JPH0315937A - Memory card system, memory card and method for accessing memory card - Google Patents

Abstract

PURPOSE:To attain inter-exchange with file data of floppy disks by including the name of a file, the head of an extent and a final address in the index area of a memory card and providing an area recording the number of recording bytes per sector. CONSTITUTION:The memory card 6 is constituted of the index area 8 and the data area 9 including plural extents where data are recorded. The recording area of the name 15 of the file, the status display area 18 recording the number of bytes per sector and the recording areas 16 and 17 of the head and final addresses of the extent 10 are included in an index area 8 corresponding with respective extents 10. The control part of a system reads the index area 8, reads the status display area 18 responding to the existence of the name 15 of the desired file and converts the given address based on the number of bytes recorded in the area 18 into the address for accessing the memory card 6. Thus, data interexchangeability with various floppy disks can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a memory card system, a memory card and a method for accessing a memory card. More specifically, the present invention relates to a system having a memory card that is versatile as a data file medium.

[Conventional technology]

Magnetic disks, such as floppy disks, are commonly used as data file media in data processing systems. Recently, memory cards with built-in IC memory chips have appeared and are being used as data file media. When using a memory card as a data file medium, its recording format can be determined independently of that of a floppy disk. However, since floppy disks have been used as a data file medium for many years and software that is based on floppy disks has been accumulated, it is necessary to match the recording format to make a memory card a versatile data file medium. is desired. The recording format 1 of the floppy disk consists of an index area and a data area, and the index area holds the file name serving as the index of the data area, the address of the data area, etc.

JP-A-63-138483 discloses an IC card device whose memory consists of a management area and a data area, and management data consisting of a label name, address, and data length of the data area is recorded in the management area.

Japanese Patent Application Laid-Open No. 63-484889 discloses an I with a built-in IC chip.
C card is disclosed, and its memory is divided into multiple areas [00-
FF], and the area [OO is the area [01
-FF], the number of bytes constituting the area, and information defining the data output method are recorded.

Both patents describe a format similar to that of a floppy disk.

[Problem to be solved by the invention]

On the other hand, a floppy disk is accessed by specifying a location using a track address and a sector address. There are various types of floppy disks, such as those with a number of recording bytes per sector of 128 bytes, 256 bytes, and 1024 bytes.
Data cannot be transferred between media with different numbers of recording bytes per sector. Memory cards do not have the concept of tracks or sectors, and data can be transferred between memory cards. However, when using them as a data file medium in place of floppy disks, there are some issues with compatibility with floppy disks and compatibility with floppy disks. Data transfer is required.

An object of the present invention is to provide a memory card that is compatible with floppy disk file data.

Another object of the invention is to provide a memory card system and method for accessing such a memory card.

[Means to solve the problem]

A memory card consists of an index area and a data area each containing a plurality of extents in which data is recorded. The index area of this memory card includes an area for recording the file name, a status display area for recording the number of recorded bytes per sector, and an area for recording the start and end addresses of the extent, corresponding to each of the extents, Compatible with floppy disks.

Furthermore, the memory card system includes a control section, and the control section uses the above index area to access one of the extents.

Furthermore, to access the memory card, read the index area, determine whether the desired file name exists, read the status display area in response to the presence of the desired file name, and record it in the status display area. Converts the given address into an address for accessing the memory card based on the number of bytes given.

[Effect]

A memory card consists of an index area and multiple extents, and the index area contains the file name, start and end address of the extent, so it matches the format of a floppy disk, and the data recorded on the memory card can be accessed by different devices. In addition, by having an area for recording the number of recording bytes per sector, file data is compatible between memory cards and floppy disk media. be able to.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 2, the terminal equipment includes an input section 2, a display section 3,
, a control section 4, and a memory card reading/writing section 5, into which a memory card 6 is inserted. The memory card 6 is, for example, an IC memory card having a built-in IC memory chip.

FIG. 1 shows recording formats 1 to 1 of the memory card 6.

The memory card 6 consists of an index area 8 and a data area 9. The data area 9 includes a plurality of extents 10 in which data is recorded.

The index area 8 includes a volume label 13 and a plurality of data set labels 14. One data set label 4 corresponds to one extent 0. Data set label 14 is file name area 15
, status display area 8, start address area 1G
and final address area 17. The file name of the corresponding extent 10 is recorded in the file name area 15. The head address area 16 contains BOE (Beginni) of the corresponding extent lO.
goof Extent), and E○E (End of Extent) is recorded in the final address area E7.

BOE. In the EOE, the address of the floppy disk, that is, the track address and the sector address, rather than the address of the memory card itself, is recorded so that it appears as a floppy disk when viewed from the terminal device 1. The status display area 8 records the number of recording bytes per sector when the data of the file recorded in the file name area 15 is recorded on a floppy disc.

3(cL) and (6) show the data write sequence, and FIGS. 4(cL) and (6) show the data read sequence.

When writing data to the memory card 6 using the terminal device l, when a guidance screen display request is inputted from the input section 2 of the terminal device {, the guidance screen data is displayed on the display section 3 under the control of the M control section 4.

When the guidance screen is displayed on the display section 3, the operator inputs data from the input section 2 according to instructions on the guidance screen. When the input of data from the input section 2 is completed, the control section 4 records the data on the memory card 6 via the memory card reading/writing section 5. Information is recorded in the format of the memory card.

When recording data on the memory card 6, as shown in FIG. 3, first read the index area 8, search the file name area 15 of the data set label 14, and select the same file name as the data to be recorded. It is determined whether there is one (steps 21-24). If there is no identical file name, the file name of the data to be recorded is registered in the first file name area 15 of the group of unregistered file name areas 15 (step 25).

