The "bond fluctuation method", a coarse-grained lattice model for polymers is discussed. This lattice model is especially useful to obtain static and dynamic properties of dense and/or branched polymers, in all spacial dimensions. The method can be tailored to a CRAY. For the sake of simplicity the vectorizing version of the algorithm is explained in an example in 2 dimensions. The source code for the d-dimensional case is given in appendix.