For n = 0 To nCols-1
GraphicsWindow.PenColor = arrCols[n+1]
x0 = cent
y0 = cent
For rad = dRad To 4*pi Step dRad
r = a * rad '' Archimedische Spirale
x = cent - r * Math.Cos(rad + n*dRot)
y = cent + r * Math.Sin(rad + n*dRot)
GraphicsWindow.DrawLine(x0,y0, x,y)
x0 = x
y0 = y
EndFor
EndFor