; This program:
; * flashes PER-PIC-LED (pin 21) with the pattern
-; [ L-Z L-H-Z L-H-L-H-Z L-H-L-H-L-H-Z ]
+; [ L-L-Z L-H-Z L-H-L-H-Z L-H-L-H-L-H-Z ]
; where each state lasts approx. 160ms (at 20MHz clock).
; * leaves all other pins set to their default states (usually Z).
start
loop
+ call red
call red
call black
+ call red
call green
call black