Re: changes made/thanks (re hardware designs)

[Richard Stallman <rms@gnu.org>]

    You wrote:

    (1)> the strength of copyleft when applied to circuits is limited.

    I am not clear what you mean by 'circuits' in the quoted
    sentence above. If you mean exactly 'circuits', it appears to contradict
    your sentence:

    (2)>Circuits cannot be copylefted because they cannot be copyrighted.

    Because of the apparent contradiction, 

I'm sorry about the ambiguous use of "circuits" here.

    I had assumed that in quoted 
    sentence (1) above, you were using the word 'circuits' as a kind of 
    shorthand for the phrase 'drawings or layouts of circuits', but that 
    in the quoted sentence (2) you were using the word 'circuit' to mean 
    the underlying definition rather than the expression in a drawing, 

That's right.

     I had assumed [not from anything you said explicitly] 
    that you were implying that this was a situation without a direct parallel
    in software, and one which made copyright law much weaker in the case
    of (say) HDL definitions than in the case of software in general.

Yes, that is true.  In general, anything you can transform software
into is also copyrightable.  But that is not true for a definition of
a circuit--the purpose of the definition of a circuit is to be
transformed into a physical piece of hardware, and that is not
copyrightable.

    Final question: you wrote:
    >However, copylefting HDL definitions and printed circuit layouts may do
    >some good nonetheless.  
    What kind of 'good' is intended here? 

The good would be discouraging (to a certain extent) people from
adapting the circuit and making the result non-free.  You cannot make
this *impossible*, since they can redraw the circuit *if they care
enough to do the work*.  But if they don't care strongly enough, they
may decide to use your drawings and obey your license, because it is
less work.