[tex-eplain] Can't use nor define my own "newlinechar"

[Laurence.Finston at gmx.net]

That's not how it works.  You type ^^J in your document, not \newlinechar.  I only ever use this in \write commands,
or \message, which is like writing to standard output:

\newlinechar=`^^J
\newwrite\abc
\openout\abc=abc.tex
\write\abc{abc^^Jdef}
\closeout\abc
\bye

This is what's written to abc.tex:
abc
def


> Gesendet: Donnerstag, 12. Oktober 2023 um 19:42 Uhr
> Von: terry.s at Safe-mail.net
> An: tex-eplain at tug.org
> Betreff: [tex-eplain] Can't use nor define my own "newlinechar"
>
> Hello,
>
> I'm trying to use \newlinechar, a documented feature of eplain. It produces the error "Missing number, treated as zero". I also loaded epsf and colordvi because they are loaded in a file in Laurence Finston's GNU 3DLDF (glyph_test.tex), and he's able to define it himself. I'm on TeX Live 2022. However, that made no difference (so they're commented here). Also, commenting eplain and using TeX by itself makes no difference.
>
> (I realize I can use \obeylines\break but I'd like to avoid the typing!)
>
> If I attempt to define it like Laurence as the error is the same (when I try to use it; merely defining it gives no error): \newlinechar=`^^J
>
> Attached is a minimal example; you can comment and uncomment various packages and my own definition.
>