anchor.diff:  	SET ENGINE_DOOM64EX=0
   	SET ENGINE_ZANDRONUM=0
   	SET SW=1
  -	SET "REQ=%~1"
   )
   REM # z-based engines; zdoom, gzdoom, zandronum
   IF /I "%~1" == "z" (
  
positive.code: 	SET ENGINE_PRBOOM=0
  	SET ENGINE_ZANDRONUM=0
  	SET "VER_GZDOOM=gzdoom-24"
  	SET "REQ=%~1"
  )
  IF /I "%~1" == "gzdoom-31" (
  	REM # disable all non-GZDoom engines
  
negative.code: 	SET ENGINE_PRBOOM=0
  	SET ENGINE_ZANDRONUM=0
  	SET "VER_GZDOOM=gzdoom-23"
  )
  IF /I "%~1" == "gzdoom-24" (
  	REM # disable all non-GZDoom engines
  