JPH1092101A - Magnetic disc apparatus and its driving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic disc apparatus which can always maintain the optimum transfer rate of information by using a simplified apparatus without generation of any delay of seek operation. SOLUTION: This apparatus is composed of a magnetic recording medium 2, a magnetic recording medium driving means 3, a rotating control means 4 of the magnetic recording medium driving means 3, a magnetic head 5, a magnetic head supporting member 6, a magnetic head supporting member driving means 7, a magnetic head supporting member movement control mean 8, a recording/reproducing control means 9 and a central control means 10. In this case, the central control means 10 includes an access state judging means 11 for judging whether the access condition for making access to the recording area in the magnetic recording medium 2 of the magnetic head 5 is the sequential access or random access and a mode changeover means 12 for setting the rotating control means 4 to the first or second rotating control mode responding to an output of the access condition judging means 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic disk drive and a method of driving the same, and more particularly, to a magnetic disk drive and a method of driving the same.
The present invention relates to a magnetic disk device in which rotation control means for rotating a magnetic recording medium is controlled in different control modes in accordance with an access state of a magnetic head to a magnetic recording medium used for a hard disk, and a driving method thereof.

[0002]

2. Description of the Related Art Conventionally, in a magnetic disk drive generally used as a hard disk used in a computer or the like, information on a magnetic recording medium to be used is kept constant while the rotation speed of the magnetic disk is fixed. The relative speed between the recording area, that is, the outermost layer portion or the innermost layer portion of the cylinder and the magnetic head is set to a rotational speed that optimizes the recording / reproducing state of the information.

In such a conventional method, the control system can be constructed relatively easily. However, as the recording / reproducing operation becomes faster and higher in density, the cylinder, which is an information recording area in the magnetic recording medium, is used. In the magnetic recording medium, the magnetic recording medium and the magnetic head in the outermost layer cylinder part, the intermediate layer part cylinder part, and the innermost layer cylinder part become surfaced. The relative speed difference causes a subtle difference in the recording / reproducing density of information, and the risk of recording / reproducing errors is increasing.

On the other hand, in order to solve such a problem, for example, Japanese Unexamined Patent Publication No. 3-222152 discloses that a magnetic recording medium rotation drive means in a magnetic disk drive is provided with a magnetic recording medium according to a seek operation of the magnetic head. A technique for controlling the rotation speed of the medium to change is disclosed. That is, in such a known example, the relative speed between the magnetic recording medium and the magnetic head is such that the magnetic head is located at any position between the innermost layer and the outermost layer of the magnetic recording medium. Even if there is, the information is kept constant, so that the information transfer speed is always constant.

However, in such a method, in recording or reproducing operation of predetermined information, the magnetic head has to be frequently moved to a position of a different cylinder portion in a magnetic recording medium. When performing a so-called random access operation, there is a problem that a seek time delay of the magnetic head occurs due to the rotation control operation. Since the configuration for detecting the number of rotations of the magnetic recording medium is employed, the control device becomes complicated and causes an increase in cost.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the above-mentioned disadvantages of the prior art, to maintain an optimum information transfer rate at all times by using a simple device, and to seek operation. It is intended to provide a magnetic disk drive and a method of driving the magnetic disk drive that do not cause a delay.

[0007]

