JPS6286580A - How to recognize the magnetic disk model - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method of controlling a magnetic disk device, and particularly to a method of recording ID information suitable for detecting the model of a magnetic disk.

[Background of the invention]

The subject of the present invention is a method for a magnetic disk control device to automatically recognize the type of a connected magnetic disk and access data. Tokukai F@58-51566
No. 58-51465, JP-A No. 58-51465, JP-A No. 58-51465
There are publications such as No. 72261.

Generally, when accessing a disk, it is checked whether head selection and seek operations were performed successfully. Therefore, information (hereinafter referred to as ID) corresponding to the cylinder and head positions is written in advance in each track.

Now, if the control device 2 tries to control multiple disks with different physical specifications (here refers to the number of cylinders and heads), since the range of ID information mentioned above is different, it may be difficult to connect them in some way. You need to know the physical specifications of the disk. Therefore, conventionally, dip-
When a switch, etc. is installed in the control device [2] and a disk f device with different physical specifications is connected, the setting of the dip switch is manually changed, and the control device 2 reads and judges this. Controls corresponding to physical specifications were implemented. In this case, since the setting of the DIP switch requires manual intervention, a setting error may occur, and there is a risk that the data stored on the disk may be destroyed.

Furthermore, when connecting a magnetic disk, it is cumbersome that the control device must be connected.

[Purpose of the invention]

An object of the present invention is to provide a method by which a device using a magnetic disk can detect the type of connected magnetic disk in a short time. [Summary of the Invention] Achieving the above object Therefore, in the present invention, recognition is made possible by setting a number including the number of heads and cylinders of the magnetic disk in the ID information for identifying the tracks of the disk.

[Embodiments of the invention]

The present invention 1331 will be explained below.

FIG. 1 shows the structure of a general magnetic disk device. The magnetic disk device 1 receives a selection signal j for a data detection head 3 (hereinafter referred to as head) and a drive for head position movement (hereinafter referred to as seek) from a magnetic disk control device 2 (hereinafter referred to as a control device). It is given a signal i and accesses data according to the 40 rotations of the disk.The seek operation of the head positioning mechanism section 5 is an operation of moving the head position at fixed distance intervals, and corresponds to the head position at this operation step. The disk surface is called a cylinder. The positional relationship between the head and the cylinder is shown in Fig. 2. A unit corresponding to one square in the figure is called a track.

The processing of the present invention is carried out using the apparatus configuration shown in FIG. A host device (hereinafter referred to as HO8) that accesses the magnetic disk device 1
(referred to as the T device) 6 outputs an instruction to read or write data to the disk controller 7, and the disk controller receives this and controls the magnetic disk device.
Controls data transfer between the 8T device and the disk. In this case, the disk controller performs a seek operation to move the reading head to the target cylinder position, reads the ID information, and locates the track position instructed by the HO8T device, as in the example of data reading in Figure 4. Compare the ID with the read ID, and if they match, read the data from the disk device and transfer it to the HO8T, and if they do not match, send an error report to the HO8T.
8T to prevent data access errors.

In order to prevent this error, the ID section generally stores the physical cylinder address and head address shown in FIG. 2 as the ID. In this case, if you try to use the ID information to find the physical specifications, you will have to search for the ID of the largest head and largest cylinder, so you will have to perform seek operations frequently. This seek operation requires a much longer time than the data access time or head selection time. Therefore, it takes a long time to recognize the physical specifications, and this is not a practical method.

For the following explanation, the symbols used will be defined.

H: Number of heads on the magnetic disk C: Number of cylinders on the magnetic disk i: Cylinder address corresponding to the physical position j: Head address corresponding to the physical position Xi: I
Information corresponding to the cylinder address written in the DKiF Yj: Information corresponding to the head address written in the ID M: Constant N: Constant In the method of the present invention, one of the following generation formulas is used as the ID. use

[1) X1=(j+H+M)xC+i...
...Formula 1Yj = j +H1N
...... Formula 2 (II, l Xi
= (j+M)xC10i ・・・・・・・・・
Equation 3Yj = j +) (+N ・
・・・・・・・・・ Formula 4 (m) X1=j+C+M
10i ...... Formula 5Yj
= j +H+N ・・・・・・・・・Formula 6
First, how to obtain the physical specifications in case (I) will be explained.

