JPS63152058A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To make the titled device small in size and low in size by recording/ reproducing data in two kinds of action modes by externally specifying the driving control circuit of a disk motor. CONSTITUTION:Data is recorded and reproduced by selectively specifying a first operation mode for recording and reproducing data by use of MFM (Modified Frequency Modulation) system while rotating a floppy disk 9 at a fixed rotating speed, and a second operation mode for recording and reproducing data by use of GCR (Group Coded Recording) system while changing rotating speed of the floppy disk 9 at every track and making the recording density of each track constant. Moreover, the driving mechanism part of a head 5 and the floppy disk 9 is used in common to obtain a structure where the recording and the data in two kinds of action modes is reproduced. Thus, the scale- down and the cost-down of the device can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic disk device that records/reproduces data using a magnetic disk.

[Summary of the invention]

The present invention provides a magnetic disk device that records/reproduces data using a magnetic disk, which has an operation mode in which the rotation speed of the magnetic disk is fixed, and an operation mode in which the rotation speed is changed for each track of the magnetic disk. By specifying externally to the drive control circuit of the disk motor, 2
This allows data to be written/reproduced in different operating modes.

[Conventional technology]

Generally, magnetic disks such as so-called floppy disks and hard disks are used as external information storage media in various data terminal devices, minicomputers, microcomputers, and the like. Conventionally, many types of magnetic disk devices that record/reproduce information (data) on such magnetic disks have been provided with different specifications such as the shape of the magnetic disk, the number of revolutions, and the data recording method. ing.

For example, a micro-floppy disk device that uses a so-called 3.5-inch micro-floppy disk uses MFM (Modify) as a data recording method.
ed Frequency Modulation)
There are devices that use a recording method that rotates a floppy disk at a rotation speed fixed at 30 or 600 rpm, and OCR (Group Code
There are devices and the like that employ the recording method (D Recording) and change the rotational speed of the floppy disk for each trunk so that the recording density of each trunk is constant.

[Problems to be solved by the invention] Conventionally, magnetic disk devices with various specifications have not been compatible with each other, and moreover, they have been provided as individual devices, and the price per unit has been low. It was relatively high. Therefore, when installing magnetic disk drives of various specifications, it is necessary to secure not only equipment costs but also a large installation space, which poses a problem of increasing the burden on the user.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, an object of the present invention is to reduce the size and cost of a magnetic disk device. It is now possible to record/play data by switching between two operating modes: one for playback, and the other for recording/playing data by changing the rotational speed of the floppy disk for each track. A magnetic disk device with a new configuration is provided.

c. Means for Solving Problems] In order to solve the above-mentioned problems, the magnetic disk drive according to the present invention includes a first rotational speed target value generation means for providing a predetermined rotational speed target value, and a magnetic disk drive. a second rotational speed target value generation means for providing a series of rotational speed target values set for each track above, and each rotational speed target value given by each rotational speed target value generation means in accordance with an external control signal. The present invention is characterized by comprising a rotational speed target value selection means for selecting, and a drive control means for controlling the rotational speed of the magnetic disk according to the rotational speed target value selected by the rotational speed target value selection means. .

[Effect]

In the magnetic disk drive according to the present invention, the rotational speed target value given by the first rotational speed target value generation means and the rotational speed target value given by the second rotational speed target value generation means are set to the rotational speed target (, l! A first operation mode in which the rotational speed of the magnetic disk is controlled by the drive control means in accordance with the selected rotational speed target value by selection according to an external control signal by the selection means, and the rotational speed of the magnetic disk is fixed. Recording/reproducing of data according to the second operation mode or recording/reproducing of data according to the second operation mode in which the rotational speed of the magnetic disk is changed for each track is selectively performed.

〔Example〕

Hereinafter, an embodiment of a magnetic disk device according to the present invention will be described in detail with reference to the drawings.

In the block diagram of FIG. 1 showing an embodiment in which the present invention is applied to a so-called 3.5-inch micro-floppy disk device, l is a command for accepting and accepting command data supplied as an external control signal from a host system. It is a decoder, and the first operation mode in which data is recorded and reproduced using the MFM method, for example, is indicated by logic rHJ, and G
Mode designation data indicating a second operation mode in which data is recorded and reproduced using the CR method using logic rLJ is decoded from the above command data. Note that once the command decoder 1 receives the mode designation data, it holds the mode designation data until it receives a command for switching to another operation mode.

The mode designation data obtained by the data decoder 1 is then transferred to the recording/reproducing circuit 2. It is supplied to the erase timing control circuit 3 and mode selection circuit 4.

