JPH0721702B2 - Color graph display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color graph display device,
In particular, the present invention relates to a color graph display device that can be easily switched between 256 color display and 16 million color display by software.

[Conventional technology]

The conventional architecture of 256-color display with fixed gradation is
For example, Minamide and Yokota "Computer Graphix", PIX
EL No. 44, p102-108. This architecture is shown in Figure 4, and the screen image 209 of the CRT is
1024 x 1280 dots, 60Hz non-interlaced,
The 8-bit display data bus 207 should have a speed of at least 12.8 ns / dot. However, if a memory having such a speed is adopted as the actual frame memory 200, the amount of hardware becomes enormous and the cost becomes high. Therefore, the frame memory 200, the decoder 203, and the color table 206 as shown in the upper part of FIG. No configuration is taken. Instead, the data is fetched from the frame memory 200 with a data width of 5 dots, that is, 40 bits, and the speed of the frame memory itself should be one fifth of the speed of the 8-bit display data bus. . A latch register 201 and a latch-and-multiplexer 202 are provided as buffers for that purpose, and 2 ⁸ = 256 color codes are selected from a color table 206 of 8 bits × 3 = 24 bits width, and a D / A of 8 bits width is selected. An analog signal was generated by three converters and color display was performed on the CRT209.

The architecture shown above is a high-density display (1024 ×
1280,60Hz non-interlaced) and fixed gradation (eg 2
This is an indispensable technology for displaying (56 pieces). Therefore, as shown in FIG. 5, it is made into one chip LSI and is commercially available. This L
The IS300 architecture has the same structure as described in Fig. 4, and has great market needs and can be obtained at low cost.

On the other hand, Programmer's Guide to Domain Graph Primitives (Progurammer's Guide to
As shown in Graphic Primitives), Apollo, and Computer, a system that uses the full power of an 8-bit D / A converter (2 ⁸ ) ³ ≈ 16 million colors (called full-color display) It is configured as shown in FIG. That is, the 40-bit width data is taken out from the three frame memories 500 to 502, converted into 9-bit width data by the multiplexers 503 to 505, and the D / A is transmitted without using the color table.
Full color was displayed by inputting to converters 506-508.

[Problems to be solved by the invention]

In the above-mentioned prior art, no consideration has been given to the point of co-ordination between fixed gradation display and full color display. Generally, the software for performing fixed gradation display discriminates the colors by the color table as shown in FIG. 4, and in the case of the full color display, as shown in FIG. 6, the color code from the frame memory is used. Identify the color. For this,
The software for fixed gradation display and the software for full color display cannot be run on the same hardware, and the user can switch between them depending on whether fixed gradation display or full color display is used. There was a problem that the hardware configuration had to be changed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a color graph display device which switches between fixed gradation display and full color display according to software instructions without changing the hardware configuration.

[Means for solving problems]

The purpose of the above is the color table for fixed gradation display and D /
A converter and D / A converter for full color display,
This is achieved by providing a switch means for selecting the fixed-gradation or full-color D / A converter output according to the instruction of the software and sending it to the CRT.

[Action]

If a command for instructing fixed grayscale display or full color display is provided at the beginning of the software, the required D / A converter output can be automatically displayed on the CRT by the above switching means, so the user can display it. There is no need to change the hardware configuration according to the law.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to Examples.

FIG. 1 shows an embodiment of the present invention, which comprises a frame memory 102 including a multiplexer, a decoder 105, a 24-bit wide color table 108, and three D / A converters 109 to 111, which are standard 256 colors. The basic control for display is contained in one package (one printed board), of which the frame memory 102 is shown in FIG. The LSI chip 300 can be used as it is. On the other hand, a package for full color
128 has 100,1 frame memory required for full color display
01 (B (blue) and R (red) respectively, G (green) frame memory 102) and corresponding decoders 103 and 104, color tables 106 and 107, D / A converters 112 and 113 (these are also LSI chips. And the coaxial relay switches 122 and 123, which are the features of the present invention, are provided. As described above, in the present embodiment, since a commercially available inexpensive LSI chip can be used, the cost of the entire device can be reduced.

Of the outputs from the D / A converters 109 to 111 of the basic control unit, G
The output terminal 115, 116 for R and B is directly connected to the corresponding terminal of the CRT 121, while the output terminal 115, 116 for R and B is connected to the contacts on the side a of the switches 122, 123 via the terminals 117, 119 on the side of the package 128, respectively. The outputs of the D / A converters 113 and 112 for full-color display are connected to the other b-side contacts of the switches 122 and 123, and the switches 122 and 123 select the signal of one of these contacts and the R via the terminals 11 and 120. Then, the B signal is sent to the CRT 121.

