[GreenKeys] Model 29 ASR

[Jim Haynes]

Converting a 28 or 35 printer to some other code was usually pretty easy,
since the character arrangement in the type box could be changed easily,
and the other functions were controlled by code bars in the stunt box
that could be changed easily.  Hence no special parts were needed.

Converting a keyboard was less easy, since the character codes are part
of the code bars; hence new code bars would have to be designed for the
purpose.  But there are only a few of them, so I guess it was a matter
of convincing Teletype that you wanted to buy enough to be worth making
the tooling to produce them.