.MCALL	.MODULE
.MODULE	JJCVT,VERSION=03,COMMENT=<INT*4 INVERT/SYSLIB>,IDENT=NO,LIB=YES

; Copyright (c) 1998 by Mentec, Inc., Nashua, NH.
; All rights reserved
;
; This software is furnished under a license for use only on a
; single computer system and  may  be  copied  only  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 except for  use  on  such
; system and to one who agrees to these license  terms.  Title
; to  and  ownership of the software shall at all times remain
; in Mentec, Inc.
;
; The information in this document is subject to change without
; notice and should not be construed as a commitment by Digital
; Equipment Corporation, or Mentec, Inc.
;
; Digital and Mentec  assume  no  responsibility for the use or
; reliability of its software on equipment which is not supplied
; by Digital  or Mentec,  and listed  in the  Software  Product
; Description.
;++
;
;
;	Edit	Who	Date		Description of modification
;	----	---	----		---------------------------
;	001	WLD	05-OCT-90	Use standard introductory comments
;					so that calling sequence can be 
;					documented.
;					Use $NXADR.
;--
;+
;COND
;	EIS$I	(0)	use SOB macro
;		 1	use SOB instruction
;
;	SLIB$M	(0)	Generate standard SYSLIB routine
;	SLIB$M	 1	Generate U mode part of Supervisor library
;	SLIB$M	 2	Generate S mode part of Supervisor library
;
;	SLIB$M values are referenced using symbols of the form *PART
;			in conditional statements.
;
;	If SLIB$M <> 0, EIS$I is forced to 1
;-
.IIF NDF EIS$I EIS$I=0
.IIF NDF SLIB$M SLIB$M=0
.IIF NE  SLIB$M EIS$I=1

OPART	= SLIB$M			;0 = generate if building old library
UPART	= SLIB$M-1			;0 = generate if building User part
SPART	= SLIB$M-2			;0 = generate if building Supy part
OSPART	= OPART*SPART			;0 = generate ... old or Supy
OUPART	= OPART*UPART			;0 = generate ... old or User
;+
; RT-11 SYSTEM LIBRARY (SYSLIB) SUBROUTINE 
;
; CALLABLE ENTRIES: JJCVT
;
; FUNCTIONAL DESCRIPTION:
; Interchange words of an INTEGER*4.
;
; CALLING SEQUENCE:
;
;	CALL JJCVT(TIME)
;	I = JJCVT(TIME)
;
; PASSED ARGUMENTS:
;
;	TIME	- INTEGER*4
;
; RETURNED ARGUMENT VALUES:
;
;	TIME	- INTEGER*4 with words reversed
;
; FUNCTION RETURN VALUE:
;
;	 0	- interchange done successfully.
;
; EXTERNAL REFERENCES:
;
;	$NXADR
;
;
; MACRO REFERENCES:
;
;	<none>
	.SBTTL	JJCVT - FORTRAN-callable system subroutine

	.GLOBL	$SYSLB, $NXADR
	.WEAK	$MSARG

.IIF EQ EIS$I	.MCALL	SOB

	.PSECT	SYS$I,I

JJCVT::	MOV	(R5)+,R4	;GET double word argument.
	CALL	$NXADR
	BCS	1$		;BR if argument omitted.
	MOV	R0,R1		;R0 points to LSW.
	TST	(R1)+		;R1 points to MSW.
	MOV	@R0,R2		;Save LSW contents.
	MOV	@R1,@R0		;Move MSW to LSW.
	MOV	R2,@R1		;Move saved LSW to MSW.
	CLR	R0		;Set to return success if needed.
	BR	2$

1$:	TRAP	$MSARG		;Handle missing argument.

2$:	RETURN
	.END