JPH05341915A - Interface device - Google Patents

Abstract

PURPOSE:To provide the interface device which exchanges data between personal computers using the MS-DOS to efficiently perform the information processing. CONSTITUTION:In an interface device 2, a format processing part 4 converts the logical format of a lower-order operating system to that of a higher-order operating system and formats an external storage device 3 by this converted logical format, and a format conversion part 21 converts the logical format on the external storage device 3 to that of the lower-order operating system at the time of access from a personal computer main body 1 using the lower- order operating system to the external storage device 3 formatted by the format processing part 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interface device for connecting a personal computer to an external storage device such as a disk device.

[0002]

2. Description of the Related Art With the development of microprocessors, personal computers have come to be used as computers for performing information processing. The application software using this personal computer is
For example, it has basic functions of accepting input data from a keyboard, displaying the input data on a screen, and saving or reproducing the data on a magnetic disk.

In such a program of a personal computer, a portion in charge of the above functions is called an operating system (OS). As this OS, recently, MS-for a 16-bit personal computer developed by Microsoft Corp. DOS (Microsoft Disk Operating S
ystem) has been used. Currently, most of the application software started up for 16-bit personal computers are used under MS-DOS.

Furthermore, the MS-DOS is upgraded year by year, for example, MS-DOS3. X to MS-DOS
4. X, and further MS-DOS4. X to MS-DO
S5. Features are increasing as we move to newer versions of X.

[0005]

However, MS-
When the new version and the old version of DOS were compared, the format format of the data stored in the magnetic disk etc. was different due to the functional relationship. Therefore, even if the magnetic disk stored in the new version is connected to the personal computer based on the old version of MS-DOS, the format format is different, and the data stored in the new version of the magnetic disk can be read. could not.

[0006] For example, in the case of MS-DOS 4.0 or later, the number of sectors that can be managed is 2 to the 32nd power.
-DOS3. In the case of X and later, since the number of sectors that can be managed is up to 2 to the 16th power, MS-DO is generally used.
Media created for S4.0 or later is MS-DOS.
3. X couldn't read or write data.

Further, the conventional MS-DOS3. X and MS-
DOS4. Comparing the formats on the magnetic disk with X, (a) personal computer main body 1
OS used by MS-DOS3. In the case of X, for example, the data area (File Alocation Table, FAT) size to be managed for the 3.5-inch magneto-optical disk is 64 Kbytes, so that 32K clusters can be managed.

In the case of using a 3.5-inch magneto-optical disk of 128 Mbytes, various management methods can be considered. However, considering efficiency, the method is as follows. The number of clusters in the cluster area is 32K and the cluster size is 4096 bytes (logical sector × 2). The logical sector size is 2048 bytes (physical sector × 4), the physical sector size is 512 bytes, and the FAT size is 64 Kbytes. (B) On the other hand, the OS used by the personal computer main body 1 is MS-DOS4. If X or later, 3.
Since the data area size managed for a 5-inch magneto-optical disk is 128 Kbytes, 64K clusters can be managed.

A 128-Mbyte 3.5-inch magneto-optical disk 3
When using, there are many possible management methods, but in consideration of efficiency, the following two methods can be selected. (B-1) The number of clusters is 64K and the cluster size is 20
It is 48 bytes (logical sector x 4). The logical sector size is 512 bytes (physical sector x 1), and the physical sector size is
It is 512 bytes and the FAT size is 128 Kbytes. (B-2) The number of clusters is 32K and the cluster size is 40
It is 96 bytes (logical sector x 8). The logical sector size is 512 bytes (physical sector x 1), and the physical sector size is
It is 512 bytes and the FAT size is 64 Kbytes.

MS-DOS3. X, 4. X, 5. If data management is the same between X and X, data compatibility can be achieved between them, but all sizes cannot be made the same due to the difference in logical sector size that can be managed between MS-DOS.

That is, since there is no data compatibility between the personal computers, information processing cannot be performed efficiently. The present invention has been made in view of the above points, and an object of the present invention is to provide an MS-
An object of the present invention is to provide an interface device capable of exchanging data between personal computers using DOS and efficiently performing information processing.

