Note that the framebuffer holding the rendered image is implemented as a simple array pointed to by nuGfxCfb_ptr. In other words, the memory area for the framebuffer is not allocated ahead of time in the N64 system. Rather, the program itself prepares a memory area (array) for use as the framebuffer.
Figure 2-2 Specifying the Memory Area
The programmer specifies how memory will be used in the N64 in this way. The framebuffer is the best example, but the audio buffer and the Z-buffer are also memory areas that are specified. Of course, if you use NuSystem, these different buffers are set aside automatically, but they can also be customized to meet the programmer's needs.
We will gradually explain the various buffers, memory and ROM in later chapters, but for now, please remember that no special area has been prepared for the framebuffer.