JPH0126071B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cathode ray tube display device that can improve display speed even if the amount of data transferred or the data transfer speed between the display and the host computer is reduced.

Since cathode ray tube display devices have traditionally been required to have intelligent functions, microcomputers have been installed inside the devices. Although 8-bit microcomputers are generally used, the actual situation is that the provision of microcomputers has caused new problems.

FIG. 1 shows a schematic configuration of a conventional cathode ray tube display device. According to this, the entire device is managed by a microcomputer 3 provided inside the cathode ray tube display device 1. That is, the microcomputer 3
In addition to transferring data with the host computer 2 via the interface circuit 4 as a data transfer control circuit, it is also capable of processing data from the keyboard 5 and light pen 6, reducing the capacity of one screen. Character or symbol selection data can be changed and written into the refresh memory 7. However, CRT 9
By reading predetermined selection data from the refresh memory 7 in synchronization with the display timing of , a video signal to which a synchronizing signal is added is obtained from the pattern generator 8, and this is applied to the cathode ray tube 9. The image will be displayed on the cathode ray tube 9.

By changing the contents of the refresh memory 7 in this manner, the displayed image is also changed, but this does not cause any particular problem when displaying by a simple character display method. When displaying normal-sized characters or symbols, since the pattern data is already stored in the ROM in the pattern generator 8, the refresh memory is used based on the address data and selection data from the host computer 2. This is because by changing only the contents of 7, it becomes possible to display these normal size characters and symbols at any position on the display screen of the cathode ray tube 9. However, when displaying characters and symbols other than normal size, it is necessary to further transfer display data corresponding to these characters and symbols from the host computer 2. this is,
The ROM in the pattern generator 8 does not store display data for characters or symbols other than normal size, so it is necessary to create display data on the host computer 2 side and then transfer it to the cathode ray tube display device 1. be. When display data is stored in the pixel memory as RAM in the pattern generator 8, it is possible to display only characters and symbols other than normal size, or a mixture of characters and symbols of normal size.

When displaying characters and symbols other than normal size, it is necessary to display them using a graphic display method, and the display data needs to be transferred from the host computer to the cathode ray tube display device. Since the amount of data to be transferred is large, it is clear that data must be transferred at a high speed in order to improve display speed. However, in the past, the actual situation is that there are considerable restrictions on the display speed of characters and symbols other than normal size. This is because an 8-bit microcomputer is used in the cathode ray tube display, and its processing speed is suppressed to about 300 ns to 1 .mu.s. Therefore, the data transfer rate is also 1
This results in a data transfer rate of about 10 to 20 kilobytes per second, which is an order of magnitude slower than a pure hardware configuration that does not use a microcomputer.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a cathode ray tube display device with a built-in microcomputer that can improve the display speed even when characters and symbols other than normal size are displayed on a graphic display.

For this purpose, the present invention stores display data corresponding to characters and symbols other than normal size in advance in an auxiliary memory means,
When it is necessary to display a character or symbol other than the normal size, a control means dedicated to display control reads the display data from the auxiliary memory and stores it in a predetermined address on the pixel memory, and also reads the display data corresponding to the display data. Selected data and the like are stored at a desired address on the refresh memory. If display data for characters and symbols other than normal size is stored in advance on the cathode ray tube display device, there is no need to transfer the display data corresponding to characters and symbols other than normal size from the host computer, and it is only used for display control. Depending on the control means, characters and symbols other than normal size can also be displayed at high speed.

The present invention will be explained below with reference to FIGS. 2 to 6.

First, the schematic structure of the apparatus according to the present invention will be explained with reference to FIG. As shown in the figure, host computer 2
According to this, the cathode ray tube display device 10 further includes a microcomputer 1 inside it.
2 and an auxiliary memory 13 are added. The microcomputer 11 functions almost in the same way as the microcomputer 3 shown in FIG. 1, except that writing to the refresh memory 7 and writing to the RAM (pixel memory) in the pattern generator 8 is not directly performed. Instead, auxiliary memory 13
It is now possible to write to directly. Also,
The additional microcomputer 12, preferably configured as a bipolar type, functions as a control means exclusively for display control, and transfers data read from the auxiliary memory 13 to the RAM in the refresh memory 7 and the pattern generator 8. I am starting to write to .

