JP2927069B2 - Floppy disk controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to read / write control of data on a floppy disk medium, and more particularly to a write data protection method.

[0002]

2. Description of the Related Art As a conventional protection method for writing data between a floppy disk control device and a floppy disk device, as shown in FIG. 5, a write enable notch or a protection switch provided on a floppy disk medium is switched. Is adopted. By covering this write enable notch with silver paper or the like, the floppy disk device itself prohibits data writing, and outputs a write prohibition signal to the floppy disk control device. By recognizing that an error has occurred, an operation such as reporting an alarm is performed in response to a write instruction from software.

[0003]

This conventional write protection method is performed for each floppy disk medium, so that a write-protected area cannot be selected arbitrarily and is required especially when a computer system fails.
In order to collect memory dump information, it was necessary to prepare a separate dump medium. Further, there is a problem that the medium is destroyed if the protection process of the medium is erroneously performed.

[0004]

According to the present invention, a floppy disk medium of a floppy disk device is provided.
In a floppy disk control device for writing and reading data, means for holding write-inhibited area information for a floppy disk medium, means for storing write-inhibited area information for the holding means in response to an instruction from software, A floppy disk control device comprising: means for comparing a write operation instruction from software with the contents of the write protected area holding means; and means for controlling output of a write signal to the floppy disk device based on the comparison result. Is obtained.

According to the present invention, in a floppy disk control device for writing and reading data to and from a floppy disk medium of a floppy disk device, means for holding write-inhibited area information for the floppy disk medium, Means for reading the write-protected area information written on the floppy disk medium, means for storing the information read by the read means in the holding means, and means for holding the write-protected area in response to a write operation instruction from software. And a means for controlling the output of a write signal to the floppy disk device based on the result of the comparison, thereby obtaining a floppy disk control device.

According to the present invention, in the floppy disk control device, the write-protected area information is
A floppy disk control device characterized by comprising means for setting by hardware without software is provided.

Further, according to the present invention, in any one of the floppy disk control devices, if the write instruction from the software is directed to a write-protected area, a means for notifying the software of an abnormality is provided. , A floppy disk controller is obtained.

That is, the floppy disk control device according to the present invention is provided with means for holding a write-protected area for a floppy disk medium and instructions from software.
Means for storing write-protected area information; means for comparing the contents of the write-protected area holding means in response to a write operation instruction from software; and means for controlling the output of a write signal to a floppy disk device based on the comparison result. And Further, there are provided means for reading the write-protected area information which has been written in advance on the floppy disk medium, and means for storing the read contents in the write-protected area holding means.

Further, there is provided means for setting a write-protected area by hardware.

Further, if the write instruction from the software corresponds to the write-protected area,
A means for notifying the software of an abnormality is provided.

[0011]

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

FIG. 1 is a block diagram of an embodiment according to claim 1 of the present invention.

The floppy disk control device 1 comprises a main control circuit 2, a write circuit 3, a holding circuit 4, a comparison circuit 5, and a write signal driver circuit 6. The floppy disk device 11 includes a control circuit 12 and a floppy disk medium 13. When a write-protected area (track number, cylinder number, etc.) is specified by software, the main control circuit 2 stores the information in the holding circuit 4. This can have a plurality.
Further, the stored contents are held until an instruction is given again.

When receiving a write instruction from software, the main control circuit 2 compares the write area designated thereby with the holding circuit 4 by the comparison circuit 5, and if no match is found, the write operation is enabled. Writing circuit 3
Is valid, and data is output to the floppy disk device 11 via the driver circuit 6. if,
If the result of comparison by the comparison circuit 5 matches, the writing circuit 3 is not operated because the writing is disabled, and no data is output to the floppy disk device 11.

FIG. 2 is a block diagram of a second embodiment according to the present invention.

The floppy disk controller 1 comprises a main control circuit 2, a write circuit 3, a holding circuit 4, a comparison circuit 5, a driver circuit 6, and a read circuit 7. The floppy disk device 11 includes a control circuit 12 and a floppy disk medium 13. Each time the floppy disk medium 13 of the floppy disk device 11 is mounted, the main control circuit 2 reads the write-inhibited area information written at a predetermined position on the floppy disk medium 13 by using the read circuit 7 and the receiver circuit. 8 and stored in the holding circuit 4. The subsequent operation is the same as the operation in FIG.

FIG. 3 is a block diagram of an embodiment according to the third aspect.

The floppy disk controller 1 comprises a main control circuit 2, a writing circuit 3, a holding circuit 4, a comparing circuit 5, a driver circuit 6, and a setting circuit 9. The main control circuit 2 reads the contents of the setting circuit 9 and stores it in the holding circuit 4 immediately after the power of the floppy disk control device 1 is turned on or when receiving an initialization instruction from software. The subsequent operation is the same as the operation in FIG. This is effective in a simple setting in which only one surface of the track 0 or the track 1 of the floppy disk medium 13 is set as the write-protected area.

FIG. 4 is a block diagram of an embodiment according to the fourth aspect.

The floppy disk controller 1 comprises a main control circuit 2, a holding circuit 4, and a comparison circuit 5, and a match notification signal 10 based on the comparison result of the comparison circuit 5 is sent to the main control circuit 2.
It is connected to the. Here, when the main control circuit 2 receives a write instruction from the software 20, the main control circuit 2 compares the write instruction with the inside of the holding circuit 4 by the comparison circuit 5. And reports an abnormality of the write instruction to the software 20.

[0021]

As described above, according to the present invention, since the floppy disk control device is provided with means for holding the write-protected area information for the floppy disk medium, the write-protected area for the floppy disk medium can be arbitrarily selected. It has the effect of being able to do it.

Further, even when the protection setting of the floppy disk medium is forgotten, the floppy disk control device protects the medium, so that the medium is prevented from being destroyed.

[Brief description of the drawings]

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

FIG. 2 is a block diagram of one embodiment of the second embodiment.

FIG. 3 is a block diagram of one embodiment of the third embodiment.

FIG. 4 is a block diagram of a fourth embodiment of the present invention;

FIG. 5 is an external view of a conventional floppy disk medium, in which a is a 5.25 inch medium, and b is 3.
Shows 5 inch media.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Floppy disk controller 2 Main control circuit 3 Writing circuit 4 Holding circuit 5 Comparison circuit 6 Driver circuit 7 Reading circuit 8 Receiver circuit 9 Setting circuit 10 Match notification signal 11 Floppy disk device 12 Control circuit 13 Floppy disk medium 20 CPU (software)

Claims (2)

(57) [Claims] 1. A floppy disk control device for writing and reading data to and from a floppy disk medium of a floppy disk device , comprising: means for holding write-protected area information for the floppy disk medium; Dressed in
Means for reading the write-protected area information previously written on the floppy disk medium every time the disc is attached, means for storing the information read by the reading means in the holding means, and means for responding to a write operation instruction from software. A means for comparing the contents of the write-protected area holding means with the contents of the write-protected area holding means; and means for controlling output of a write signal to the floppy disk device based on the result of the comparison. Write instruction from wherein software, as long as for the write-protected area, characterized in that it comprises means for notifying the software as an abnormal 請
The floppy disk control device according to claim 1.