PROGRAM		CKSUM2

	PARAMETER	IOBLK=16
	PARAMETER	IORVB="21*"400

	REAL*4		TIME
	INTEGER*2	SUMADD,SUMEOR
	INTEGER*2	IOST1(2),IOPRM1(6),BUF1(256*IOBLK)
	INTEGER*2	IOST2(2),IOPRM2(6),BUF2(256*IOBLK)

	DATA IOPRM1/6*0/,IOPRM2/6*0/

	OPEN	(UNIT=1,FILE='TEST.DAT',STATUS='OLD',BUFFERCOUNT=-1)

	SUMADD = 0
	SUMEOR = 0
	CALL GETADR(IOPRM1(1),BUF1(1))
	IOPRM1(2) = 512*IOBLK
	CALL GETADR(IOPRM2(1),BUF2(1))
	IOPRM2(2) = 512*IOBLK
	TIME   = SECNDS(0.0)

	IOPRM1(5) = 1
	CALL QIO(IORVB,1,1,,IOST1,IOPRM1)
	IOPRM2(5) = IOPRM1(5) + IOBLK
	CALL QIO(IORVB,1,2,,IOST2,IOPRM2)

  100	CALL WAITFR(1)
	IF (IOST1(2) .EQ. 0) GOTO 999
	DO 110 I = 1,IOST1(2)/2
 		SUMADD = SUMADD + BUF1(I)
		SUMEOR = IEOR(SUMEOR,BUF1(I))
  110		CONTINUE
	IOPRM1(5) = IOPRM2(5) + IOBLK
	CALL QIO(IORVB,1,1,,IOST1,IOPRM1)

	CALL WAITFR(2)
	IF (IOST2(2) .EQ. 0) GOTO 999
	DO 120 I = 1,IOST2(2)/2
 		SUMADD = SUMADD + BUF2(I)
		SUMEOR = IEOR(SUMEOR,BUF2(I))
  120		CONTINUE
	IOPRM2(5) = IOPRM1(5) + IOBLK
	CALL QIO(IORVB,1,2,,IOST2,IOPRM2)
	GOTO 100

  999	TIME = SECNDS(TIME)
	WRITE  (5,1000) TIME,SUMADD,SUMEOR
 1000	FORMAT (' Elapse seconds = ',F6.2,' Checksums = ',O6,1X,O6)
	STOP
	END