To think that prior to 2005 there wasn't any page up / page down functionality. After all, that's when Microsoft filed a patent application for "Method and system for navigating paginated content in page-based increments."
To be exact, March 4, 2005 was the date of the application, and the patent was granted on Tuesday. And it's:
A method and system in a document viewer for scrolling a substantially exact increment in a document, such as one page, regardless of whether the zoom is such that some, all or one page is currently being viewed. In one implementation, pressing a Page Down or Page Up keyboard key/button allows a user to begin at any starting vertical location within a page, and navigate to that same location on the next or previous page.
Shoot, I can't imagine how this works. And I'm trying to remember when I saw the first Page Up and Page Down keys on a keyboard.
I suppose this is almost as silly as trying to trademark "cloud computing."
http://technologyexpert.blogspot.com...page-down.html