| 摘要 |
<p>PURPOSE:To cut the window of a second graphic sub system at an arbitrary position in a display picture by emulating the second graphic sub system by using a first graphic sub system. CONSTITUTION:A video RAM 7 is functionally divided into first and second areas 7a and 7c, and the area 7a is utilized for the first graphic sub system and accessed only by a graphic system processor(GSP) 5. The area 7c is utilized for the second graphic sub system and accessed by a CPU 3 and the GSP 5. When a power source is turned on, an initialize routine is executed, initial setting is executed, and an emulation program for VGA mode is down loaded in an area 7b. When an application program prepared for VGA is executed, the CPU 3 sets display data in the area 7c. The GSP 5 transfers these data to the area 7a.</p> |
