; user control of noise flag.  Auxiliary to BYERSX
;
bdos	equ	5
fcb	equ	05ch
;
	aseg
	org	0100h
;
	lxi	h,0
	dad	sp
	lxi	sp,stack
	push	h
	mvi	c,87
	lxi	d,0
	call	bdos
	ora	a
	lxi	d,norsx
	jz	exit
	lxi	h,fcb
	mov	a,m
	ora	a
	jnz	nhelp
	inx	h
	mov	a,m
	cpi	'O'
	inx	h
	mov	a,m
	jnz	nhelp
	inx	h
	cpi	'F'
	jz	noff
	cpi	'N'
	jz	non
nhelp:	lxi	d,hlpmsg
exit:	mvi	c,9
	call	bdos
	pop	h
	sphl
	ret
;
; suppress noise
noff:	mov	a,m
	cpi	'F'
	jnz	nhelp
	inx	h
	mov	a,m
	cpi	' '
	jnz	nhelp
	mvi	e,7
	mvi	c,87
	call	bdos
	lxi	d,onmsg
	jmp	exit
;
; allow '{' characters
non:	mov	a,m
	cpi	' '
	jnz	nhelp
	mvi	e,8
	mvi	c,87
	call	bdos
	lxi	d,offmsg
	jmp	exit
;
hlpmsg:	db	'usage: NOISY [ON|OFF] (controls "{" absorbance)$'
offmsg:	db	'Absorbing "{" as noise$'
onmsg:	db	'Allowing "{" to pass$'
norsx:	db	'BYERSX not running$'
;
	ds	48
stack:	ds	0
;
	end