'STEP_1.BAS
'
' Stores stepping motor patterns in memory.  Then turns motor CW or CCW 
' based on input at pin7.  Motor windings use lower four pins.  See 
' Parallel Port Manual - Vol 1 for typical circuitry.
'
'P. H. Anderson, MSU, 17 Nov, '96

symbol base=b2
symbol ptr=b3
symbol index=b4
symbol patt=b5

	dirs=%00001111
	pins=%00000000
	
init:
	EEPROM 0,(1, 3, 2, 6, 4, $c, 8, 9) 'set stepping motor patts
	' store stepping motor patterns, beginning at address 0	
	ptr=0

top:
	if pin7=1 then CW
        goto CCW

CW:
	for index=0 to 7	'go through array in one direction
           ptr=base+index
	   read ptr, patt 	
	   debug patt
           pins=patt
	   pause 10
        next
        goto top

CCW:

	for index=7 to 0 step -1   'go through array in the other direction
           ptr=base+index
	   read ptr, patt 	
	   debug patt
           pins=patt
	   pause 10
        next
        goto top