ISO 9315:1989
(Main)Information processing systems — Interface between flexible disk cartridge drives and their host controllers
Information processing systems — Interface between flexible disk cartridge drives and their host controllers
La présente norme internationale spécifie une unité périphérique à cartouches de disques souples et définit les besoins fonctionnels et électriques (y compris les signaux logiques), ainsi que les exigences mécaniques de l'interface pour la connexion d'unités de disques souples conformes au système hôte. Cela inclut les périphériques utilisant des supports spécifiques dans de nombreuses normes, mais n'exclut pas des périphériques utilisant d'autres types de supports. La présente norme internationale diffère d'une spécification en ce qu'elle délimite un jeu minimum d'exigences cohérent avec la compatibilité et l'interchangeabilité au niveau de l'interface. La présente norme a pour objet de faciliter l'interconnexion d'unités de disques flexibles à un système hôte par un utilisateur ayant les capacités techniques de mener des tests vérifiant le niveau fonctionnel. L'utilisateur devrait aussi voir la capacité de spécifier le système global, matériel et logiciel, qui sera unique pour cet appareil particulier, et devrait aussi pouvoir spécifier la combinaison du contrôleur pour l'application envisagée et l'utilisation finale. La présente norme internationale s'applique à la fois aux unités à disques simple et double face utilisant des enveloppes de disques de 200 mm (8 in) ou 130 mm (5,25 in). Elle ne prescrit pas de méthode d'encodage/décodage magnétique, de technique d'enregistrement ou de format servant à lire ou à éc 648rire des données. Elle ne s'applique pas aux sous-systèmes hôtes/périphériques où il n'y a pas de séparation fonctionnelle nette entre l'hôte et ses ou son périphérique. La présente norme, telle que développée à l'origine, a été spécifiquement écrite pour des unités de disques souples de 200 mm et 130 mm. La norme peut cependant s'appliquer à d'autres tailles de disques. En particulier, pour des applications à des unités de disques plus petits envisageant cette norme, il est recommandé que les unités de disques plus petits et leurs contrôleurs
Systèmes de traitement de l'information — Interface entre dispositifs d'entraînement pour cartouches de disques souples et leurs contrôleurs hôtes
General Information
Standards Content (Sample)
INTERNATIONAL
IS0
STANDARD
9315
First edition
1989-07-15
Information processing systems - Interface
between flexible disk cartridge drives and their
host controllers
S yst&mes de traitemen t de l’informa tion -
In tetface en tre dispositifs d’en trainemen t
pour cartouches de disques souples et leurs contr6leurs h&es
Reference number
IS0 9315 : 1989 (E)
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IS0 9315 :I989 (El
Foreword
IS0 (the International Organization for Standardization) is a worldwide federation of
national standards bodies (IS0 member bodies). The work of preparing International
Standards is normally carried out through IS0 technical committees. Each member
body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, govern-
mental and non-governmental, in liaison with ISO, also take part in the work. IS0
collaborates closely with the International Electrotechnical Commission (IEC) on all
matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for approval before their acceptance as International Standards by
the IS0 Council. They are approved in accordance with IS0 procedures requiring at
least 75 % approval by the member bodies voting.
International Standard IS0 9315 was prepared by Technical Committee ISO/TC 97,
lnforma tion processing s ys terns.
0 IS0 1989
All rights reserved. No part of this publication may be reproduced or utilized in any form or by any
means, electronic or mechanical, including photocopying and microfilm, without permission in
writing from the publisher.
International Organization for Standardization
Case postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
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IS0 9315 : 1989 (E)
INTERNATIONAL STANDARD
Information processing systems - Interface between
flexible disk cartridge drives and their host controllers
2.3 cartridge: An assembly consisting of a jacket and a disk.
