JPS61275790A - Character font management system for character display unit - 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 method for managing characters displayed on a character display device, which includes a character font management table managed by upper and lower bytes of character codes, and a buffer memory for character data corresponding to the character font management table. to shorten the access time for character data.

[Industrial application field]

The present invention relates to a method for managing character codes displayed in a character display device.

In a character display device, characters entered from the keyboard are converted into character codes to be displayed on the display screen.
Character data is read from the memory that stores character data according to the character code and displayed on the screen.

There are far more Japanese characters, including kanji, than in foreign languages.
In addition, in order to express characters with complicated glyph shapes using dots, a large number of dots are required, and therefore the capacity of memory for storing these character data becomes extremely large.

Furthermore, in order to search and read out the requested character data from a huge amount of memory, a correspondingly long readout time is required.

Therefore, there is a need for a method that shortens the time required to access a huge amount of memory.

[Conventional technology]

Characters typed from the keyboard are converted into character codes, and the contents of a character memory (for example, a magnetic disk) in which character data is stored are searched, character data corresponding to the character code is read out, and the character data is displayed as characters on the display screen. .

At this time, since the character data is accessed from the memory one character at a time, it takes the same amount of time as the number of characters to display to display one screen, but if the access time is long, the device becomes unusable.

[Problem that the invention seeks to solve]

In this conventional method, all character data for characters to be displayed is stored in one memory, so the number of character types that can be displayed increases, and the number of dots that make up a character increases when trying to express a character shape. The more the memory capacity increases, the more time it takes to access the memory.

The present invention was created in view of these points, and an object of the present invention is to provide a character font management method that can shorten the access time from memory.

[Means for solving problems]

FIG. 1 shows a block diagram of the principle of the character font management system of the present invention.

In FIG. 1, 1 is a processor that controls the device, 2 is a main memory that stores programs necessary for controlling the device, and 3 is a character memory, such as a magnetic disk device, which stores all the character data necessary for the character display device. Store.

Reference numeral 4 denotes a display control unit to which an input device of a keyboard 5 and a display 6 are connected.

The main storage section 2, magnetic disk device 3, and display control section 4 are connected to the bus line of the processor 1, and data is exchanged.

The display control unit 4 includes a code conversion circuit 41 that converts a signal input from the keyboard 5 into a character code, and a character font management table (hereinafter referred to as a management table) based on the upper byte and lower byte of the character code output by the code conversion circuit 41. a pointer 42 for allocating characters on 43;
It is comprised of a buffer memory 44 that stores character data of characters stored in a management table 43, and a read register 45 that stores read character data.

The input from the keyboard 5 is converted into a character code by the code conversion circuit 4, and if it can be indexed in the management table 43 by the pointer 42, the character data is read out by the buffer memory 44, stored in the readout register 45, and displayed on the display 6. be done.

If the corresponding character code is not stored in the management table 43, the character code is sent to the magnetic disk 3 and the character data is indexed.

[Effect]

A signal input from the keyboard and converted into a character code is first indexed into a management table to check whether it is registered in the management table.

Since the memory capacity of the buffer memory is not as large as that of the character memory, the access time can be shortened.

Furthermore, the read character codes are managed in a management table, and a flag code indicating this is added to the recently used characters, so that frequently used character fonts are stored.

Since the characters used by the device are considerably limited depending on the user and the business content, the frequency of use of these characters is high.

Therefore, the average access time for character codes is reduced.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is an explanatory diagram of an embodiment of the character font management method of the present invention, FIG. 3 is an explanatory diagram of character code storage, and FIG. 4 is an explanatory diagram of a flowchart.

Note that the same reference numerals indicate the same objects throughout the figures.

Assume that one character code consists of 4 bytes: upper 2 bytes and lower 2 bytes.

A character code table 31 shown in FIG. 2 that indexes character data (for example, 72 bytes per character) by character code is stored in a character memory, for example, the magnetic disk 3.

The management table 43 is located in the display control unit 4 and is divided into storage areas of m rows and n columns, and one storage area can store, for example, two character codes, as shown in FIG. .

