JPH0347516B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical field of the invention] The present invention displays an image such as a graph display.
This invention relates to a scroll control method suitable for use in CRT displays. [Technical background of the invention and its problems] The equipment configuration in an electronic computer system consists of an arithmetic control unit, a main storage device, an input/output device, and an external storage device. CRT displays are the main output devices in the field of office computers, and typically display 40 characters x 25 lines on one screen. However, this is not sufficient to display the amount of data used in general business, and a large amount is required. As a means to that end,
Use the screen scroll function between multiple lines,
The screen is continuously changed. Conventionally, the above-mentioned scrolling has been realized by moving the current display and then rewriting all the data in the scroll start line to space data. FIG. 1 shows an example of display data before and after scrolling, and FIG. 2 shows a flowchart of conventional scrolling processing and an example of changes in screen display caused by this. In the figure, A shows an example of the display screen before scrolling, B shows an example of the display screen after screen movement, and C shows an example of the front screen after scrolling. According to this example, the display of the scroll start line changes from HHHH...→AAAA...→Space, and there is a display of B in the middle, which causes flickering. Especially displaying image images such as graph processing
CRT displays had the disadvantage that it took a considerable amount of time to rewrite the data in the scroll start line, and the display before the scrolling process remained for a moment, making the screen difficult to read. [Object of the Invention] The present invention has been made in view of the above-mentioned drawbacks, and it is an object of the present invention to provide a scroll control method that can reduce the burden on the operator's eyes during scroll processing and can quickly perform scroll display. . [Summary of the Invention] The present invention provides a line table (second RAM) in front of a refresh memory (first RAM) in a CRT display in which scrolling is controlled by a microprocessor. The microprocessor writes pace data to the scroll end line data obtained from the refresh memory, and after detecting this clearing operation changes the contents of the line table to refresh the refresh memory. The structure is such that the screen can be moved without changing the contents. As a result, the scrolling process can be performed quickly without causing the operator to feel flickering on the screen. [Embodiments of the Invention] The present invention will be described in detail below using FIG. 3 and subsequent figures. FIG. 3 is a block diagram showing an embodiment of the present invention. In the figure, 31 is a refresh memory in which screen information is stored. Refresh memory 3
A line table 32 is installed in the front stage of 1, and the display or data READ/
Address for WRITE is provided. Screen addresses (rows) are stored in the line table 32, and the screen is moved by rewriting the contents when a scroll command arrives from the outside.
That is, due to the existence of this line table 32, screen movement can be realized without rewriting the contents of the refresh memory 31. 33 is an address multiplexer. The address multiplexer 33 has a microprocessor 3.
4 outputs and a display controller 35 output are supplied, and are switched by a display signal output from the display controller 35. Microprocessor 3
4 incorporates the control procedure shown in FIG. 4 as firmware, and in addition to performing scroll processing based on this content, controls the entire CRT display. The display controller 35 interfaces the microprocessor 34 with a CRT monitor (not shown), and generates various timing signals necessary for display, as well as refresh memory addresses,
Generate raster addresses, etc. Note that 36 is an internal bus possessed by the microprocessor 34, and is composed of a plurality of lines for address/data control. FIG. 4 is a flowchart of scroll processing according to the present invention and an example of changes in screen display caused by the scroll processing. In the figure, D shows an example of the display screen before scrolling, E shows the display screen before scrolling, E shows the display screen after clearing the scroll end line, and F shows the display screen after scrolling. As you can clearly see from this figure, the scroll start line is displayed as HHHH
...→I don't feel any flickering because it changes with space. In this figure, A and D in the conventional example and C and F in the conventional example are the same display screen. The operation of the present invention will be explained in detail below. First, the microprocessor 34 reads the display information of the scroll end line and writes space information only to the portion where no space has been set. By this operation, the screen display changes from D to E. Here, in the scroll end line of D,
No writing is performed in areas where space information has been set in advance. Next, the line table 32 is changed in order to move the display screen. This is done by the microprocessor 34 decoding a scroll command coming from the outside. For convenience of explanation, the output of the line table 32 when the screen address is 0 to 7 and one line roll up/down is specified is as follows.

〔Effect of the invention〕

As described above, according to the present invention, after the screen is moved, there is no need to erase the data after the movement, so flickering on the screen is not felt. Therefore, the display screen becomes easier to see and the strain on the operator's eyes is reduced. Furthermore, since the above processing step can be omitted, the scrolling processing speed is improved.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of display data before and after scrolling, Fig. 2 is a flowchart of conventional scrolling processing and a diagram showing changes in screen display, and Fig. 3 is a block diagram showing an embodiment of the present invention. figure,
FIG. 4 is a flowchart of scroll processing according to the present invention and a diagram showing changes in screen display. 31... Refresh memory, 32... Line table, 33... Address multiplexer, 3
4...Microprocessor, 35...Display controller, 36...Internal bus.

Claims (1)

[Scope of Claims] 1. In a CRT display device that is controlled by a processor unit and scrolls according to a procedure stored in a control memory, a first RAM for storing screen information and a stage preceding the first RAM are provided. In this case, there is a second method that outputs the display position information that is normally input as is, and converts and outputs the input only when a scroll instruction is received.
The processor unit writes space information to the scroll end line obtained from the first RAM when a scroll instruction is received, and after detecting the end of this writing operation, the processor unit writes space information to the scroll end line obtained from the first RAM. A scroll control method characterized by moving the screen by changing the contents of the screen. 2 The processor unit is connected to the first RAM.
Scroll control method according to claim 1, characterized in that the data obtained by reading the data of the scroll end line is determined from the data, and when data other than spaces is present, the data is rewritten to space data. .