Welcome Joe!
RDSS is the modern Sartin software - does the older TPR numbers, updated versions of Brohamer's MPH velocities (aka Phase III) plus everything that Doc Sartin created in the later stages of his work.
Here:
http://www.sartinmethodology.com/how_to_obtain_rdss
Also check anything in the RDSS Forums, including video tutorials, etc.
All the best,
Ted