The control device has a signal to (1) move the head to cylinder address 0 (indicating that the disk drive has been positioned to cylinder address 0), so in this case, the ID information for positioning is do not need).

(2) Select head address 0, IDXo.

Read yo.

(3) Perform the following calculations from Xo and Yo to find the physical specifications C and H.

H== yo −N ・・・・・・・・・
Formula 7C=XO/(H+M) ---
-・-・ Equation 8 Note that the control device stores xo and yo for each model, and also stores the H corresponding to xo and yo.
It is clear that if the values of , C are stored for each model, H and C can be determined from XO and yo, so the calculation in (6) can be omitted.

By using the above method, only one seek operation is required, and processing can be realized in a short time.

Next, we will explain how to obtain the physical specifications in the case of (ID).

The control device: (1) Selects head address 0 and reads IDX1°yo.

(2) Perform the following calculation from Yo to find the physical number of heads.

H= yo −N , −9−19, −Equation 9
(3) Store Xi and define it as Xl.

(4) Next, select the head address (H-1) and IDX
Read 1.

(5) Find the physical number of cylinders C from Xi and X'i by the following calculation.

C=(Xi-Xi)/H...Equation 10 By using the above method, it is possible to obtain the physical specifications without performing a single seek operation, and it is possible to obtain the physical specifications in a short time. processing can be realized.

How to obtain the physical specifications in the case of K(m) will be explained below.

The control device is (1) Move the head to cylinder address 0.

(2) Select head address 0 and read IDX0°Yo.

(3) Perform the following calculations from Xo and Yo to find the physical specifications C and H.

c==xo-M ......Formula 1
1H==yo-N ・・・・・・・・・
...Equation 12 By using the above method, the seek operation is reduced to 1
This process can be completed in a short time because it only takes a few times.

What the three methods described above have in common is that the ID information includes information about the number of cylinders and the number of heads, which are the physical specifications of the magnetic disk.

The advantages of this method will be explained in comparison with other methods.

Another example of a method is to store the number of heads and cylinders of the magnetic disk itself as data in a specific track. In this case, the specific track cannot be any other than cylinder 0. Therefore, when this track is a defective track and cannot be used, another track is substituted, but at this time, since the ID for confirming the seek operation cannot be used, another head of cylinder 0 must be used. Therefore, the problem arises that cylinder 0 cannot be used as an area for other data.

On this point, the method of the present invention does not use a data storage area, so physical specifications are definitely required.

The procedure for obtaining the physical specifications described above is shown in FIG. 5, and an example of ID setting in [n] is shown in FIG.

〔Effect of the invention〕

According to the present invention, the number of heads and the number of cylinders can be recognized in a short time for magnetic disks having different numbers of heads and cylinders.

[Brief explanation of drawings]

FIG. 1 is a schematic structural diagram of a magnetic disk device according to an embodiment of the present invention, FIG. 2 is a diagram of the physical positional relationship of a head and a cylinder, FIG. 3 is a diagram of the device configuration of the embodiment, and FIG. 5 is a block diagram showing a control example, FIG. 5 is an explanatory diagram of the procedure of the present invention, and FIG. 6 is an explanatory diagram showing an example of ID setting. 1...Magnetic disk device 2...Magnetic disk control device 3...Head 4...Disk 5...Head positioning mechanism section 6... ...HO8T device 7...Magnetic disk control device 1 4 times 2 countries 3 times 50 calculations] 0 place now H; Yo-p4 C: Xo-M

Claims (1)

[Claims] A magnetic disk characterized in that a value including a maximum head address and a maximum cylinder address of the magnetic disk is stored as a physical head address as part of the ID information indicating the track position of the magnetic disk. How to recognize the model.