Believe it or not, these lines are same length each other.
ACLS
GLINE 100,70,300,70,#LIME
X=100:Y=70:GOSUB @LD:X=300:Y=70:GOSUB @RD
GLINE 100,170,300,170,#LIME
X=100:Y=170:GOSUB @RD:X=300:Y=170:GOSUB @LD
END
@LD
GLINE X,Y,X+16,Y-16,#LIME:GLINE X,Y,X+16,Y+16,#LIME
RETURN
@RD
GLINE X,Y,X-16,Y-16,#LIME:GLINE X,Y,X-16,Y+16,#LIME
RETURN
Believe it or not, every crossroad is pure white.
ACLS:GCLS #WHITE
FOR Y=5 TO 245 STEP 40
FOR X=5 TO 405 STEP 40
GFILL X,Y,X+30,Y+30,#BLACK
NEXT X
NEXT Y