不同的显示器适配器有不同的图形分辨率。即使是同一显示器适配器，在不同模式下也有不同分辨率。因此，在屏幕作图之前，必须根据显示器适配器的种类将显示器设置成为某种图形模式。在未设置图形模式之前，微机系统默认屏幕为文本模式(80列，25行字符模式)，此时所有图形函数均不能工作。-different display adapters with different graphics resolution. Even with the same display adapter, in different modes have different resolution. Thus, drawing on the screen before, must be based on the type of display adapter will be set up as some kind of display graphics mode. Failure to put in graphics mode, the system default computer screen text mode (80, 25 character line mode), At this time all graphics functions will not work.