/o of the Rcfcrcnce Ficld. It shall be mcasurcd usingf,
on track 254 on both sidcs.
ISO/IEC 13422:lW4(E)
@ ISO/IEC
10.3.1.3 Average Signal Amplitude
When the disk under test has becn recorded with the Test Recording Current, then rcad back and compared with the
Secondary Standard Reference Flexible Disk Cartridge recorded under the same conditions, the Average Signal
Amplitude shall be
- on track 000, usingf,: less than 130 % of SRA-f,
- on track 254, usingf,: morc than 85 % of SRA-i,
This test shall be performed on both sides, using the Secondary Standard Reference Flexible Disk Cartridge.
Resolution
10.3.1.4
After recording on track 254, using the Test Recording Current, the ratio
ASA-f,
x 100%
ASA-f,
shall be (100 & 15) % of the same ratio for the Master Standard Reference Flexible Disk Cartridge.
This test shall be performed on both sides.
10.3.1s Peak shift
The average peak shift measured on the disk cartridge under test, using the method specified in annex H, shall be
(100 t 37) % of that of thc Master Standard Reference Flexible Disk Cartridge when measured on the Secondary
Standard Reference Flexible Disk Cartridge under the sarne conditions. This test shall be performed on track 254 on
both sides.
10.3.1.6 Overwrite
The overwrite ratio
Residual Average Signal Amplitude at& after overwrite usingf,
Average Signal Amplitude after first recording usingf,
shall not exceed 125 % of the value of the same ratio for the Master Standard Reference Flexible Disk Cartridge for
each side, when measured according to the following procedure.
Erase track 000 using direct current, then record atf, for one revolution on track 000 using the Test Recording
Current.
Read back and note thc Average Signal Amplitude Off,.
c
f2 for one revolution.
Overwrite with
Read back and note the Residual Average Signal Amplitude Off,.
Reading shall be takcn with a frequency-selectivc Voltmeter.
10.3.1.7 Modulation
Modulation shall be
A-B
x 100%
A+B
A is the maximum valuc of thc average values of the amplitude modulatcdoutput voltagc of about 2 Wo
consecutive flux transitions in a track. Output voltagc shall bc mcasurcd pcak-to-pcak, in voltagc.
B is thc minimum valuc of thc avcragc valucs of thc amplitudc modulatcd output voltagc of‘ about 2 Ooo
consecutivc flux transitions in a track. Output voltagc shall bc nmsured pak-to-peak, in voltqy.
On track (XK) to track 254 using jY,, modulation shall & lcss than IO %. This twt shall tx prl’orrwd on both sidcs.
4.
@ ISO/IEC
10.3.2 Track quality tests
These tests shall apply to all 255 tracks at the defined positions on each side. The appropriate Test Recording
Current shall be used.
10.3.2.1 Missing pulse
Write a track withf, and measure the Average Signal Amplitude. Any playback Signal which, when measured base-
to-peak, is less than 65 % of half the Average Signal Amplitude of the track, shall be a missing pulse.
10.3.2.2 Extra pulse
Write a track withf, and measure the Average Signal Amplitude. Then erase the track for one revolution with a
direct current equal to the quiescent value (Iq) of the Test Recording Current applied to the head (see figure 1). Any
playback Signal which, when measured base-to-peak, exceeds 20 % of half the Average Signal Amplitude shall be an
extra pulse.
Figure 1 - Quiescent value of Test Recording Current
10.3.3
Rejection criteria
10.3.3.1 Requirement for tracks
A defective Position is a Position where missing and/or extra pulses are detected on three consecutive Passes.
10.3.3.1.1 Tracks 000 to 003
As initially received from the medium supplier, the cartridge shall have no defects for track 000 to track 003.
10.3.3.1.2 Tracks 004 to 254
As initially received from the medium supplier, the cartridge shall have no more than one defect on each track, and it
is recommended that the total number of the defects on both sides should be no more than 10, for track 004 to track
254 .
10.3.3.1.3 Guard areas out of track -001 and track 255
These areas shall comprise a 7-track wide band on the outer side of track -001 and a 3-track wide band on the inner
side of track 255, and it is recommended that the total number of the defects on both sides should be no more than
100 in these areas.
ISOIIEC 13422:1994(E)
@ ISO/IEC
10.3.3.2 Rejected cartridge
A cartridge which does not meet the requirements of 10.3.3.1 shall be rejected.
