  In this paper we show the usability of the Gray code with constant weight
words for computing linear combinations of codewords. This can lead to a big
improvement of the computation time for finding the minimum distance of a code.
We have also considered the usefulness of combinatorial $2$-$(t,k,1)$ designs
when there are memory limitations to the number of objects (linear codes in
particular) that can be tested for equivalence.
