[pdftex] Plain TeX commands.

[John R. Culleton]

Pdftex is based on the original TeX plus plain.tex combination as
described in the TeXbook. In pdftex some of the functionality of
older plain.tex commands has been replaced by newer ones. An example is
\hoffset which is no longer needed. 

My question is this: laying aside \special commands for the
moment, are there plain TeX cammands that no longer exist at all
in pdftex? Is there a list of them somewhere?

I am of course inquiring about pdftex/pdfetex and not pdflatex.
-- 
John Culleton
Able Indexers and Typesetters
http://wexfordpress.com