| 摘要 |
<p>PURPOSE:To heighten the degree of freedom of a program which performs display on a window and to improve the operability of a user by providing a logical double buffer at every window in a multi-window system. CONSTITUTION:Image data generated by a processor 1 according to a display instruction read out from a command memory 5 is written on frame memories 6 and 7. In such a case, a write operation is performed on the frame 6 or 7 selected by a frame memory change-over switch 10 for write. By allocating a buffer of two logical planes on respective window in the multi-window system, it is possible to perform the switching of a display buffer and a write buffer by the program on respective window in spite of another window.</p> |
