Hi all,  I'm interested in the process of expression coding in
reproducing pianos (in particular on the Welte system).  It seems to me
that,  whatever method was used for recording the expression (if at all),
coding must have been done by hand since the expression controllers
respond with a state-dependent delay to a code, thus code holes *must*
"precede" their affected notes.  

I believe that automatic registration would have been very difficult
with that time's technology.  I could imagine that they used some kind of
pattern or ruler to estimate the positions of the code holes (and maybe
they iterated a couple of times).  Can anyone confirm this?  Or are there
any other explanations?

Zoli Janosy