anchor.diff:  :iwad_shareware
   REM # if the user is trying to play just DOOM as-is without a PWAD,
   REM # then the best thing to do is offer them the shareware version:
  -IF /I "%SAVE_WAD%" == "DOOM" (
  +IF /I "%IWAD%" == "DOOM.WAD" (
   	ECHO:
   	ECHO   WARNING! Could not find registered DOOM.WAD:
   	ECHO:
  
positive.code: :iwad_tnt
  REM --------------------------------------------------------------------------------------------------------------------
  REM # are we looking for "Final DOOM: Evilution"?
  IF /I NOT "%IWAD%" == "TNT.WAD" GOTO :iwad_plutonia
  	
  REM # is Steam : Final DOOM installed?
  
negative.code: REM # if this was DOOM or DOOM2, we could use FreeDOOM instead
  SET "FREEDOOM="
  REM # TODO: check these files exist too
  IF /I "%IWAD%" == "DOOM.WAD"  SET "FREEDOOM=%IWADS%\freedoom\freedoom1.wad"
  IF /I "%IWAD%" == "DOOM2.WAD" SET "FREEDOOM=%IWADS%\freedoom\freedoom2.wad"
  
  IF NOT "%FREEDOOM%" == "" (
  	ECHO:
  