JPH05158465A - Graphic display method in crt device - Google Patents

Abstract

PURPOSE:To attain a high resolution display of a large amount of graphic data using a normal standard CRT device by combining the normal standard CRT and an exclusive display controller. CONSTITUTION:The display controller is provided with a graphic memory 11, a CRT controller and shift register, etc. The vertical scan of the CRT controller can be specified for a noninterlace system or an interlace system, a screen display starting position can be specified at least in the vertical direction and a cursor control function is provided. Moreover, normal standard horizontal dots, horizontal bits whose number is larger than the number of vertical lines and a vertical bit graphic memory 11 are provided. A screen S is used to display by selecting an interlace system screen corresponding to the whole region of the memory 11 and a noninterlace system screen corresponding to a partial region. The latter screen is scrolled in the vertical direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphic display method in a CRT device for displaying a large amount of graphic information by using a normal standard CRT device in a microcomputer system including a personal computer.

[0002]

2. Description of the Related Art CRT devices (CRT display devices; the same applies hereinafter) are widely and generally used as display devices in personal computers, so-called personal computers.

The most popular CRT device for personal computers in Japan today is a non-interlaced color CRT display device with horizontal dots 640 and vertical lines 400, and the number of colors that can be displayed is 16 colors. Limited. Hereinafter, the CRT device of this specification is referred to as a normal standard CRT device.

In this system, the display controller 1a housed in the computer main body 1 has a horizontal bit 64.
Four graphic memories of 0 and vertical bit 400 are held (FIG. 8), and the CRT device 2 displays a non-interlaced fixed screen corresponding to the entire area of the graphic memory. The computer body 1
Is a central processing unit (C) having a main memory (MRY) 1c.
The PU) 1b controls the display controller 1a via the input / output port (IOP) 1d. The CRT device 2 includes a CRT 2a and a video amplifier 2b1 corresponding to three colors of red, green and blue. 2b2, 2b3 and the deflection circuit 2c are provided to form a so-called external synchronization type display device.

From the display controller 1a to the video amplifiers 2b1, 2b2, 2b3 and the deflection circuit 2c, red, green and blue video signals R, G and B, a horizontal synchronizing signal H and a vertical synchronizing signal V are supplied. And are output. However, each of the video signals R, G, and B is an analog signal whose resolution is the number 4 of graphic memories, and CR
Each pixel dot on T2a corresponds to each bit of the graphic memory and can be changed to 16 colors out of 4096 maximum colors based on the graphic data written in the graphic memory. In addition, normal standard C
In the RT device 2, the horizontal data display period of the video signals R, G, B is 30.4 μsec / 640 dots (dot frequency about 21.05 MHz), and each of the horizontal synchronization signal H and the vertical synchronization signal V is The frequency, that is, the horizontal sync frequency and the vertical sync frequency are 24.83 kHz and 5 respectively.
It is 6.4 Hz.

[0006]

According to the prior art, since the total number of pixel dots that can be displayed on the CRT device is limited to 640 × 400, a large-sized spreadsheet or a screen can be displayed. When opening a plurality of windows above, there was an unavoidable problem that the display information was insufficient and it was difficult to use. In addition, since CRT devices other than the normal standard used for such applications, so-called high-resolution display devices, have extremely few manufacturing and sales,
It has the drawback of being extremely expensive and difficult to obtain.

Therefore, an object of the present invention is to combine a conventional normal-standard CRT device and a dedicated display controller to handle a large amount of display information, which is almost equivalent to a commercially available high-resolution display device. It is to provide a graphic display method in a device.

[0008]

SUMMARY OF THE INVENTION To achieve the above object, the structure of the present invention is designed to display more horizontal dots and vertical bits than normal standard horizontal dots and vertical lines when displaying graphics on a normal standard CRT device. It is an object of the present invention to switch and display an interlaced screen and a non-interlaced screen having more horizontal dots than the normal standard through a display controller having a graphic memory provided therein and a CRT controller for controlling the graphic memory. And

The interlaced screen and the non-interlaced screen can be scrolled independently of each other in at least one vertical and horizontal direction.

[0010]

According to the structure of the present invention, the CRT device itself is a normal standard, but the display controller alternately scans even lines and odd lines to form an interlaced screen so that vertical lines are formed. Can be increased up to 400 x 2 = 800,
Also, by increasing the horizontal dot frequency,
The number of horizontal dots can be arbitrarily increased. However,
At this time, the display controller has a graphic memory of horizontal bits and vertical bits corresponding to the horizontal dots and vertical lines thus increased. Further, the number of colors that can be represented by the CRT device depends on the number of graphic memories, and this can also be arbitrarily increased by making the number of graphic memories four or more.

When the CRT device is operated by the interlace system, the vertical period becomes (2 / 56.4) seconds, so that some flicker is recognized on the screen, but this is practically acceptable. In addition, it is practical that the horizontal dots are set to 2 ¹⁰ = 1024 by applying a number that is a power of 2, and the vertical line of the interlaced screen is 102
It is preferable that 4 × (3/4) = 768. This is because the aspect ratio of the screen is 4: 3 and the characters and figures on the screen will not be extremely distorted even when a graphic display is made by a standard application program prepared for a normal standard CRT device.

