Continue buffer in other window?

[PL]

Hi!  

I've heard it's possible to have a buffer to run over two paralell
windows, but I cannot find any info on that.
I *don't* mean C-x 3 to have two separate windows, viewing the same
buffer individually. I *do* mean showing, for instance row 1-80 i left
window, row 81-160 in right window. If I add one row in left window,
one row shall be shifted in right window aswell.

I've tried to post this earlier, but the article never showed up. Even
more strange is that I got an e-mail from Eric Hanchrow, suggesting I
should use two-buffer mode.

Q1: How *exactly* do I set two-buffer mode?

Q2: How could Eric Hanchrow answer my posting when I can't see it?

Rgds
A very confused Peter...