JPH1020841A - Display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent coloring of a first picture from changing even when the coloring of a second picture is revised and to reduce a circuit scale by dividing an address of a palette to a fixed address area and a variable address area and prohibiting the rewrite of the contents of the fixed address area. SOLUTION: A first and a second address data storage parts 30, 40 are provided respectively with the addresses corresponding to respective dots of the first, second pictures, and store the address data for specifying the address of a coloring data storage part 10 in respective addresses. A rewrite address decision part 60 decides whether or not the address of the coloring data to be rewritten is incorporated in a beforehand set area when the coloring information of the second picture is rewritten. Then, when not incorporated, an error is informed, and when incorporated, the rewrite of the coloring data is specified. A coloring data rewrite part 50 receives the specification of the rewrite, and performs the rewrite of the coloring data stored in the coloring data storage part 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display system, and more particularly, to a display system in a personal computer or the like.

[0002]

2. Description of the Related Art Generally, personal computers and the like
It has a memory called a palette. This pallet is a memory for storing coloring data corresponding to the display color on the display screen of the monitor display.

A conventional display system is disclosed in Japanese Patent Application Laid-Open No. 4-2912.
No. 96. In this display system,
Although one data pallet is used for both character screen and graphic screen coloring, it is an object of the present invention to prevent the coloring of the character screen from being changed even if the coloring of the graphic screen is changed. This conventional display system will be described with reference to the block diagram of FIG.

In FIG. 1, a conventional display system includes a coloring data storage means 1, first and second address data storage means 3 and 4, a coloring data rewriting means 5, and an address data rewriting means 7. Have been. In such a configuration, the address data in the first address data storage means 3 is rewritten based on the coloring data of the second screen. The color that no longer exists due to rewriting is interpolated by the closest color among the colors existing in the coloring data storage unit 1.

[0005]

The above-mentioned conventional display system has a disadvantage that the circuit becomes large-scale. That is, it is necessary to detect the rewriting of the coloring data of the second screen by the address data rewriting means 7 and rewrite the storage contents of the first address data storage means 3 according to the rewriting information. The circuit scale becomes large.

Further, when displaying the first screen and the second screen at the same time, there is a drawback that it is not possible to specify which screen is displayed with priority. This is because the address data of the first screen and the address data of the second screen are directly input to the coloring data storage means.

Further, there is a disadvantage that when the coloring of the second screen is changed, the coloring of the first screen changes.
This is because colors that no longer exist due to rewriting are interpolated by the closest color among the colors existing in the coloring data storage unit 1.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned disadvantages of the prior art. It is an object of the present invention to reduce the circuit scale and to simultaneously display the first screen and the second screen. Another object of the present invention is to provide a display system that can specify which screen is displayed with priority.

It is another object of the present invention to provide a display system in which the coloring of the first screen does not change at all even when the coloring of the second screen changes.

[0010]

According to the present invention, there is provided a display system comprising: a data pallet having a non-rewritable fixed address area and a rewritable variable address area; When the color data stored in the variable address area is rewritten when the address where the color data is stored is an address in the fixed address area, the color data is stored in an unused address where the color data is not stored in the variable address area. And data to be displayed are displayed in a color corresponding to the coloring data written in the data palette.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of the present invention is as follows.

A pallet is provided with a non-rewritable fixed address area and a rewritable variable address area.

When rewriting the coloring data, if it is determined that the address cannot be rewritten, the address is not rewritten. Therefore, it is not necessary to detect the rewriting of the coloring data on the second screen and rewrite the storage contents of the first address data storage means in accordance with the rewriting information, it is possible to realize with a simple circuit, and to interpolate the coloring data. Since there is no need to perform this, the coloring of the first screen does not change.

Since the address data of the first screen and the address data of the second screen are selected and output, it is possible to specify which screen is displayed with priority.

Next, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, the coloring data storage unit 10 has a plurality of addresses, and each address is a pallet for storing coloring data. This palette is used for coloring the first screen and the second screen for character data. The first address data storage unit 30 is a memory that has an address corresponding to each dot on the first screen and stores address data for specifying an address of the coloring data storage unit 10 at each address. The second address data storage unit 40 has an address corresponding to each dot on the second screen, and each address has a color data storage unit 1.
This is a memory for storing address data for specifying an address of 0. The address data selection unit 20 selects the address data of the first screen and the address data of the second screen, and outputs the address data to the coloring data storage unit 10. When rewriting the coloring information on the second screen, the rewriting address determining unit 60 determines whether the address of the recoloring data to be rewritten is included in a preset area or not. Then, if it is determined that they are not included, an error is notified. On the other hand, when it is determined that the color data is included, the rewriting of the coloring data is instructed. The coloring data rewriting unit 50 rewrites the coloring data stored in the coloring data storage unit 10 by receiving the rewriting instruction.

