Na minha pesquisa, encontrei isto:
(setq default-truncate-lines t)
(defun point-of-beginning-of-bottom-line ()
(save-excursion
(move-to-window-line -1)
(point)))
(defun point-of-beginning-of-line ()
(save-excursion
(beginning-of-line)
(point)))
(defun next-one-line () (interactive)
(if (= (point-of-beginning-of-bottom-line) (point-of-beginning-of-line))
(progn (scroll-up 1)
(next-line 1))
(next-line 1)))
(defun point-of-beginning-of-top-line ()
(save-excursion
(move-to-window-line 0)
(point)))
(defun previous-one-line () (interactive)
(if (= (point-of-beginning-of-top-line) (point-of-beginning-of-line))
(progn (scroll-down 1)
(previous-line 1))
(previous-line 1)))
(global-set-key (kbd "<down>") 'next-one-line)
(global-set-key (kbd "<up>") 'previous-one-line)
Que tipo de me ajudou em aquamacs e mac os x. Talvez possa ser útil para WIN também.
Eu peguei do wiki do emacs