| 摘要 |
<p>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.</p> |
