Re: gEDA-user: PCB help . . . .

[DJ Delorie <dj@delorie.com>]

> My questions:

I'm not much versed on the library side (I make my own) but...

> Dan's HOWTO.  Also, there are zillions of names for each type of part,
> so it is hard to figure out which to use.

Bring up an empty PCB file and use the Windows->Library dialog to
paste them in and see what they look like.  That assumes, of course,
that the library's directory contains one of each symbol, which isn't
usually the case.

> *  I am used to systems where the different footprints are just
> individual files holding some graphical information.  Here, it looks
> like the footprints are generated by a collection of m4 scripts, and
> one script might generate many different footprints, depending upon
> its calling arguments.  Is this true?  How does PCB know where to look
> when generating the footprints on the screen?

Yes, this is true.  PCB finds symbols by running a template line
through the M4 processor, and seeing what spits out the other end.
The resulting symbol definition is included in the PCB file itself, so
the library need not be referenced after that.

To see a particular symbol, do this:

   QueryLibrary.sh . pcblib a b SO28

SO28 is the package, "a" is the template, "b" is the value (a string,
can be anything).  I'm not sure what the standards are for "a" and
"b".  Replace "." with the location of your pcb library (pcblib).