anchor.diff:     Integer(IntKi)                        :: iIn
      integer(intKi)                        :: Un
      
  -   TYPE(ProgDesc), PARAMETER             :: progdesc = ProgDesc( 'MoorDyn Driver' )
  -  
  -   CALL NWTC_Init()
  +   CHARACTER(20)                         :: FlagArg              ! flag argument from command line
  +   CHARACTER(1024)                       :: PlatformInitInputFile
  +   CHARACTER(200)                        :: git_commit    ! String containing the current git commit hash
  +   TYPE(ProgDesc), PARAMETER             :: version = ProgDesc( 'MoorDyn Driver', '', '' )
  +  
  +   CALL NWTC_Init( ProgNameIn=version%Name )
  +
  +   MD_InitInput%FileName = "MoorDyn.dat"  ! initialize to empty string to make sure it's input from the command line
  +   CALL CheckArgs( MD_InitInput%FileName, Arg2=PlatformInitInputFile, Flag=FlagArg )
  +   IF ( LEN( TRIM(FlagArg) ) > 0 ) CALL NormStop()
  +
         ! Display the copyright notice
  -   CALL DispCopyrightLicense( progdesc%Name )
  +   CALL DispCopyrightLicense( version%Name, 'Copyright (C) 2020 Matthew Hall' )
         ! Obtain OpenFAST git commit hash
      git_commit = QueryGitVersion()
         ! Tell our users what they're running
  -   CALL WrScr( ' Running '//TRIM( progdesc%Name )//' a part of OpenFAST - '//TRIM(git_Commit)//NewLine//' linked with '//TRIM( NWTC_Ver%Name )//NewLine )
  +   CALL WrScr( ' Running '//TRIM( version%Name )//' a part of OpenFAST - '//TRIM(git_commit)//NewLine//' linked with '//TRIM( NWTC_Ver%Name )//NewLine )
   
      ! -------------------------------------------------------------------------
      ! Read in prescribed motions from text file if available 
      ! (single 6DOF platform for now, plus one active tensioning command)
      ! (to be updated for versatile coupling in future)
      ! -------------------------------------------------------------------------
  -   
  -   CALL GetNewUnit( UnPtfmMotIn ) 
  -   
  -   CALL OpenFInpFile ( UnPtfmMotIn, "PtfmMotion.txt", ErrStat, ErrMsg ) 
  -   
  -   IF (ErrStat == 0 ) THEN
  -   
  -      print *, "Reading platform motion input data from PtfmMotion.txt"
  -         
  +   IF( LEN( TRIM(PlatformInitInputFile) ) < 1 ) THEN
  +      ntIn = 0   ! flag to indicate no motion input file
  +
  +   ELSE
  +      CALL GetNewUnit( UnPtfmMotIn ) 
  +   
  +      CALL OpenFInpFile ( UnPtfmMotIn, PlatformInitInputFile, ErrStat, ErrMsg ) 
  +      IF (ErrStat /= 0 ) THEN
  +         print *, ErrStat, ErrMsg
  +         RETURN
  +      ENDIF
  +   
  +      print *, "Reading platform motion input data from ", PlatformInitInputFile
  +
         ! Read through length of file to find its length
         i = 1  ! start counter
         DO
  
positive.code:    Allocate(MD_Input(MD_interp_order + 1))
       
     ! set the input file name and other environment terms.
     MD_InitInput%FileName    = "MoorDyn.dat" 
     !MD_InitInput%NStepWave   = 1        ! an arbitrary number > 0 (to set the size of the wave data, which currently contains all zero values)     
     MD_InitInput%g           = 9.81     ! This need to be according to g used in ElastoDyn 
     MD_InitInput%rhoW        = 1025     ! This needs to be set according to seawater density in HydroDyn      
  
negative.code:       
        print *, "read ", ntIn, " time steps from input file."
        print *, PtfmMotIn
     END IF
  
    
  