11 General requirements of the data track recording
11.1 Method of recording
The method of recording shall be Modified Frequency Modulation (MFM).
11.2 Track location tolerante of the recorded Flexible Disk Cartridge
Within the testing environment specified in 7.1.1 the centrelines of the recorded data tracks shall be within & 0,028
mm of the nominal track locations.
11.3 Recording offset angle (figure 2)
At the instant of writing or reading a magnetic transition, the transition shall have an angle of:
d
0 = arc sin 7 3- 0’ 15’
where Rn is the radius through that transition in millimeters (see 10.2.3.1), and d = 0,35 mm.
rTrack
cent reline
n
d
Line of
access
--I
Figure 2 - Recording offset angle
11.4 Density of recording
11.4.1 The nominal density of recording shall be 33 157 ftprad. The resulting nominal bit cell length is 30,16
.
JA rad.
11.4.2 The long-term average bit cell length shall be the average bit cell length measured over a sector. It shall
be within t 1,l % of the nominal bit cell length.
11.4.3 The short-term average bit cell length, referred to a particular bit cell, shall be the average of the lengths
of the preceding eight bit cells. It shall be within t 8 % of the long-term average bit cell length.
11.5 Flux transition spacing (figure 3)
The instantaneous spacing between flux transition is influenced by the reading and writing process, the bit sequence
(pulse crowding effects) and other factors. The locations of the transitions are defined as the locations of the peaks
in the Signal when reading. Tests shall be carried out according to annexes D and E.
11.51 The spacing between the flux transitions of a sequence of ONEs shall be between 80 % and 120 % of
the short-term average bit cell length.
11.52 The spacing between the flux transition for a ONE and that between two ZEROS preceding or
following it shall be between 130 % and 165 % of the short-term average bit cell length.
11.53 The spacing between the flux transitions of two ONEs surrounding a ZERO shall be between 185 %
and 225 % of the short-term average bit cell length.
1 0 0 1 0
1 1
b 4 4 4 *
130% to 165% 130% to 165% 185% to 225%
L.
b
*4
Figure 3 - Flux transition spacings
@ISO/.IEC
11.6 Average Signal Amplitude
For each side of the disk the Average Signal Amplitude on any track of the interchanged Flexible Disk Cartridge shall
be less than 160 % of SRA-f, and more than 40 % of SRA-f,.
11.7 Byte
A byte is an ordered set of eight bits, identified by B, to B,, where B, is the most significant bit.
11.8 Seetor
The track shall contain 39 sectors. Esch sector contains 512 bytes.
11.9 Cylinder
A pair of tracks, one on each side, having the same track number.
11.10 Cylinder number
The cylinder number shall be a three-digit number identical with the track number of the tracks of the cylinder.
11.11 Data capacity of a track
The data capacity of a track shall be 19 968 bytes.
11.12 Special MFM recording Signals
erase-by te This shall be defined as the area having no flux transition written by the direct current (Iq)
(see figure 1), estimated by a byte length.
(Al)* byte A byte set to (Al)* shall be used for detecting the Identifier Mark or the Data Mark. In this
byte the boundary transition between the bit B, and B, is missing as shown in figure 4.
B B B B B B B B
8 7 6 5 4 3 2 1
1 0 1 0 0 0 0 1
r r
,
Figure 4 - Flux transition Chart of (Al)* byte
11.13 Error Detecting Code
The two EDC bytes are hardware-generated by shifting serially the relevant bits, specified later for each part of the
track, through a 16-bit shift register described by the generator polynomial:
x16 +x12 +x5 +l
See also annex F.
11.14 Defective sector
A sector in which EDC is incorrect shall be a defective sector. The number of defective sectors shall be no more
than one per track and shall be no more than ten in all tracks on both sides.
No defective sector shall be permitted in cylinder 000 to cylinder 003.
@ ISO/IEC
12 Data track layout
During formatting the rotational Speed of the disk shall be
- averaged Index-to-Index: 360,O rpm t 3,6 rpm
- averaged over a sector: 360,O rpm & 3,6 rpm
After formatting, there shall be 39 sectors on each track. The layout of each track shall be as shown in figure 5.
First
Data
Index Servo Seetor
Identifier
Data Block
Field Identifier
GaP
GaP
Block
GaP
I
.--m-m- -
1st Seetor
39th Seetor --+
1 / _ / d
...