How has plain.tex been updated?

Question

I've noticed that on CTAN there is a new version of the file plain.tex, dating 2021-01-17. But nowehere I see what the changes are. What has changed?

David Carlisle · Accepted Answer · 2021-02-23T16:07:50.793

7

$ diff  /usr/local/texlive/2020/texmf-dist/tex/plain/base/plain.tex .
228c228
< \outer\def\newmuskip{\alloc@3\muskip\muskipdef\@cclvi}
---
> \outer\def\newmuskip{\alloc@3\muskip\muskipdef\@cclv}
232c232
< \outer\def\newtoks{\alloc@5\toks\toksdef\@cclvi}
---
> \outer\def\newtoks{\alloc@5\toks\toksdef\@cclv}
1241c1241
< \def\fmtname{plain}\def\fmtversion{3.141592653} % identifies the current format
---
> \def\fmtname{plain}\def\fmtversion{3.1415926535} % identifies the current format

So you can allocate one less muskip and one less toks registers.

Campa cites the official documentation here:

Knuth's explanation can be found in https://tug.org/TUGboat/tb42-1/tb130knuth-tuneup21.pdf

Plain TEX has also changed in a minor way, for consistency: It now ensures that \muskip255 and \toks255 are available as “scratch registers” (never allocated by \newmuskip or \newtoks). The new incarnation defines \fmtversion as 3.1415926535.

edited Feb 23 '21 at 16:07

answered Feb 23 '21 at 09:20

David Carlisle

757,742

1

Isn't it the other way around? One can allocate one muskip and one toks register less than before. – egreg Feb 23 '21 at 09:52
4

@egreg clearly I can't read Roman: I'm not as old or as Italian as you... I'll fix thanks – David Carlisle Feb 23 '21 at 15:57
@campa thanks.. – David Carlisle Feb 23 '21 at 16:08

How has plain.tex been updated?

1 Answers1