> Turns out that for the purpose of impedance a power plane is exactly > the same as a ground plane.
That's true unless you have a split power plane. The whole field of high speed PCB layout is much more complex than is warranted on this list, which is why I made a sweeping generalization. I think for people who don't know better (and don't need to know better), keeping ground near most of the signals is a simple rule that will cover most of the problems. _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user