[0012]

In order to solve the above problems and achieve the object, the present invention has the following constitution. FIG. 1 shows the principle of the present invention. As shown in FIG. 1, the interface device connects a main body of a personal computer having an upper operating system or a lower operating system and an external storage device managed by any one of the operating systems.

The format processing unit uses the MS-DOS3.
X logical format is MS-DOS4. The external storage device is formatted with the converted logical format.

When the personal computer body using the lower operating system accesses the external storage device formatted by the format processing unit, the format converting unit sets the logical format on the external storage device to the logical format of the lower operating system. Is configured to convert to.

The operating system is Microsoft's MS-DOS, and the subordinate operating system is MS-DOS3. X, and the upper operating system is, for example, MS-DOS4. It is X.

The external storage device is, for example, a hard disk,
These include magneto-optical disks, cartridge disks, cassette streamer tapes, compact disk read-only memories, and so on.

Further, the format processing unit obtains the coefficient such that the value obtained by dividing the total number of physical sectors of the external storage device by a certain coefficient is the closest to the number of sectors of the lower operating system, and the value is the total logical value. The number of sectors, the value obtained by multiplying the physical sector size by the coefficient is defined as the logical sector size, and the parameters of other logical formats are obtained using the total number of logical sectors and the logical sector size,
The coefficient is used to perform conversion into the logical format of the higher level operating system.

Further, the format conversion unit converts the logical format on the external storage device when the personal computer main body using the host operating system accesses the external storage device formatted by the format processing unit. Configure not to do.

[0019]

According to the present invention, the format processing section 4 is
S-DOS3. X logical format is MS-DOS
4. It is converted to the X logical format and the logical format is written in the external storage device.

When the main body of the personal computer using the lower operating system accesses the external storage device formatted by the upper operating system, the format conversion unit provided in the interface device causes the logical format of the data on the external storage device. To the logical format of the data by the lower operating system.

Therefore, even the lower operating system can access the data of the external storage device created by the upper operating system, and the data can be compatible.

[0022]

EXAMPLES Specific examples of the present invention will be described below.
FIG. 2 is a configuration block diagram of an embodiment of a peripheral device including an interface device according to the present invention.

In FIG. 2, the interface device 2
Is a personal computer body 1 and a magneto-optical disk 3
And are connected. The personal computer main body 1 includes a microprocessor 11, O as a central processing unit.
An S section 12, a keyboard 13 for inputting data and commands, and a display device 14 for displaying data are provided. The OS is Microsoft disk operating system MS-DOS3. X, 4. X and the like.

FIG. 3 is a block diagram of the operating system user memory. This operating system user memory is provided in the above-mentioned OS section 12,
It consists of 1 MB. That is, the maximum memory space that can be used by the operating system is 1 Mbytes, and as shown in FIG. 3, at least the application program, the OS kernel, and the system program are stored in the 1 MB memory space.

The system program is a resident COMM.
AND. It is composed of COM and the like, and is a portion that interfaces a computer and a user. The DOS kernel indicates the MS-DOS itself, MS-DOS during system initialization.
DOS. Read from SYS.

The magneto-optical disk 3 has a size of 3.5 inches and stores a program and data in which instructions are sequentially arranged. FIG. 4 is a diagram showing the arrangement of each area on the magneto-optical disk 3. In FIG. 4, a data area (cluster area) for writing the main body of the file, a root directory area for managing reading and writing of the file, and a file allocation table (FAT) area are arranged on the magneto-optical disk 3. In addition, a system reserved area having a boot program for activating MS-DOS is arranged. These areas are assigned in order from the smallest track number and sector number of the disc.

FIG. 5 is a diagram showing the relationship between sectors and tracks on the disk. The circumference of the disk is divided into a plurality of sectors to provide a plurality of sectors, and sector numbers are sequentially assigned along the circumference. Track numbers are sequentially assigned from the inner circumference to the outer circumference of the disc.