1 Scope
This International Standard specifies a flexible disk cartridge
2.4 cylinder: The track(s) available under the read/write
drive and defines the necessary functional and electrical re-
head at each radial head position. Each cylinder on a double-
quirements (including logic signals) and the mechanical re-
sided drive includes two tracks. On a single-sided drive,
quirements of the interface for the connection of conforming
cylinders and tracks are synonymous.
flexible disk drives to a host system. It includes drives using
media specified in many standards but does not exclude drives
2.5 disk: A flat circular device having a magnetic coating on
using other media.
at least one side.
This International Standard is distinct from a specification in
that it delineates a minimum set of requirements consistent 2.6 disk drive: A mechanism consisting of a spindle to sup-
port and rotate a disk, one or more read/write heads positioned
with compatibility and interchangeability at the interface level.
to read or write digital information on a track of the disk, an ac-
This standard is intended to facilitate the interconnection of
tuator to move the heads to any track, and logic circuits and
flexible disk drives to a host system by a user who has available
the technical capability to verify test performance up through amplifying circuits as required.
the functional level. The user should also have the capability of
specifying the overall system hardware and software that will
2.7 format: The arrangement of coded flux patterns on a
be unique for this particular device, and should also have the
track of a disk to represent tolerance gaps, preamble fields, ad-
capability of specifying the controller combination for the
dress fields, data fields, sector marks, etc.
desired application and end use.
2.8 hard sectoring: The use of mechanical means such as
This International Standard applies to both single- and double-
multiplicity of holes in the index track to define fixed angular
sided disk drives using 200 mm (8 in) or 130 mm (5,25 in)
positions on the disk.
envelope-size flexible disks. It does not prescribe the magnetic
encoding or decoding method, the recording techniques, or the
format used to write or read data. It does not apply to
2.9 index hole track: A concentric track on a disk contain-
host/drive subsystems where there is no clear physical and
ing at least one round hole. It is used to establish a rotational
functional separation between the host and its drive or drives.
reference position by photoelectric means. Some types of disk
This standard, as originally developed, was written specifically
drives and media combinations use other equivalent means for
for 200 mm and 130 mm flexible disk drives. However, the
this function, i.e. the use of a magnetized spot on the media
standard may be applied to other disk sizes. In particular, for
hub along with a magnetic transducer in the drive.
smaller drive applications considering this standard it is recom-
mended that smaller-size flexible disk drives and their con-
2.10 jacket: An assembly consisting of outer cover and
trollers use the descriptions applicable to 130 mm flexible disk
liner.
drives.
2.11 level: A term used to designate the following:
2 Definitions
a) A voltage level;
For the purposes of this International Standard, the following
b) One of two logic levels, high or low;
definitions apply.
c) A signal that remains fixed at a low or high level for the
2.1 active filter: A network used to maintain compatibility duration of a logical sequence, such as SELECT, DIREC-
with post-compensated flexible disk cartridges. TION, READY, as contrasted to a pulse.
2.2 actuator: An electrically driven positioner for one or 2.12 logical false : The non-asserted or non-active state of a
more read/write heads that are controlled by step and direction control signal. In this International Standard it is the high level
select signals. of the signal (2,4 V to 5,25 VI.
1
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Is0 9315 : 1989 E)
above. When this signal interface is false (high) and the disk
2.13
logical true: The asserted or active state of a control
drive is selected, the higher value of the write current is
signal. In this International Standard it is the low level of the
selected for a write operation on cylinders 0 (decimal) through
signal (0 V to 0,4 VI.
42 (decimal).
2.14 mandatory: A term signifying that an item shall be pro-
3.1.2 Active read filter - read mode
vided by the source of the interface signal and need not be
utilized by the receiver.
