The device is at the traditional address of 02. Without more information, this implementation stops printing from a PDT before the RM (character at RM is not printed). This also means that if the first character has a RM, nothing is printed. The PDT control character C3 determins whether the output is terminated with Line Feed(s) or various vertical tab (form feed) actions. An automatic LF is inserted after reaching column 132.
The line printer window is hidden by default. It may be made visible, and raised to the top, using the Front Panel menu "I/O" and selecting LinePrinter. Closing the line printer window only hides it, no output is lost or changed. A program that prints to the line printer will cause it to be made visible, if not already.
Menus allow for saving the current output (printed) buffer to a file, or discarding all current output (Tear Off). Also there are options for advancing the paper one line or to top of form.
An additional menu under "Form Ctl" allows for managing the Forms Control Tape used to specify vertical "tab" stops and paper length. The forms control tape may be loaded from a file, saved to a file, or directly edited in a small GUI window. The edit window responds to digits "1" through "8" to punch a hole in that respective column (channel), or SPACE to magically clear all punches for the current line. Insert and Delete keys may be used to magically add or remove one line from the tape. Up and Down arrow keys move the current (punch position) accordingly. Closing the edit window, when changes were made, will prompt you to keep or discard those changes.