The display controller has a graphic memory of horizontal bits and vertical bits larger than the horizontal dots and vertical lines of the screen, so that the display controller can be used as a graphic memory regardless of whether it is an interlaced screen or a non-interlaced screen. Partial areas can be displayed. Therefore, at this time, by controlling the CRT controller by software and continuously changing the display area, the screen is scrolled vertically and horizontally,
Furthermore, a large amount of display information can be handled.

[0013]

Embodiments Embodiments will be described below with reference to the drawings.

The graphic display method in the CRT device is carried out by a combination of the computer main body 1 and the normal standard CRT device 2 (FIG. 1).

The computer main body 1 includes a main memory (MR
Y) 1c, central processing unit (CPU) 1b with input / output port (IOP) 1d, and display controller 10
A mouse 1e for controlling the cursor position is connected to the input / output port 1d. The computer main body 1 and the CRT device 2 are the same as the conventional one shown in FIG. 8 except for the display controller 10.

The display controller 10 includes a graphic memory 11 and a CRT controller (CRTC) 1.
2, a shift register 13, and a DA converter (DAC) 14 with a built-in color palette (look-up table) (FIG. 2).

The input / output port 1d and the graphic memory 11 are bidirectionally connected via the interface circuit 15, and the CRT controller 12 is connected to the input / output port 1d via the interface circuit 15. There is. A crystal oscillator XT that determines the dot frequency is connected to the CRT controller 12, and each output of the CRT controller 12 includes a graphic memory 11 and
In addition to being connected to the shift register 13 and the DA converter 14, it is output as a horizontal synchronizing signal H and a vertical synchronizing signal V to the CRT device 2. The output of the graphic memory 11 is transferred to the DA converter 1 via the shift register 13.
4 and the output of the DA converter 14 is output to the CRT device 2 as video signals R, G, and B.

The graphic memory 11 has a horizontal bit 1
This is a RAM memory with 024, vertical bits 768, and 8 sheets (FIG. 3). Further, the CRT controller 12 can specify vertical scanning in a non-interlace system and an interlace system, a display start position of the screen can be specified in at least a vertical direction, and a cursor control function is attached. As such a CRT controller, for example, Hitachi HD6445 is commercially available.
The crystal oscillator XT connected to the CRT controller 12 is
In order to realize the horizontal data display period of 30.4 μsec / 1024 dots, the frequency is about 33.68 MHz. DA
As the converter 14, a color palette built-in type having a resolution of 8 bits and an update rate of about 34 MHz or more is used.

The shift register 13 reads the graphic data from the graphic memory 11 and, when transferring the graphic data to the DA converter 14 (FIG. 2), converts the data from parallel to serial to reduce the required access time of the graphic memory 11. It is for. Further, the DA converter 14 refers to the built-in color palette based on the data stored in each sheet of the graphic memory 11, changes the pixel bit corresponding to each bit of the graphic memory 11 to 256 colors, and the CRT device 2 Can be displayed in color on the screen.

In such a system, the central processing unit 1b instructs the CRT controller 12 of the display controller 10 to specify the interlace method by software, so that a fixed screen corresponding to the entire area of the graphic memory 11, that is, horizontal dots 1024. The screen of the vertical line 768 can be displayed on the CRT device 2. However, the fixed screen referred to here means a screen on which all the graphic data written in the graphic memory 11 from the central processing unit 1b is displayed as it is.
If the contents of 1 are rewritten, the contents of the display screen can express an arbitrary motion accordingly.

At this time, the CRT controller 12 causes the C
The horizontal synchronizing signal H and the vertical synchronizing signal V are sent to the RT device 2, and the timing signals are sent to the shift register 13 and the DA converter 14, and the video signal R,
Update G and B. Further, the screen at this time is a high-resolution screen of horizontal dots 1024 and vertical lines 768, but since the CRT controller 12 operates in the interlace system, the odd lines and even lines in the vertical direction are alternately refreshed, The vertical cycle as a whole is (2/5
6.4) seconds. Also, the horizontal data display period is 3
Since it is 0.4 μsec / 1024 dots, the horizontal synchronization frequency and the vertical synchronization frequency can maintain the normal standard.

The system uses the central processing unit 1b to control the C
By designating the non-interlaced method for the RT controller 12, a vertical scroll screen corresponding to a partial area of the graphic memory 11 can be displayed.

Now, if the non-interlace system is designated for the CRT controller 12 and the maximum number of rasters is set to 400, the screen of the non-interlace system of horizontal dots 1024 and vertical lines 400 is displayed on the CRT device 2. S can be displayed (FIG. 3), and the vertical start address y of the screen S at this time can be arbitrarily set by specifying the display start position to the CRT controller 12 by software. it can. However, the origin y = 0 of the start address y is assumed to be the origin address (0, 0) of the graphic memory 11. The maximum number of rasters 400 is determined from the normal standard horizontal sync frequency and vertical sync frequency.

