SCREEN 12
WINDOW (-2.67, -2!)-(2.67, 2!)
PI = 4 * ATN(1)
H = PI / 40
A = .2: B = .05
PSET (A, 0)
FOR I = 0 TO 400
    T = I * H
    X = (A + B * T) * COS(T)
    Y = (A + B * T) * SIN(T)
    LINE -(X, Y)
NEXT