Microsoft Patents "Pg Up" and "Pg Dn"

An anonymous reader notes that Microsoft has been granted a patent on "Page Up" and "Page Down" keystrokes. The article links an image of an IBM PC keyboard from 1981 with such keys in evidence. "The software giant applied for the patent in 2005, and was granted it on August 19, 2008. US patent number 7,415,666 describes '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.'... The company received its 5,000th patent from the US Patent and Trademark Office in March 2006, and is currently approaching the 10,000 mark."

Comments

Re:No they didn't

[Repton]

Isn't that what Acrobat Reader does? You hit space, and it scrolls you down to the next screen-sized bit of document. Or, you hit pagedown, and it scrolls you exactly one page worth (which takes you to the same place on the next page).

Re:No they didn't

[spazdor]

Well, yeah. But the tricky word is "substantial", and its moving goalposts.

If a particular implementation A of a function M is patented, but M is the type of thing that other software developers need to accomplish too, then I will need another implementation B of that same function.

But since B can differ from A as much or as little as I like, the question is "how much is substantial?" I could just take A, add a NOP at the end, and call it a distinct function. That probably doesn't meet the definition.

Now what about two NOPs? What if I unroll all the loops, or switch around register names, or swap the operands of all the 'Add' instructions?

Turing-Church essentially promises that regardless of a little bit of obfuscation, or a lot, or none at all, the underlying computation going on in B is isometric to that in implementation A.

That there are an infinite number of alternative implementations, will just be used as a slippery slope argument by a good lawyer. "Why, if we allowed the defendant to publish implementation B, because it's a different algorithm, then we'd have to allow every software patent to be violated by anyone who knows how to obfuscate an algorithm! Nazis would once again ride on dinosaurs!"

Re:No they didn't

[smallfries]

It is a lovely feature. When I was writing up my thesis a few years I found it to be completely invaluable. It meant that I could line up the rendered output of a thesis page on the screen so that the margins were cropped, and the view was zoomed in on the actual text. When I hit forward / backward the viewer would skip the exact same point on the adjacent page. It saved a lot of time, and it's feature that is missing from a lot of document viewers *cough* Adobe Acroread I'm looking at you.

Of course I'm talking about using ghostview which has supported this feature for decades. But I'm sure Microsoft don't believe it's a real patent either. They're just playing the numbers game.