Spiral

    1 REM "SPIRAL"
    2 REM By Joe E. Jenkins               3100 Mockingbird                Amarillo, TX 79109              11 NOV 85
    3 REM a conversion by Ted             Knyszek from Apple II           to TS-2068                      See Creative Computing          Feb 1984
   20 LET c=COS (PI/3)
   30 LET s=SIN (PI/3)
   40 LET c1=COS (PI/36)
   50 LET s1=SIN (PI/36)
   60 LET sf=.95
   70 LET x=95
   80 LET y=0
   90 LET cx=130
  100 LET cy=88
  110 LET sc=1.16
  120 FOR j=1 TO 43
  130 FOR i=0 TO 6
  140 LET sx=x*sc+cx
  150 LET sy=cy+y
  160 IF i=0 THEN GO TO 190
  170 PLOT sx1,sy1
  180 DRAW (sx-sx1),(sy-sy1)
  190 LET sx1=sx: LET sy1=sy
  200 LET xn=x*c-y*s
  210 LET y=x*s+y*c
  220 LET x=xn
  230 NEXT i
  240 LET xn=sf*(x*c1-y*s1)
  250 LET y=sf*(x*s1+y*c1)
  260 LET x=xn
  270 NEXT j
  280 STOP