plain TeX double-page layout?

I suppose it's easy in LaTeX but wonder if it's possible in plain TeX to have a
double-page layout, i.e. a big page with same height and double width of the
original which contains two pages together, one aside the other, of the
original file.  I'm sure it must be possible in plain TeX but can't have an
idea of how.  Thanks for any suggestion.  Otherwise, I'll have to get what I
want on the final PDF using some tools like qpdf or similar...  but preserving
the internal links of the PDF.

Bye,

Rodolfo