A method of converting m-bit information words to a run-length constrained
modulated signal includes converting the information words into n-bit
code words. The available code words are distributed over at least one
group (G1) of a first type and at least one group (G2) of a second type.
The selection of a code word belonging to the group of the first or
second type establishes a coding state of the first type (S1) or one of a
number r of coding states (S2, S3) of the second type, depending on the
current information word. For each information word, a subset of code
words is available, this subset having at least one disjunct code word
for each of the r coding states. The selection from the subset of the
code word to be delivered is based the coding state, on dynamically
verifying the run-length constraint for the sequence of code words, and
on an additional criterion, like the low frequency content of the
modulated signal.