C*	DSXFBN	- FIND FILE WITH REQUESTED BLOCK NUMBER
C
	SUBROUTINE DSXFBN (IHDR, IRT, NB, IFLN, ISEQ)
C
	INCLUDE 'DSMCM.COM/NOLIST'
C
	DIMENSION IHDR(256)
	DIMENSION BTEMP(4)
	EQUIVALENCE (KTEMP,BTEMP)
C
C	OKAY - COMPARE KBTF TO BLOCKS ALLOCATED IN HEADER
C
	KTEMP = 0
	CALL SMCHR (IHDR, IRT+2, BTEMP, 1, 2)		! LOW ORDER WORD
	CALL SMCHR (IHDR, IRT,   BTEMP, 3, 1)		! HIGH ORDER HALF-WORD
C
D	TYPE 490,KTEMP
D490	FORMAT (' KTEMP=',I10)
	IF (KBTF.LT.KTEMP .OR. KBTF.GT.KTEMP+NB) GO TO 400
C
C	THIS IS IT !!
C
	LBTF = .TRUE.
	IFLNFB = IFLN
	ISEQFB = ISEQ
 400	RETURN
	END