FIG. 2 is a flowchart showing the operation of rewriting the coloring information in the display system of the present embodiment. When the software rewrites the coloring information of the second screen, the software issues a command to rewrite the coloring information of the second screen to a device (not shown), for example, a central processing unit (step 101).
The central processing unit that has received the command transmits the command to the display system.

In the display system receiving the instruction, the rewriting address determining section 6 determines whether or not the address of the coloring data to be rewritten is included in the preset area, and determines that the address is not included. If so, signal an error. The software determines whether there is an error notification (step 102). If there is no error notification, it means that the coloring information on the second screen has been executed, and the rewriting operation ends (steps 102 → 10).
7). On the other hand, if there is an error notification, the software reads the data in the coloring data storage unit 1 and searches for an unused address from the coloring data addresses (step 1).
02 → 103).

Next, it is determined whether an unused address is found as a result of the search (step 104). If an unused address cannot be retrieved, it is determined that rewriting cannot be performed, and a notification that coloring information cannot be rewritten is output (steps 104 → 105 → 107). On the other hand, if an unused address can be retrieved, the second address data storage unit 4
The contents of the address data designating the coloring data to be rewritten are rewritten to the searched unused addresses (steps 104 → 106). Then, by rewriting the contents of the unused addresses in the coloring data storage unit 1, the rewriting operation of the coloring information on the second screen is completed.

Next, an embodiment of the present invention will be described in more detail with reference to FIG. FIG. 3 is a block diagram showing a more detailed configuration of the present display system. In the figure, drawing of characters and figures is performed as follows. A device (not shown), for example, a central processing unit notifies a command for drawing a character or a graphic via a system bus. Drawing of a character is performed by designating a character code and a character attribute. Drawing of a figure is performed by writing color information indicating address data of the palette 18 for each dot into the figure memory 15 as character address data.

Next, the display of characters and figures will be described. The character pattern generator 11 generates and outputs a character pattern corresponding to a character code specified in advance. The character attribute modification unit 12 receives a character pattern, modifies the character according to a character attribute specified in advance, and stores the result in the character memory 13 as character address data. Here, the character pattern is a sequence of data representing the font of the character, and the character attribute modification means adding a ruled line, blinking display, reverse display,
Indicates bold character display, enlarged display, and character color designation.

The selector 14 receives the character address data from the character memory 13 and the graphic address data from the graphic memory 15, and selects and outputs one of them according to a predetermined selection criterion. The pallet 18 is the selection unit 14
The coloring data stored at the address specified by the address data input from the printer is output. The output coloring data is converted into an analog signal by the digital-to-analog converter 19, and then displayed on a display device 21 such as a CRT.

Next, a method of specifying coloring data will be described. Coloring data is system bus, address judgment unit 1
6, Palette 1 via pallet data rewriting unit 17
8 is stored. The pallet is a memory that has a plurality of addresses, stores the corresponding coloring data for each address, and outputs the corresponding coloring data when the address is input.

FIG. 4 is a diagram showing an example of a pallet storage structure in the present system. Referring to FIG. 4, the palette of this example has addresses from "0" to "255", and stores 24-bit coloring data for each address. Specifically, the address “0” is such that the 8-bit data string indicating red is all “0”, the 8-bit data string indicating green is all “0”, and the 8-bit data indicating blue. The columns are all “0”, and are colored data that becomes black when combined. Similarly, address “1” is colored data that is blue, address “2” is green, address “7” is white, address “8” is dark blue, and address “254” is colored light blue.

Further, among the coloring data of this palette, the coloring data from address "0" to address "7" is fixed (cannot be rewritten), and the coloring data from address "8" to address "255" is fixed. Variable (rewritable).

Referring back to FIG. 3, when the address judging section 16 receives the rewriting instruction of the coloring data from the system bus, the address is an address included in the rewritable variable address area in the pallet 18 or is not rewritable. It is determined whether the address is included in the fixed address area. If the result of the determination is that the address is in the fixed address area, an error notification is made to the system bus. If it is in the variable address area, the palette data rewriting unit 17
The rewriting of the coloring data is transmitted via the. And the rewriting of the coloring data is performed.

The flow of the rewriting operation is as described with reference to FIG. 2, but will be further described with reference to FIG. The coloring data fixed address area A from address "0" to address "7" is coloring data used for character coloring, and the coloring data variable address area B from address "8" to address "255" is used for figure coloring. This is the coloring data used.

As an example of rewriting the coloring data, consider a case where the coloring data at address "8" is rewritten, for example. In this case, since the address “8” is in the variable address area B, the coloring data of the pallet is rewritten. On the other hand, when rewriting the coloring data at the address “7”, the error is notified without rewriting the coloring data because the address “7” is in the fixed address area A.