The signal used as active read filter is optional on 200 mm
drives. When this interface signal is true (low) active and the
2.15 optional: A term signifying that an item may be used
disk drive is selected in a read operation, the read signal is
on certain configurations, but is not mandatory. If used it shall
passed through an active filter network to form composite read
be used as defined in clause 3 and shall be on the connector pin
data (see 3.12) on cylinders 60 (decimal) and above. When this
defined in clause 3.
interface signal is false (high) inactive and the disk drive is
selected in a read operation, the read signal is passed directly to
pulse: A signal that is asserted for a relatively brief time
2.16
form composite read data (see 3.12). The use of this signal
period during a logical sequence (a series of brief assertions).
eliminates the need for a write precompensation. When a flexi-
ble disk cartridge that has been recorded by using write
precompensation is being read, this signal should remain in the
2.17 read/write head: A magnetic recording and playback
false (high) inactive state.
head. There may be one or more of these heads.
3.2 Drive select (four signal lines)
step: The function that locates one or more read/write
2.18
heads over a particular track.
200 mm M To the drive Pins 26, 28, 30, 32; four lines
mandatory
2.19 track: A concentric path on a magnetic surface of the
disk on which data may be written and later recovered by a read
130 mm M To the drive Pins 10, 12, 14; three lines
operation.
mandatory
Pin 6; optional
2.20 vendor unique: A term signifying that use of a par-
The SELECT lines provide a means of selecting and deselecting
ticular function is defined by the vendor.
a disk drive. These four lines select one of the four disk drives
attached to the controller. When the signal line logic level is
true (low), the disk drive electronics are activated for the
3 Functional signals
execution of any step or read/write commands that might be
issued. When the signal line logic level is false (high), all
Figure 1 for 200 mm (8 in) cartridge drives and figure 2 for
input/output bus interface lines are deselected. If the head load
130 mm (5,25 in) cartridge disk drives list the functional signals
signal (see 3.15) is not used, these lines are also used for the
required between the flexible disk drive and the host system.
head load function.
Included in the figures are the pin number assignments of the
signal interface connector. The mandatory signals are required
for the minimum interface. The optional signals, if im-
3.3 Direction select
plemented, shall appear on the pins assigned. The vendor
unique function only exists when it is defined by the vendor. To the drive Pin 34
200 mm M
130 mm M To the drive Pin 18
Head current switch/active read filter
3.1
When the drive is selected, this interface signal defines the
200 mm M To the drive Pin 2; head current switch
direction of motion of one or more read/write heads when the
STEP (see 3.4) line is pulsed. If an open circuit or logical false
0 To the drive active read filter
(high) level is applied, the direction of motion is defined as
“out”, and if a pulse is applied to the STEP line the read/write
130 mm V To the drive Pin 2
heads will move away from the centre of the disk. Conversely,
V To the host
if a logical true (low) level is applied, the direction of motion is
defined as “in”, and if a pulse is applied to the STEP (see 3.4)
This interface signal is used for multiple functions, depending
line, the read/write heads will move toward the centre of the
on whether the drive is in the write or the read mode and
disk.
whether it is a 200 mm or 130 mm drive. This signal should be
in a stable condition before attempting to read or write.
3.4 Step
3.1.1 Head current switch - write mode
200 mm M To the drive Pin 36
The signal used as head current switch is mandatory on
130 mm M To the drive
Pin 20
200 mm drives only. When this interface signal is true (low) and
the disk drive is selected, the lower value of the write current is When the drive is selected, this interface line is a control signal
selected for a write operation on cylinders 43 (decimal) and on which a pulse causes one or more read/write heads to be
2
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IS0 9315 : 1989 (E)
moved one cylinder, with the direction of motion set by the 3.10 Cylinder 0
DIRECTION SELECT line (see 3.3). The quiescent state is
200 mm M To the host Pin 42
logical false (high).
130 mm M To the host Pin 26
3.5 Composite write data
When the disk is selected, the CYLINDER 0 interface signal
200 mm M To the drive Pin 38
indicates to the host that one or more read/write heads are
positioned on cylinder 0. The CYLINDER 0 signal remains
Pin 22
130 mm M To the drive
logically true (low) until the heads are moved away from
cylinder 0.
