|u | up |d | down |l | left |r | right |f | forward |tl | turn left |tr | turn right |uu | u,u |dd | d,d |ll | l,l |rr | r,r |ff | f,f |tll | tl,tl |trr | tr,tr |uuu | uu,u |ddd | dd,d |lll | ll,l |rrr | rr,r |fff | ff,f |tlll | tll,tl |trrr | trr,tr |uuuu | uu,uu |dddd | dd,dd |llll | ll,ll |rrrr | rr,rr |ffff | ff,ff |tllll | tll,tll |trrrr | trr,trr |up | @pen-up |down | @pen-down |left | @pen-left |right | @pen-right |forward | @pen-forward |turn left | @pen-turn-left |turn right| @pen-turn-right |pen down | @pen-start |pen up | @pen-stop |@pen-start| @pen-draw |@pen-stop, @pen-draw| @pen-stop |@pen-stop| ||@pen-direction-right |@pen-forward, @pen-direction-up | @pen-up, @pen-direction-up |@pen-forward, @pen-direction-down | @pen-down, @pen-direction-down |@pen-forward, @pen-direction-left | @pen-left, @pen-direction-left |@pen-forward, @pen-direction-right| @pen-right, @pen-direction-right |@pen-turn-left, @pen-direction-up | @pen-direction-left |@pen-turn-left, @pen-direction-down | @pen-direction-right |@pen-turn-left, @pen-direction-left | @pen-direction-down |@pen-turn-left, @pen-direction-right| @pen-direction-up |@pen-turn-right, @pen-direction-up | @pen-direction-right |@pen-turn-right, @pen-direction-down | @pen-direction-left |@pen-turn-right, @pen-direction-left | @pen-direction-up |@pen-turn-right, @pen-direction-right| @pen-direction-down |@pen-lift, @pen-draw| @pen-lift |@pen-lift| |@pixel-x = @pen-x:max| @pixel-x = @pen-x:4294967295 |@pixel-y = @pen-y:max| @pixel-y = @pen-y:4294967295 |@pen-x <- @pen-x-temp:max| @pen-x <- @pen-x-temp:4294967295 |@pen-y <- @pen-y-temp:max| @pen-y <- @pen-y-temp:4294967295 |@pixel-x = @pen-x, @pen-x | @pen-x-temp, @pixel-x, @pixel-x = @pen-x |@pixel-x = @pen-x | @pen-x <- @pen-x-temp |@pen-x <- @pen-x-temp, @pen-x-temp | @pen-x, @pen-x <- @pen-x-temp |@pen-x <- @pen-x-temp | |@pixel-y = @pen-y, @pen-y | @pen-y-temp, @pixel-y, @pixel-y = @pen-y |@pixel-y = @pen-y | @pen-y <- @pen-y-temp |@pen-y <- @pen-y-temp, @pen-y-temp | @pen-y, @pen-y <- @pen-y-temp |@pen-y <- @pen-y-temp | |@trigger-set-pixel| @set-pixel |@pen-x++| @pen-x |@pen-x--, @pen-x| |@pen-x--| |@pen-y++| @pen-y |@pen-y--, @pen-y| |@pen-y--| |@pen-left, @pen-draw| @pixel-x = @pen-x:max, @pixel-y = @pen-y:max, @pen-draw, @trigger-set-pixel, @pen-x-- |@pen-left| @pen-x-- |@pen-right, @pen-draw| @pixel-x = @pen-x:max, @pixel-y = @pen-y:max, @pen-draw, @trigger-set-pixel, @pen-x++ |@pen-right| @pen-x++ |@pen-up, @pen-draw| @pixel-x = @pen-x:max, @pixel-y = @pen-y:max, @pen-draw, @trigger-set-pixel, @pen-y-- |@pen-up| @pen-y-- |@pen-down, @pen-draw| @pixel-x = @pen-x:max, @pixel-y = @pen-y:max, @pen-draw, @trigger-set-pixel, @pen-y++ |@pen-down| @pen-y++ || start |start| pen up, rrrr,rrrr,rrrr,rrrr, dddd,dddd,dddd,dddd, main |main| draw a frame, display |draw a frame|1 |1|2, pen down, rrrr, rrrr, rrrr, rrrr |2|3, dddd, dddd, dddd, dddd |3|4, llll, llll, llll, llll |4| uuuu, uuuu, uuuu, uuuu |display| @display