SUMMARY OF THE INVENTION The present invention basically employs the following technical configuration to achieve the above object. That is, a first aspect of the present invention is a magnetic recording medium driving means for rotating a magnetic recording medium, a rotation control means for controlling rotation of the magnetic recording medium driving means, and recording of information on the magnetic recording medium. Alternatively, a magnetic head support member for supporting a magnetic head for reproduction, a magnetic head support member driving unit for moving the magnetic head support member on the magnetic recording medium, and a magnetic head support member movement for controlling the movement of the magnetic head support member A magnetic disk device comprising: control means; recording / reproduction control means for controlling recording or reproduction operation of information on the magnetic recording medium via the magnetic head; and central control means for controlling each of the above means. The central control means stores the magnetic recording medium of the magnetic head when recording or reproducing predetermined information by the magnetic head. Access state determining means for determining whether a state of accessing a predetermined recording area in the predetermined recording area is sequential access or random access, and in response to an output of the access state determining means, if the access state is sequential access, A mode switching unit that sets the rotation control unit to the first rotation control mode, and sets the rotation control unit to the second rotation control mode when the access state is random access. A magnetic disk drive, and as a second aspect, a magnetic recording medium driving means for rotating a magnetic recording medium, a rotation control means for controlling the rotation of the magnetic recording medium driving means, and information transfer to the magnetic recording medium A magnetic head support member for supporting a magnetic head for performing recording or reproduction; A magnetic head support member driving unit that moves on the recording medium; a magnetic head support member movement control unit that controls the movement of the magnetic head support member; and a recording or reproducing operation of information on the magnetic recording medium via the magnetic head. In a magnetic disk drive comprising a recording / reproducing control means for controlling and a central control means for controlling each of the above means, when recording or reproducing predetermined information by the magnetic head, the rotation control means is controlled by the magnetic head. This is a method of driving a magnetic disk drive in which a predetermined recording area in the magnetic recording medium is accessed in a different rotation control mode depending on whether the access is sequential access or random access.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Since a magnetic disk drive and a method of driving the same according to the present invention employ the above-mentioned technical configuration, the magnetic head accesses a predetermined information recording / reproducing area of the magnetic recording medium. The rotation condition of the magnetic recording medium by the magnetic recording medium driving unit is appropriately changed according to the state of the sequential access or the random access according to the cylinder position of the magnetic recording medium where the magnetic head is present. Or the rotation speed
Since the magnetic head is configured to be fixed at a constant value regardless of the cylinder position of the magnetic recording medium that is currently present, even if the access state of the magnetic head to the magnetic recording medium changes, the optimum value is always maintained. The information transfer rate can be ensured, and the rotational speed of the magnetic recording medium can be detected by the magnetic head using position information recorded in each sector of the magnetic head. Therefore, the method of controlling the rotation of the magnetic head becomes simpler than in the conventional configuration, which can contribute to cost reduction.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific example of a magnetic disk drive and a method of driving the same according to the present invention will be described below in detail with reference to FIGS. FIG. 1 is a block diagram schematically showing a configuration of a magnetic disk drive 1 according to one embodiment of the present invention, in which a magnetic recording medium driving means 3 for rotating a magnetic recording medium 2 and the magnetic recording medium driving means 3 are shown. A rotation control means 4 for controlling the rotation of the magnetic recording medium 2, a magnetic head supporting member 6 for supporting a magnetic head 5 for recording or reproducing information on or from the magnetic recording medium 2, and a magnetic head supporting member 6 on the magnetic recording medium 2. A magnetic head supporting member driving means 7 for moving the magnetic head supporting member 6; a magnetic head supporting member movement controlling means 8 for controlling the movement of the magnetic head supporting member 6; It comprises a recording / reproduction control means 9 for controlling a reproduction operation of information from the magnetic recording medium 2 and a central control means 10 for controlling the above means 4, 8, 9 and the like. In the magnetic disk device 1, which is, in the central control unit 10, upon recording or reproduction of predetermined information by the magnetic head 5,
An access state determining means 11 for determining whether the magnetic head 5 accesses a predetermined recording area in the magnetic recording medium 2 is a sequential access or a random access, and responds to an output of the access state determining means 11. If the access state is a sequential access, the rotation control unit 4 is set to the first rotation control mode, and if the access state is a random access, the rotation control unit 4 is set to the second rotation control mode. The magnetic disk drive 1 includes a mode switching means 12 for setting the rotation control mode.

In FIG. 1, reference numeral 13 denotes an interface for supplying various kinds of control information relating to the control of the magnetic disk device 1. The magnetic disk drive 1 according to the present invention comprises:
In particular, it is desirable that the hard disk be used as a hard disk provided inside a computer or the like. The magnetic recording medium driving means 4 for rotating and driving the magnetic recording medium 2 in FIG. 1 may be constituted by a motor having an appropriate spindle, and the rotation control means 4 may be, for example, a spindle for driving the spindle motor. Driver 18
And a spindle controller 19 for driving and controlling the spindle driver 18.

