JPS5964890A - Display control system - 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] Technical Field> The present invention provides a Japanese word and language computer using a CRT as a display device.
Display when characters with different pixel configurations (characters with different numbers of pixels in the scanning line direction, kanji and ASCII/JIS characters, etc.) are mixed and displayed on the CRT screen of a processor, personal computer, etc. This concerns the control method.

<Prior art> As a conventional display control method, a dot pattern of each character is written in a video memory for display, and that pattern is used as one of the dot patterns. ,′! f. There is a display method, but this method has the disadvantage that the capacity of the video memory is large and it takes time to change the screen.

<Object of the Invention> The present invention has been made with the object of obtaining a display control method that can eliminate the drawbacks of the above-mentioned conventional methods, reduce the capacity of the video memory, and change the display screen at high speed. be.

<Embodiment> The present invention will be described in detail below based on an embodiment. A block diagram of the embodiment is shown in FIG.
Figure 2 shows the configuration of the V-RAM (RAM), Figure 3 shows the code assignment on the V-RAM, and Figure 4 shows the code setting method on the V-RAM.
As shown in the figure.

This example uses ASCII characters (8×
8 or gx+6) and kanji (+6 All you need is a general-purpose CRT controller.
By setting the system bus 11 and display format, display address 21° raster address 2
2 and horizontal/vertical synchronization signals 23. 2 and 3 are video memories V-RAM (A) and V-RAM (B). In this embodiment, 2000 characters can be displayed in terms of 8 x 8 pixels, and RAM(B)
are RAMs each consisting of 2×8 y' bits. In Figure 2, (1) is a map from the system bus, (2)
is the map when displayed.

In order to display characters on the CRT, V-RAM (A)
2. It is necessary to write the code of the character to be displayed in V-RAM (B) 3, but there are 256 types of ASCII characters,
The kanji characters are 2965 characters of JIS level 1, and the bit allocation is shown in FIG. In addition to Do ``DI+, which represents characters, distinguish between ASCII characters and Kanji characters.)A/
K (if it is an ASCI I character, set -0 to A//, if it is a Kanji, set = 1 to '/) and the pixel that divides the pixels of the Kanji into the left half and the right half and distinguishes between them) L/R (for the left half, '/R-0, for the right half, '/R=1
) is added to the bit allocation. Note that the remaining two pinpoints are used for storing attribute information, etc.

The method of setting codes to the V-RAM is as shown in FIG. 4, where one ASCII character consists of 2 bytes, and one Kanji character consists of 4 bytes. For ASCII characters,
In V-RAM (B), only the bit A/ is valid.

The code of the character to be displayed is written on the V-RAM in the format described above.

Next, the method of displaying characters on a CRT based on this V-RAM code is to set the CRT controller 1 shown in Figure 1, and set the display address to ASCII characters with a small number of pixels in the horizontal direction. A total of 8 bits is used as one address, and in the vertical direction, settings are made so that one address is output with 16 rasters according to the kanji character with a large number of pixels.

By setting the display format of the CRT in this way, the display address 21 and raster address 22 are output from the controller 1. Controller 1
The code on the V-RAM is output at the display address output from the character generator 4 and 5 (RO
M) is developed into a bit image, but V-RAM
(B) The chip select circuit 6 selects either the ASCII character generator 4 or the Kanji character generator 5 based on the ~8 bit output, and the J-/R bit selects the left half of the Kanji pixel. is displayed, but it is selected whether to display the right half. 7 in Figure 1 indicates that when the pixels of an ASCII character are 8 x 8, the pixel unit output from the CRT controller 1 is 8 x 16, so it is necessary to erase the 8 x 8 pixel dots in the lower half. This is an unnecessary dot erasing circuit.

8 of the bit image data to be displayed outputted from the character generator 4.5 as described above.
The bits are connected to the video signal input terminal 31 of the CRT display through a parallel/serial conversion circuit 8 which converts the parallel 8 bits into serial bits in order to match the format of the CRT display. The synchronization signal is
The signal is directly supplied from the CRT controller 1 to the synchronizing signal input terminal 32 of the CRT display device.

In the manner described above, it is possible to display a mixture of characters with different pixel configurations on a CRT screen.

Note that in this embodiment, writing to the video memories 2 and 3 is performed by the controller! Controller 1
It is also possible to switch between the display address bus and the system bus using a multiplexer or the like, and write from the system bus.

<Effects> As explained in detail below, the display control method of the present invention allows the number of pixels in the scanning line direction to be N and IL-M (N: positive integer, M: A positive integer of 2 or more) In a display control method that does not display a mixture of type 1 and type 2 characters, the code indicating the type 1 character and the type 2 character are M codes indicating each equally divided portion are sequentially stored in the video memory in the order in which they are displayed.
By sequentially reading out each code from the memory in code units, converting it into a dot pattern of the first type character or a dot pattern of a predetermined part of the second type character using a character generator, and supplying the dot pattern to the CRT. ,
The present invention is characterized in that the above-mentioned type 1 characters and type 2 characters are mixed and displayed on the same line on the CRT screen, and according to the present invention, characters with different pixel configurations can be displayed on the CRT screen. In the case of displaying a mixture of images, it is possible to obtain a display control method that can reduce the capacity of the video memory and can change the screen at high speed.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a diagram showing the configuration of the video memo IJ (V-RAM) in the same embodiment, and FIG. 3 is a diagram showing the configuration of the video memo IJ (V-RAM) in the same embodiment. FIG. 4 is a diagram showing a code assignment method, FIG. 4 is a diagram showing a method of setting codes to RAM, and FIG. 5 is a diagram showing a screen configuration in which ASCII characters and Chinese characters are mixed. Code explanation 1: CRT controller, 2.3 = video memory, 4
:ASCII character generator, 5: Kanji character generator, 6: Chip select circuit, 7
: Unnecessary dot erase circuit, 8: Part 7, n, /Serial conversion circuit, II system bar a21: Display address, 22 star address, 23: Horizontal/vertical synchronization signal, 3I: Video Signal input terminal, 32: Synchronous signal input terminal. Agent Patent attorney Aihiko Fukushi (and 2 others) Ward
U ~ ~ Mourning Procedural Amendment (Method) (1, Mr. Y License Office) Sumire, Matter A. Patent Application No. 175497 of 1983 2. Invention Name Display Control System 3 Supplement 11 Related Patent Applicant 4, Agent Address 22-22 Nagaike-cho, Abeno-ku, Osaka 8545 February 22, 1982 No change) 21549-

Claims (1)

[Claims] 1. Type 1 characters whose number of pixels in the scanning line direction is N and N-M (N: positive integer, M: positive integer greater than or equal to 2) in the same line on the cRT screen, respectively. In a display control method for displaying a mixture of type 2 characters, a code indicating the type 1 character and M codes indicating each part of the type 2 character divided into M equal parts are displayed. The codes are sequentially stored in the video memory according to the order in which they are displayed, and at the time of display, the above codes are sequentially read out code by code from the video memory, and a character generator is used to display the codes.
By converting the dot pattern of the first type character or the dot pattern of a predetermined portion of the second type character and supplying it to the CRT, the first type character can be displayed in the same line on the CR7 screen.
1. To display a mixture of type 2 characters and type 2 characters. A display control method characterized by: