[GreenKeys] BSP - AT&T vs TC versions?

[Jim Haynes]

I don't have the knowledge to explain it.  All I know is that

In earlier times, Teletype published their own customer manuals.
Then AT&T Bell Labs used those to reformat and perhaps rewrite and
issue as BSPs for the Bell System.  Then around 1965 a decision was
made that Teletype should produce the BSPs directly rather than
having Bell Labs rework them.  And those that were produced by Teletype
had the TC suffix to the BSP number.

So in earlier times there was 216B, General Description and Theory
of Operation, Model 28 Printer, and 217B Adjustments and Lubrication,
Model 28 printer, and 1149B Parts. Model 28 Printer, and each of these
was a complete manual.  After the change 216B and 217B would have
been just a few pages of cover followed by all the BSPs under the same
subject heading.  And similarly 1149B was a few pages of cover followed
by all the parts BSPs for the whole set.  I presume the Bell System
users didn't get 216B, 217B and 1149B but just got the BSPs.  And that
prior to that time there was no way for non-Bell users to get the BSPs -
they had to take the Teletype full manuals.

Also I don't know if Teletype ever produced any of the handbook-size
BSPs for Teletype equipment, or if they continued to be produced at
all after Teletype took over producing the BSPs.