AUCTeX ⇒ compilation output for source source screen

[Haines]

I reinstalled my operating system and lost a LaTeX prrocess function that apparently had previously been automatic. My practice had been to put a master LaTeX file in one emacs split screen and the included LaTeX file I'm working on in the other screen. When I process the master file, the output used to appear in the same screen as the master file. Now, however it shows up in the screen that displays the included file. How can I control in which screen the processing output is displayed?