page	255
	.z80
	
	global	msg_fifo
	global	msginit
	global	msg.out,msg.sout,msg.co
	
	extrn	buf.init

	include config.inc
	include	z180reg.inc

;--------------------------------------------------------------

	dseg

	mkbuf	msg_fifo, 0


;--------------------------------------------------------------

	cseg

;
; Init buffer
;
	
msginit:
	ld	ix,msg_fifo
	ld	a,msg_fb_len-1
	jp	buf.init


;--------------------------------------------------------------

msg.sts:
	push	ix
	ld	ix,msg_fifo		;

	ld	a,(ix+o.in_idx)		;
	inc	a
	and	(ix+o.mask)
	sub	(ix+o.out_idx)		;
	pop	ix
	ret	z
	or	0ffh
	ret

;--------------------------------------------------------------

msg.out:
	push	ix
	ld	ix,msg_fifo		;

	push	bc
	ld	b,a			;save char
	ld	a,(ix+o.in_idx)		;
	inc	a
	and	(ix+o.mask)
bp.wait:
	cp	(ix+o.out_idx)		;
	jr	z,bp.wait
	ld	c,a
	ld	a,b
	out	(PMSG),a
	ld	(ix+o.in_idx),c
	
	pop	bc
	pop	ix
	ret

;--------------------------------------------------------------
;
; (hl): data
  
msg.sout:
	push	ix
	ld	ix,msg_fifo		;
	push	bc

	ld	b,(hl)			;count
	inc	hl
obs_1:
	ld	a,(ix+o.out_idx)	;
	sub	(ix+o.in_idx)		;
	dec	a
	and	(ix+o.mask)
	cp	b
	jr	c,obs_1

	ld	c,(hl)			;port address
	inc	hl
	ld	a,b
	otir
	add	(ix+o.in_idx)
	and	(ix+o.mask)
	ld	(ix+o.in_idx),a
	pop	bc
	pop	ix
	ret

;----------------------------------------------------------------------

msg.co:
	push	af
	push	hl
	ld	(buf_char),a
	ld	hl,buf
	call	msg.sout
	pop	hl
	pop	af
	ret
	
	
buf:
	db	buf_end - $ - 2		;output string length
	db	PMSG			;output port
	db	0AEh			; message start token
	db	buf_end - $ - 1		; message length
	db	1			; command
	db	1			; subcommand
buf_char:
	db	0			; pay load
buf_end:

;----------------------------------------------------------------------

	end