gEDA-dev: Newbie developer guidelines.

[Svenn Are Bjerkem]

On 4/25/07, Timmerman, Bert <bert.timmerman at corusgroup.com> wrote:
> Hi Bernd and all,
>
> Would that be a patent on (1) the implementation of a topologigal
> autorouter, or would it be a patent on (2) the principle of a
> topological autorouter ?

They have patented (1) a method of extending a path in space with a
piecewise linear cost function. (2) This method used in Computer
programs.

>
> 1) gEDA-developers therefor should never ever have a look at the Cadence
> (?) code base how this feature is implemented, my bet is that the
> Cadence (?) code base is not open source anyway.

They haven't patented the source code, they have patented what the
source code does. Even if you do not look at the source code, you may
infringe the patent. Copying source code is violating copyright.

>
> 2) A patent on a principle is absurd, somebody must have been sleeping
> at the patent office.

They have patented a particular way of doing something and in the same
way patented the implementation in a computer program.

Without reading the patent with the glasses of a patent lawyer, I
would say that further investigation is nescessary. There may be loads
of prior art out there rendering this patent invalid, but I guess this
prior art was not available to the patent officer.

>
> BTW: does Ohm have a patent on the Ohms Law of resistance ?.

If he had, it would have expired a long time ago. Remember patents do
expire. That's why GIF is still around. The Unisys LZW patent expired
in time for GIF not totally get wiped out.

In 25 years you can expect this Cadence patent to expire and until
then, the codebase of PCB should be stable enough....

-- 
Svenn