The Windows->OS/2 menu item opens an OS/2 command window with the path of the active file window and the environment of FS/2. If the Settings Notebook Page 2_1 option Open OS/2 session full screen is checked, the session is opened full screen. Otherwise, it is opened in a windowed session. The OS/2 windowed sessions, opened with FS/2, are titled with a numeric reference so that they may be identified in the Window Task List.
Using a combination of a LMB click and the following modifier keys, the following is possible if the Open OS/2 session full screen is not checked:
There should be a os2start.cmd file in the FS/2 directory. If one is found, it is run after the window is opened to set any environment it commands. It may be modified as desired.
Accelerator Keys - Alt Shift O