JPS58108061A - Magnetic disk control system - Google Patents

Abstract

PURPOSE:To prevent recording information from being destroyed completely, by supplying electric power during writing operation through a switch means with a low response speed, and bringing this switch means under the control of a disk rotation drive control signal. CONSTITUTION:A switch circuit 1 is composed of a reed microswitch having a low response speed, and a signal writing circuit 2 is powered up through said circuit 1. Consequently, the circuit 2 operates only while the power source is stable to prevent the occurrence of malfunction completely.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic disk control system (2), more specifically, when the electric voltage of a magnetic disk device rises or falls, the data writing circuit malfunctions (2), and the recorded information is destroyed. The present invention relates to a magnetic disk control method 6 that prevents.

For example, a floppy disk device is used as a magnetic recording/reproducing device connected to an electronic computer. A floppy disk device (:) requires a driving power source (for example, 12V) to supply power to drive the mechanism, and a control power source (for example, 5V) to supply power to operate the control circuit.

Conventional floppy disk drives are equipped with a magnetic head loading mechanism, and this loading mechanism employs a mechanism that reads and writes only when a magnetic disk is used, and accesses the disk by placing the head in close contact with the magnetic disk. ing. This prevents the recorded data from being destroyed due to unstable operation of the circuit during a short period of time when the power is turned on or turned off.

However, in a device with a simplified structure that does not have a head loading mechanism, when a magnetic disk is installed in the recording/reproducing device, the recording medium and the read/write head are always in close contact, so when the power is turned on or turned off, There is a risk that the recorded data may be destroyed due to unstable operation of the circuit that occurs at a momentary moment.

The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional magnetic disk device, and is a magnetic disk device that prevents data destruction due to unstable circuit operation52 in a simple magnetic disk device without a head loading mechanism. The purpose is to provide a disk control method.

In order to achieve the above object, the present invention supplies power for writing to the magnetic disk through a switch means with a slow response operation, and controls this switch using a control signal ( We adopted a two-up structure.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention. In the figure, reference numerals 5a and 5b are switch circuits that receive two control signals sent from a control device (not shown), that is, an ON signal for a stepping motor. , and is controlled by a pulley drive motor ON signal, and specifically comprises an electronic switch circuit illustrated in FIG. 4, which will be described later.

These switch circuits 5a and 5b are connected to C;
It is configured. That is, these switch circuits 5a, 5
b is two transistors Tr5. The base of Tr5 and the collector of Tr6 are connected via a resistor R6, and between the base and collector of Tr5 (: is connected to a resistor R7, and the base of Tr6 is connected to a resistor R5. is connected to the switch, and is configured as a quick-response semiconductor switch.

A magnetic head 9 that performs recording and reproduction on the magnetic disk 8
The stepping motor 7a that operates the switch 5
When the switch 5b is turned on, the motor 7b that rotates the magnetic disk 8 is rotated twice by C when the switch 5b is turned on.

The stepping motor 7a is rotated according to the contents of the four phases by inputting a four-phase step signal 16 for driving the carriage through the driver 6. When the motor 7a rotates and the screw 10 rotates, the screwed carriage 11 moves in the axial direction of the lead screw 10 (=
The magnetic head 9 is moved along the carriage 111 via the arm 12 attached to the carriage 111.

Therefore, the rotation of the motor 7a allows the magnetic head 9 to face any desired track on the magnetic disk 8.

On the other hand, the motor 1b rotates in response to the pulley drive motor ON signal input to the control input terminal of the switch circuit 5b, and the magnetic disk 8 is moved to the spindle 14 by the clamp 15.
b-=The magnetic disk 8 is rotated via the bell (bell) 14c, which is stretched between the bell 914a and the bell 914a because it is pressed.

The index hole detection circuit 3 is a circuit for detecting an index hole 8a from the magnetic disk 8 and detecting an index signal. This detects an index signal once per rotation of the magnetic disk 8 rotated by the rotation of the motor 7b, which is a pulley drive motor, and sends it to the control circuit C2.

Reference numeral 4 denotes a signal readout circuit from the magnetic disk 8, which includes amplification and waveform shaping circuits for readout signals from the magnetic head 9 for reading and writing.

Reference numeral 2 designates a signal write circuit which receives a control signal and supplies a write current to the magnetic head 9, and is supplied with power via a switch circuit 1. The details of the switch circuit 1 are as shown in FIG.
It is assembled around the collector 1ljll
The second is connected to a micro reed switch M. This micro reed switch M has an extremely slow response time compared to a semiconductor switch.

Next, the operation of this embodiment, which has a hole configured as described above, will be explained.

Figure 2 is a timing chart explaining the operation.
As is clear from the figure, there is a moment when the various control signals operate unstable when the C2 power is turned on and when it is turned off.
If power is supplied to the write circuit 2I in such a case, an unexpected current will be supplied to the head 9, resulting in data destruction on the magnetic disk 8.

However, in the present invention, since the micro reed switch with a slow response speed (=therefore, the switch circuit 1 is used to supply power to the circuit 2), the signal writing circuit 2 starts up only when the power supply is turned on, as shown in FIG. This is only in a stable state, and there is no inconvenience that malfunctions may occur.

During normal access, the switch circuit 1 is turned on in response to the pulley drive motor ON signal, so there is a delay in the power supply voltage of the signal writing circuit 2, as shown in FIG. The area is 10 to 20 m5, and there is no problem when accessing it.

Furthermore, since not only the signal writing circuit 2 but also all other signals are generated only during stable operation of the power supply (2), there is no risk of malfunction.

As is clear from the above description, according to the present invention, power is supplied to the magnetic disk during writing via a switch means with a slow response speed, and this switch means is controlled by a control signal of the rotation drive means for the magnetic disk. Therefore, it is possible to completely prevent recorded information from being destroyed due to malfunction of the data writing circuit when the power supply voltage rises or falls.

[Brief explanation of the drawing]

The drawings are for explaining one embodiment of the present invention. Fig. 1 is a schematic configuration diagram, Fig. 2 is a timing chart diagram, Fig. 3 is a switch circuit diagram, and Fig. 4 is a diagram of a head and magnetic disk rotation motor. FIG. 2 is a circuit diagram showing the structure of a switch. 1...Switch circuit 2...Signal writing circuit 4
...Signal readout circuit 7a, 7b...Motor
・Magnetic disk 7, 9...Magnetic head.

Claims (1)

[Claims] Power is supplied to the circuit for writing signals to the magnetic disk through a switch means with a slow response operation, and the switch means is controlled by a control signal for the rotation drive means for the magnetic disk. A magnetic disk control method featuring: