  It is shown how to model any automorphism of a totally disconnected, locally
compact group by a symbolic dynamical system. The model is an inverse limit of
a product of a full-shift, on a finite number of symbols, with one of two types
of systems. One is a countable discrete space with a permutation having every
point periodic and the other is an essentially wandering, countable state
Markov shift. Some of the ideas used are from dynamics and some from the study
of totally disconnected, locally compact groups. The later ideas concern the
scale function and tidy subgroups. There is a discussion of the connections
between those ideas and the dynamical ideas. It is seen that only the
essentially wandering, countable state Markov shift affects the scale function.
Finally, it's shown that transitivity or ergodicity with respect to Haar
measure implies that the system has no countable discrete or essentially
wandering component.
