JPS59101726A - Magnetic disc unit - 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 Technical Field The present invention relates to a magnetic disk device, and more specifically, a magnetic disk device configured to be capable of recording and reproducing data on and from a magnetic disk having a predetermined track density and twice that track density. The present invention relates to a magnetic disk device.

BACKGROUND ART Magnetic disk drives are often used as external storage devices for various computers, but as the unit price of memory decreases and main storage capacity increases, external storage devices with large capacities are also required.

In response to these demands, for example, in a magnetic disk device using a 5-inch magnetic/magnetic disk, it is possible to record on and read from a magnetic disk at a track density twice that of conventional magnetic disks. A magnetic disk device has been proposed.

However, when such a magnetic disk device is used, information cannot be read from a magnetic disk recorded at a conventional track density.

Purpose The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional technology, and is capable of reproducing a magnetic disk recorded at a conventional track density with a track density twice that of the conventional track density. It is an object of the present invention to provide a magnetic disk device configured such that playback can be performed using the configured magnetic disk device.

EXAMPLES Hereinafter, the present invention will be explained in detail based on examples shown in the drawings.

Figure 1 and the following diagrams explain one embodiment of the present invention.
The figure explains the track arrangement of magnetic disk A, which has a conventional track density, and magnetic disk B, which has twice the track density.As is clear from comparing the two, magnetic disk B has every other track. Compatible with conventional trucks.

Therefore, if you specify a track number that is twice the track number on a conventional magnetic disk and move the magnetic head, even if you use a magnetic disk device that performs recording and playback at double the track density, you will be able to move the track number that is twice the track number on a conventional magnetic disk. I am aware that it is possible to read the above records.

Therefore, in the present invention, a circuit configuration as shown in FIGS. 2 and 3 is adopted. That is, FIG. 2 explains the control circuit for doubling the track movement. In the figure, the reference numeral 1 indicates a seek pulse from a processing device (not shown), and the reference numeral 2 indicates a seek pulse for the conventional track density. Indicates an instruction signal. Seek pulse 1 is AND gate 3, 4
The instruction signal 2 is input to the AND gate 3 via the inverter 5, and also to the AND gate 4.

Reference numeral 6 denotes a double pulse generating circuit, which is connected between the AND gate 4 and the OR gate 7, and the output of the AND gate 3 is also input to the OR gate 7. What is indicated by reference numeral 8 is a black pulse output to the magnetic disk device.

When attempting to read a double track density magnetic disk using the circuit configuration described above, conventional track density signal 2 is turned OFF and seek pulse 1 is set at an interval determined by the magnetic disk device. When a seek pulse is inputted, the AND gate 3 opens, and a seek pulse output to the magnetic disk device can be obtained via the OR gate 7. As a result, the magnetic head (not shown) can be moved onto the target track.

On the other hand, when reading a record on a magnetic disk with a conventional track density, when the conventional track density signal 2 is turned on and seek pulses 1 are inputted to the magnetic disk device at twice the interval specified, the AND gate 4 opens. A signal is input to the OR gate 7 via the double pulse generation circuit 6, and a double seek pulse is output to the magnetic disk device.

Therefore, the amount of movement of the magnetic head of the double-track magnetic disk device is doubled, and the magnetic head can be positioned at the target track of the conventional track.

The seek pulse 1 and the conventional track signal 2 are controlled by a processing device (not shown). Setting the seek pulse interval can be easily done by simply setting software when using an LSI for driving a magnetic disk device.

Further, the conventional track signal can be turned on and off by software by assigning a flip 70 knob to a specific I10 address.

On the other hand, FIG. 3 is a schematic configuration diagram showing an example of a double pulse generation circuit. Since the seek pulse interval is a constant value determined by the connected magnetic disk device, a simple circuit configuration is sufficient. In FIG. 3, the delay caused by the D flip-flop 9 is used.

In Fig. 3, the reference numeral 10 is the input pulse.
Delay the input pulse with D slip 70 knob 9, sign 11
The output pulse 12 is obtained by adding the input pulse and doubling the pulse using the OR gate shown by .

The delay time can be set by the counter 13 to a value determined by the connected magnetic disk device.

Since the present embodiment is constructed as described above, it is possible to use a magnetic disk with a conventional track density and read out the recordings thereof very easily using the double trunk magnetic disk device.

As a result, there is no need to prepare two types of magnetic disk drives for data conversion, and it is now possible to read data from a magnetic disk with conventional track density using a magnetic disk drive with double track density. becomes extremely easy.

Effects As is clear from the above explanation, the present invention employs a structure in which head seek pulses are generated twice as many as the number of seek pulses calculated corresponding to the track number of the conventional track density. Therefore, an excellent effect can be obtained in that information can be read from a magnetic disk having a conventional track density using a magnetic disk device that performs recording and reproduction at double the track density.

[Brief explanation of drawings]

The figures are for explaining one embodiment of the present invention, and FIG. 1 is an explanatory diagram showing the track arrangement of a conventional track density and double track density magnetic disk, FIG. 2 is a block diagram of a control circuit, and FIG. is a block diagram of a double pulse generation circuit. 1... Seek pulse 2... Conventional track density instruction signal 3.4... AND gate 5... Inverter 6... Double pulse generation circuit 7... OR gate 8.
・Nok pulse output

Claims (1)

[Claims] In a magnetic disk device configured to use a magnetic disk having a track density twice that of a predetermined track density, a front pulse is generated when reproducing information from the magnetic disk having the predetermined track density. magnetic disk device.