JPS62172387A - Character code conversion control system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] A character code conversion control method for a computer system that searches for character patterns from character codes. Divide the character code into first and second partial codes, search the first table with the first partial code, obtain address information of the second table area, and search the second table determined based on the address information with the second partial code. It is configured to search and obtain the storage area address of the desired character pattern. This method makes it possible to efficiently allocate the storage area of a character code conversion table, especially in a system where the character code length is relatively long and there are character patterns for a plurality of character types.

[Industrial application field]

The present invention relates to a control method for searching character patterns from character codes in a computer system, and in particular, enables reduction of character code conversion tables in systems that have relatively long character codes and handle multiple character types. Concerning character code conversion control method.

In computer systems that process Japanese, etc., it is necessary to know the character pattern for outputting and displaying each character on a display, printer, etc. from the character code representing each character. This process involves indexing a character code conversion table to obtain a storage area address for storing a character pattern.

[Prior art and problems to be solved by the invention] FIG. 2 is a block diagram showing an example of the configuration of a computer system.

The processing device 1 is connected to a suitable host device via a signal line 3.
It has a function of outputting characters specified by a character code sent together with necessary control information to an output unit 2 such as a printer.

For this purpose, the processing device 1 indexes the conversion table 5 held on the storage unit 4 using the specified character code to obtain the storage address of the character pattern, and reads the character pattern from the character pattern storage area 6 using the address. The data is transferred to the output unit 2, and the output unit 2 displays and outputs characters according to the character pattern.

The conversion table 5 allows an address generated from, for example, a character code to be indexed as a relative address within the table.

For example, character codes indicating characters including kanji, etc. cannot correspond to all the required characters with a length of 1 byte (8 bits), so a code with a length of 2 bytes is used as is well known, but among them, The code is expressed as a hexadecimal number, and the range from the upper byte '41' to 'FE' and the lower byte '^1' to 'FE' are used as valid character codes.

For convenience of control, the area on the storage unit 4 is generally allocated to a continuous area for each type of use. If it is possible to directly change the pan to a relative address, considering an area based on a certain address, an area of about 47 kilograms from the relative address "41A1" to °FEFE' within that area will be used for the conversion table. It occupies the area.

In order to reduce this area, replace the upper and lower bytes of the character code and use it as a relative address, and create an area from 'A141' to 'FEFIE'.
In the above case, the area is about 172 and about 23 kilograms.

In addition, in many cases, storage area allocation management is performed in appropriately large blocks rather than one word block, and in that case, for example, from relative address 'A000' to I'FI'
r” becomes the area of the conversion table 5.

FIG. 3 is a diagram illustrating the structure of the conversion table 5 allocated in this manner in correspondence with character codes.

The figure shows the upper byte value of the character code in the horizontal direction, and F in the vertical direction.
The outermost rectangle represents the total space specified by the double-byte character code.

Therefore, the area allocated to the conversion table 5 as described above is the part not enclosed by the bold rectangle in the figure, and the part corresponding to the valid code is the area indicated by - in the figure.

In other words, the invalid character codes °0〇81''~``0OPB'', which are character codes that are not used, are changed to
The area corresponding to r"E' (indicated by :ii; : in the figure) is wasted. This area has approximately 6 kilowords.

In the above description, it is assumed that each entry indexed by each character code in the conversion table 5 consists of one word for holding an address indicating one type of character pattern.

In the past, this was sufficient, but with the advancement of Japanese language processing, character patterns are changing, for example, not only one Mincho font, but also Gothic fonts, half-width/full-width sizes, horizontal/vertical writing, etc. It has become necessary to have various types of character patterns such as writing.

If you have such a wide variety of character patterns, each entry in the conversion table must contain multiple words that hold the addresses of the character patterns corresponding to the number of types of character patterns, so you can create a conversion table using the method described above. In this case, the waste area corresponding to the invalid code is also multiplied by the same number as the number of character pattern types, resulting in a problem that the storage area usage efficiency is deteriorated.

[Means for solving problems]

FIG. 1 is a block diagram showing the configuration of the present invention.

The figure shows the configuration of the conversion table, 10 is the first table,
11 is a second table.

[For production]

In the index of the conversion table, the character code is divided into, for example, an upper part code and a lower part code.

The first table 10 is a table indexed by an address generated from the upper part code of the character code, and each entry holds address information for indexing the second table 11.

The second table 11 determined by the index of the first table IO is
The table is indexed by addresses generated from the lower part code of the character code, and each entry holds addresses indicating the required number of character pattern areas.

With this configuration, there is no wasted area caused by the conventional invalid character codes, and the storage area can be used effectively.

〔Example〕

Taking the 2-byte character code described above as an example, the character code is divided into two parts, an upper byte and a lower byte, in the index of the conversion table.

The first table 10 is a table that is indexed by reading out each term using a word address generated by adding a predetermined base address to the upper hide value, and each term has a base for indexing the second table 11. Retain address.

For example, term 12, which is the first effective term in the first table, is
For example, its base address should be indexed by 41°, which is the minimum value of the upper byte of the valid character code, and indexed by the lower byte of the character code with the upper byte l - '41'. Holds the desired address value.

Each second table 11 determined by each term of the first table has a configuration in which the term address is determined by an address generated by adding the lower byte of the character code to the base address held in the first table, and the area determined by this address. for,
Depending on the types of character patterns that this system has, for example, if there are four types of character patterns, it will consist of four words as shown in the figure, and each word will hold the storage address of one type of character pattern.

Out of these four types of character patterns, for example, which one to use is determined by control information specified separately from the character code from the host device, and one item of the second table is selected according to the determined type. Select one word.

With this configuration, in the case of the above-mentioned conventional method of indexing 2-byte character codes as one, there is no wasted area generated corresponding to invalid character codes, and the 10 areas mentioned above are made effective. can be used.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, in the process of indexing a character pattern from the character code of a computer system, especially when the character code is long and there are many types of character patterns, conversion for the index is possible. Since the tables can be configured using storage space efficiently, there is a significant industrial effect of improving the economics of the system.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a block diagram of an example of the configuration of a computer system, and FIG. 3 is a diagram illustrating the configuration of a conventional conversion table. In the figure, l is a processing device, 2 is an output section, 4 is a storage section,
5 is a conversion table; 6 is a character pattern storage area; 10 is a first table; 11 is a second table;

Claims (1)

[Scope of Claims] A storage area that holds required character patterns from character codes in a computer system that has character patterns of one or more character types and displays characters corresponding to each character code. In the process of determining the character code, the character code is divided into two parts: a first partial code and a second partial code, and a first table (10) consisting of terms indexed by the first partial code; a plurality of second tables (11) consisting of terms indexed by partial codes, each term of the first table indicating a storage area holding one of the second tables; A character code conversion control method, wherein the term is configured to designate one or more storage areas for character patterns of the desired character type.