iodefsf.src

	.page
	.subttl  iodefsf

;************************************************
;*		i/o definitions			*
;************************************************

unlsn 	= $3f		;ieee unlisten command
untlk 	= $5f		;ieee untalk command
notrdy	= $0 		;not ready
talker	= $80		;ieee talker flag
lisner	= 1		;ieee listener flag
eoiout	= $80		;talk with eoi
eoisnd	= $08		;not(eoi) to send
eoi	= $08		;not(eoi) to send
rdytlk	= $88		;talk no eoi
rdylst	= $1 		;ready to listen
rndrdy	= rdytlk+rdylst	;random chnrdy
rndeoi	= eoiout+rdylst	;random w/ eoi

;  i/o registers

;  MOS 6522A

	* = $1800

pb	 *=*+1		;serial port
pa1      *=*+1		; unused port
ddrb1    *=*+1       	;serial data dir
ddra1    *=*+1		; unused ddra
t1lc1    *=*+1       	;timer 1 low counter
t1hc1    *=*+1       	;timer 1 hi counter
t1ll1    *=*+1       	;timer 1 low latch
t1hl1    *=*+1       	;timer 1 hi latch
t2lc1    *=*+1       	;timer 2 low counter
t2hc1    *=*+1       	;timer 2 hi counter
sr1      *=*+1       	;shift reg
acr1     *=*+1       	;aux control reg
pcr1     *=*+1		;
ifr1     *=*+1		;
ier1     *=*+1		;
pota1    *=*+1		;unused (251968-02 was d0=photo sensor)

;  bits for serial handshake

datin 	= $1    	;data in line
datout	= $2 		;data out
clkin 	= $4		;clock in
clkout	= $8		;clock out
atna  	= $10		;atna ack
atn   	= $80		;atn in

led0  	= 8  		;act led
led1  	= 0  		;no led
ledprt	= $1c00		;on pb of $1c00
ledout	= $1c02		;ddrb of $1c00 for output-led

;	.end