.MCALL	.MODULE
.MODULE	ITTINR,VERSION=04,COMMENT=<ITTINR,ITTOUR/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.
	.SBTTL	Module Declaration

	.NLIST
	.ENABL	LC
	.DSABL	GBL
	.NLIST	CND
	.LIST
; ++
; FACILITY:
;
;    RT-11 System Subroutine Library
;
; CALLABLE ENTRIES:
;
; 	ITTINR, ITTOUR
;
; ENVIRONMENT:
;
;    These routines can be used by any job running in a single-job or 
;    multi-job environment . They use "TRAP" to provide error processing.
;
;
; INCLUDE FILES:
;

	; SYSMAC.SML		; RT-11 system macro library.

	.MCALL	.TTINR		; .TTINR programmed request.
	.MCALL 	.TTOUTR		; .TTOUTR programmed request

;
; EXTERNAL REFERENCES:
;

	.GLOBL	$SYSLB		; Include system library work area.
	.WEAK	$MSARG		; Trap code for missing argument

	.SBTTL	ITTINR,ITTOUR - Fortran-callable routine
; ++
; FUNCTIONAL DESCRIPTION:
;
;   The ITTINR function transfers a character from the console 
;   terminal to the user program. If no characters are available,
;   system action is determined by setting of bit 6 of the JSW.
;   	    
;   The ITTOUR function transfers a character from the the user
;   program to the console terminal. If it is not currently possible
;   to output a character, an error flag is returned.
;   	    
; CALLING SEQUENCE:
;
;    i = ITTOUR(char)
;
;    i = ITTINR( )
;
;
; OUTPUT PARAMETERS:
;
;    R0	    - status of transfering character
;
; RETURNED FUNCTION VALUE:
; 
; ITTOUR
;	0 	-  Character was output 
;	1 	-  Ring buffer is full
;
; ITTINR
;	I > 0 	-  Character read 
;	I < 0 	-  No character available
;
; --

	.PSECT	SYS$I

ITTINR::.TTINR			;.TTINR
	BCC	10$
	ROR	R0		;
10$:	RETURN

ITTOUR::
	CMPB	#1,@R5		; arg present ?
	BLT	ERR		; no then err
	TST	(R5)+		; R5 -> character
	MOVB	@(R5),R0	; R0 cnts character
	.TTOUTR	
	BIC	R0,R0		;*C* clear error flag
	ADC	R0		; set function result(0 or 1)
	RETURN

ERR:	TRAP	$MSARG		; trap on any missing argument in call
	RETURN

	.END