The software that has received the error notification sequentially reads the coloring data in the variable area and searches for an unused address. Here, for example, when all the bits are “0” or all the bits are “1”, it is determined that the address is an unused address. In the example of the storage structure shown in FIG. 4, the address “255” is an unused address. The software rewrites all the address data indicating the address “7” among the address data in the graphic memory 15 into the address data indicating the address “255”.
Next, rewriting of the coloring data is executed by writing a desired coloring into the address “255”.

Next, an example in which the selector 14 selects character address data and graphic address data in FIG. 3 will be described. When the character data to be displayed and the graphic data are present at the same position on the display screen (when the display positions match), the character memory 13 stores the character address data and the graphic memory 15 stores the graphic address data. The data is input to the selection unit 14, and one of them is selected and output according to a selection criterion.

As a selection criterion, a method of selecting according to the value of character address data is desirable. This is because it is possible to select whether to display characters or figures in dot units. More specifically, if the value of the character address data indicates, for example, an address “0”, the address data for graphics is selected. If the value of the address data indicates an address other than “0”, the address data for characters is selected. "0" is preferably a system indicating black coloring. This is because colors other than black are generally used for coloring characters.

In short, when the display position of the character data to be displayed matches the display position of the graphic data, if the color data of the character data to be displayed has a content of displaying black, the display position is displayed in the display position of the graphic data. Is displayed, and when the content is to display a color other than black, a character based on the character data is displayed at the display position.

As another selection criterion, there is a method in which selection is made in accordance with the value of graphic address data. More specifically, the value of the graphic address data is, for example, the address “25”.
When "5" is indicated, character address data is selected, and when an address other than address "255" is indicated, figure address data may be selected.

In the case where the display position of the character data to be displayed matches the display position of the graphic data, if the coloring data of the graphic data to be displayed is the coloring data written by the coloring data rewriting unit, the display position is changed to that color data. Displays a character based on character data, and displays the graphic based on the graphic data at the display position when the color data is other than the colored data.

As described above, the present display system has a simple configuration in which it is determined whether or not an address to be rewritten is within a fixed address area. Therefore, the circuit scale is small.

In this system, the pallet address is divided into a non-rewritable fixed address area and a rewritable variable address area, and rewriting of the contents of the fixed address area is prohibited. Even if the coloring of the screen is changed, the coloring of the first screen (text screen) does not change. That is, in the above-described related art, the coloring may change in order to interpolate the coloring data, but in the present system, the coloring does not change.

Further, in the present system, when the display positions of the character data and the graphic data coincide with each other, it is possible to select which is displayed with priority.

[0037]

As described above, the present invention divides a pallet address into a non-rewritable fixed address area and a rewritable variable address area, and further prohibits rewriting of the contents of the fixed address area. Even when the coloring of the second screen (graphic screen) is changed, the coloring of the first screen (character screen) does not change, and the circuit scale can be reduced. In addition, by selecting and displaying appropriate data according to the contents of the character data or graphic data, when the display positions of the character data and the graphic data match each other, it is possible to determine which one has priority. There is also the effect that you can choose.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a display system according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of the display system according to the embodiment of the present invention.

FIG. 3 is a block diagram illustrating a more detailed configuration of a display system according to an embodiment of the present invention.

FIG. 4 is a diagram showing a storage structure of a pallet in the embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a conventional display system.

[Explanation of symbols]

 Reference Signs List 10 coloring data storage unit 20 address data selection unit 30, 40 address data storage unit 50 coloring data rewriting unit 60 rewriting address determination unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location G09G 5/40 G09G 5/40

Claims (4)

[Claims] 1. A data pallet having a non-rewritable fixed address area and a rewritable variable address area, in which coloring data is stored in each of these areas, and a method for rewriting coloring data held in the data palette. Coloring data writing means for writing the coloring data to an unused address where the coloring data in the variable address area is not stored when the address where the coloring data is stored is an address in the fixed address area, A display system for displaying data to be displayed in a color corresponding to the coloring data written in the data palette. 2. The data to be displayed comprises character data and graphic data. Coloring data for the character data is stored in the fixed address area, and coloring data for the graphic data is stored in the variable address area. The display system according to claim 1, wherein: 3. When the display positions of the character data to be displayed and the graphic data to be displayed match,
When the coloring data of the character data to be displayed has the content of displaying black, the display position displays a graphic according to the graphic data to be displayed, and when the content of displaying a color other than black is displayed at the display position. 3. The display system according to claim 1, further comprising display control means for displaying characters based on the character data to be displayed. 4. When the display positions of the character data to be displayed and the graphic data to be displayed match,
When the coloring data of the graphic data to be displayed is the coloring data written by the coloring data writing means, the character corresponding to the character data to be displayed is displayed at the display position, and when the coloring data is other than the above. 3. The display system according to claim 1, further comprising a display control means for displaying a graphic based on the graphic data to be displayed at the display position.