File Load creates a window to ask for the filename of the program you want to load.  After you enter it, the program development environment loads and displays the program in the main text area(1) .

After programs are loaded, only the PROLOG is displayed.  View Function will display other functions.

File Save creates a window to ask for the filename you want to save the text or program as.  Edit the filename in the little window if it's not already what you want, then select the Save button.

File Mode creates a window to ask for the edit mode you want.  You can choose text or program mode.  If you want to edit anything other than a program, select text mode.  If you want to edit a program, it's usually more convenient to select program mode and view the program one function at a time.  Sometimes you may prefer to edit programs as normal text.  File Mode switches back and forth between text and program mode.

File Rename creates a dialog window to ask for the new name you want to give the text or program currently loaded in the environment.  Enter a valid filename to update the name of the file.

File Quit ends the program development session.  If the text or program file has been modified since it was last saved, a dialog window appears to warn you.  You can then cancel File Quit and save the file, or continue and permanently lose the contents of the main text window.

1. The PDE loads the program, breaks it up into language elements (keywords, variables, operators, etc), converts each into a 32-bit token, and holds the program in this form.  To display the program in the text area, the PDE converts tokens back into text form.  Reproduction of the original text is generally quite accurate.