PCAA> SHOW SELECT
  screen mode not set
  display selections:
      scroll = PLOT
      input  = none
      output = OUT
      error = PROMPT
      source = SRC
      program = PROMPT
      prompt = PROMPT
      plot = PLOT

      The SHOW SELECT command shows that screen display OUT is the
      current output display, display PLOT is the current scrolling
      display, and so on.