! 	  From: "COMPUTATIONAL PHYSICS, 2nd Ed" 
! 		by RH Landau, MJ Paez, and CC Bordeianu 
! 		Copyright Wiley - VCH, 2007.
! 		Electronic Materials copyright: R Landau, Oregon State Univ, 2007;
! 		MJ Paez, Univ Antioquia, 2007; and CC Bordeianu, Univ Bucharest, 2007.
! 		Supported by the US National Science Foundation				 
! 		
! 	  overflow.f90: determine overflow and underflow limits			

Program overflow

  Implicit none
  Integer :: I, N
	Real*8 :: under, over
	N = 1024                    ! number of iterations, may need bigger
	under = 1.                                     ! set initial values
	over	 = 1. 
  Do I = 1, N         ! calc underflow and overflow, output to screen
	  under = under / 2
		over = over * 2
		write (*, *) I, over, under
  End Do	 
	Stop 'overflow'
End Program overflow