plain TeX: different \hsize and \vsize for odd and even pages (was: plain TeX: different margins for odd and even pages)

Rodolfo Medina <[email protected]> writes:

> [...] suppose I want to set different margins for add and even pages, say 5mm
> left and 10mm right for odd pages and the opposite for even pages: please
> suggest whoever can a proper way to do it.


Solved that problem with listers TeX-perts' help, now suppose I want to do the
same with \vsize and \hsize, i.e. set a different \vsize (and/or \hsize) value
from odd to even pages: is it possibile?  I mean in `pure' plain TeX.

Thanks,

Rodolfo