JPS58208783A - Color display - 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] The present invention is based on a pit map method (one dot displayed on the screen with #
This relates to a color display RK (1/clear corresponds to 1 bit 0N10FF in memory).

On a bitmap color display device, the display 1 on the screen
A memory (hereinafter referred to as color RAM) is provided for storing color selection codes for specifying colors for dots. For example, a color CRT display device that can display 640 x 400 F' knots in 7 colors on the screen uses 32 bytes of color RAM in red and green.

It has three separate membranes corresponding to the blue color. When displaying characters in color on such a display device, the color of the above three sides corresponding to one dot of the display font = the same address V on the RAM (for example, if it is yellow, it is necessary to write a color selection code of 110 for a certain 1 bit). There is.

Conventionally, as a method of writing this color selection code, there was a method in which the three sides of the color RAM were written separately one side at a time, but this had the drawback of slow processing speed.

In contrast, 1 byte of color selection data for font pattern gator is stored in advance in a register provided on the data input line of each color RAM, and once at the same address of 3 pages of power%-RAM. There is a method that speeds up the processing speed by writing in, but for example, if the background display is yellow and you want to display text in the desired color, it is necessary to calculate the color selection data and write the data. This method is complicated and has the drawback of lowering the processing speed.

The present invention eliminates the drawbacks of the conventional example described above, and by arranging a simple logic circuit, the color selection code can be written only once for multiple color RAMKs. It is an object of the present invention to provide a color display device that allows easy selection of combinations.

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a block diagram showing the configuration of an embodiment in which logic circuits are arranged and color selection codes are generated. 1 to 3 in the figure
is a color register, and the code specifying the color for the back ground is stored in the register of the signals C1°C□ and Cbata□. Furthermore, the signal Co e Cu + Cat is a bit that specifies red, green, and blue, respectively. For example, to specify yellow, C
11,C□.

Cs, = 1, 1, 0 are stored in the register. The code for specifying the color for characters is the signal C+or Ca. +Cs. stored in the register.

Similarly, the signal Cl1) tel. , C1° are bits that specify red, green, and one color, respectively, but a code specifying the desired color (for example, C1 for red) is input to this color register.
1.

C7゜, Cs0=IIO10) and the color designation code for the pack ground (C11, C鵞*, Cmt=
1.1,0) and the resulting value (C+o.

C116*Cs. =Q, 1.0). 4～
Reference numeral 6 denotes a logic circuit having the same circuit configuration as the color designation code and 1-byte font pattern gators D0 to D.

When input, the color selection data for one font font (logic circuit 4 is red selection data ate-att, -
The logic circuit 5 outputs green selection data ago-d11, and the logic circuit 6 outputs blue selection data dso-dsma).

Therefore, the set of output signals d1°, d2°+d3° forms a color selection code for one bit of the font.

7.8.9 is a color RAM that stores color selection data corresponding to red and green 1%J', respectively, and the color control information for one display dot on the screen is stored in one pit of 0N10FF at the same address in each memory. It is stored as a combination of states (the color selection code).

IO is a mask register that stores information for masking a specific color selection code on the color RAMs 7, 8, and 9 so that it is not rewritten with a new code. Since the function of the mask register 10 is not directly related to the gist of the present invention, the explanation will be continued assuming that it is not masked.

FIG. 2 is a block diagram showing the logical configuration of the logic circuit 4. As shown in FIG. In the diagram, A is AND dart and EOR is EXCLU
SIVE ORri-) (hereinafter referred to as EORf-)
It is. As a common input signal to the logic circuit 4, the background red designation bit CII and the character red designation bit Cr. and VC information are given, the color selection r-data output dlH (n-=0 to 7) corresponds to the foreground pi p-n input Dn (n-θ to 7), and the logical formula dIH=
They are connected by the following relationship: (C+.△D11)■Ct+.

In the configuration described above, the process of forming a color selection code will be described below using an example in which yellow characters are displayed on a red background. First of all, I want to make the pack ground red, so I set the color register Cor C
! Set the red designation code 1°0.0 to I p Cat. Next, since we want to display yellow characters in it, the exclusive OR of the yellow designation code 1.1.0 and the red designation codes i, o, o of the i4 background is formed in the CPU, and its value 0. 1.0 to color register C1or
Set to Ctor Cso.

In this state, the font pattern data I)n (n=0 to 7)
) is input, looking at the individual bits, D11=
Corresponds to the constituent pixels of the character font. When the above input conditions are met, the color selection code output is formed as shown below according to the logical configuration.

(a) Red color selection bit output din is Dn=
At 00, dty1=(0△0)■1=1 When Dn=1, dtn=(OΔ1)■1=1(b) Green color selection bit output d2n is at Dn=00, dlIn
= (1△0)■0=01) When n=1, d, n=(
1△1)■0=1(cl is the color selection bit output d3H is when Dn=00 dxn=(0△0)■0=
When 0Dn=1, d11n=(O△1)■0-0.

To summarize the above, for the input Dn=0 corresponding to the background of the font pattern data, the color selection code output is dtIl, d2n, dsn=1.
The result is 0+0, which indicates that the pack ground is displayed in red. Also, the input Dn corresponding to the character font
For =1, the color selection code output is dtH+d 2n
l dan =1 r 1 r O, which indicates that the characters are displayed in yellow.

This embodiment has color RAM for three screens, each with red,
Although it is assumed that the display corresponds to green and blue, the principles of the present invention can be similarly applied to color display devices having other configurations. For example, a display device has screen memory for four or more screens corresponding to one dot displayed on the screen, or the contents of the screen m1 memory are directly red or green.

The present invention can also be applied to a display device that does not support blue color information and in which the contents of three screens are coded for the display color (a so-called color/color type display device).

In addition, in this embodiment, when setting the character color specification code to the color register, the CPH performs an exclusive OR of the background color specification code and the character color specification code, and then uses the resulting value as the character color specification code. This process can easily be performed by a hardware logic circuit.

As described above, according to the present invention, by arranging a simple logic circuit, a color selection code for a complicated display color orientation can be immediately obtained, which reduces the load on the display control of the CPU and achieves high-speed processing. This also has the effect of providing an inexpensive and high-performance color display device t for color image processing.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of the embodiment;
The figure is a block diagram showing the logical configuration of a logic circuit. 1.2.3...Color register 4.5.6...Logic circuit 7.8.9...Color RAM 10...Mask register Patent applicant Can Co., Ltd.

Claims (1)

Claims: (1.) A color display device having a logic circuit for forming a color selection code from a set display color designation. (2.) The display device according to item 1, wherein the display device is a CRT display device.