; HDW.MAC - 10/27/85 - Deal with hardware ports.

	.z80
	maclib	TNC.LIB

	entry		pioini,scana,scanb,priora,priorb

	external	@wait
	tncdefs
	timdef

pio.ad	equ	8	; PIO data port
pio.as	equ	9	; PIO control port

scan.a	equ	1	; Bit for scan resume COMM port
prio.a	equ	2	; Bit to force priority channel COMM port
scan.b	equ	4	; Bit for scan resume PRINTER port
prio.b	equ	8	; Bit to force priority channel PRINTER port

	cseg

; Initialize the PIO.

pioini:	ld	a,0cfh
	out	(pio.as),a
	ld	a,0f0h
	out	(pio.as),a
	ld	a,0fh
	out	(pio.ad),a
	ret

scana:	ld	c,scan.a
	jr	pulse
scanb:	ld	c,scan.b
	jr	pulse

priora:	ld	c,prio.a
	jr	pulse
priorb:	ld	c,prio.b
	jr	pulse


; Pulse a bit for 2 seconds, using the mask in C.

pulse:	in	a,(pio.ad)
	or	c		; Set the bit
	out	(pio.ad),a
	wait	2
	in	a,(pio.ad)
	xor	c		; Clear the bit
	out	(pio.ad),a
	ret
	end