Save

Select the save menu item to save the block diagram in a binary file already selected by a previous select the Save As menu item. If you select this menu item and you have never clicked on the Save As menu item, the diagram is saved in the current directory as $<$window_name$>$.cos where $<$window_name$>$ is the name of the window appearing on top of the window (usually Untitled or Super Block).

The .cos binary files are machine independent.