anchor.diff:          do i=1,npoints
             read(kr,*,end=30,err=30) time,hload
           end do
  -        nhist=nhist+1
  +        nhist=nhist+ione
           go to 40
   c
   c...  normal return
  
positive.code: c
  c...  open input file
  c
        ierr=0
        nhist=0
        open(kr,file=hfile,status="old",err=10)
  c
  c... scan the file, counting the number of entries.
  
negative.code: c         1:  Error opening input file (no exception should be raised
  c             in this case since a load history definition file is
  c             optional)
  c         3:  Read error
  c
        include "implicit.inc"
  c
  c...  parameter definitions
  c
        include "nconsts.inc"
  c
  c...  subroutine arguments
  c
        integer nhist,kr,ierr
        character hfile*(*),errstrng*(*)
  c
  c...  local variables
  c
  