First I thought that the mention of using pneumatic triggered switches
as part of transcribing rolls was a spoof!  Then reading some of the
reaction I realize that some people may be taking it serious.

I have all along assumed that those involved in efforts to create
electronic files of punched paper rolls were striving for highly
accurate results and I still believe that.  That goal cannot be
obtained using triggers or switches that have mass, thus inertia.

The entity "hysteresis" was mentioned also, and any hysteresis -- and
mechanical devices have plenty of it -- is unwanted: it is a source
of error and thus stands in the way of accuracy.  Sensing a change of
state, such as the transition of no-hole to hole, should be done with
a "massless" trigger.  Usage of optical means, and there are several,
should be the only one considered.  That is of course if the end goal
is accurate transcriptions (facsimile), which is the basic premise,
RIGHT ?!

Any errors caused by paper problems, warpage, shrinkage can be
corrected via programming of the initial data.  Those involved with
doing just that know that to be the case (Stahnke did it in creating
the highly admired Telarc CD).

There are several highly qualified people diligently plugging along
with efforts that will result in accurate electronic files and those,
for as far as I know from direct contact, would not think one minute
of using "pneumatic operated switches".

The whole idea is preposterous !!!!

Sorry for being so opinionated...  On second thought, I'm not sorry at
all.  Note to Robbie: Please do not "edit", I mean what I say.

Albert de Boer

 [ Don't worry, Albert, your letter is neither libelous nor profane. ;)
 [ But you just laid down your gauntlet saying, in effect, "My technique
 [ can beat your technique!"  Please propose for us a suitable proof
 [ of your statements above -- the dueling grounds and the Rules of
 [ Engagement and the judgment process (which, of course, can be dupli-
 [ cated by other researchers) -- and then await the respondents.
 [ We'll see whether modern technique can beat century-old pneumatics
 [ in a fair contest!  :-)  -- Robbie