JPS62259270A - Method for controlling floppy disk device - Google Patents

Abstract

PURPOSE:To suppress the abnormal abrasion or damage of only a specific track by successively changing the saving track positions of a head and uniformly distributing saving positions at the time of non-operation into many tracks. CONSTITUTION:When a power supply of a floppy disk device 1 is applied or a prescribed system is led, the state is detected and program loading is executed from the device 1. At that time, head saving position specifying information ADR stored in the track TA of a floppy disk 2 is read out and a track No.N specified by one of numbers T00-T76 is rewritten by the positional information ADR and stored in the track TA. The value of N uses 00 as the initial value, and when the result of N N+1 becomes 77, the contents are replaced by 00. Consequently, the saving track positions of the head 5 can be successively changed and the saving position can be uniformly distributed into many tracks.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to controlling the movement of a head relative to a magnetic disk, and particularly to a method of controlling track position when the head is not operating.

(Prior art) Figure 2 shows a commonly used floppy disk device (
1 is a control system diagram of FDD (hereinafter referred to as FDD).
, 2 is a floppy disk.

3 is the drive motor, which speeds up the access time.
Keep it constantly rotating. 4 is a stepping motor for tracking and positions the head 5! , 1ltll. 6 is a magnet that controls the operation and non-operation of the head 5.
111! 11. , 7 is the central processing unit (CPU)
and peripheral circuits; 8 is a memory consisting of ROM and RAM;
9 is an FDDilJt111 circuit, which is generally an LSI (for example, μPD765, etc.).

10 is the circuit of the number.

As an example of a control method, a DMA (direct access) system centered on the central processing unit 7 is used to transfer the data on the floppy disk 2 to the memory 8 when reading from the floppy disk 2, and transfer the data from the floppy disk 2 to the memory 8 when writing. In this case, the data in the memory 8 is transferred to the floppy disk 2.

Figure 3 shows floppy disk 2 in an 8-inch FDD.
In this diagram, a floppy disk 2 mounted on a spindle hub 11 is constantly rotating. The pair of heads 5A and 5B are arranged facing each other with the floppy disk 2 in between, and when the heads are not in operation, they are shown in FIG. 3(a).
Move away from floppy disk 2 as shown in
When the head is in operation, it comes into contact with the floppy disk 2 to perform reading or writing, as shown in FIG. 3(b).

The magnet 6 is used to drive the head between non-operation and operation.

FIG. 4 is a diagram showing the relationship between the floppy disk 2 and the head 5 in a 5, 25-inch FDD. During head operation, as shown in FIG. 4(b), the head 5A, as in FIG. 3(b), 5B is in contact with the floppy disk 2, and when the head is not operating, the head 5B separates from the 70-bit disk 2, as shown in FIG. 4(a), but since the head 5A has a fixed structure, It is in unstable contact with the floppy disk 2. Therefore, when the head is not operating as shown in FIG. 4(a), the rotating floppy disk 2 is unstable and the head 5 is not in operation.
Sliding contact with A.

Due to the operation of the FDD system, there is a track Tx (see Figure 5) that is frequently accessed when the head is in operation, and the head 5 is often positioned on this track Tx even when the head is not in operation. .

(Problems to be solved by the invention) However, as shown in FIG. 4(a) above,
One head 5A is on a specific track T when the head is not in operation.
If the floppy disk 2 is in constant contact with X and continues to rotate, there is a problem in that the track Tx portion may be abnormally worn or damaged, causing trouble in reading or writing data.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a floppy disk device in which the head is able to come into contact with the floppy disk at a retracted position with respect to the track. A track is provided on the floppy disk for writing and reading evacuation position designation information that specifies the evacuation track position when the evacuation position designation information is used. The designation of the evacuation track position is read out, and the evacuation designation information is rewritten to specify the next evacuation track position by advancing or retracting the evacuation track position, and the non-operation is performed after the power is turned on or the system starts up. In this case, the head is moved to the read evacuation track position.