The format processing section 4 checks the capacity of the magneto-optical disk 3 to generate a logical format from the physical format, and outputs the MS-DOS3. X logical format is MS-DOS4. A format program for converting to the X logical format is stored.

The interface device 2 is stored in the magneto-optical disk 3 in the form of MS-DOS4. X and O
S section 12 is MS-DOS3. MS only if X
-DOS4. The logical format of X is MS-DOS3.
Device driver 2 for converting to X logical format
1, an interface card 2 for connecting the computer main body 1, the format processing unit 4 and the magneto-optical disk 3
2 and.

The device driver 21 discriminates the version of MS-DOS used in the personal computer main body 1, and the form of storage in the magneto-optical disc 3 is MS-DOS.
DOS4. X and the OS unit 12 is MS-DOS3. X-only if MS-DOS4. The logical format of X is MS-DOS3. By converting to the X logical format, data is exchanged between different versions of MS-DOS.

Next, the processing contents of the format processing unit 4 and the device driver 21 will be specifically described. MS-D
In the case of OS 4.0 or later, the number of sectors that can be managed is 2 to the 32nd power, and MS-DOS3. In the case of X, the number of manageable sectors is 2 to the 16th power. MS-DO
Media created for S4.0 or later is MS-DOS.
3. X cannot read or write data.

Therefore, MS-DOS3. X-accessible MS-DOS 4.0 / MS-DOS 5.0 media creation method and MS-DO of such media
S3. The access method in X will be described.

<Processing Content of Format Processing Unit 4> (a) MS-DOS 3. Creating a logical format of X First, the format processing unit 4 checks the storage capacity of the magneto-optical disk 3 via the interface card 22,
The following processing is performed. Here, the total number of physical sectors of the medium is Pn, and the physical sector size of the medium is Ps.
And the total number of logical sectors of the medium is Ln,
The logical sector size of the medium is calculated as Ls.

First, from the total number of physical sectors Pn and the physical sector size Ps to the total number of logical sectors Ln and the logical sector size L
In order to obtain s, the following positive integer f is obtained. Pn / f <2 to the 16th power (1) Note that f is a power of 2. For example, if Pn is 250,000 sectors, f will be 4. Using this f, the total logical sector number Ln and the logical sector size Ls are calculated by the following equations.

Ln = Pn / f Ls = Ps * f ... (2) Ls obtained here is one logical sector size, Ln is the number of logical sectors on the medium, and other MS- DOS3.
Calculate the disk parameters of X.

Rn and Fn shown below are arbitrary values. Cs may be any value, but logical sector size *
(Power of 2) is required. Dn may be an arbitrary value, but is required to be a multiple of (logical sector size / 32). Cn and Fs are calculated from the other terms.

Total logical sector number Ln of media, logical sector size Ls, number of sectors per cluster Cn = Cs /
Ls, the number of reserved sectors Rn, the number of FATs Fn, the number of sectors per FAT Fs = ((Cs / Ls) * 2) / Ls, and the number of directories Dn ... (3) (3) <65536
Becomes

Thus, using f, MS-DOS3. X
Parameters can be created. Therefore, MS
-DOS3. Even X can be accessed. However, in MS-DOS 4.0 or later, the total number of logical sectors is allowed up to 4G, but the logical sector size must be the physical sector size. (B) MS-DOS 3. X logical format to MS
-DOS4. Conversion of X to logical format Therefore, MS-DOS3. When the disk parameters of X are actually written on the medium, the above-mentioned f is used, and the MS-DOS4. Convert to parameters for X.

Total number of logical sectors of media Ln ₁ = Ln *
f, logical sector size Ls ₁ = Ls / f (Pn), number of sectors per cluster Cn ₁ = (Cs / Ls) * f, number of reserved sectors Rn ₁ = Rn * f, number of FATs Fn, FAT ₁
Number of sectors per piece Fs ₁ = (((Cs / Ls)) * 2)
/ Ls) * f, the number of directories Dn ... (4).

<Processing of Device Driver 21> The device driver 21 checks the version of the OS when the OS section 12 loads the driver software, and performs the following processing at the time of actually accessing the medium.

