In this work, we present methods to obtain binary codes starting from (geometric) Goppa codes, and we also present several examples obtained from such methods. This constructions were only possible because we used computer algebra systems such as KASH, MACAULAY and SINGULAR, which work with algebraic function fields of prime characteristic. Among the codes that we built, we found some with parameters similar to the binary BCH codes, and this hints the possibility to build codes with better parameters than those of the binary BCH codes, and arbitrary code length.