PROGRAM WriteBytes
  IMPLICIT NONE
  
  INTEGER :: unit
  CHARACTER(55) :: data
  INTEGER :: i, j
  
  j = 1
  DO i = 1, LEN(data)
    data(i:i) = ACHAR(j)
    j = MOD(j+1, 256)
  END DO
  
  OPEN(  &
      NEWUNIT=unit,  &
      FILE='test.bin',  &
      ACCESS='STREAM',  &
      FORM='UNFORMATTED',  &
      ACTION='WRITE',  &
      STATUS='REPLACE' )
  WRITE (unit) data
  CLOSE(unit)
END PROGRAM WriteBytes