*
* interrupt-driver
*


	section	"text"

	xdef	_settimeout
TIMEOUT	dc.l	$4fffff
_settimeout:
	lea	TIMEOUT(pc),a0	; 4 bytes
	move.l	d0,(a0)		; 2 bytes
	rts

	xdef	_parinit
	xdef	_testbusy
	xdef	_setbusy
	xdef	_waitinputtoggle
	xdef	_outputtoggle
	xdef	_setciaoutput
	xdef	_sampleinput
	xdef	_testpout
	xdef	_setpout
	xdef	@intcode

currentinput:	dc.w	0
iamclient:	dc.w	0	

_sampleinput:	
	lea	currentinput(pc),a0
	moveq	#0,d0
	move.w	2(a0),d0	; iamclient
	bchg	#0,d0
	btst.b	d0,$bfd000
	sne.b	(a0)		; currentinput
	rts

_waitinputtoggle:
	lea	currentinput(pc),a0
	lea	$bfd000,a1	; ciaa
	move.l	TIMEOUT(pc),d1
	moveq	#0,d0
	move.w	2(a0),d0	; iamclient
	bchg	#0,d0
	tst.b	(a0)
	beq.s	inputnotset
itl1:
	btst.b	d0,(a1)
	beq.s	exa1
	subq.l	#1,d1
	bpl.s	itl1
exa1:
	addq.l	#1,d1
	move.l	d1,d0
	beq.s	rettt
	clr.b	(a0)	; currentinput
	rts

inputnotset:
	btst.b	d0,(a1)
	bne.s	exa2
	subq.l	#1,d1
	bpl.s	inputnotset
exa2:
	addq.l	#1,d1
	move.l	d1,d0
	beq.s	rettt
	move.b	#42,(a0)	; currentinput
rettt:
	rts

_outputtoggle:
	moveq	#0,d0
	move.w	iamclient(pc),d0
	bchg.b	d0,$bfd000
	rts

_setciaoutput:
	move.b	#$ff,$bfe301	; data out
	rts

_testbusy:
	moveq	#0,d0
	btst.b	#0,$bfd000
	sne	d0
	rts

_testpout:
	moveq	#0,d0
	btst.b	#1,$bfd000
	sne	d0
	rts

_setbusy:
	tst.l	d0
	bne.s	sb1
	bclr.b	#0,$bfd000
	rts
sb1:
	bset.b	#0,$bfd000
	rts

_setpout:
	tst.l	d0
	bne.s	sp1
	bclr.b	#1,$bfd000
	rts
sp1:
	bset.b	#1,$bfd000
	rts


; Init parallel port
; d0==1 = client-mode
_parinit:
	lea	$bfd000,a0
;	move.b	#0,$bfe301	; all parallel bits input
	move.b	#0,$bfe301-$bfd000(a0)
	move.w	d0,iamclient	; client?
	beq.s	servermode
	bset.b	#1,$200(a0)	; pout output
	bclr.b	#0,$200(a0)	; busy input
	bclr.b	#1,(a0)	; POUT low
	rts
servermode:
	bclr.b	#1,$200(a0)	; pout input
	bset.b	#0,$200(a0)	; busy output
	bset.b	#0,(a0)		; BUSY high (send enable)
consetup:
	rts

; Der eigentliche Interrupt-Server
; a1 = data
@intcode:
	move.w	(a1),d0	; mode-word
	btst	#1,d0	; sende?
	beq.s	recmode
return:
	rts

; Empfangs-Modus: a1 = data, d0 = modes
recmode:
	btst	#2,d0		; schon recmode?
	bne.s	return

; Prüfen, ob Arbitration richtig
	btst	#0,d0
	bne.s	clientrec
	btst.b	#1,$bfd000	; POUT high?
	bne.s	recmodeok	; wenn nein, dann belegt
	rts
clientrec:
	btst.b	#0,$bfd000	; busy low?
	bne.s	return
recmodeok:
	or.w	#4,(a1)	; RECEIVE setzen

; load params
	movem.l	4(a1),d0/a1/a6
;	move.l	4(a1),d0
;	move.l	8(a1),a1
;	move.l	4,a6
	jmp	-324(a6)	; Signal (Empfangsbeginn)
	
	END