A summary of the general aims of TUG:
To encourage and expand the use of TeX, LaTeX, Metafont and related
To ensure the integrity and portability of TeX, LaTeX, Metafont and
To foster innovation in high-quality electronic document preparation.
The most important reason to join TUG is to support these goals.
Great news: all issues prior to the current one are now publicly available for download as PDF. That's a treasure of now 39 years of TeX articles.
Only the access to the current issue is restricted and is for TUG members only. Until earlier this year, issues became publicly available one year after publication. That was relaxed after a successful open ...
We submitted TUGboat to Thomson Reuters (hope I'm remembering that right) some years ago, and got (as expected) no response whatsoever. Therefore I can only suppose that TUB's "impact factor" in academic circles is zero, or, at most, epsilon :(.
A copy of the document “TeX and METAFONT: Errata and Changes”, originally distributed as
a supplement to TUGboat 4:2 (1983), has been scanned from the possibly only remaining
original, and posted with that issue on the TUG website. (The original files no longer
exist, or at least cannot be found. The scanned copy is a bit fuzzy, but it's complete
-- all 47 ...
the editors will perform any necessary cleanup and return the edited version to you
for approval. but be warned -- the editors are absolutely beastly about consistency.
they also believe that readers come first, so remember that please. if you find an
existing article that you like the looks of, you could do worse than use that as a model.
the editors do ...
The main difference is that the \ninepoint you defined was using a 6pt script size, but tugboat uses 7pt, copying a few more tugboat definitions gives
@\penalty via @@5 b=10 p=500 d=250400
from a modified document
For what it's worth, the additional document that @barbarabeeton provided (at least something very close to it; in fact I think it's more complete even though it is dated earlier than the scan) can be found in its original form here:
ERRATA.TXT[TEX,DEK] at the SAILDART archive. If anyone who is interested in the minutiae about early TeX history isn't already ...
in retrospect it seems obvious that for Udo's examples, we should have turned off tugboat.sty's hyphenation exceptions (and anything else that might have affected line breaking). None of us thought of it. Sorry.