The rotation control means 4, especially the spindle controller 19, responds to a rotation control mode command from the central control means 10 to control the rotation speed of the magnetic recording medium driving means 3 comprising the spindle motor 3. To control. At this time, the rotation control unit 4 takes in the rotation speed of the spindle output from an appropriate spindle rotation speed detection unit provided in the magnetic recording medium driving unit 4 via the servo circuit unit 22, and May be configured to control the number of rotations to match the predetermined number of rotations.

In the above embodiment of the present invention, the number of revolutions of the magnetic recording medium 2 is detected by using the magnetic head 5 during a predetermined clock pulse. The number of position information recorded in each predetermined portion of each sector portion (S1 to Sn shown in FIG. 2) provided in the magnetic recording medium 2 is counted, and the number of the position information is counted from the count value. Counting means 15 for converting the rotation speed of the magnetic recording medium 2 is provided, and the output result of the counting means 15 is supplied to the rotation control means 4 to control the rotation speed of the magnetic recording medium 2. good.

In such a case, it is desirable to use a clock pulse built in the magnetic disk device 1 as the predetermined clock pulse.
Between the input and the next clock pulse input, each of the sector portions S1 to Sn provided in each cylinder of the magnetic recording medium 2 is arranged at a predetermined position in each ID field. Based on how many specific position information pulses consisting of information or codes are detected,
The rotational speed of the magnetic recording medium 2 may be obtained.

On the other hand, in the above embodiment according to the present invention, the magnetic head supporting member 6 for supporting the magnetic head 5 is provided.
Is supported by an appropriate magnetic head support member 7, and the configuration thereof is not particularly limited. For example, it is preferable that the device be constituted by a voice coil motor (VCM). Further, the magnetic head support member 6 is swung right and left by the magnetic head support member movement control means 8 to move the magnetic head 5 in the radial direction of the magnetic recording medium 2 and an arbitrary distance, that is, to seek. Perform the operation.

In a specific embodiment according to the present invention, the magnetic head supporting member movement control means 8 for driving the magnetic head supporting member 7 includes, for example, an actuator driver 16 for driving the magnetic head supporting member 7 and the actuator Servo controller 1 that directly controls driver 16
7 is desirable. The magnetic head support member movement control means 8 outputs to the central control means 10 in accordance with the address on the magnetic recording medium 2 at which recording / reproduction relating to predetermined information is to be performed, which is input from the interface 13. The magnetic head supporting member 7 is controlled in response to the address information from the central control means 10, thereby moving the magnetic head 5 to a predetermined cylinder on the magnetic recording medium 2 at a high speed. ing.

In the above specific example, predetermined information is written to a predetermined address position of the magnetic recording medium via the magnetic head, or predetermined information is written from a predetermined address position of the magnetic recording medium. In the case of reading, the information is transferred via the recording / reproduction control means 9 constituted by, for example, a read / write channel. Next, as a feature of the specific example according to the present invention, the central control means 10 records the predetermined information on the magnetic recording medium 2 by the magnetic head 5 or the predetermined information from the magnetic recording medium 2. At the time of reading / reproducing, there is provided an access state determining means 11 for determining whether the state of accessing a predetermined recording area of the magnetic recording medium 2 of the magnetic head 5 is a sequential access or a random access.

Generally, the magnetic recording medium 2 has a structure shown in FIG.
As shown in FIG. 2, a plurality of cylinders (C1 to Cn) are provided from the inner layer to the outer layer of the magnetic recording medium 2, and each of the cylinders has a plurality of, preferably, Sector portions (S1 to Sn) having the same length are provided. It is desirable that the length of the sector portion be equal between the cylinder portions.

Each of the sector sections is provided with, for example, an ID field. A predetermined portion of the ID field has, for example, position information indicating the start position of the sector section, address information (ie, address information). Disk number H, cylinder number C, sector number S, etc.), data length information of various data following the ID field, types of commands, and the like are recorded.

Therefore, in the present invention, a predetermined recording and
When executing the reproduction control operation, the central control means 10
Indicates in which cylinder of the magnetic recording medium 2 the magnetic head 5 is currently located, and where the address position of the next information to be processed (disk number information, cylinder information and sector information) is located. In consideration of this, a predetermined control command is output to the magnetic head support member movement control means 8,
The magnetic head supporting member 6 is moved to a predetermined cylinder portion position. At this time, whether the access state of the magnetic head 5 is a sequential access state or a random access state is determined based on the above information. This is determined by the state determination unit 11.