In MS-DOS 4.0 or later, the parameters written in the medium are used as they are. MS
-DOS3. In X, the disk parameters are calculated as follows based on the parameters described in the medium.

Total logical sector number of media Ln ₁ / f, logical sector size Ls ₁ / f, number of sectors per cluster Cn ₁ / f, number of reserved sectors Rn ₁ / f, number of FATs Fn, F
The number of sectors per AT is Fs ₁ / f and the number of directories is Dn ... (5).

Since Ln ₁ = Ln * f, Ln ₁ / f
Becomes Ln, which is less than 65536, so MS-DOS
3. You can also access it with X. <Operation of Embodiment> FIG. 6 is a processing flowchart in the embodiment, and FIG. 7 is a diagram showing a logical format of the 3.5-inch magneto-optical disk 3.

First, the format processing section 4 uses the MS-D.
OS4. The total number of formatted disk spaces of the magneto-optical disk 3 of X, 127,774,720, is checked, and the total number of physical sectors is 24.
Based on 9,848, f is determined to be 4 from the equation (1). And
The total number of logical sectors Ln and the logical sector size Ls are obtained from equation (2), and MS-DOS3. The respective parameters of MS-DOS3.X shown in FIG. Get the logical format of X.

That is, the FAT type is set to 16, the boot sector is set to 1, and the total number of logical sectors is set to 62462. 2048 bytes per sector, 2 sectors per cluster
, The number of bytes per cluster to 4096 and the total number of clusters to
Set to 31195. The total number of disk spaces to be formatted is 127,774,720, the number of FATs is 2, and the first sector of FAT is 1.

Further, the number of sectors per FAT is set to 31, the first sector of the root directory is set to 63, and the number of sectors in the root directory is set to 8. Set the maximum root directory file entry to 512 and the first sector number of the data area to 71.

Then, the format processing section 4 (4)
By the formula MS-DOS4. When converted into the parameters for X, the MS-DOS4. It becomes the X logical format.

That is, the FAT type is set to 16, the boot sector number is set to 4, and the total number of logical sectors is set to 249848. The number of bytes per sector is 512, the number of sectors per cluster is 8, and the number of bytes per cluster is 4096. The total number of clusters is 31195, the total disk space to be formatted is 127,774,720, the number of FATs is 2, and F
Set the first sector of AT to 4.

Further, the number of sectors per FAT is set to 124, the first sector of the root directory is set to 252, the sector number in the root directory is set to 32, the maximum root directory file entry is set to 512, and the first sector number of the data area is set. Set to 284.

Then, MS-DOS4. The data is written in the magneto-optical disk 3 in the X logical format. Next, the format processing unit 4 preliminarily causes the MS-DOS 4. X
The OS unit 12 accesses the magneto-optical disk 3 written in the logical format of.

First, in FIG. 6, in step 101,
Make a file access request from the application program. Next, in step 102, the MS-DOS F
The AT file system is read into the OS section 12. Furthermore, the device driver 21 is loaded into the OS section 12,
In step 103, the device driver 21 causes the OS to
The OS used by the unit 12 is MS-DOS3. It is determined whether it is X or not. (C) Here, the OS is MS-DOS3. If it is X, the device driver 21 determines in step 104 that the MS-DOS 4 .. Set the parameter of X to M
S-DOS3. Convert to X parameter.

That is, as shown in FIG. 7, MS-DOS
3. X and MS-DOS 4. The superficial size of X, for example, the cluster size, the FAT type, and the like are matched.
For other parameters, the OS is MS-DOS
3. If X, MS-DO on the magneto-optical disk 3
S4. The value written in X is converted to 4 times or 1/4 times.

Next, at step 105, writing or reading of data on the magneto-optical disk 3 is performed through the interface card 22. (D) On the other hand, MS-DOS4. In X, step 106
Then, the device driver 21 uses the parameters as they are without converting the parameters on the medium.

