JPS62128328A - Picture switching control system in multitask - Google Patents

Abstract

PURPOSE:To reduce a time required to switch a program, and to reduce the capacity of a main memory area by providing the same number of screen memories as that of simultaneous execution possible programs. CONSTITUTION:It is assumed that the picture image of a program 11 is positioned at a VRAM21, and that of a program 12 at a VRAM22, and that of a program 1n at a VRAM2n. While the program 11 is executed, the image of the VRAM21 is displayed on a CRT scope 4. At such a time, when the switching of the program is required and a control is shifted to the program 12, the image of the VRAM22 is displayed simultaneously on the CRT scope. Thus, by performing the switching of the control of the program and those of VRAMs 21-2n simultaneously when the switching to programs 11-1n is required, it is possible to switch rapidly the picture display, and the usage quantity of the main memory can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a screen switching control method in multitasking.

[Technical background of the invention and its problems]

In recent years, computers have been shipped equipped with advanced operating systems that enable multitasking.
Its scale is increasing year by year. My computer is medium-
This is accomplished through a man-machine interface such as a port or CRT display. Considering the purpose of use of a personal computer, a man-machine interface is an essential element, even more than the functions provided by the operating system. Therefore, there is a need for an improved man-machine interface that can be adapted to the operating system that implements the multitasking described above.

By the way, the above-mentioned personal computer is equipped with only one Ifi display unit. Therefore, the screen memo 'J (V
Since RAM only has enough space for one screen, in order to run two or more tasks (programs) in full parallel, save the screen image used by one program from VRAM to the main memory, and save the screen image of another zologram to the main memory. It must be restored from memory to VRAM. Therefore, it is necessary to move the VRAM each time a different program can be processed, which has disadvantages in that it takes time to switch programs and that a large amount of main memory is used to save screen images.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned drawbacks, and provides a screen memory equal to the number of programs that can be executed simultaneously, thereby shortening the time required for program switching and reducing the main memory area. The purpose is to provide a screen switching control method.

[Summary of the invention]

In order to achieve the above object, the present invention has a configuration in which screen memories are provided for the number of programs that can be executed simultaneously, and when switching programs, the screen memories displayed on the CR7 screen are also switched at the same time. According to the present invention, main memory usage can be reduced because each program is stored in the screen image 't-v corner M, and since the CRT display screen can be switched only by selecting the VRAM, task switching is possible. Processing is simplified and screen displays can be switched instantly.

[Embodiments of the invention]

Hereinafter, embodiments of the present invention will be described in detail using the drawings.

FIG. 1 is a block diagram showing an example of the configuration of an information processing device in which the present invention is implemented. In the figure, 1 is a microprocessor μCPU capable of multitask processing. 2 is a main memory, and in the embodiment of the present invention, this microprocessor and main memory 2 are collectively referred to as CMUI and will be described below.

3 is keyboard display control 5 (KB/C
(RTC), a 70-point disk controller (FDC), each of 1, 2, and 3.4 above are commonly connected via a system path 7 consisting of a plurality of address, data, and control lines. . KB/C
The RTC3 executes key keys on the key gonide display unit (KB/CRT5) that is the only one connected to the system, converts it into a key code, and transfers it to the CMU J, as well as multiple screen memos IJ (VRAM
) Controls O control and rask timing control. FDC
4 reads/writes data in a floppy disk unit (FDC6) used as an auxiliary memory.

FIG. 2 is a diagram cited to explain the operation of the embodiment of the present invention, and is a memory diagram conceptually showing the relationship between programs and data developed on the main memory 2, and the CRT display screen. In the figure, O8 is an operating system which is a control monitor including a processing program for KB/CRT. It is assumed that this operating system has multi-task processing capability. Further, it is assumed that n application programs and programs are rolled and executed in the main memory 2. VRAM 27~
2n corresponds to the programs 11 to 1 and 1 to 1, and there are as many programs as there are programs. However, it only has one CRT display screen. The application programs 11 to 11-In perform a certain task by using a man-machine interface with the KB/CRT 5 shown in FIG. 1, and operate simultaneously.

Hereinafter, the operation of the embodiment of the present invention will be explained in detail. When n programs are being executed on main memory 2,
The screen image of program 11 is VRAM x J,
It is assumed that the screen image of the f program 12 is stored in the VRM 22, and the screen image of the program 1n is stored in the VRAM 2n. Here, when program 1 is being executed, an image of VRAM J 1 is displayed on the CRT screen. At this time, when program switching occurs and control is transferred to program 12, the image of VRAM 22 is simultaneously displayed on the CRT screen. This program switching is based on the 4th rating system, and is a commercial that can perform multitasking.
This is a standard function of TJ 1 and will not be described in detail here. Further, switching of the CRT screen is simply by selecting the VRAM.

In this way, when switching to programs IJ to In occurs, VRAM control is switched simultaneously with program control switching.
By switching between 21 and 2n, the screen display can be switched quickly.

Incidentally, the use of main memory can be further reduced by not only having a screen image for each program, but also by providing a necessary data area for program switching.

〔Effect of the invention〕

As described above, according to the present invention, the amount of main memory used can be reduced by having a screen image for each program in VRAM. Furthermore, since the CRT screen can be switched simply by selecting the VRAM, the switching process is simplified and the screen display can be switched instantly.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a diagram cited to explain the operation of the embodiment of the present invention.
Programs and data expanded on main memory and C
This is a memory map conceptually showing the relationship between RT display screens. ! ... Microprocessor, 2... Main memory, 3.
・・Key gate/display controller (KB/C
RTC), 4...Key and display unit (KB/CRT), 11~J n-program, 2
1-2n...Screen memory (VRAM).

Claims (1)

[Claims] In an information processing system that performs multi-task processing using the only display unit that exists in the system and serves as a common resource, it is equipped with a screen memory in which display screen information is prepared for each task, and is used under the control of the processor unit. A screen switching control method in multitasking, characterized in that actual display screen information of a task to which the right has been granted is selected, display information is obtained from the corresponding screen memory, and desired data is switched and displayed.