Therefore, the central control means 1 in the present invention
It is preferable that an address detecting means 20 for detecting address information relating to the various types of information described above is further provided at 0. That is, the access operation of the magnetic head 5 is
For example, as in the case where the same command is continuously input or the data length is longer than a predetermined length as in image processing, access is repeated in the same cylinder portion on the magnetic recording medium 2. When one record / playback control is executed for a long time in the same cylinder unit, or when a plurality of record / playback control operations are performed continuously, each address change is performed by one cylinder. A case in which the access is performed between the unit and another cylinder adjacent to the unit is referred to as a sequential access, and the other access state is referred to as a random access state.

Therefore, according to the present invention, in the access state determining means 11, first, in which cylinder of the magnetic recording medium 2 the magnetic head 5 is currently located, and then the address of the information to be processed. Position information (cylinder part information and sector part information) and respective address position information in one or more recording / reproducing operations to be executed in the next and subsequent times are detected. Judgment of the sequence of these commands or detection of the information on the command data length of the information in the recording / reproducing operation to be executed next, and when the above-mentioned criteria are met, the sequential access And the mode switching means 12 is driven to control the rotation control means 4 in the first rotation control mode. Seth state determining means 11, if it is determined that the random access is switched the mode switching means 12 to the second rotation control mode is intended to such control in the rotation control means 4.

That is, in the first rotation control mode of the present invention, the rotation speed of the magnetic recording medium driving means 3 is controlled by the rotation control means 4 so that the rotation speed of the magnetic head 5 on the magnetic recording medium 2 is reduced. Control to change according to the access position,
The control is performed such that the relative speed between the magnetic head 5 and the magnetic recording medium 2 is constant regardless of the access position of the magnetic head 5 on the magnetic recording medium 2.

In the second rotation control mode according to the present invention, the rotation speed of the magnetic recording medium driving means 3 is controlled by the rotation control means 4 so that the rotation speed of the magnetic head 5 on the magnetic recording medium 2 is reduced. Control is performed by fixedly setting a fixed value regardless of the access position. In the present invention, when the second rotation control mode is used, the rotation speed of the magnetic recording medium driving unit 3 is controlled by the rotation control unit 4.
The optimum relative speed between the magnetic head 5 and the recording area of the innermost cylinder portion or the outermost cylinder portion of the magnetic recording medium 2 is set.

In the above specific example of the present invention,
In particular, when the first rotation control mode is executed, each of the cylinder portions (C1 to C1) in the magnetic recording medium 2 is used.
In the case where information recording / reproducing operations are individually performed on Cn), the optimum rotation speed of the magnetic recording medium 2 is individually provided for each cylinder, so that the optimum magnetic recording corresponding to each cylinder is performed. A table 14 indicating the rotation speed of the medium 2 is prepared in advance, and the central control means 10 reads out predetermined rotation speed data directly from the table 14 and transmits the information to the rotation control means 4 or the central control means It is also desirable that the rotation control means 4 reads out predetermined rotation speed data from the table 14 and executes drive control of the magnetic recording medium drive means 3 based on a command from the means 10.

Next, the drive processing method of the magnetic disk drive according to the present invention will be described. As described above, an example of the drive method of the magnetic disk drive according to the present invention is the magnetic recording medium 2. Magnetic recording medium driving means 3 for rotating the magnetic recording medium, rotation control means 4 for controlling the rotation of the magnetic recording medium driving means 3, and a magnetic head for supporting a magnetic head 5 for recording or reproducing information on or from the magnetic recording medium 2. A support member 6, a magnetic head support member driving means 7 for moving the magnetic head support member 6 on the magnetic recording medium 2, a magnetic head support member movement control means 8 for controlling the movement of the magnetic head support member 6, A recording / reproducing control means 9 for controlling a recording or reproducing operation of information on the magnetic recording medium 2 via the head 5 and the above-mentioned respective means 4, 8, 9 are controlled. When recording or reproducing predetermined information by the magnetic head 5, the rotation control means 4 is applied to the magnetic recording medium 2 of the magnetic head 5. This is a driving method of a magnetic disk drive configured to drive in a different rotation control mode depending on whether a predetermined recording area is accessed in sequential access or random access.

