Daniel Martin wrote: > That pulls bytes off m five bytes at a time. The goal is to try to > strike a balance between letting m get too large (which makes > manipulating it in memory slightly slower) and letting pack - written > in C - do its job efficiently. (pack is going to be more efficient > the larger the input) Thanks (and to everyone else who replied) for a really good bunch of suggestions. Packing ten bytes at a time seems to be optimal and has shaved a whole load of the execution time. Thanks again, Richard :) -- Posted via http://www.ruby-forum.com/.