| 摘要 |
<p>PURPOSE:To attain the operations of both high resolution and normal modes with use of a single program by deciding automatically whether the high resolution or normal mode is presently working. CONSTITUTION:A read-out character pattern is compared with all '1' by an instruction 6 so as to decide whether a high resolution or normal mode is presently working. In the normal mode the address of a text screen VRAM of the normal mode and the base address of a graphic VRAM are set with an instruction 7. Meanwhile the address of the text screen VRAM of a high resolution mode is set together with the base address of the graphic VRAM with an instruction 8 in the high resolution mode. Thus it is not required to prepare each program that is accordant with each working mode.</p> |