In the driving method according to the present invention, the different rotation control modes are, as described above, a state in which the magnetic head accesses a predetermined recording area in the magnetic recording medium, in a sequential manner. If the access is an access, the first rotation control mode is set. If the access state is a random access, the second rotation control mode is set.

An example of a specific procedure for a method of driving a magnetic disk drive according to the present invention will be described with reference to the flowchart of FIG. That is, when the process is first started, in step (1), for example, the command data of the newly input information for performing the predetermined recording / reproducing operation is looked at, and the process proceeds to step (2), where one or more pieces of the information are read. In step (3), the detected address or data length is compared with an access state determination criterion. In step (4), the access state is a sequential access. Is determined.

If NO in step (4), that is, if the access state is determined to be random access, the second rotation control mode is set in step (5), and In 6), a predetermined recording / reproducing operation is executed. In step (7), it is determined whether or not the recording / reproducing operation has been completed. If NO, the process returns to step (6) to continue the recording / reproducing operation, and YES in step (7). If so, the process proceeds to step (16) to determine whether there is a subsequent command. If YES, the process returns to step (1) to wait for the input of a new command, and if NO in step (16). If it is END.

On the other hand, if YES in step (4), that is, if it is determined that the access state is the sequential access, the first rotation control mode is set in step (8), and step (9) In step (2), the position information of the cylinder portion of the magnetic recording medium 2 with which the current magnetic head 5 is in contact is read, and the process proceeds to step (10), where the cylinder with which the magnetic head 5 is in contact from the table 14 described above. Reads out the optimum rotation speed information in the section.

Next, in step (11), the two data are compared, and in step (12), it is determined whether or not the two data match, and if NO, the process proceeds to step (13). In this case, a servo operation is performed, and control is performed such that the rotational speed of the magnetic recording medium 2 matches a reference value defined in the table. Next, if YES is obtained in step (12), step (14)
And a predetermined recording / reproducing operation is executed.

It is determined in step (15) whether or not the recording / reproducing operation has been completed. If NO, the process returns to step (14), where the recording / reproducing operation is continued, and the process proceeds to step (15). If the answer is YES in step (1),
Proceeds to 7), and it is determined whether or not there is a subsequent command.
If so, the process returns to step (1) to wait for the input of a new command, and if NO in step (17), EN
D.

[0032]

As described above, in the magnetic disk drive and the drive method of the magnetic disk drive particularly used for the hard disk according to the present invention, the magnetic recording medium 2 is not used in the sequential access state. Since the number of rotations of the magnetic recording medium driving means to be rotated is variable, the transfer speed of predetermined information is always maintained at the optimum and highest transfer rate without depending on the position of each cylinder on the magnetic recording medium 2. In addition, in the case of the random access state, the rotation speed of the magnetic recording medium driving means is fixed, so that the seek operation of the magnetic head 5 is not delayed by the overhead of the rotation speed control. .

Further, in the present invention, the rotation speed of the magnetic recording medium 2 is controlled by using an interface signal and ID field data on the magnetic recording medium 2 for the rotation control of the rotation control means 4. Since no new detection means for detection is required, the circuit configuration is simplified, and the cost can be reduced and downsizing can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of one specific example of a magnetic disk drive according to the present invention.

FIG. 2 is a diagram illustrating a data recording state of a magnetic recording medium used in the present invention.

FIG. 3 is a flowchart illustrating a procedure of a specific example of a method of driving a magnetic disk drive according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Magnetic disk drive 2 ... Magnetic recording medium 3 ... Magnetic recording medium drive means 4 ... Rotation control means 5 ... Magnetic head 6 ... Magnetic head support member 8 ... Magnetic head support member movement control means 9 ... Recording / playback control means 10 ... Central control means 11 Access state determination means 12 Mode switching means 13 Interface means 14 Table 15 Counting means 16 Actuator driver 17 Servo controller 18 Spindle driver 19 Spindle controller 20 Address information detection means 22 Servo circuit means

Claims (10)

