SUBROUTINE CLS ( )
Description
Clears the screen. 
Put machine dependent code here.
Source file:animated_pendulum_cls.f
I/O Operations:
Unit ID  Unit No       Access  Form   Operation
               5          SEQ  FMTD           W  

Operation codes A=rewind,B=backspace,C=close,E=endfile
                I=inquire,O=open,R=read,W=write
Intrinsic Functions Called
CHARACTER          CHAR
Local Variables (+ indicates altered content)
CHARACTER*6       +CLEAR_STRING
CHARACTER         +ESC