¹The code may use a simplified magnetic equilibrium with circular plasma cross-sections, that is valid in the large aspect ration limit ϵ ≪ 1. More realistic equilibria are determined numericaly. First, the external shape of the plasma equilibrium is evaluated by specifying positions of X-points and derivatives at this point. Then the full magnetic equilibrium is calculated using pressure and current density profiles, in agreemnt with the shape required at the plasma boundary. This procedure avoids numerical instabilities that may arise from coarse estimate of the plasma shape.