The recording/reproducing circuit 2 supplies data supplied from the host system during a recording operation to the head 5 as recording data in the MFM method or GCR method, and during a reproducing operation, outputs the reproduction output from the head 5 into the MFM method or GCR method. The data is supplied to the host system as reproduction data for the first operation mode, that is, the MFM method, and the second operation mode, that is, the data recording and reproduction operation for the GCR method, is the mode specification data. It is designed to be specified selectively.

Further, the erase timing control circuit 3 supplies the head 5 with an erase timing signal corresponding to the recording operation by the MFM method or the GCR method selectively designated by the mode designation data.

Further, the mode selection circuit 4 selects a first rotational speed target value (DA) read from the first initial bias memory 6.
) or the second rotation speed target value (DB) read from the second initial bias memory 7 is selectively supplied to the measurement counter 8 according to the mode designation data.

Here, the first initial bias memory 6 stores the M
The floppy disk 6 has two rotational speeds (3
A rotational speed target value specifying 00 rpm, 600 rpm) is stored. In this embodiment, the first bias selection circuit 11 is operated by the detection signal from the switch 10 that detects the index indicating the type of the floppy disk 6, and the rotation speed is determined according to the type of the floppy disk 6. In other words, the first rotational speed target value (D
A) is read out from the first initial bias memory 6.

Further, the second initial bias memory 7 includes the GC
A series of rotational speed target values set for each track of the floppy disk 6 in the second operation mode in which recording/reproducing operations are performed according to the R method are stored. In this embodiment, the output of the track register 16 indicating the track position on the floppy disk 6 that is being traced by the head 5 which is step-fed by the step motor 13 driven by the first motor drive circuit 12 is used. A second rotational speed target value (DB) corresponding to the track position is determined by the second bias selection circuit 11 which operates accordingly.
is read out from the second initial bias memory 7.

The measurement counter 8 receives the first or second rotational speed target value (D) supplied via the mode selection circuit 4.
A), (DB) is loaded, a motor drive circuit counts clock pulses with a number of pulses proportional to the rotational speed of a disk motor 17 that rotates the floppy disk 6, and uses the counted output to drive the disk motor 17. 19 control circuits 18. Here, by changing the rotational speed target value loaded into the measurement counter 8, servo control can be performed to rotate the floppy disk 6 at an arbitrary rotational speed.
For example, by supplying the counting output when loading (600) h to the measurement counter 8 to the control circuit 18, the floppy disk 6 can be
Assuming that a servo circuit that is controlled to rotate at pm is configured, (300) h is set as the first rotational speed target value CDAl and the measurement counter 8 is set to [600
) h, the floppy disk 6 can be servo-controlled to rotate at 60 rpm.

In the embodiment configured as described above, the floppy disk 9
The first operation mode records and reproduces data using the MFM method by rotating the floppy disk at a fixed rotation speed of 30 Orpm or 600 rpm, and the second operation mode changes the rotation speed of the floppy disk 9 for each track to increase the recording density of each track. Recording and reproducing data is performed by selectively specifying a second operation mode in which data is recorded and reproduced using a constant GCR method using command data supplied as an external control signal to the data decoder l. I can do it.

In the floppy disk device of this embodiment,
Since the drive mechanism of the head 5 and the floppy disk 9 are shared to record and reproduce data in the two operating modes, the device can be made smaller and less expensive.

〔Effect of the invention〕

As is clear from the description of the embodiments above, in the magnetic disk device according to the present invention, the rotation speed target value given by the first rotation speed target value generation means and the rotation given by the second rotation speed target value generation means By selecting the speed target value by the rotation speed target value selection means in accordance with an external control signal, the rotation speed of the magnetic disk is controlled by the drive control means according to the selected rotation speed target value. The first method was to fix the rotational speed of the magnetic disk, which required multiple devices.
It is possible to selectively record/reproduce data using the first operation mode or the second operation mode that changes the rotational speed of the magnetic disk for each trunk with a single device. By using both, it is possible to reduce the size and cost of the magnetic disk device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of a magnetic disk device according to the present invention, and FIG. 2 is an explanatory diagram for explaining the operation of the embodiment.

Claims (1)

[Scope of Claims] First rotational speed target value generation means for generating a predetermined rotational speed target value; and second rotational speed target value generation means for generating a series of rotational speed target values set for each track on a magnetic disk. rotation speed target value selection means for selecting each rotation speed target value given by each rotation speed target value generation means in accordance with an external control signal; and rotation selected by the rotation speed target value selection means. a drive control means for controlling the rotational speed of the magnetic disk according to a speed target value; a first operation mode for recording/reproducing data while fixing the rotational speed of the magnetic disk; A magnetic disk device characterized in that a second operation mode in which data is recorded/reproduced with different changes is selected by an external control signal to record/reproduce data.