VideoSync is an extension of the Monitors Control Panel. VideoSync needs to be in the same folder as the Monitors Control Panel for the VideoSync controls to show in the Options section of the Monitors Control Panel.
VideoSync stores information in its resource fork. VideoSync expects itself to be at the root level of the System Folder.
For VideoSync to work properly, it needs to be in the same folder as the Monitors Control Panel and be at the root level of the System Folder. With System 6, this isn't a problem, in fact it is the only way it will work. With System 7, you need to be a little more creative. The Monitors Control Panel doesn't resolve aliases, so an alias for VideoSync in the Control Panels folder doesn't work.
One solution is to put a copy of VideoSync in the Control Panels folder and at the root level of the System Folder. This isn't good since the VideoSync INIT is loaded twice at startup.
The best solution is to put VideoSync and the Monitors Control Panel at the root level of the System Folder and put an alias of the Monitors Control Panel in the Control Panels folder (for convenience). Then restart your Macintosh.
Those using the 8*24 GC software will have to remove it.
For information on the VideoSyncII extension please see TIL article number 26110: VideoSyncII