Scrollback buffer?  you mean hitting shift + pageup?  already is there.  As for
changing text mode res, not a clue, but maybe this link might help:

http://www.digitalhermit.com/linux/hiresconsole.html

> I've got a Red Hat 7.1 installation.  How do I change the resolution of the
> console to 43 or 50 lines?  The 80x25 mode sucks.  Also, is there any way to
> implement a scroll-back buffer on a console?  I'm so used to working through a
> terminal emulator window that when I have to use the console it's really
> difficult...