[Claims] 1. A magnetic recording medium driving means for rotating a magnetic recording medium, a rotation control means for controlling the rotation of the magnetic recording medium driving means, and a magnetic head for recording or reproducing information on the magnetic recording medium. Magnetic head support member, magnetic head support member driving means for moving the magnetic head support member on the magnetic recording medium, magnetic head support member movement control means for controlling the movement of the magnetic head support member, and the magnetic head Thus, in a magnetic disk drive comprising a recording / reproduction control means for controlling the recording or reproduction operation of information on the magnetic recording medium and a central control means for controlling each of the above means, the central control means includes: When recording or reproducing predetermined information by the magnetic head, a predetermined recording area of the magnetic head on the magnetic recording medium. Access state determination means for determining whether the state of access to is sequential access or random access, and in response to the output of the access state determination means, when the access state is sequential access, the rotation control means A mode switching means for setting the first rotation control mode and setting the rotation control means to the second rotation control mode when the access state is random access; Disk device. 2. The method according to claim 1, wherein the first rotation control mode controls the rotation speed of the magnetic recording medium driving unit by the rotation control unit.
The magnetic head is variable according to the access position on the magnetic recording medium, and the relative speed between the magnetic head and the magnetic recording medium is constant regardless of the access position of the magnetic head on the magnetic recording medium. 2. The magnetic disk drive according to claim 1, wherein the control is performed in the following manner. 3. The rotation control mode according to claim 2, wherein the rotation control means controls the number of rotations of the magnetic recording medium drive means.
2. The magnetic disk drive according to claim 1, wherein the control is performed by setting the magnetic head to a fixed value irrespective of an access position on the magnetic recording medium. 4. The access state determining means includes: a data length of predetermined information for recording or reproducing the access state;
2. The magnetic disk drive according to claim 1, wherein the determination is made based on addresses of a plurality of pieces of the information in succession. 5. The rotation control mode according to claim 2, wherein the rotation control means controls the number of rotations of the magnetic recording medium drive means.
4. The magnetic disk drive according to claim 3, wherein an optimum relative speed between the magnetic head and the innermost or outermost recording area of the magnetic recording medium is set. 6. A table in which a relationship between each cylinder position of the magnetic recording medium and an optimum rotation speed of the magnetic recording medium at each cylinder position is set in the central control means or the rotation control means. 6. The magnetic disk drive according to claim 1, wherein the magnetic disk drive is connected. 7. The rotation control means, wherein the magnetic head comprises:
Connected to the magnetic head via a coefficient means for counting the number of position information recorded in a predetermined portion of each sector portion provided on the magnetic recording medium, detected between predetermined clock pulses. 2. The magnetic disk drive according to claim 1, wherein: 8. A magnetic recording medium driving means for rotating the magnetic recording medium, a rotation control means for controlling the rotation of the magnetic recording medium driving means, and a magnetic head for recording or reproducing information on or from the magnetic recording medium. Magnetic head support member, magnetic head support member driving means for moving the magnetic head support member on the magnetic recording medium, magnetic head support member movement control means for controlling the movement of the magnetic head support member, and the magnetic head In a magnetic disk drive composed of recording / reproduction control means for controlling the recording or reproduction operation of information on the magnetic recording medium and central control means for controlling each of the above-mentioned means, predetermined information by the magnetic head is provided. When recording or reproducing the data, the rotation control means is applied to a predetermined recording area of the magnetic recording medium of the magnetic head. A method for driving a magnetic disk drive, characterized in that driving is performed in a different rotation control mode depending on whether a state of access is sequential access or random access. 9. The different rotation control mode is set to a first rotation control mode when a state in which the magnetic head accesses a predetermined recording area in the magnetic recording medium is a sequential access. A method for driving the magnetic disk device, wherein when the access state is random access, the second rotation control mode is set. 10. The first rotation control mode, wherein the rotation control means makes the number of rotations of the magnetic recording medium driving means variable according to an access position of the magnetic head on the magnetic recording medium, and Controlling the relative speed between the magnetic head and the magnetic recording medium to be constant regardless of the access position of the magnetic head on the magnetic recording medium;
In the second rotation control mode, the rotation control means sets the number of rotations of the magnetic recording medium driving means to a fixed value irrespective of the access position of the magnetic head on the magnetic recording medium. 10. The method of driving a magnetic disk drive according to claim 8, wherein the control is performed by performing the following operations.