To further explain the auxiliary memory 13 and the microcomputer 12, the auxiliary memory 1
3 stores display data commands consisting of various data. The display data command will be described later, but the display data command may be data for the entire screen, or may be partial microsymbol data in some cases. The macro symbol referred to here is the overall pattern formed by aggregating patterns corresponding to multiple normal size areas into a square or rectangular shape, and all symbols and characters other than normal size are normal size. It can be formed by aggregating a plurality of patterns corresponding to areas. In other words, if a plurality of appropriate normal size pixel patterns are included in one display data command, desired symbols and characters other than normal size can be displayed by combining these pixel patterns later. It is something.

The microcomputer 12 is activated by the microcomputer 11, and when activated, reads and decodes a predetermined data command from the auxiliary memory 13, and stores the data in the RAM in the refresh memory 7 and pattern generator 8. This is where you will write. Since selection data for one screen is written in the refresh memory 7, the selection data is sequentially read out in synchronization with the CRT display timing and then selectively applied to the ROM or RAM in the pattern generator 8. Then, the character pattern signal from ROM,
Alternatively, the pixel pattern signal from the RAM is given to the cathode ray tube 9 in the form of a video signal, so that characters and symbols of sizes other than the normal size can also be displayed.

The outline of the present invention has been described above, but a more detailed explanation will be given below.

That is, FIG. 3 extracts only the parts directly related to the present invention and shows them in detail. According to this, display data corresponding to frequently displayed symbols and characters other than the normal size are stored in advance in the auxiliary memory 13 prior to the start of display. For example, when the computer system is started up, the data is stored in the auxiliary memory 13 from the host computer 2 via the data converter 14 under the intervention control of the microcomputer 11. By the way, the auxiliary memory 13 consists of two register parts 13a and 13b, of which the register part 13b stores display data and selection data corresponding to symbols in a predetermined address order, and the register part 13a stores various data corresponding to symbols. is the register part 13
It is designed to indicate at which address of b. According to the illustrated example, the address value A is stored at the address α, but this is greater than the address A of the register portion 13b.
This indicates that display data, selection data, etc. related to the corresponding symbol are stored. Similarly, various data corresponding to other symbols are stored from addresses B and C, respectively. FIG. 4 shows the storage format of various data corresponding to symbols in the register portion 13b. As shown in the figure, this is about the symbol corresponding to address α, and according to this, the pixel address start value is stored in address A, followed by pixel data as display data, rectangular area data specifying the size area, and selection. Refresh memory data is stored in a predetermined order. In addition,
The pixel data referred to here is not originally in units of dots, but in units of normal size areas. If the normal size area is made up of N pieces of dot data, then the N pieces of dot data collectively constitute one pixel data.

To further explain the various types of data that correspond to symbols, data converters now add function codes to each data to identify the type of data and specify the display format. There is. This is the microcomputer 12
When the data is read out by the microcomputer 12, it is necessary to control the storage of the data in the refresh memory 7 and the pixel memory 8 using those function codes, and also control the display mode such as color. This is because it is necessary. By the way, among various data, pixel data is stored in the pixel memory 8 based on the pixel address start value, and refresh memory data is stored in the refresh memory 7 in the form of a function code that controls the display mode. However, even though the storage location of pixel data is temporarily determined by the pixel address head value, that of refresh memory data is variable. The storage position of the refresh memory data is first determined by the rectangular area data and the display start position information on the cathode ray tube from the host computer. This allows characters and symbols other than normal size to be displayed at any display position.

Now, regarding the specific symbol display, see Figure 5.
The explanation will be as follows with reference to FIG.

That is, FIG. 5a shows an example of a symbol having a size other than the normal size, and the symbol has 25 normal size areas and has a square shape as a whole. For example, if such a symbol is displayed at two locations on a cathode ray tube display screen as shown in FIG. 5b, each display start position information (X ₀ , Y ₀ ),
(X ₁ , Y ₁ ) and the address information on the register section 13a for specifying the symbol can be transferred from the host computer 2 to the cathode ray tube display device in the format shown in FIG. . In this format, α is transferred as information for specifying a symbol, and from this point on, various data corresponding to that symbol are sequentially read from addresses A to B-1 on the register portion 13b. be.

