;ENTER
;       R4 CONTAINS THE NUMBER OF OPTIONAL PARAMETERS REMAINING
;       IN THE ARGUMENT LIST.
;       R5 IS POINTING TO THE ADDRESS OF THE FIRST OF TWO POSSIBLE
;       OPTIONAL PARAMETERS.
;EXIT
;       IF PRESENT THE TWO OPTIONAL PARAMETERS /NBT/ AND /IER/
;       ARE RETURNED TO THE FORTRAN CALLING PROGRAM
;       THE NUMBER OF BYTES TRANSFERRED (NBT) IS TAKEN FROM THE
;       "F.NBRD" OFFSET OF THE FDB.  THUS THIS ROUTINE SHOULD
;       ONLY BE CALLED BY MODULES WHICH ARE PERFORMING RECORD
;       I/O (GET$,PUT$,GET$R,PUT$R).
;       R4 IS DECREASED BY 2.
        .TITLE  RIOCMP - FOR RECORD I/O, UPDATE /NBT/,/IER/
        .IDENT  /V01/
       .PSECT
        .GLOBL  RIOCMP
        .GLOBL  IOFERR
RIOCMP: JSR     PC,NBTRIO       ;TRY TO UPDATE THE NUMBER OF BYTES
                                ;TRANSFERRED FROM THE "F.NBRD"
                                ;OFFSET IN THE FDB.
        JSR     PC,IOFERR       ;TEST THE  F.ERR  OFFSET IN
                                ;THE FDB AND RETURN THE STATUS TO
                                ;THE CALLING FORTRAN PROGRAM.
        RTS     PC
       .PAGE
        .SBTTL  NBTRIO - UPDATE THE  NBT  FOR RECORD I/O
;ENTER
;       R5 POINTS TO THE ADDRESS IN THE ARGUMENT LIST, AT WHICH
;       THE CALLING FORTRAN PROGRAM WISHES THE NUMBER OF BYTES
;       TRANSFERRED (NBT) TO BE STORED.
;       R4 CONTAINS THE NUMBER OF OPTIONAL PARAMETERS REMAINING
;       IN THE ARGUMENT LIST
;EXIT
;       THE WBT SPECIFIED IN THE "F.NBRD" OFFSET OF THE FDB ARE
;       RETURNED TO THE CALLING PROGRAM.
;
;       IF THE ADDRESS POINTED TO BY R5 IS EQUAL TO -1, NO STORAGE
;       TAKES PLACE.
;       IN EITHER CASE R5 IS INCREMENTED BY 2.
;       R4 IS DECREMENTED
NBTRIO: DEC     R4              ;DECREMENT THE NUMBER OF PARAMETERS
                                ;ARE THERE ANY PARAMETERS LEFT ?
        BLT     1$              ;YES-THEN EXIT
        CMP     (R5),#-1        ;IS THE ADDRESS SPECIFIED EQUAL TO -1 ?
        BEQ     1$              ;YES- THEN EXIT
        MOV     F.NRBD(R0),@(R5);NO-STORE THE NBR OF BYTES TRANSFERRED
1$:     TST     (R5)+           ;ADVANCE R5 TO THE NEXT PARAMETER
        RTS     PC
        .END