JPS60119601A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To increase memory capacity without increasing number of tracks by recording information on a track of a small magnetic disk medium dividing the circle into halves. CONSTITUTION:A track 5 of the small magnetic disk medium 4 is divided into semicircles, and information corresponding to a track of side 0 and a track of side 1 of conventional large magnetic disk medium is recorded in each of them, and all tracks of side 0 and side 1 of conventional large magnetic disks are recorded in one side. Selection of index 1 and index 2 is made corresponding to side select signal from a disk controller of conventional systems, and information of only a half period is recorded and reproduced from the selected index signal. Thus, information of one half of a track of the small magnetic disk medium 4 is recorded and reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a compact, large-capacity magnetic disk device that is compatible with conventional systems without requiring any changes.

Conventional configuration and its problems Improvements in the head/medium system of magnetic disk drives Achieving the same capacity as conventional large magnetic disk media with small magnetic disk media by increasing the linear density and track density becomes possible. At this time, compatibility with conventional system programs and disk controllers is a major advantage, and for this reason, conventionally, each track has the same storage capacity. - As an example, Table 1 lists the linear density and track density when a double-sided flophy disk medium with a diameter of 8 inches and a storage capacity of 1.6 MB is downsized to diameters of 5.25 inches and 35 inches.

The 5- and 25-inch, 1.6 MB floppy disk devices shown in Table 1 have already been commercialized, and 3.5-inch, 16 MB devices are also technically possible. In order to further increase the storage capacity of these devices and to make them compatible with conventional system controllers, it is generally considered to increase the number of tracks without significantly changing the linear density. For example, to achieve 3.2 MB/both sides on a 525-inch or 3.5-inch disk medium, the number of tracks is increased to 154/one side. At this time, the track density becomes 192 TPI or 270 TPI, which requires higher accuracy in head positioning, improvement in dimensional changes due to temperature and humidity of the magnetic disk medium, etc., which is difficult to realize. Although it is possible to achieve high track density using servo technology,
Equipment becomes expensive.

As mentioned above, when introducing new heads and media to increase the capacity of small magnetic disk drives and replacing conventional large magnetic disk drives, the track density will be significantly increased compared to the increase in linear density. This has the disadvantage that it is difficult to realize a compact, inexpensive, large-capacity device.

OBJECTS OF THE INVENTION The present invention eliminates the drawbacks of the conventional example described above, and provides a small magnetic disk device that is compatible with the conventional system and can increase storage capacity. - Structure of the Invention In order to achieve the above object, the present invention provides information corresponding to one trunk on side 0 of a conventional large magnetic disk medium and information corresponding to one track on side 1 of the large magnetic disk medium. information - one of the small magnetic disk media
By recording data in half-rounds on two tracks, the storage capacity can be increased without increasing the number of trunks.In addition, an index signal corresponding to information for each half-circle of the small magnetic disk medium is provided. By generating and selecting this by the side select signal of the conventional system controller, it becomes possible to replace the conventional large magnetic disk device.

DESCRIPTION OF EMBODIMENTS The configuration of an embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1a and 1b show recording patterns of one track on side O and one track on side 1, respectively, of a conventional large magnetic disk medium.

FIG. 2 shows that one track of the small magnetic disk medium according to the present invention is divided into half circles, and information corresponding to one track on side 0 and one trunk on side 1 of the conventional large magnetic disk medium is recorded on each half. The recorded pattern is shown below. Although FIGS. 1a, 1] and 2 only show the recording pattern of one trunk, in reality, all tracks on side O and side 1 of the conventional large magnetic disk are recorded on one side of the small magnetic disk medium. recorded in By doing so, the storage capacity can be increased to twice that of conventional large disk media without increasing the number of tracks. However, in this case, the linear density also increases. - As an example according to the invention 5.25 inches and 3
．． Storage capacity of 3 using 5 inch diameter magnetic disk media
．． Table 2 shows the linear density and track density when a 2 MB device is realized.

Table 2 The track density shown in Table 2 can be achieved without using the servo system and has already been commercialized.

As for the linear density, a linear density of 40'KBPI or more has been achieved using recent isotropic magnetic fine particle coating media, perpendicular magnetization recording systems using Co-Or gold metal thin films, and the like.

Next, using the disk controller of the conventional system,
A method for recording or reproducing information will be explained. FIG. 3 shows the intex signal pulses of the device according to the invention. It has two index outputs, index 1 and index 2, and each index output generates one pulse per rotation of the magnetic disk medium.
Both pulses are temporally shifted by a half period of disk rotation, and are generated corresponding to information of each half period.

Above index 1. As a method of obtaining the index 2 signal, (1) one index hole is provided in the magnetic disk medium, the index 1 signal is generated by a detector placed at the corresponding position in the device, and this signal is delayed. A method of generating the index 2 signal by delaying it by half a cycle using a circuit.

