[GreenKeys] Teletypesetter and other codes

[dmm at lemur.com]

A few weeks ago, one of the esteemed members of the list posed
a technical question offlist.  As I read it, I could just see my
evenings vanish for the next month :-)

The question itself was quite rational (was the layout of ASCII
perhaps due to the Teletypesetter code?)  The literal answer is,
I think, quite simple ("no").  The process of figuring this out,
however, leads to a great deal of research into the details
of pre-ASCII character codes.  I have a weak spot for character
codes, and a deep interest in Linotypes and the Teletypesetter,
so I was pretty much doomed.

The research itself has been fascinating, at least to me.
I fear, though, that to anyone else it must be like sitting through
47 reels of super-8 home movies.  Still, there are a few pretty
pictures (some of unusual equipment, such as the TTS Selective Allotter).
For what it is or isn't worth, then, here's the writeup:

http://www.circuitousroot.com/artifice/telegraphy/tty1/codes/index.html

It is still very much a draft.  I guarantee that there will be
errors (small and large).  I'd welcome comments, either on-list
or offlist.

(At very least, the SVG source files for the various code charts
might be useful for someone who needs to make such a chart - grab the
SVG source and look down at the left of the full page (not visible
in the "exported bitmap") - the "single punch" images for various
kinds of code are there.  The charts were done in Inkscape under
Linux.)

Regards,
David M.
===
Dr. David M. MacMillan * dmm at lemur.com * www.lemur.com & www.CircuitousRoot.com

There are two ways of constructing a software design.  One way is to make
it so simple that there are obviously no deficiencies and the other is to
make it so complicated that there are no obvious deficiencies.
                    - Charles Anthony Richard Hoare