Menus are plain text files with the cui extension. There are main menus, for instance Bricscad's default.cui, and partial menus. Partial menus are used for storing menu customizations. It is possible to automatically load lisp files with a (partial) menu (see here) and some of the programs on this website use this feature.
Although the loading and unloading of cui files is very reliable it is advisable to always make a backup of existing customizations before loading a (partial) cui file. Bricscad provides a backup for the default.cui.
To load a partial cui file in Bricscad type _customize on the command line and choose: File > Load partial CUI file. Then browse to the cui file and select it.
Some (partial) cui files come with additional files such as a dll file (in which the images are stored) and an mnl file. These files must be put in the same folder as the cui file. This folder does not have to be in the search path.
Programs with a partial menu that can be downloaded from this website typically use four files. Apart from a cui, dll and mnl file, there is also a des file. This is the encrypted lisp file containing the main program. All four files must be put in the same folder which, again, does not have to be in the search path.
Note that if your main cui file is the Bricscad default.cui, and you use the new default.cui that comes with each Bricscad update, you will have to reload all partial menus.
To unload a partial cui file in Bricscad type _customize on the command line and on the Menu tab right click the partial menu you wish to unload and choose: Unload.
In the rare event that you do encounter problems when loading a partial cui file, try the following tips:
In Bricscad prior to version 12.1.12 there has been a problem adding partial menus to cui files generated from mnu files (SR32571). If this applies to you, you should try upgrading to the latest Bricscad version.
If you have been experimenting with partial menus you may have accidentally added an (almost) empty partial cui file. The presence of this partial menu can prevent new partial menus from loading properly. The solution is simple: unload the empty partial cui file and try again.
If you have trouble loading a partial menu and have already loaded other partial menus, try loading them in a different order. The partial menus on this site can be loaded in any order. They can even be loaded as the main menu.
If all else fails you may have to use the "Revert to defaults..." button in the Customize dialog. But this does mean loosing existing customizations.