A flag code is added to the stored character code.

Then, one of the storage areas of the management table 43, row i and column j (
i, j) The w4 area corresponds to an area when the character code table 31 is divided into m rows and n columns.

That is, the upper byte group is divided into m parts, and the lower byte group is divided into n parts.

The pointer 42 includes a pointer A 421 that allocates a storage area for the upper byte of a character code, and a pointer B 422 that allocates a storage area for the lower byte, and allocates the character code on the management table 43.

The flag code "1" indicates the character code that was stored later, that is, the most recently used character code among the two character codes, and "0"
indicates the previously stored character code.

The newly stored character code is the flag code r
It will be replaced with the OJ character code, and the flag code will be “
1”.

Therefore, the character code whose flag code was "1" remains as is, but its flag code becomes "O".

The buffer memory 44 stores character data of the character codes stored in the management table 43, and when the character code is rewritten, the character data is also rewritten.

The character font management method of the present invention will be explained in more detail below.

Now, the display input signal from the keyboard 5 is converted into a 4-byte character code A64B (hereinafter character codes are shown in parentheses) by the code conversion circuit 41, and the display input signal is sent to the pointer 42.
The (i, j) storage area of the management table 43 is indexed.

For example, the upper two bytes of character code table 31 are A6 to A8.
, the six-character code whose lower two bytes are 4B and 4C corresponds to the (i, j) storage area of the management table 43.

For example, in the (i, j) storage area of the management table 43, (A8
4C), (flag code “1”) and [A64B) (flag code “0”), character data of (A64B) is read from the buffer memory 44 and stored in the read register 45. .

Further, the flag code of (A64B) registered in the management table 43 becomes rlJ, and the flag code of (A 84C) becomes rOJ (FIG. 3(a)).

Also, in the (i, j) storage area of the management table 43, (A6
4B) are stored, for example, [A34C) (flag code "1") and (A74B) (flag code "0")
is stored, the pointer 42 cannot be indexed, and (A64B) is indexed on the magnetic disk 3, and its character data is stored in the read register 45.

On the other hand, the (i, j) storage area of the management table 43 is (A6
4B) (Flag code “1”) and (A84C)
(Flag code "0") (Figure 3(b)).

Note that in the above example, the number of character codes stored in one storage area of the management table is two, which is "1".

Although a flag code of "0" is given, it goes without saying that two or more character codes may be stored in one storage area and a flag code may be given to each of them.

Further, the method of the present invention can be used to manage not only character data but also image data, and can be used not only for display devices but also for printing devices.

〔Effect of the invention〕

As described above, according to the present invention, by managing character codes using a character character font management table, the reading speed of character data can be increased, which is extremely useful in practice.

[Brief explanation of drawings]

Figure 1 is a block diagram of the principle of the present invention. FIG. 2 is an explanatory diagram of the character font management table of the present invention. Figure 3 is an explanatory diagram of character code storage. FIG. 4 is a flowchart explanatory diagram. In the figure, 3 is character memory (magnetic disk), 6 is the display, 42 is a pointer, 43 is a character font management table, 44 is a buffer memory. Sweaty ku ^ Manhi Rifu Oy7jiJ Figure 1 Q Food = qtlat, L”llImFigure 3

Claims (1)

[Claims] The character data is read from the character memory (3) that stores the character data according to the character code, and the character data is displayed on the display (6).
The character display device has a storage area allocated by a pointer (42) based on the upper byte and lower byte of the character code, and has a flag code indicating a storage time series added to the storage area. A character font management table (43) that stores character codes; and a buffer memory (4) that stores character data of the character codes stored in the character font management table (43).
4) and set the character code to be displayed in the character font management table (
43) and reads the character data of the character code from the buffer memory (44), and if it is not registered in the character font management table (43), reads it from the character memory (3) and at the same time reads the character data of the character code from the buffer memory (44). A character font management method for a character display device, characterized in that the character code and the flag code registered in a character font management table (43) are updated.