When the drive is selected, this interface line provides the data
to be written on the disk if the WRITE GATE (see 3.6) is active.
3.11 Write protected
Each transition from the logical false (high) level to the logical
true (low) level causes the current through the selected
200 mm M To the host Pin 44
read/write head to be reversed.
130 mm M To the host Pin 28
3.6 Write gate
When the disk drive is protected, this signal line logic level goes
M To the drive Pin 40
200 mm true (low) if the cartridge is write protected. The write elec-
tronics in the disk drive is internally disabled if the disk is write
M To the drive Pin 24
130 mm
protected. When the level on this line is false (high), the write
electronics is enabled and the write operation can be per-
When the drive is selected, a logical true (low) active level on
formed.
this line enables composite write data (see 3.5) to be written on
the disk. Erase timing is internally generated from the write
3.12 Composite read data
gate.
200 mm M To the host Pin 46
3.7 Index
130 mm M To the host Pin 30
Pin 20
200 mm M To the host
Data from the selected drive are provided as an output to the
130 mm NA
host system in the same form as write data from the host
system. Each flux reversal sensed on the storage element will
This interface signal is pulsed logical true (low) by the selected
result in a pulse to the logical true (low) active level. The
drive once each revolution to indicate the beginning of the
leading edge of this signal shall always be used to ensure timing
cylinder. The leading edge of this signal shall always be used to
accuracy.
ensure timing accuracy. This interface signal may be a com-
posite of the index and sector pulses. The index signal is always
3.13 Side one select
present; the sector signal appears only when hard sector car-
tridges are used and the drive is configured without index/
200 mm 0 To the drive Pin 14
sector separation.
130 mm 0 To the drive Pin 32
3.8 Sector
When the drive is selected, this interface signal defines which
Pin 24
200 mm 0 To the host
side of a two-sided cartridge is used for reading or writing. An
open circuit, or logical false (high) level, selects the read/write
130 mm NA
head on the SIDE 0 surface of the cartridge. An active state, or
logical true (low) level, selects the read/write head on the SIDE
When a hard-sectored cartridge is being utilized, this interface
1 surface of the cartridge.
signal is pulsed true (low) by the selected drive for each sector
to indicate to the host the beginning of the sector. The leading
3.14 In-use control
edge of this signal shall always be used to ensure timing
accuracy.
200 mm 0 To the drive Pin 16
3.9 Drive ready 130 mm 0 To the drive Pin 4
This line is assigned for special control functions available as
200 mm M To the host Pin 22
optional configurations from various manufacturers. It may be
130 mm 0 To the host Pin 34
qualified by drive select or for some functions used
independently of drive select. Typical functions that may be
A logical true (low) active level on this line indicates that a car-
implemented are busy indicator or door lock, or both. The pro-
tridge is loaded properly and rotating in the selected drive and
tocol for this line is dependent upon the particular control func-
that the door is closed.
tion selected.
3
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Iso9315:1989 (El
operation. The signal is a pulse, the leading edge of which
3.15 Head load
defines the beginning of the new (next) bit cell. The line is at
0 To the drive Pin 18 the logical true (low) level during the time of the pulse. The
200 mm
leading edge of this signal shall always be used to ensure timing
130 mm 0 To the drive Pin 4
accuracy.
This interface signal line, when activated to a logical true (low) NOTE - Separated read data and read clock are optional and may be
used only with a particular recording method, i.e, double frequency
level and provided the cartridge access door is closed, will load
(frequency modulation). These lines may lose synchronization during
one or more read/write heads against the disk.
missing clock occurrences. The manufacturer of the drive should be
consulted for the proper use of these lines.
3.16 Drive busy
3.21 Not assigned
0 To the host Pin 8
200 mm
200 mm 0 To the host Pin 6
130 mm NA
130 mm NA
This line is assigned for special status functions available as
optional configurations available from various manufacturers. It
This line is reserved for future use and shall not be used for any
may be qualified by drive select or for some functions used
other p
...
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