| 摘要 |
<p>PURPOSE:To execute a screen division and a window control at a high speed by writing new information to a frame memory, and simultaneously, storing old information on a frame memory, in an image memory, and executing a data conversion. CONSTITUTION:A plotting means 6 stores an old data in an image memory in a main storage device 4, simultaneously with data plotting to a frame memory 7. In such a way, at the time of generating new window data, old picture information which has been constituted in a window area is stored onto the image memory, therefore, a window which is being displayed is erased, and when it has been returned to the original picture it can be returned to an old picture by executing a data exchange of the frame memory 7 and the image memory again. In this case, with regard to the data of the window area, as well, it can be reflected on the screen in accordance with necessity. In such a way, a picture division and a window control can be executed at a high speed without limiting its use range.</p> |
