Path: utzoo!utgpu!attcan!uunet!husc6!uwvax!dogie!uwmcsd1!mailrus!iuvax!pur-ee!hankd
From: hankd@pur-ee.UUCP (Hank Dietz)
Newsgroups: comp.arch
Subject: Re: Split I and D caches and IBM lawyers
Summary: What a patent means
Message-ID: <8729@pur-ee.UUCP>
Date: 3 Aug 88 21:39:19 GMT
References: <62370@sun.uucp> <15086@apple.Apple.COM> <62555@sun.uucp>
Organization: Purdue University Engineering Computer Network
Lines: 39

In article <62555@sun.uucp>, dre%ember@Sun.COM (David Emberson) writes:
> In article <15086@apple.Apple.COM>, baum@Apple.COM (Allen J. Baum) writes:
> > In summary: IBM patents are not without foundation. They are diligent about
> > researching prior art. The patents are strong, well written patents, and do
> > not make wild claims about inventing fundamental concepts (unless, of course,
> > they actually did, which is not an uncommon case).
...
> The idea of managing the contents of a cache memory under software control 
> sounds like something that is a fundamental, obvious idea to me.

Well, complete software control IS new, but it isn't neatly patentable and
IBM isn't doing that -- Chi-Hung Chi and I are and we've been publishing on
it for a year and a half.  Further, the crude control IBM has patented seems
to me seems SIMILAR to the control used in many machines and proposals.
However, I read IBM's patent (as summarized by Allen Baum) as claiming
specific cache control instructions:  not claiming the general, abstract,
concept of software cache control.

...
> The patent system was intended to protect inventors, not monopolies.

No.  The patent system was designed to protect investment in technological
development, hence encouraging development of innovative new devices.  An
invention is not supposed to be patented UNLESS you will market it -- this
is the logic behind patent-maintenance fees.

The unfortunate thing about the IBM patents is not the patents themselves,
but the PUBLIC USE OF THEM AS A SCARE TACTIC.  As far as I can tell, the
patents are really quite weak -- they protect very little and, although very
carefully written, are easily challenged or circumvented.  But who would
dare challenge IBM?  Worse still, who is large enough to survive the legal
costs of being challenged (rightly or not) by IBM?

It's just my opinion, but I think IBM stepped way over the line in saying
that these patents were to be used to "reclaim" their inventions which other
companies have stolen.  However, it's a moral line -- not a legal line --
that they've crossed.

						-hankd