As described above, according to this embodiment, the format processing unit 4 makes the total number of physical sectors Pn of the magneto-optical disk 3 Pn.
Is obtained by dividing by a coefficient f, the coefficient f is closest to the number of sectors of the lower operating system.
With the above value as the total number of logical sectors Ln, the physical sector size P
A value obtained by multiplying s by the coefficient f is defined as a logical sector size Ls, and the total number of logical sectors Ln and the logical sector size L
Use s to find parameters for other logical formats. Then, using the coefficient f, MS-DOS3. X
The logical format of MS-DOS4. It is converted to the X logical format and the logical format is written in the external storage device.

Then, MS-DOS3. The personal computer main body using X is MS-DOS4. When accessing the magneto-optical disk 3 formatted by X, the device driver 21 provided in the interface device 2 sets the logical format on the magneto-optical disk 3 to MS-DOS3. Convert to X logical format.

That is, in this embodiment, unlike the normal format, the coefficient f is appropriately set and the MS-DOS is previously set.
3. X to MS-DOS4. Since the conversion to X is performed, even if the OS used by the computer main body is the lower OS and the OS of the magneto-optical disk 3 is the upper OS, the device driver 21 can easily perform the MS-DOS.
4. X to MS-DOS3. By converting to MS-DOS3.X. Even if X, M
S-DOS 4. The X magneto-optical disk 3 can be easily accessed. The same applies to the opposite case.

As a result, the data can be accessed, and the data can be interchanged. The present invention is not limited to the above embodiment. In the embodiment, MS-DOS3. X, 4. X has been described, but if the device driver 21 is used, MS-DOS 3.1,
3.3X, 4.0X, 5.0, 5. It can correspond to X and the like.

[0058]

According to the present invention, the format processing unit 4
Converts the logical format of the lower operating system into the logical format of the upper operating system and writes the logical format in the external storage device.

When the main body of the personal computer using the lower operating system accesses the external storage device formatted by the upper operating system, the format conversion unit provided in the interface device makes the logical format of the data on the external storage device. To the logical format of the data by the lower operating system.

Therefore, even the lower operating system can access the data of the external storage device created by the upper operating system, and the data can be compatible.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration block diagram of a first embodiment of the present invention.

FIG. 3 is a configuration diagram of an operating system user memory.

FIG. 4 is a diagram showing an arrangement of areas on a disc.

FIG. 5 is a diagram showing a relationship with sectors and tracks on a disc.

FIG. 6 is a processing flowchart in the first embodiment.

FIG. 7 is a diagram showing a logical format of a 3.5-inch optical disc.

[Explanation of symbols]

 1 ... Personal computer main body 2 ... Interface device 3 ... Magneto-optical disk 4 ... Format processing unit 11 ... Microprocessor 12 ... OS unit 13 ... Keyboard 14 ... Display device 21 ... Device driver 22 ... Interface card 31 ... Terminator

Claims (3)

[Claims] 1. An interface device for connecting a personal computer main body having a higher operating system or a lower operating system to an external storage device managed by any one of the operating systems, wherein a logical format of the lower operating system is set to a higher level. A format processing unit for converting the logical format of the operating system and formatting the external storage device in the converted logical format; and a personal computer main body using the lower operating system, the external storage device formatted by the format processing unit. When accessing, a format for converting the logical format on the external storage device into the logical format of the lower operating system. Interface device being characterized in that a mat conversion unit. 2. The format processing unit obtains the coefficient such that a value obtained by dividing the total number of physical sectors of the external storage device by a certain coefficient is the closest to the number of sectors of the lower operating system, and the value is calculated. The total number of logical sectors is defined as the total number of logical sectors, and the value obtained by multiplying the physical sector size by the coefficient is defined as the logical sector size. Using these total number of logical sectors and logical sector size, parameters for other logical formats are obtained, and the coefficient is used to determine the upper order. The interface device according to claim 1, wherein the interface device converts the operating system into a logical format. 3. The format conversion unit converts a logical format on the external storage device when a personal computer main body using the higher level operating system accesses the external storage device formatted by the format processing unit. The interface device according to claim 1, wherein