JPH0294182A - Write/readout circuit for magnetic disk device - Google Patents

Abstract

PURPOSE:To eliminate the occurrence of a data readout disabled state by providing two sets of write and readout circuits and writing data from a host device on two difference magnetic disks, namely, writing the same data at two locations. CONSTITUTION:When a host device instructs the selection of magnetic head #0, head selection circuits 3a and 3b respectively select magnetic heads #0 out of magnetic heads 4a and 4b of #0-#4. When writing data 11 from the host device are written on a magnetic disk, write circuits 1a and 1b respectively write the same data 11 on corresponding magnetic disks 5 by using the magnetic heads 4a and 4b. As a result, the same data are written on two different magnetic disks (two locations). At the time of reading out the data written on the magnetic disks 5, the same data simultaneously read out by each one magnetic head designated out of the plural magnetic heads 4a and 4b are sent to the host device as read-out data 12 after the data are respectively amplified by readout circuits 2a and 2b. Therefore, no data readout disabled state occurs.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a write/read circuit for writing or reading data to or from a magnetic disk in a magnetic disk device.

[Conventional technology]

A data write/read circuit in a conventional magnetic disk device has a configuration as shown in FIG. That is, in FIG. 2, the head selection circuit 26 is a circuit that selects "-" designated by the device from among the plurality of magnetic heads 23 included in the magnetic disk device. The write circuit 21 selects one selected by the head selection circuit 26.
The write data 31 sent from the host device is written to the corresponding magnetic disk 27 by the magnetic heads 23 . On the other hand, when data written on the magnetic disk 27 is not to be read, first, the head selection circuit 26 selects one magnetic head designated by the device from among the plurality of magnetic heads 23, and this selection is performed. Data is read from the corresponding magnetic disk 27 by the magnetic head 23, and the read weak signal is amplified by the read circuit 22 and sent as read data 32 to the host device.

[Problem to be solved by the invention]

-L As mentioned above, in conventional magnetic disk devices, write data sent from a higher-level device is written to one magnetic disk designated by the higher-level device. On the other hand, a magnetic head is placed on a magnetic disk at a very small distance from its surface! (
0.4 μm), therefore, if the magnetic head comes into contact with the magnetic disk while the magnetic disk is rotating, the magnetic disk may be damaged. In such a case, there is a drawback that the data written on the magnetic disk may become unreadable.

[Means to solve the problem]

The write/read circuit of the magnetic disk device of the present invention has two sets of write circuits and read circuits, and writes data from the host device to two different magnetic disks, that is, the same data is written to two locations. It is something.

That is, the write/read circuit of the magnetic disk device of the present invention performs a two-head selection process that selects a specified magnetic head from among a plurality of magnetic spatulas 1 to which it belongs based on an instruction from a binary device. A circuit is provided corresponding to each of the two head selection circuits, and the write data sent from the host device is inputted and the one magnetic head selected by the spatula 1 to the selection circuit Two write circuits for writing to the corresponding magnetic disks, and the one selected by the head selection circuit provided corresponding to each of the two eight l-selection circuits.
and two readout circuits that amplify data read from the corresponding magnetic disks by the two magnetic heads and send the amplified data to the host device.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

In FIG. 1, write circuits 1a and ]b are circuits that input write data 11 from an upper position device and write it onto a magnetic disk 5 using magnetic heads 4a and 4b, respectively. Read circuits 2a and 2b are circuits that amplify data read by magnetic heads 4a and 4b, respectively, and send the amplified data as read data 12 to a host device. The head selection circuits 3a and 3b are circuits that select one magnetic head designated by the host device from among the plurality of magnetic heads 4a and 4b, respectively.

For example, when the host device specifies that the write/read circuit configured as described above selects the #0 magnetic head, the head selection circuits 3a and 3b select the magnetic head #0 to #4 from among the magnetic heads 4a and 4b, respectively. Select #0 magnetic head. ``When writing write data 11 from a binary device onto a magnetic disk, write circuits 1a and 1b write the same write data 1'' onto the corresponding magnetic disk 5 using magnetic heads 4a and 4b. As a result, the same data is written to two different magnetic disks (two locations). When data written on the magnetic disk 5 is not read, the read circuits 2a and 2b read the same data simultaneously with one designated magnetic head among the plurality of magnetic heads 4a and 4b, respectively. The data is amplified and sent as read data 12 to the host device.

〔Effect of the invention〕

As explained above, the write/read circuit of the magnetic disk device of the present invention has two sets of write circuits and read circuits, writes write data from the host device to two magnetic disks at the same time, and writes write data from the host device to two magnetic disks at the same time. When reading data, the same data written on two magnetic disks is simultaneously read and sent out as read data, so that the data is written onto one magnetic disk by contact between the magnetic head and the magnetic disk. Even if the stored data becomes unreadable, the unreadable data can be read from the other magnetic disk, which prevents the data from becoming unreadable. There is.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a write/read circuit of a magnetic disk device of the present invention, and FIG. 2 is a block diagram showing an example of a write/read circuit of a conventional magnetic disk device. ], a -1b -21-...Writing circuit, 2 a
-21) 22...Readout circuit, 3a/3b 26...
- Head selection circuit, 4a, 4b, 23... Magnetic head, 5, 27... Magnetic disk, 11, 31, Write data, 12, 32... Promotional data.

Claims (1)

[Claims] two head selection circuits for selecting one specified magnetic head from among the plurality of magnetic heads belonging to it in response to an instruction from a host device; and a head selection circuit provided corresponding to each of the two head selection circuits. two write circuits that input write data sent from the host device and write to a corresponding magnetic disk by the one magnetic head selected by the head selection circuit; two reading circuits provided corresponding to each of the circuits and amplifying data read from the corresponding magnetic disk by the one magnetic head selected by the head selection circuit and sending the amplified data to the host device; A write/read circuit for a magnetic disk device, comprising: a write/read circuit for a magnetic disk device.