Article gives parts list, adjustment and applications info. I hastily added a page of notes at the front of the source listing to orient the reader. Without the hardware description and schematic it's only likely to be of casual interest to anyone but a fairly hardcore PIC user. They have fixed a number of bugs and have modified many of the subroutines to make them more efficient and easier to understand. Most of all, they documented the code thoroughly.
Subroutines now have headers with inputs and outputs listed.
Also there are quite extensive comments throughout the code itself. Their purpose was to make the code easy to understand so that it can be used in other projects as well. We still list Curt, WB2V , as the author. They have not really added major functionality, but did changed some limits, such as extending the upper limit to 30 MHz. Craig redesiged the output low-pass filter to accommodate this.