I have been reading the PICLIST for about a month and have seen several
methods of doing quadrature decoding on a PIC. One method, the one in the
Microchip Applications Handbook suggests monitoring one channel and when it
changes check the other channel to determine direction. Doesn't this reduce
the resolution of the encoder by half?  This method would be great if it
didn't because the project I am working on, a six degree of freedom
trackball, needs to monitor three encoders, and the 16c65 chip I'm using
only has four interrupt on change pins. However I can't sacrifice
resolution.
        BTW, I just wanted to comment on how impressed I am at the helpfulness(?
)
of everyone on the PICLIST. Keep up the good work!

                                                        Jeff Kroll