Re: gEDA: repairing or recreating symbols

[Eric Winsor <eric_dot_winsor-at-NOSPAMsdl_dot_usu_dot_edu>]

Thanks Werner!

Werner Hoch wrote:
> 
> > Hi,
> >
> > I have been following gEDA for a few years now, lurking.  Now in my
> > current job I am free to use which ever schematic capture software (and
> > operating system) I choose and have been using gschem for a few months
> > now.  I am in need of creating new symbols but am confused searching
> > through the libraries for an example of a properly done, up to spec
> > symbol for an example.  Please point me to one.
> 
> http://www.geda.seul.org/docs/index.html
>   Component Symbol creation guide (HTML)
>   Master Attribute list for gEDA (TXT)
>   How to specify power/ground info using net attribute (TXT)

I have been using these, I'm just looking for a properly done .sym
file.  I looked at the ones that you attached and they look great and
complete when it comes to the use of attributes.  As for the libraries
in the tarball, I have not seen consistent use of pin spacing as 400
mils.  Many are 300 mils.  I had yet to see pin names have the label=
attribute and the type= attribute.  Footprint= is used sporadically as
is net=.

Unless anyone warns me otherwise I am going to use Weerner's symbols as
examples of to-spec symbols.

> 
> > Also, I am willing to help recreate old symbols to bring them up to
> > spec.  I am in favor of making new symbols for the new specs and leaving
> > the old symbols compatible with existing schematics.  (i.e. make only
> > those changes to old symbols that would not damage compatibility with
> > old schematics)   I went through a similar situation in the past using
> > VeriBest design capture where we had to upgrade the old symbol
> > libraries.  We differentiated by attaching a rev number to the end of
> > the symbol name.  If we did this we could cause the add-component menu
> > to filter on this rev number.
> 
> Repairing old symbols can change the look of the schematics.
> I've attached some repaired symbols. Would someone say that they will
> break existing schematics? The pins are on the same place as before

I would think that the only thing that should break an old schematic
would be when we fix the pin spacing to 400 mils.  This will cause some
symbols to be stretched.

Why not just name the repaired symbols 7493-1-02.sym or something like
this to show rev/spec level.   All old symbols would be of the name
NAME-#.sym and any created new would be verified as "to spec" and named
NAME-#-SPEC#.sym.  This way, old schematics can be used with the old
schematics and new schematics would inspire the creation of "to spec"
symbols.  Eventually the old symbols would be unused and could be
dropped from the tarball to an archive if desired, or just left in (they
don't take too much disk space).  Anyone who found that an old schematic
was important enough to bring back into use AND didn't want to kept the
old symbols would likely be interested enough to upgrade it to spec
symbols.

Or...  the spec could be spec could be an attribute in the symbol.  A
thought.


Eric Winsor