How do you use line-wrap in emacs? So that the portion that doesn't fit on the screen isn't shown as opposed to shown on the next line?
What you describe sounds more like linewrap than scrolling. If that's what you're actually interested in, it's controlled with buffer-local variable truncate-lines. You can use customization to set it globally, or use hooks. For example, I used to prevent linewrap in dired with this:
(add-hook 'dired-mode-hook (lambda () (setq truncate-lines t)))