/C  NRWD:  FORTRAN INTERFACE FOR QIO REWIND RTNE0C  IR=NRWD(LTAPE,UNLOAD) WHERE UNLOAD IS LOGICAL5C   TRUE TO UNLOAD TAPE, FALSE OTHERWISE.  LTAPE NOT 1C   PRESENTLY IN USE.  ASSUMES TAPE DRIVE IS MSA07C   AND NO FILE IS OPEN ON TAPE.  OPERATION IS COMPLETE(C   AS SOON AS ISSUED (NOWAIT MODIFIER).2C  FUNCTION RETURNS ERROR CODE FROM QIO OR ASSIGN.)C  CALLS SYS$QIOW, SYS$ASSIGN, SYS$DASSGN0C     10/28/83  LOGICAL TAPE DRIVE NAME 'TDRIVE'/C@ RMX 5/11/82  FUNCTIONS MADE EXTERNAL 9/16/83!      FUNCTION NRWD(LTAPE,UNLOAD)3      EXTERNAL IO$_REWIND,IO$_REWINDOFF,IO$M_NOWAIT4      INTEGER*4 SYS$QIOW,SYS$ASSIGN,SYS$DASSGN,MFUNC      INTEGER*2 MCHAN,MIOSB(4)      LOGICAL UNLOADC1      MFUNC=%LOC(IO$_REWIND).OR.%LOC(IO$M_NOWAIT)@      IF (UNLOAD) MFUNC=%LOC(IO$_REWINDOFF).OR.%LOC(IO$M_NOWAIT)'      NRWD=SYS$ASSIGN('TDRIVE',MCHAN,,)      IF (.NOT.NRWD) RETURN;      NRWD=SYS$QIOW(,%VAL(MCHAN),%VAL(MFUNC),MIOSB,,,,,,,,)      IF (.NOT.NRWD) RETURN"      NRWD=SYS$DASSGN(%VAL(MCHAN))      RETURN	      END