*  Simple program that uses STAF to determine when a new value has been presented 
*  by the user on PortC and strobed STRA from off to on.




*    Define symbolic names for the port addresses
portc  equ $1003
portb  equ  $1004
portcl equ  $1005
ddrc   equ  $1007
pioc   equ $1002
lcd    equ  $1040

	org $e000
start	lds  #$FF      It is  a good idea to initialize the stack pointer
loop	ldaa  Pioc     copy PIOC into A
	bpl loop        STAF bit is msb.  If 0, number looks positive and we check again
	ldaa portcl      STAF had changed from 0 to 1 so new value is portcl
*                        Reading portcl causes STAF to be cleared
	staa portb       Display number on port b
	staa lcd         a single character is displayed on the lcd for each stra flip
	
	bra loop        repeat indefinitely



	org $fffe         reset vector tells processor where to start on power on.
	fdb start