JPH0654583B2 - Auxiliary storage device data writing method - Google Patents

Description

DETAILED DESCRIPTION [Outline] When a designated sector in a designated cylinder in a floppy disk is accessed, the counter starts counting the number of write bytes at the same time, and when the designated count value is reached, the update data is updated to the sector. Write to.

[Industrial application field]

The present invention relates to improvement of a data writing method for an auxiliary storage device.

[Conventional technology]

FIG. 3 is a diagram showing an example of a data writing method for a conventional auxiliary storage device.

In the figure, 1 is a read / write controller, 2 is a memory, and 3 is a floppy disk. The same signal represents the same object throughout the drawings.

Conventionally, a data writing method for an auxiliary storage device such as a floppy disk or a hard disk has been performed in units of sectors.

When writing / reading to / from the floppy disk 3, the cylinder is designated, and the sector is designated to write / read.

The memory area of the floppy disk 3 is composed of a large number of concentric cylinders C _m , C _{m + 1,} etc.
As shown in FIG. 3, a large number of sectors S _{1 to} S _n are accommodated in each sector, and each sector S _{1 to} S _n is composed of 256 bytes as an example.

For example, when updating data on the floppy disk 3, a read command specifying the address of the cylinder C and the address of the sector S is issued from the processing unit (not shown).

When the read / write control unit 1 receives this read command, it accesses the sector of the specified address in the cylinder C of the specified address, once reads the contents (256 bytes) of that sector, and stores it in the memory. Store in 2.

Therefore, the memory 2 has a storage capacity of at least one sector (25
6 bytes) is required.

Next, the read / write controller 1 updates the data at the designated byte position in the memory 2.

After updating the data in the memory 2, the read / write control unit 1 again accesses the same sector S as before and moves all the data of 256 bytes in the memory 2 to the sector-writing-method. There is.

That is, once for each sector, once for writing, and once for writing, a total of 2
The method of accessing once is adopted.

[Problems to be solved by the invention]

As described above, when updating the data in the floppy disk, the conventional method has a drawback that it must be accessed twice.

[Means for solving problems]

As for the above-mentioned problem, as shown in the principle diagram of FIG. 1, the read / write control unit 1 specifies the cylinder and sector in the auxiliary storage device 3 by the read / write command to access, and performs the read / write in sector units. In the data writing method,
This can be solved by adding a counter 4 for counting the number of write bytes in a sector to the read / write control unit 1.

[Action]

According to the present invention, the read / write control unit 1 accesses a designated sector in a designated cylinder by a write command. At the same time, the counter 4 starts counting the number of write bytes, and when the count value of the counter 4 reaches the designated value, the read / write control unit 1 writes the update data sent from the processing unit 5 to the sector. Since it is included, the access to the auxiliary storage device 3 is required only once.

〔Example〕

FIG. 2 is a diagram showing an embodiment of the data writing method of the auxiliary storage device according to the present invention.

In the figure, 4 is a counter, 5 is a processing unit, and 6 is an I / O control program.

Based on the I / O control program 6, the processing unit 5 reads /
A write command is issued to the write control unit 1 to specify the address of the desired cylinder and the desired sector.

The read / write control unit 1 sets the addresses of the cylinder C and the sector S in the floppy disk 3 by the above command and accesses the floppy disk 3.

At the same time as the access, the counter 4 starts counting the number of write bytes, and when the count value of the counter 4 reaches a specified value, the read / write control unit 1 transfers the update data sent from the processing unit 5 to the sector S. Write.

As described above, writing can be performed at a predetermined position in the sector by one access.

〔The invention's effect〕

As described in detail above, according to the present invention, there is a great effect that the data can be written in a predetermined position of the floppy disk by one access.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention. FIG. 2 is a diagram showing an embodiment of the data writing method of the auxiliary storage device according to the present invention. FIG. 3 is a diagram showing an example of a data writing method of a conventional auxiliary storage device. In the figure, 1 is a read / write control unit, 2 is a memory, 3 is a floppy disk auxiliary storage device, 4 is a counter, 5 is a processing unit, and 6 is an I / O control program.

Claims (1)

[Claims] 1. A data write system in which a read / write control unit (1) specifies a cylinder and a sector in an auxiliary storage device (3) to access by a read / write command, and performs read / write in sector units. In this case, a counter (4) for counting the number of write bytes in the sector is added to the read / write control unit (1), and the read / write control unit (1) is designated by the write command. The counter (4) starts counting the number of write bytes at the same time when the designated sector in the counter is accessed, and when the count value of the counter (4) reaches the designated value, the read / write control unit (1 ) Writes the update data, the data writing method of the auxiliary storage device.