.TITLE	VT
	.IDENT	/V1.0/

;*******************************************************************
;
; VT.TSK
;
;	THIS TASK CANE BE RUN FROM WITHIN A COMMAND FILE TO FIND OUT
;	IF IT IS RUNNING IN THE BATCH SYSTEM.
;	TO USE THIS PROGRAM:
;
;		RUN $VT
;
;	THE OUTPUTS PROVIDED ARE:
;
;	EXIT STATUS=0	TI: IS A TT: DEVICE
;	EXIT STATUS=6	TI: IS VT1:
;	EXIT STATUS=7	TI: IS VT2:
;	EXIT STATUS=N+5	TI: IS VTN:
;
;	S.M. THOMPSON, 4 FEBRUARY 1980.
;
;*******************************************************************

	.MCALL	DIR$,EXST$,GLUN$S

LUNBUF:	.BLKW	6	; LUN INFORMATION BUFFER
EXST:	EXST$	0	; NORMAL EXIT WITH CODE ZERO.

$VTEP:
	MOV	#LUNBUF,R0	; GET ADDRESS OF LUN INFORMATION BUFFER
	MOV	#EXST,R1	; GET ADDRESS OF EXIT WITH STATUS DPB
	GLUN$S	#1,R0		; GET INFO. ABOUT LUN=1
	CMP	#"VT,G.LUNA(R0)	; IS TI: A VT:?
	BNE	EXIT		; NO, JUST EXIT WITH CODE=0
	BISB	G.LUNU(R0),E.XSTS(R1) ; SET IN VT: UNIT NUMBER
	ADD	#5,E.XSTS(R1)	; ADD REQUIRED BIAS
EXIT:	DIR$	R1		; AND EXIT

	.END	$VTEP