.TITLE GBLSECUFO	Global Section UFO (User FIle Open)
	.IDENT	'X-1'

;****************************************************************************
;*									    *
;*  COPYRIGHT (c) 1978, 1980, 1982, 1984 BY				    *
;*  DIGITAL EQUIPMENT CORPORATION, MAYNARD, MASSACHUSETTS.		    *
;*  ALL RIGHTS RESERVED.						    *
;* 									    *
;*  THIS SOFTWARE IS FURNISHED UNDER A LICENSE AND MAY BE USED AND COPIED   *
;*  ONLY IN  ACCORDANCE WITH  THE  TERMS  OF  SUCH  LICENSE  AND WITH THE   *
;*  INCLUSION OF THE ABOVE COPYRIGHT NOTICE. THIS SOFTWARE OR  ANY  OTHER   *
;*  COPIES THEREOF MAY NOT BE PROVIDED OR OTHERWISE MADE AVAILABLE TO ANY   *
;*  OTHER PERSON.  NO TITLE TO AND OWNERSHIP OF  THE  SOFTWARE IS  HEREBY   *
;*  TRANSFERRED.							    *
;* 									    *
;*  THE INFORMATION IN THIS SOFTWARE IS  SUBJECT TO CHANGE WITHOUT NOTICE   *
;*  AND  SHOULD  NOT  BE  CONSTRUED AS  A COMMITMENT BY DIGITAL EQUIPMENT   *
;*  CORPORATION.							    *
;* 									    *
;*  DIGITAL ASSUMES NO RESPONSIBILITY FOR THE USE  OR  RELIABILITY OF ITS   *
;*  SOFTWARE ON EQUIPMENT WHICH IS NOT SUPPLIED BY DIGITAL.		    *
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;*									    *
;****************************************************************************

;This routine opens a file to be used as a global section
;An RMS OPEN is performed with the file options (FOP) of 
;User File Open (UFO). The calling routine specifies the
;file name and number of blocks; this routine returns the
;channel number on which the file was openned. 
;If the specified file does not exist, the file is created
;
;The calling sequence is
;
;	Call GBL_SECTION_UFO( blkcnt,file-name,chan )
;
; Where 	
;		blkcnt => Number of blocks in the file
;		file-name => filename descriptor block
;		chan => channel openned
;
;
;
;Example:
;	Integer*4 CHANNEL
;	   :
;	   :
;	Call GBL_SECTION_UFO(10,'LABIO_DATA.DAT',CHANNEL )

.SBTTL	GBL_SEC_UFO

; RMS FAB for a $CREATE

GBLFAB:	$FAB	FAC=PUT,-
		FOP=<UFO,CIF,CBT>

	NUM_ARG  = 3 			;Number of arguments

	.ENTRY	GBL_SECTION_UFO,0

	MOVL	#SS$_INSFARG,R0		;Assume bad arg count
	CMPB	(AP),#NUM_ARG		;Check arg count
	BLSS	EXIT			;Too few

	MOVL	8(AP),R1		;Get file name address string descriptor
	MOVB	(R1),GBLFAB+FAB$B_FNS	;Store string length in FAB
	MOVL	4(R1),GBLFAB+FAB$L_FNA	;And file name
	
	MOVL	@4(AP),GBLFAB+FAB$L_ALQ	;Number of blocks to allocate


	$CREATE	FAB=GBLFAB		;Open data file, Create it if
					;if it does not exist
	MOVL	GBLFAB+FAB$L_STV,@12(AP);Store channel number			

EXIT:	RET				;Return with error code in R)

	.END