A mainframe door assembly for a frame is provided. The mainframe door assembly includes a door having opposed first and second sides and first and second mount assemblies. The first and second mount assemblies are configured to mount the first and second sides of the door to the frame, respectively, such that the door can occupy and move between an installed position and a loading position. In the installed position, the door is flush with the frame. In the loading position, the first mount assemblies support and the second mount assemblies permit a swinging of the door about the first side or the second mount assemblies support and the first mount assemblies permit a swinging of the door about the second side.