When α, X ₀ and Y ₀ are first transferred from the host computer 2, α is stored in the symbol designation register 12c, X ₀ and Y ₀ are stored in the refresh memory address counter 12e, and the microcomputer 11 The microcomputer 12 is activated by setting the mode register 12b. When α is stored in the symbol designation register 12c, the address value A is read from the address α in the register portion 13a by this α, this is set in the auxiliary memory address counter 12d, and from then on, the address value A is read out from the address α in the register portion 13a.
The contents from addresses A to B-1 in 3b are read out continuously.
That is, address A from address counter 12d
Depending on the pixel address, the first value is register part 1.
After that, the address counter 12d is sequentially incremented until a function code indicating "END" is detected. Data sequentially read from the register portion 13b has its function code decoded by the function register 12a, and is used for address control and termination control, as well as becoming data to the memory. First, when it is detected that the first read data is the pixel address head value, the pixel address head value is loaded into the pixel memory address counter 12f. Following the pixel address start value, pixel data is read out sequentially, but after the first pixel data is stored in the pixel address start value in the pixel memory 8, each time it is detected that it is pixel data. By incrementing the pixel memory address counter 12f, all of the pixel data is stored in the pixel memory 8 in the order of predetermined addresses. Following the pixel data, rectangular area data that defines the _display size area is read out.This rectangular area data and the _values of The storage location in the refresh memory 7 is uniquely determined. In the refresh memory address counter 12e, X ₀ and Y ₀ are loaded into the address counters in the X direction and Y direction, respectively, but the refresh memory data read first is defined by (X ₀ , Y ₀ ). The data is stored at an address on the refresh memory 7. Thereafter, if the X-direction counter and the Y-direction counter are appropriately controlled each time the refreshim memory data is read out, the refreshment memory data will be stored in a predetermined address area on the refresh memory 7. From the previous symbol example,
It is stored in an address area defined by X ₀ XX ₀ +4 and Y ₀ YY ₀ +4. Following the refresh memory data, a function code indicating "END" is finally detected, and this detection is output to reset the mode register 12b, and an end interrupt is applied to the microcomputer 11. The microcomputer 11 is responsible for determining the completion of data storage in the refresh memory 7 and pixel memory 8.

However, after this, the microcomputer 11
Similar control and data storage are performed based on α, X ₁ , and Y ₁ from , and since this is clear from the previous explanation, no special explanation is required. Note that the display of normal-sized characters and symbols is already known and does not require any particular explanation.

As explained above, the present invention stores display data corresponding to characters and symbols other than normal size in advance in an auxiliary memory means, and when it becomes necessary to display these symbols and characters, display control is performed. Display data and the like are read out by a dedicated control means, and data stored in the refresh memory and pixel memory is updated. Therefore, according to the present invention, even when displaying characters or symbols other than normal size, it is only necessary to provide a small amount of information from the host computer, and the display speed can be improved by 5 to 10 times. effective.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a schematic configuration of a cathode ray tube display device according to the prior art, FIG. 2 is a diagram showing a schematic configuration of a device according to the present invention, and FIG. 3 is only a portion of the configuration directly related to the present invention. FIG. 4 is a diagram showing an example of the storage format of various data stored in the auxiliary memory, and FIG.
Figures a and b show an example of a symbol with a size other than normal size and an example of how that symbol is displayed on a cathode ray tube display screen. FIG. 3 is a diagram showing an example format of display control output data output from a computer. 7...Refresh memory, 8...Pattern generator (or pixel memory in the pattern generator), 9...Cathode ray tube, 11...Microcomputer (for overall supervision and control), 12...Microcomputer (for display control only) , 13...Auxiliary memory.

Claims (1)

[Claims] 1 Under the control of a microcomputer for overall supervision and control, selected data is read out from the refresh memory in which screen display information is stored as changeable, and based on this data, the ROM is used as a pattern generator in the pattern generator, and the pixel memory is used as a pixel memory. A cathode ray tube display device which generates a video signal from the generator with one of the RAMs selected and displays information on a raster scanning type cathode ray tube display screen using the signal, An auxiliary memory means is provided in which display data, selection data, and storage control data corresponding to characters and symbols other than normal size are stored in advance, and when it becomes necessary to display the above-mentioned characters and symbols, based on instructions from the microcomputer. A control means dedicated to display control reads out display data, selection data, and storage control data corresponding to the display object from the auxiliary memory means, stores the display data in the pixel memory based on the control data, and further displays it from the outside. A cathode ray tube display device characterized by a configuration that also uses start position designation data to control storage of selected data in a refresh memory.