(2) Two index holes are provided at suitable positions on the circumference of the magnetic disk medium with different radii, and two index holes are detected at two positions shifted by a half period from each other using two detectors placed at corresponding positions in the device. How to generate two index signals.

(3) A hole or protrusion is provided in the magnetic disk medium for positioning during disk chucking, and a detector is installed to detect a certain position on the circumference of the rotating mechanism that has a unique positional relationship with the hole or protrusion. A method in which a signal of index 1 is generated by placing the signal at a corresponding position in the device, and a signal of index 2 is generated by delaying the signal by a half period using this signal delay circuit.

(A method in which two detectors similar to 41f31 are placed at corresponding positions in the device to generate two index signals that are shifted by a half period from each other.

Use one of the following methods.

One of the disk controller signals in the conventional system is a side select signal, and in the conventional drive, side 0 or side 1 is selected.

In the apparatus according to the present invention, the above-mentioned index 1 or index 2 is selected in response to a side select signal from the disk controller of the conventional system, and information is recorded and reproduced for only half a cycle from this selected index signal. Do it like this. By using such a method, one of the small magnetic disk media shown in FIG.
It is possible to record and reproduce information on one half of two tracks, that is, information corresponding to one track on side 0 or side 1 of the conventional disk medium in FIG. A compact, large-capacity magnetic disk device can be realized without increasing the capacity.

Note that the drive select signal in the disk controller of the conventional system can be used to perform site selection and drive selection of the apparatus according to the present invention. - As an example, if the control system for four conventional 8-inch 1.6 MB double-sided floppy disk drives is replaced with two 35-inch 3.2 MB double-sided floppy disk drives, which are an embodiment of the present invention. Table 3 shows how the drive side index is selected in response to the drive select and side select signals of the conventional disk controller.

Effects of the Invention The present invention has the above-described configuration, and provides the following effects.

(a) By storing information equivalent to one track of side 0 and side 1 of a conventional large magnetic disk medium in one track of a small magnetic disk medium, storage can be achieved without increasing the number of tracks. It is possible to increase the capacity, eliminate the need for high precision head positioning, and obtain a device with low bit cost.

(b) Divide each track of the small disk medium into half circles, and independently generate two index signals of index 1 and index 2 corresponding to each half circle, thereby eliminating the side select signal from the disk controller in the conventional system. By selecting the above-mentioned index, it is possible to obtain a small-sized, large-capacity magnetic tisf device in which the program and controller of the conventional system can be used as they are.

[Brief explanation of the drawing]

FIGS. 1a and 1b are diagrams schematically showing the recording pattern of one track on side 0 and side 1 of a conventional large magnetic disk medium, respectively, and FIG. FIG. 3 is a diagram schematically showing a recording pattern of one track of a disk medium, and FIG. 3 is a diagram showing an index signal pulse of the apparatus according to the present invention. 4. Disc medium, 5. Track. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (1)

Scope of Claims: (1) Information to be recorded on one track on side O of the first magnetic disk medium and information to be recorded on one track on side 1 of the first magnetic disk medium are , a second magnetic disk medium capable of recording on each half circumference of one track of the magnetic disk medium, a recording/reproducing means for the second magnetic disk medium, and side O and side 1 of the first magnetic disk medium. A magnetic disk drive comprising index signal generating means for generating an index signal corresponding to information. (2) detecting one index hole provided in the second magnetic disk medium and the index hole to generate a first index signal; 2. The magnetic disk drive according to claim 1, wherein the index signal generating means is constituted by the means for generating an index signal of No. 2. (3) Two index holes provided at appropriate positions on the circumference of the second magnetic disk medium with different radii, and means for detecting the index holes and generating two index signals shifted by half a cycle from each other. (4) Generating a first index signal by detecting a positioning hole or protrusion of the second magnetic disk medium during disk chucking and a constant rotational position of the disk rotation mechanism, and generating a first index signal; 2. A magnetic disk drive according to claim 1, wherein the index signal generating means comprises means for generating a second index signal which is shifted by 172 cycles from the signal. (5) Two detectors detect the hole or protrusion provided in the second magnetic disk medium for positioning during disk chucking and the two constant rotational positions of the disk rotation mechanism, and 2. A magnetic disk drive according to claim 1, wherein the index signal generating means is constituted by means for generating two index signals having a period shifted from each other. (6) A patent claim for selecting an index signal in response to a side select signal of a controller for a magnetic disk device using a first magnetic disk medium, and recording or reproducing information for 172 cycles from the selected index signal. A magnetic disk device according to item 1. (7) A drive sesect signal from a disk controller that controls two or more magnetic disk devices using the first magnetic disk medium causes side 0 of the second magnetic disk medium to be set. Side 1. 2. The magnetic disk device according to claim 1, wherein: and a drive are selected.