In the above configuration, when displaying 256 colors, the coaxial relay switches 122 and 123 are connected to the a side so as to output the R signal and the B signal from the terminals 115 and 116 on the basic control unit side to the color CRT 121. Therefore, at this time, the frame memory 102
The intensities of G, R, and B colors (8 bits each) are read from the color table 108 corresponding to the 8-bit color code, and these are D / A converted and displayed.

On the other hand, when displaying full color of 16 million colors, the coaxial relay switches 122 and 123 are D / A converters for full color.
It is connected to the b side so that the R and B signals from 113 and 112 are sent to the color CRT 121. In full-color display, as described with reference to FIG. 6, the color code from the frame memories 100 to 102 may be directly D / A converted. However, in the present embodiment, a commercially available LSI is used. Decoders 103 to 106 and color tables 106 to 108 are inserted before D / A conversion. Therefore, the contents of the color tables 106 to 108 are set in advance so that the color code from the frame memory is directly input to the D / A converter when passing through the decoder and the color table. By doing this, it is possible to display 16 million colors on the CRT 121 in full color display.

In the above operation, a display mode switching mechanism by software will be described with reference to the flow chart of FIG. Before using the system, the index section at the beginning of each software determines whether the software being used is a 16 million color display graphic software (step 401), and depending on the result. The reset register (flip-flop) 402 is reset when displaying 256 colors (step 404), and set when displaying 16 million full colors (step 403).
The coaxial relay switches 122 and 123 are switched according to the information set in the register 402. In addition, 1600
When displaying full colors in all colors, as described above, the color code from each frame memory 100-102 remains unchanged for each D /
The tables 106 to 108 are also set so as to be input to the A converters 112, 113 and 109 (step 403).

FIG. 3 shows another embodiment of the present invention, and the basic control unit is the same as that of the embodiment shown in FIG. The difference is that the decoders 103, 1 from the portion of the package 128 for full color in FIG.
04, the color tables 106 and 107 are removed. In FIG. 1, the contents of the color tables 106 and 107 are set so that the color codes output from the frame memories 100 and 101 are directly input into the D / A converters 122 and 113 (step 403 in FIG. 2). With this configuration, the commercially available LSI chip as shown in FIG. 5 cannot be used as it is, but the configuration is simple.

〔The invention's effect〕

According to the present invention, 256-color fixed gradation display or 16 million full-color display can be automatically discriminated and selected at the head of the software to be used, without the user having to change the hardware configuration. There is an advantage that a required display method can be used, and a commercially available LSI chip can be used, which is an advantage that it can be realized at low cost.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flow chart showing a display method switching procedure according to a software instruction, and FIG. 3 is a block diagram showing another embodiment of the present invention. 4 and 5 are block diagrams of conventional fixed gradation display hardware, and FIG. 6 is a block diagram of conventional full color display hardware. 100 to 102 …… Frame memory, 108 …… Color table, 109 to 113 …… D / A converter, 122,123 …… Coaxial relay switch.

Claims (1)

[Claims] 1. A first frame memory for storing a color code representing a color tone of each pixel on a screen, and a color table for converting the color code into a color digital signal of three primary color components of a corresponding color tone. And a color graph display device having three color digital signals from the table and converting the analog signals into analog signals and sending the analog signals to the display means. Second and third frame memories having the same capacity as the first frame memory and for storing color digital signals of two primary colors corresponding to respective pixels; and the second and third frame memories, The fourth and fifth D / A converters for converting a color digital signal into an analog color signal and switch means are provided, When pre-color digital signal a defined three primary components corresponding to the tone group is excisional and color code of each pixel corresponding to the first frame memory over the table is a fixed gradation display is excisional is
The switch means selects the second and third D / A converter outputs, the selected signal and the first D / A converter output are sent to the display means as color signals of the three primary colors, and A full-color set to the second and third frame memories in which color digital signals of the three primary colors corresponding to each pixel are set and the color table outputs the same signal as the color digital signal from the frame memory. When displaying, the switch means selects the fourth and fifth D / A converter outputs, and the selected signal and the first D / A converter output are sent to the display means as color signals of three primary colors. A color graph display device characterized in that