The start address y of the screen S is controlled by the program shown in FIG. 4, for example. That is, in the program, if the start address y is ym <y with respect to the cursor position (xm, ym) on the screen S (program step (1) in FIG. 4, hereinafter, simply described as (1). ), It is determined that the cursor has deviated above the screen S, and y = ym (2), ym ≧ y + b
(However, if b is the designated maximum number of rasters, and here b = 400) (3), it is assumed that the deviation is downward, y = ym-b + 1 (4), and a new start address y is set. Output to the CRT controller 12 (5).
Since the CRT controller 12 displays the screen with the start address y thus output as the display start position of the screen S, the screen S is displayed on the CRT device 2.
It is possible to scroll vertically according to the cursor position (xm, ym).

The cursor position (xm, ym) is C
The cursor stored in the RT controller 12 is stored in the cursor register. When the mouse 1e is moved, the cursor on the screen reads the amount of horizontal and vertical movement of the mouse 1e via the input / output port 1d, and another cursor is displayed. By updating the contents of the cursor register via software,
It can be freely moved on the CRT device 2 via the graphic memory 11. Therefore, the program of FIG. 4 is provided with a cursor coordinate management memory having the same contents as the cursor register on the main memory 1c, and by reading the memory, the current cursor position (xm, ym) can be read. The cursor does not use the cursor register built in the CRT controller 12 but is CR through the graphic memory 11 only by software.
It is also possible to display on the T device 2, and in this case also,
The cursor position (xm, ym) may be read from the cursor coordinate management memory on the main memory 1c.

In the above description, the screen S on the CRT device 2 can be scrolled vertically even when it is an interlaced screen. At this time, in FIG. 3, B> 2 × 400 may be prepared as the vertical bit B of the graphic memory 11.

Generally, a horizontal dot a, a vertical line b, and a graphic memory 11 of a non-interlaced screen S
When the horizontal bit A and the vertical bit B are set (FIG. 5), the possibility of scrolling in the non-interlaced screen and the interlaced screen in the vertical and horizontal directions can be summarized as shown in FIG. .. Therefore, in the present invention,
Regardless of whether the screen S is a non-interlaced system or an interlaced system, the screen S can be scrolled in at least one of vertical and horizontal directions. However, when the screen S is scrolled in the horizontal direction, the CRT controller 12 must be able to specify the display start position also in the horizontal direction.

The horizontal scrolling of the screen S can be executed by the program shown in FIG. 7, for example, as shown in FIG. However, in the figure, x is the x coordinate of the start address (x, y) of the screen S, and xm is the x coordinate of the cursor position (xm, ym). Further, when the screen S is scrolled both vertically and horizontally, the program of FIG. 4 and the program of FIG. 7 may be operated in cascade.

The display controller 10 is
It can be mounted as an expansion board on a main body of a personal computer having a conventional standard CRT device 2. At this time, in addition to the display controller 10, a display controller for driving the CRT device 2 of the normal standard is also mounted on the main body of the personal computer, so that the video signals R, G, and By switching B, the horizontal synchronizing signal H, and the vertical synchronizing signal V to be input to the CRT device 2, it is possible to realize the screen display of the normal standard together.

[0030]

As described above, according to the present invention, more horizontal dots than the normal standard are provided through the display controller having the graphic memory of the horizontal standard dots, the horizontal bits more than the vertical lines, and the vertical bits. By switching between an interlaced screen and a non-interlaced screen for display, even if the CRT device is in the standard standard, it is possible to handle a large amount of display information that is almost the same as in a so-called high-resolution display device. Therefore, there is an excellent effect that it is possible to easily avoid a situation in which the display information is insufficient even when executing a large-scale spreadsheet, for example.

[Brief description of drawings]

[Figure 1] Overall schematic block system diagram

[Fig. 2] Detailed block system diagram of main parts

FIG. 3 is a conceptual diagram of the configuration of a graphic memory.

FIG. 4 Program flow chart (1)

[Figure 5] Display screen explanatory diagram

[Figure 6] Chart showing scrollability

[Figure 7] Program flow chart (2)

FIG. 8 is a view corresponding to FIG. 1 showing a conventional technique.

[Explanation of symbols]

 S ... Screen A ... Horizontal bit B ... Vertical bit a ... Horizontal dot b ... Vertical line 2 ... CRT device 10 ... Display controller 11 ... Graphic memory 12 ... CRT controller

Claims (3)

[Claims] 1. A graphic memory having normal standard horizontal dots, more horizontal bits than vertical lines, and more vertical bits when a graphic display is performed on a normal standard CRT device, and a CR for controlling the graphic memory.
A graphic display method in a CRT device, wherein an interlace screen and a non-interlace screen having more horizontal dots than the normal standard are switched and displayed through a display controller including a T controller. 2. The graphic display method in a CRT device according to claim 1, wherein the interlaced screen is scrolled in at least one of vertical and horizontal directions. 3. The graphic display method in a CRT device according to claim 1, wherein the non-interlaced screen is scrolled in at least one of vertical and horizontal directions.