.TITLE	CARY.MAC				08-AUG-83

;	GENERAL SCIENTIFIC CORPORATION
;	1684 EAST GUDE DRIVE
;	ROCKVILLE, MD. 20850
;	(301) 340-2773
;
;
;	SUBROUTINE FOR DBL TO CHECK STATUS OF DZ MODEM-STATUS REGSTER BY MEANS
;	OF EMT PEEK AND BIT-TEST FOR DESIRED PORT (ARGUMENT 1). STATUS IS
;	RETURNED FOR DTR, RING, OR CARRIER DETECT, SELECTED IN ARGUMENT 2,
;	INTO ARGUMENT 3, WHERE 1 IS HIGH AND 0 IS LOW.
;
;		IT IS ASSUMED THAT 1 IS THE CONSOLE, ON A DL DEVICE AND THAT
;	ADDITIONAL PORT #'S ARE ASSOCIATED IN A 7-TO-1 RELATIONSHIP TO SUCCES-
;	-SIVE DZ MUXES.  1ST. DZ AT 160010, 2ND. DZ AT 160020, ETC.



;
;CALLING SEQUENCE:
;
;	XCALL CARY (PORT,SELECT,STATUS)
;
;WHERE:	PORT SELECTS THE DZ MUX ADDRESS AND BIT IN THE I/O PAGE TO BE ACCESSED
;     : SELECT INDICATES WHETHER TO CHECK DTR, CARRIER, OR RING
;     : STATUS IS 0 OR 1, I.E. LOW OR HIGH
;


.SBTTL	DIRECTIVES

	.IDENT	\X1.0\
	.PSECT	OPTLIB
	.GLOBL	$POPNM	$FMTNM	$CKARG	$ERR



;PEEK AT THE I/O PAGE TO OBTAIN SET/CLEAR STATUS OF MODEM CARRIER DETECT.
;
CARY::	MOV	#140	,R1		;EMT CODE
	MOV	#1	,R3		;EMT ID
	JSR	PC	,PEEK		;PEEK AT THE PAGE
	RTS	PC


PEEK:	JSR	R0	,$CKARG
	.WORD	3
	MOV	-(R5)	,-(SP)		; SAVE DESCRIPTION OF 3RD ARG.
	MOV	-(R5)	,-(SP)		; SAVE POINTER TO 3RD ARGUMENT
	CALL	$POPNM			; DECODE 2ND. ARG. INTO BINARY IN R2
	MOV	R2	,SELECT
	MOV	-(R5)	,-(SP)		; SAVE DESCRIPTION OF 2ND ARG.
	MOV	-(R5)	,-(SP)		; SAVE POINTER TO 2ND ARGUMENT
	CALL	$POPNM			; DECODE 1ST. ARG. INTO BINARY IN R2
	MOV	R2	,PORT
	MOV	(SP)+	,(R5)+		; RESTORE SP AND R5 STACKS        --
	MOV	(SP)+	,(R5)+
	MOV	(SP)+	,(R5)+
	MOV	(SP)+	,(R5)+
	MOV	#160014	,ADDRES
1$:	CMP	PORT	,#12
	BLT	2$
	ADD	#10	,ADDRES		; USE NEXT DX MUX
	SUB	#10	,PORT		; STANDARDIZE PORT #'S
	BR	1$			; FOR AS MANY DZ'S
2$:	CMP	SELECT	,#0
	BEQ	3$
	ADD	#2	,ADDRES		; SELECT NEXT WORD
3$:	MOV	ADDRES	,-(SP)
	MOV	R3	,-(SP)		;LO BYTE = EMT ID
	MOV	SP	,R0		;EMT POINTER
	MOVB	R1	,1(R0)		;HI BYTE = EMT CODE
	EMT	375			;LET TSX DO IT
	BCC	4$			; IF NO EMT ERROR CONTINUE
	JSR	R0	,$ERR		; GENERATE DBL ERROR

4$:	CMP	PORT	,#2		; TEST PORT # NOT 0 OR CONSOLE
	BGE	5$
	JSR	R0	,$ERR		; SHOULD BE AT LEAST 2

5$:	CMP	SELECT	,#2
	BNE	6$
	SWAB	R0		; CHECK RING
6$:	CMP	PORT	,#2		; TEST PORT 2 OR 10
	BNE	10$
	BIT	#400	,R0
	BEQ	7$
	JMP	SETHI
7$:	JMP	SETLO

10$:	CMP	PORT	,#3		; TEST PORT 3 OR 11
	BNE	20$
	BIT	#1000	,R0
	BEQ	11$
	JMP	SETHI
11$:	JMP	SETLO

20$:	CMP	PORT	,#4		; TEST PORT 4 OR 12
	BNE	30$
	BIT	#2000	,R0
	BEQ	21$
	JMP	SETHI
21$:	JMP	SETLO

30$:	CMP	PORT	,#5		; TEST PORT 5 OR 13
	BNE	40$
	BIT	#4000	,R0
	BEQ	31$
	JMP	SETHI
31$:	JMP	SETLO

40$:	CMP	PORT	,#6		; TEST PORT 6 OR 14
	BNE	50$
	BIT	#10000	,R0
	BEQ	41$
	JMP	SETHI
41$:	JMP	SETLO

50$:	CMP	PORT	,#7		; TEST PORT 7 OR 15
	BNE	60$
	BIT	#20000	,R0
	BEQ	51$
	JMP	SETHI
51$:	JMP	SETLO

60$:	CMP	PORT	,#10		; TEST PORT 8 OR 16
	BNE	70$
	BIT	#40000	,R0
	BEQ	61$
	JMP	SETHI
61$:	JMP	SETLO

70$:	CMP	PORT	,#11		; TEST PORT 9 OR 17
	BEQ	71$			; TEST THAT MAX HAS NOT BEEN EXCEEDED
	JSR	R0	,$ERR		; ELSE GENERATE DBL ERROR (104)
71$:	BIT	#100000	,R0
	BEQ	72$
	JMP	SETHI
72$:	JMP	SETLO

;		RETURN STATUS OF CARRIER DETECT FOR MUX PORT

SETHI:	MOV	#1	,R4
	JMP	CNVRT
SETLO:	MOV	#0	,R4
CNVRT:	JSR	R4	,$FMTNM		; CONVERT TO DECIMAL IN ARGUMENT 2
	CMP	(SP)+	,(R5)+		; RESTORE DBL R5 AND SP STACKS
	ADD	#2	,SP	; FINAL SP STACK RESTORATION
	RTS	PC

PORT:	.WORD	0
ADDRES:	.WORD	0
SELECT:	.WORD	0


.SBTTL END

	.END

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