▄ Compile│Primary File...
The Compile│Primary File command leads to the, where you specify which .PAS file will be compiled when you choose (F9) or .
Use Primary File when you're working on a program that uses several unit (.TPU) or Include files.
No matter which file you've been editing, Make or Build always operates on your primary file.
If you specify another file as a primary file, but want to compile only the file in the active Edit window, choose(Alt-F9).