From QB64.org wiki
The $SCREENSHOW metacommand can be used to display the main program window throughout the program.
- The metacommand is intended to be used in a modular program when a screen surface is necessary in one or more modules.
- $SCREENSHOW can only be used after $SCREENHIDE or _SCREENHIDE have been used in another program module.
- If $SCREENHIDE and then $SCREENSHOW are used in the same program module the window will not be hidden.
- QB64 metacommands cannot be commented out with apostrophe or REM.