PCAA> SHOW DISPLAY
  display SRC at Q123, size = 64, removed, dynamic, kind = SOURCE
  display PLOT at Q123, size = 64, dynamic, kind = PLOT
  display OUT at E7, size = 100, dynamic, kind = OUTPUT
  display PROMPT at E8, size = 64, dynamic, kind = PROGRAM

      This command displays the definitions of the default screen
      displays SRC, PLOT, OUT and PROMPT.