PROGRAM SEQIO
   IMPLICIT NONE
   INCLUDE 'mpif.h'

   INTEGER :: I
   INTEGER :: MYRANK
   INTEGER :: NUMPROCS
   INTEGER :: IERROR
   INTEGER :: ISTATUS
   INTEGER :: BUFSIZE
   INTEGER :: BUF(100)
! ----------------------------------------------------------------------
   BUFSIZE = 100
   IERROR = 0
   CALL MPI_INIT(IERROR)
   
   CALL MPI_COMM_RANK(MPI_COMM_WORLD, MYRANK, IERROR)
   CALL MPI_COMM_SIZE(MPI_COMM_WORLD, NUMPROCS, IERROR)

   DO I=1,BUFSIZE
      BUF(I)=MYRANK * BUFSIZE + I
   ENDDO
   
   IF (MYRANK /= 0) THEN
      CALL MPI_SEND(BUF, BUFSIZE, MPI_INTEGER, 0, 99, MPI_COMM_WORLD, IERROR)
   ELSE
      OPEN(7,FILE="testfile")
      WRITE(7,*) BUF(1:BUFSIZE)

      DO I=2,NUMPROCS
         CALL MPI_RECV(BUF, BUFSIZE, MPI_INTEGER, (I-1), 99, MPI_COMM_WORLD, &
                       ISTATUS, IERROR)
         WRITE(7,*) BUF(1:BUFSIZE)
      ENDDO
      CLOSE(7)
   ENDIF

   WRITE(6,*) 'MYRANK:',MYRANK,' BEFORE FINALIZE'
   CALL MPI_FINALIZE(IERROR)
   
END PROGRAM SEQIO