.title	DECUS C .POINT
	.enabl	lc
;+
; SEEK.MAC	By Jan Brittenson 30-Oct-86
;
; Call:
;
;	seek(iov, byteseq);
;		FILE *iov;	/* File to be positioned	*/
;		long byteseq;	/* Byte number inside file	*/
;
; Description:
;
;	The 'byteseq' and the 'iov' arguments are used to set up
;	parameters for a FCS-11 .POSIT call.
;
; Bugs:
;
;	No checks are performed. (Isn't that nice?)
;	All ungetch()'s as well as EOF conditions are flushed.
;
;-

seek::
	jsr	r5, csv$		; C entry
	mov	c$pmtr(r5), r0		; R0 = IOV
	add	#v$fdb, r0		; R0 = FDB
	mov	c$pmtr+2(r5), r2	; R2 = Byte #, high
	mov	c$pmtr+4(r5), r3	; R3 = Byte #, low
	mov	r3, r4
	bic	#^C777, r4		; Keep byte # (9 bits)
	ashc	#-9., r2		; R2:R3 /= 9.
	mov	r2, r1			; VBN, high
	mov	r3, r2			; VBN, low
	mov	r4, r3			; Byte #, 0-511
	call	.point			; Position file pointer

	mov	c$pmtr(r5), r4		; R4 = IOV
	bic	#vf$eor, (r4)		; No end of file condition
	mov	#-1, v$uget(r4)		; Remove ungetch()'s

	mov	#1, r0			; Always return 1
	jmp	cret$			; Return

	.end