When the file name registration is completed, an area (extent) for recording the corresponding data is secured in the data area 9. (Step 26). Then, the number of recorded data bytes per sector given from the control unit 4 is set in the status display area 18, and the BOE and EOE of extent 10 secured in the data area 9 are set in the area l.
6 and 17, respectively (step 27-2
9).

Next, the status display area l8 is read again and the number of bytes per sector is determined (step 30). If the file name of the data to be recorded is already in the file name enoa 15 of the data set label 14, a step is reached in which the number of bytes is determined. The address is counted according to the number of bytes recorded in the area 18 (steps 31cL/316/31G). In other words, the address recognized by the control unit 4 is an address represented by a track address and a sector address, and the address is It is necessary to convert the code to the address to be accessed. Conversion is as follows: MCA=n-TA0 (SA-1) DMCA: Byte address of memory card n: Number of sectors/track (for example, 26) TA: l-Rack address, starting from O.

SA: Sector address, starting from the king.

D=number of bytes recorded in area 18/sector (eg 128, 256 or 1024) As a result, the control unit 4 converts the track address and sector address into the address of the memory card, making it possible to access the memory card.

When reading data recorded on the memory card 6 with the terminal device 1, as shown in FIG. It is determined whether there is one (steps 41-44). If so, the status display area 18 is read, the number of bytes per sector is determined, and the address is counted according to the recorded number of bytes (steps 45-46c). That is, the track addresses and sector addresses recorded in the B○E and EOE areas 16 and 17 are converted into memory card addresses using the above-mentioned calculation formula. And this converted BO
E. Data within the range specified by the EOE is read from the data area (extent) 10 (step 47). Also, file name area l5 of dataset label 14
If there is no name of the file you are trying to read,
Display an error message on the display unit 3 (step 51)
).

When recording data on the memory card 6, the data recording format is a standard one, and in order to provide versatility, the data recording format is made to conform to, for example, the data writing format of a floppy disk medium. As mentioned above, the inside of the memory card 6 is divided into at least an index area 8 and a data area 9, the index area 8 is provided with at least a volume label 13 and a data set area 14, and the data center label 14 is provided with at least a file name 15 and a status display area. 18,BOE1
6 and EOE1 7 are provided. This makes it possible to standardize the data recording format of the memory card 6.

Furthermore, by matching the data recording format of the memory card 6 to the data recording format of the floppy disk medium, it is possible to maintain compatibility of file data between the memory card 6 and the floppy disk medium, and the status display area 18 By displaying the number of recorded data bytes per sector, it is 128 bytes/sector, 256 bytes/sector, 1,024 pi!・
It is also possible to provide data compatibility with various types of floppy disks, such as / sectors.

As a data error check method, when data is written to the memory card 6 and the recording data has been written to extensions 1 to 10, a CRC check method is used to check the recorded data from the beginning to the end, as shown in Figure 3. , and set the result in the error check code set 12 provided at the end of this extent 10 (step 33). When reading a memory card, as shown in Figure 4, the data from the beginning of the data recorded in extensions 1 to 10 to just before the error check code set 1-area is read in C.
Calculation is performed using the RC check method, and the calculated result is compared with the contents of the error check code set area. If -M is found, it can be assumed that data writing and reading were performed correctly. (Steps 48-50). Furthermore, if the comparison results do not match, it is assumed that data writing and reading were not performed correctly, and an error message can be displayed on the display section 3. [Effects of the Invention] According to the present invention, a memory card can be used as a versatile medium at the same time as, for example, a floppy disc medium, so it can be used as one of the media that can transfer data between different devices. ．．

[Brief explanation of drawings]

FIG. 1 is a recording format diagram in a memory card, FIG. 2 is a hardware configuration diagram for implementing the present invention, and FIG. 3 ((L) and (6) is a flowchart 1 showing a data writing sequence.・, FIGS. 4(Q) and (b) are flowcharts showing the data reading sequence. Engineering: terminal device, 4: control section, 5: memory card reading/writing section, 6. ...Memory card, 7...Memory card recording format, 8...Index area, 9...Data area, 10...Extent, 1l...Start address (BOE).12...Last address (EOE), 14... Data set label, 15... File name, 16... BOE recording area, 17... EOE recording area, 18... Status display area. 7 1st mouth 3rd ward ( (1) 2nd obturator muscle 4 flash (α)

Claims (4)

[Claims] (1) A memory card comprising a data area including an index area and a plurality of extents each recording data, and a control means for accessing one of the extents by referring to the index area,
The above index area corresponds to each of the plurality of extents and includes an area for recording at least the file name, a status display area for recording the number of recorded bytes per sector, an area for recording the start address of the extent, and an area for recording the end address of the extent. A memory card system characterized by having an area for recording. (2) The control means includes means for converting a given address into an address for accessing the memory card based on the number of bytes recorded in the status display area. Memory card system described. (3) It consists of an index area and a data area including a plurality of extents in which data is recorded, and the index area is an area in which at least a file name is recorded corresponding to each of the plurality of extents, and a recording byte per sector. A memory card comprising: a status display area for recording a number; an area for recording a start address of an extent; and an area for recording a final address of an extent. (4) In the access method for reading data from or writing data to a memory card, the memory card is composed of an index area and a data area each including a plurality of extents in which data is recorded, and the index area is For each of the multiple extents, at least an area for recording the file name, a status display area for recording the number of recorded bytes per sector, an area for recording the start address of the extent, and an area for recording the final address of the extent are provided. reading the index area to determine whether a desired file name exists; responsive to the presence of the desired file name, reading a status display area; and recording in the status display area. An access method comprising the steps of: converting a given address into an address for accessing the memory card based on the number of bytes obtained; and accessing the memory card.