When you write to a window, the output goes into the window buffer. You can write to the window whether or not it is on the video screen. When the window is displayed on the video screen, the contents of the window buffer are displayed in the window's interior work area.
The video output functions used to write to a window begin writing in the window buffer at the location specified by the virtual cursor. There is one virtual cursor for each window, and its coordinates are relative to the window's buffer, not the physical screen.
If the buffer is larger than the window, it is possible to be writing to a part of the buffer that is not covered by the window. By default, Vermont Views takes care of this situation by automatically adjusting the portion of the buffer that is displayed, so that the last output to the window is always visible.
