CONIN:	LD	A,10H
	OUT	(1DH),A
	IN	A,(1DH)
	AND	0CH
	CP	0CH
	JP	NZ,CONIN
	LD	A,C
	OUT	(1CH),A
	RET

INIT:	XOR	A
	OUT	(1DH),A
	IN	A,(1DH)
	AND	1
	RET	Z
	LD	A,0FFH
	RET

CONST:	CALL	INIT
	JP	Z,CONST
	IN	A,(1CH)
	AND	7FH
	RET

CONOUT:	LD	A,10H
	OUT	(1FH),A
	IN	A,(1FH)
	AND	0CH
	CP	0CH
	JP	NZ,CONOUT
	LD	A,C
	OUT	(01EH),A
	RET
	END