JPS63167393A - Crt display device - 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] <Industrial Application Field> The present invention is applicable to CRT (C1tkod Ray Tube)
The present invention relates to a CRT display device with improved color display.

<Prior Art> FIG. 2 is a block circuit diagram for explaining a conventional CRT display device. Hereinafter, a conventional example of a CRT display device will be explained using this diagram.

Conventionally, the color display on CRT4 was red (Red),
The image memories 21 to 2c are allocated to the so-called three primary colors of m (Green) and blue (Blue), respectively.
PU (central processing unit) l is the image memory 21 to 2c.
At the same time, the CRT controller 3 converts the contents of each image memory 21 to 2c into a CRT signal and sends it to the CR.
By sending the signal to T4, color display was performed on the CRT4. In addition, in order to display colors other than the above three primary colors on the CRT 4, the image memories 21 to 2
Can you combine the three primary colors as appropriate, such as assigning C to the address space of CPU 1 and then developing the three primary colors? It was. In this way, the CRT 4 was capable of displaying seven colors in addition to the three primary colors mentioned above.

<Problems to be Solved by the Invention> However, in the conventional example described above, when displaying, for example, white on the CRT 4, the image memories 2a to 2c are
After allocating it to the UI address space, the image memory 2
It was necessary to sequentially write information to 1 to 2c, so to speak, to write t* information into the image memory three times. On the other hand, since a monochrome (single color) CRT has only one image memory, it is only necessary to write information to the image memory once. Therefore, CI? T color display requires more accesses to the image memory than monochrome display, which ultimately significantly hinders speeding up of CRT display.

The present invention has been made in view of this situation, and its purpose is to reduce the number of accesses to the image memory and to reduce the number of times the image memory is accessed.
An object of the present invention is to provide a CRT display device that can display images at high speed.

Specific Means for Solving the Problems> A feature of the present invention that solves the problems described above is that in a CRT display device, a plurality of switches for opening and closing connections between the CPU and each image memory are connected to the CPU. The CPU is configured to access a required combination of image memories at one time by opening and closing them via registers in response to color commands from the CPU.

<Example> Hereinafter, the present invention will be explained in detail using the drawings. 1st
The figure is a block circuit diagram of an embodiment of the present invention.
The same symbols as in the figures are used with the same meaning, and redundant explanation will be omitted here. Further, 5 receives and stores a color designation command from CPtJl, and also switches 61 in accordance with the command.
This is a register that turns on ~6C. In the embodiment of the present invention having such a configuration, first, for example, black, blue, green, sky blue, red, purple, yellow, and white are colored at 0, 1, 2 degrees, 3.4 degrees, 5, 6 degrees, respectively. and 7, such that C
The PUI specifies a color and issues a color specification instruction to register 5 using the I10 instruction. The instruction is stored in the register 5 and the switches 61 to 61 are stored in accordance with the instruction (i.e., the specified color).
Necessary switches of εC are turned on. In this state, among the image memories 2-2c, switches 61-6c
The CPUI writes information to the image memory that is turned on. The information written to the image memory in this way is processed by the CRT controller 3 as a color signal (
CRT signal), and the color signal is converted into a CRT signal.
4, color display will be performed. Note that the present invention is not limited to the above-described embodiments and can be modified in various ways. For example, by issuing a brightness designation command from the CPU to the register 5 in parallel with the color designation command described above, the CRT
It is also possible to increase the types of colors displayed in 4. In this case, the number of image memories 21 to 2c and registers 5 may be increased to increase the number of colors displayed on the CRT 4.

<Effects of the Invention> According to the present invention as described in detail above, a CRT display device is realized in which the number of accesses to the image memory is reduced and the CRT display speed is increased. That is, the image memory 21
Since the configuration is such that the CPU accesses the combination of image memories necessary for a specified color among ~2C at once, the number of accesses to the image memory is smaller than in the conventional example, and the image is displayed on the CRT4. Therefore, the time will be significantly reduced. Furthermore, according to the present invention, the CP
There is also the advantage that program development is easy because only a color specification command is issued from the UI.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram of an embodiment of the present invention, and FIG. 2 is a block circuit diagram of a conventional example. l...CPU, 2*~2c...image memory, 3...CRT controller, 4...C1? T, 5
...Register, i-6c...switch.

Claims (2)

[Claims] (1) A CPU (Central Processing Unit), a register that receives and stores color specification instructions from the CPU, multiple image memories into which information is written by the CPU, and converts the contents of these image memories into CRT signals. CRT
The device includes a controller, a CRT that displays colors in accordance with the CRT signal, and a plurality of switches that open and close connections between the CPU and each of the image memories, and the register opens and closes the switches in response to the color designation command. A CRT display device characterized in that the CPU accesses a necessary combination of image memories among the image memories at one time. (2) The plurality of image memories include a red image memory, a green image memory, and a blue image memory, and the plurality of switches include three switches that open and close connections between these image memories and the CPU. A CRT display device according to claim (1), comprising a switch.