(Function) According to the present invention, evacuation position designation information that specifies the evacuation track position when the floppy disk device is not in operation is written each time the power is turned on to the floppy disk device or every time a suitably set system starts up, and the evacuation position designation information is read out each time. Since the designation of the evacuation track position based on the evacuation position designation information is read from the track and the evacuation track position is moved forward or backward to designate the next evacuation track position, the evacuation track position of the head when the head is not in operation is It is changed sequentially each time the power is turned on or the system is started up.

(Example) Figure 5 shows the tracks of the floppy disk 2 and their information according to the present invention. 111, and the floppy disk 2 in this case is a 5.25 inch one,
For example, the unformatted size is 1.6 MB, the formatted type is IMB, and 77 tracks from the outermost track Too to the innermost track "76" are set.

C is a track that stores the position information ADH of the head evacuation position track, and any number from tracks T00 to "76" is stored together with the designation information ADR.
x is the track that is frequently accessed as described above.

FIG. 1 is a flowchart of the control of the present invention, which is not shown in FIG. 2 and is operated by an FDD.

When the FDD is powered on or a predetermined system starts up, this is detected and the program is loaded from the FDD (steps 20, 21 and 22). The head evacuation position designation information ADR stored in the track T of the floppy disk 2 is read, and the track number N designated by the numbers OO to 76 is stored in the register M of the memory 8. This data is called track number M (steps 23 and 24). Then, the calculation N←N+1 is performed, and the resulting track number N is rewritten as position information ADR and stored in the track TA (step 25.2
6). Note that the initial value of N is OO, and N+N-1・1
If the result is 77, it is replaced with OO.

When the FDD is designated for normal reading or writing (these are called operations), the head 5 is moved to the designated position and is operated normally (steps 27 and 28>. When the FDD is not in operation, the above operations are performed). starts a timer (step 27.29), which ensures that short pauses during normal read or write cycles do not cause an immediate transition to a non-operational state. For example, it is set to 10 seconds. Therefore, if FDD operation is specified during this time, it will operate normally (step 30° 31.28). After the specified time by the timer has elapsed, If there is no FDD operation designation during that time, the head 5 is moved to the track M according to the position designation information ADH stored in the memory 8 (
Step 30.32).

This series of operations is repeated every time the power is turned on or the system starts up, so each time the track number N advances by one from OO, and when it reaches 76, it returns to OO, and this is repeated.

Note that the range of change of N described above can be set in advance to exclude tracks that are accessed relatively frequently, thereby reducing the access frequency. It is also possible to set track numbers 74 → 75 → 76 to be used repeatedly only in the alternative track area by similar control. In this case, tracks that are not used during normal operation can be set to be used repeatedly when not in operation. It will be used effectively.

(Effects of the Invention) As explained above, according to the present invention, since the head evacuation track position is sequentially changed, the evacuation position during non-operation is distributed evenly among many tracks. Therefore, only a specific track will not be abnormally worn or damaged.

[Brief explanation of drawings]

FIG. 1 is a control flowchart showing an embodiment of the present invention;
Fig. 2 is a control system diagram of a floppy disk device according to the present invention, Fig. 3 is a diagram showing the positional relationship between a floppy disk and a head in an 8-inch FDD, and Fig. 4 is a diagram showing the positional relationship between a floppy disk and a head in a 5.25-inch FDD. 21
FIG. 5 is a diagram showing the relationship between the tracks of the floppy disk and the information recording positions. 2... Floppy disk 5... Head ■A... Track for recording evacuation position designation information.

Claims (1)

[Scope of Claims] In a floppy disk device in which a head can make contact with a floppy disk at a retracted position relative to a track, retraction position designation information specifying a retraction track position when the head is not in operation is written and read. A track is provided on the floppy disk, and each time the floppy disk device is powered on or an appropriately set system is started up, the designation of the evacuation track position by the evacuation position designation information is read out, and the evacuation track position is moved forward or backward. the evacuation designation information is rewritten to designate the next evacuation track position, and the head is operated to the read evacuation track position during the non-operation after the power is turned on or the system starts up. A method for controlling a floppy disk device.