Tue May 13 10:18:22 EDT 2014

Square wave output noise

What about powering a CD4049 CMOS hex inverter from a separate
decoupled power supply?  This wouls also allow differential outputs to
be constructed easily without having to generate them in the PIC.

Care needs to be taken to properly decouple if more than one signal is
to be presented that is not always on.  Maybe it's good to use 3